Patent Publication Number: US-2021164562-A1

Title: Vehicle anomaly analysis apparatus

Description:
This application claims priority from Japanese Patent Application No. 2019-215821 filed on Nov. 28, 2019, the disclosure of which is herein incorporated by reference in its entirety. 
     FIELD OF THE INVENTION 
     The present invention relates to a vehicle anomaly analysis apparatus for analyzing an anomaly in a shift control operation executed in an automatic transmission. 
     BACKGROUND OF THE INVENTION 
     There is well-known a vehicle anomaly analysis apparatus for analyzing an anomaly having occurred in a shift control operation executed in an automatic transmission that constitutes a part of a drive-force transmission path between a drive force source and drive wheels of a vehicle, by using a rotational speed changed in a process of execution of the shift control operation. A transmission-failure detection apparatus disclosed in JP2000-240784A is an example of such an apparatus. This Japanese Patent Application Publication discloses that failure of the automatic transmission is detected based on change of a rotational speed of an engine, wherein the change of the rotational speed of the engine is caused by change of a gear ratio of the automatic transmission to which a drive force of the engine is inputted. 
     SUMMARY OF THE INVENTION 
     By the way, there is a case in which it is difficult to specify cause of an anomaly having occurred in the shift control operation executed in the automatic transmission of the vehicle. The occurrence of the anomaly in the shift control operation can be detected, for example, when a rotational speed becomes an abnormal value in process of execution of the shift control operation, more specifically, when a racing amount of the rotational speed becomes an abnormal value deviated from a normal range in the process of the execution of the shift control operation. However, there are cases of occurrences of anomalies in which the racing amount of the rotational speed becomes an abnormal value deviated from the normal range in substantially the same manner even if causes of the respective anomalies are different from each other. Thus, the cause of the anomaly is not necessarily easy to be specified by only seeing an indication that the racing amount becomes an abnormal value. 
     The present invention was made in view of the background art described above. It is therefore an object of the present invention to provide a vehicle anomaly analysis apparatus capable of improving accuracy in specifying cause of an anomaly in a shift control operation executed in an automatic transmission. 
     The object indicated above is achieved according to the following aspects of the present invention. 
     According to a first aspect of the invention, there is provided a vehicle anomaly analysis apparatus for analyzing an anomaly having occurred in a shift control operation executed in an automatic transmission that constitutes a part of a drive-force transmission path between a drive force source and drive wheels of a vehicle, by using a rotational speed changed in process of execution of the shift control operation. The vehicle anomaly analysis apparatus is configured to specify cause of the anomaly in the shift control operation, by applying an anomaly-cause specifying model that indicates a relationship between a manner of chronological change of a racing amount and the cause of the anomaly in the shift control operation, to the manner of the chronological change of the racing amount upon occurrence of the anomaly in the shift control operation, wherein the racing amount is an amount of increase of the rotational speed in the process of the execution of the shift control operation, relative to a reference rotational speed that is based on a gear ratio and an output rotational speed of the automatic transmission. Namely, the vehicle anomaly analysis apparatus is configured to specify cause of the anomaly in the shift control operation, in accordance with the anomaly-cause specifying model, based on the manner of the chronological change of the racing amount upon the occurrence of the anomaly in the shift control operation. Further, the vehicle anomaly analysis apparatus may comprise: a state determining portion configured to determine whether the anomaly has occurred in the shift control operation executed in the automatic transmission of the vehicle; and an anomaly-cause specifying portion configured, when it is determined by the state determining portion that the anomaly has occurred in the shift control operation executed in the automatic transmission of the vehicle, to obtain data representing at least the manner of the chronological change of the racing amount upon the occurrence of the anomaly in the shift control operation, and to specify the cause of the anomaly in the shift control operation, by using the obtained data and the anomaly-cause specifying model. 
     According to a second aspect of the invention, in the vehicle anomaly analysis apparatus according to the first aspect of the invention, the anomaly-cause specifying model is realized by a supervised learning that is a machine learning using, as teaching data, the manner of chronological change of the racing amount upon the occurrence of the anomaly in the shift control operation and the cause of the anomaly in the shift control operation. 
     According to a third aspect of the invention, in the vehicle anomaly analysis apparatus according to the first or second aspect of the invention, the anomaly in the shift control operation is shifting malfunction of the automatic transmission that includes a hydraulically-operated frictional engagement device, wherein an operation state of the frictional engagement device is to be switched in the execution of the shift control operation. 
     According to a fourth aspect of the invention, in the vehicle anomaly analysis apparatus according to the third aspect of the invention, the cause of the anomaly in the shift control operation is suction of air by an oil pump that is provided to output a working fluid used to switch the operation state of the frictional engagement device. 
     According to a fifth aspect of the invention, in the vehicle anomaly analysis apparatus according to the third or fourth aspect of the invention, the cause of the anomaly in the shift control operation is malfunction of a control valve that is provided to regulate a hydraulic pressure of a working fluid used to switch the operation state of the frictional engagement device. 
     According to a sixth aspect of the invention, in the vehicle anomaly analysis apparatus according to any one of the third through fifth aspects of the invention, the cause of the anomaly in the shift control operation is malfunction of a drive unit configured to drive a control valve that is provided to regulate a hydraulic pressure of a working fluid used to switch the operation state of the frictional engagement device. 
     According to a seventh aspect of the invention, in the vehicle anomaly analysis apparatus according to any one of the first through sixth aspects of the invention, the anomaly-cause specifying model indicates the relationship between the manner of the chronological change of the racing amount and, as the cause of the anomaly in the shift control operation, a cause that is predetermined based on an operation-state representing value representing an operation state of the vehicle, wherein the cause of the anomaly in the shift control operation is to be specified by the operation-state representing value, easier than by the rotational speed. 
     According to an eighth aspect of the invention, in the vehicle anomaly analysis apparatus according to the seventh aspect of the invention, the operation-state representing value is a value of a hydraulic pressure of a working fluid used to switch an operation state of a hydraulically-operated frictional engagement device included in the automatic transmission, in the execution of the shift control operation. 
     According to a ninth aspect of the invention, in the vehicle anomaly analysis apparatus according to the first aspect of the invention, the anomaly-cause specifying model further indicates a relationship between a number of occurrences of the anomaly in the shift control operation and the cause of the anomaly in the shift control operation, wherein the cause of the anomaly in the shift control operation is reduction of durability of the automatic transmission. 
     According to a tenth aspect of the invention, in the vehicle anomaly analysis apparatus according to the ninth aspect of the invention, the anomaly-cause specifying model is realized by a supervised learning that is a machine learning using, as teaching data, the manner of chronological change of the racing amount upon the occurrence of the anomaly in the shift control operation, the number of occurrences of the anomaly in the shift control operation and the reduction of the durability of the automatic transmission. 
     In the vehicle anomaly analysis apparatus according to the first aspect of the invention, the cause of the anomaly in the shift control operation is determined or specified, by applying the predetermined anomaly-cause specifying model that indicates the relationship between the manner of the chronological change of the racing amount and the cause of the anomaly in the shift control operation, to the manner of the chronological change of the racing amount upon occurrence of the anomaly in the shift control operation, so that it is possible to improve accuracy in specifying the cause of the anomaly in the shift control operation executed in the automatic transmission. 
     In the vehicle anomaly analysis apparatus according to the second aspect of the invention, the anomaly-cause specifying model is realized by the supervised learning that is the machine learning using, as the teaching data, the manner of the chronological change of the racing amount upon the occurrence of the anomaly in the shift control operation and the cause of the anomaly in the shift control operation, so that it is possible to construct a learning model by which the cause of the anomaly in the shift control operation can be specified with an improved accuracy. 
     In the vehicle anomaly analysis apparatus according to the third aspect of the invention, the anomaly in the shift control operation is the shifting malfunction of the automatic transmission, so that the cause of the shifting malfunction of the automatic transmission can be specified with an improved accuracy by using the anomaly-cause specifying model. 
     In the vehicle anomaly analysis apparatus according to the fourth aspect of the invention, the cause of the anomaly in the shift control operation is the suction of the air by the oil pump. Therefore, even in event of occurrence of the anomaly in the shift control operation, which causes the racing amount of the rotational speed to become an abnormal value, the cause of the anomaly can be specified with an improved accuracy by using the anomaly-cause specifying model. 
     In the vehicle anomaly analysis apparatus according to the fifth aspect of the invention, the cause of the anomaly in the shift control operation is the malfunction of the control valve. Therefore, even in event of occurrence of the anomaly in the shift control operation, which causes the racing amount of the rotational speed to become an abnormal value, the cause of the anomaly can be specified with an improved accuracy by using the anomaly-cause specifying model. 
     In the vehicle anomaly analysis apparatus according to the sixth aspect of the invention, the cause of the anomaly in the shift control operation is the malfunction of the drive unit configured to drive the control valve. Therefore, even in event of occurrence of the anomaly in the shift control operation, which causes the racing amount of the rotational speed to become an abnormal value, the cause of the anomaly can be specified with an improved accuracy by using the anomaly-cause specifying model. 
     In the vehicle anomaly analysis apparatus according to the seventh aspect of the invention, the anomaly-cause specifying model indicates the relationship between the manner of the chronological change of the racing amount and, as the cause of the anomaly in the shift control operation, the cause that is predetermined based on the operation-state representing value, wherein the cause of the anomaly in the shift control operation can be specified by the operation-state representing value, easier than by the rotational speed. Therefore, the cause of the anomaly in the shift control operation can be specified with an improved accuracy in the anomaly-cause specifying model. 
     In the vehicle anomaly analysis apparatus according to the eighth aspect of the invention, the operation-state representing value is the value of the hydraulic pressure of the working fluid used to switch the operation state of a hydraulically-operated frictional engagement device included in the automatic transmission, in the execution of the shift control operation. Therefore, the cause of the anomaly in the shift control operation can be appropriately specified in the anomaly-cause specifying model. 
     In the vehicle anomaly analysis apparatus according to the ninth aspect of the invention, the anomaly-cause specifying model further indicates the relationship between the number of occurrences of the anomaly in the shift control operation and the reduction of the durability of the automatic transmission. Therefore, even where the cause of the anomaly in the shift control operation is the reduction of the durability of the automatic transmission, the cause of the anomaly can be specified with an improved accuracy by using the anomaly-cause specifying model. 
     In the vehicle anomaly analysis apparatus according to the tenth aspect of the invention, the anomaly-cause specifying model is realized by the supervised learning that is the machine learning using, as the teaching data, the manner of chronological change of the racing amount upon the occurrence of the anomaly in the shift control operation, the number of occurrences of the anomaly in the shift control operation and the reduction of the durability of the automatic transmission. Therefore, it is possible to construct a learning model by which the cause of the anomaly in the shift control operation can be specified with an improved accuracy. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view schematically showing a construction of a vehicle to which the present invention is applied, for explaining major portions of control functions and control systems that are provided to perform various control operations in the vehicle; 
         FIG. 2  is a table indicating a relationship between each gear position of a mechanically-operated step-variable transmission portion (shown by way of example in  FIG. 1 ) and a combination of engagement devices of the step-variable transmission portion, which are placed in engaged states to establish the gear position in the step-variable transmission portion; 
         FIG. 3  is a collinear chart indicating a relationship among rotational speeds of rotary elements of an electrically-controlled continuously-variable transmission portion and the mechanically-operated step-variable transmission portion; 
         FIG. 4  is a view for explaining a hydraulic control unit and a hydraulic source that is configured to supply a working fluid to the hydraulic control unit; 
         FIG. 5  is a cross sectional view for explaining a linear solenoid valve configured to regulate a hydraulic pressure supplied to a corresponding one of the engagement devices provided in the hydraulic control unit of  FIG. 4 ; 
         FIG. 6  is a view showing, by way of example, a valve characteristic of the linear solenoid valve of  FIG. 5 ; 
         FIG. 7  is a view for explaining, by way of example, a drive current applied to a solenoid valve in process of engagement of a frictional engagement device in a shift control operation executed in a step-variable transmission portion; 
         FIG. 8  is a view showing, by way of examples, a shifting map used for controlling gear shifting in the step-variable transmission portion, a drive-force-source switching map used for switching between a hybrid running and a motor running, and a relationship between the shifting map and the drive-force-source switching map; 
         FIG. 9  is a time chart for explaining, by way of example, shifting malfunction of the step-variable transmission portion; 
         FIGS. 10-13  are views for showing, by way of examples, a normal case and anomaly cases, in an arrangement in which an engaging pressure is controlled directly by the solenoid valve, wherein the views of  FIG. 10  show the normal case, the views of  FIG. 11  show the anomaly case with an air suction, the views of  FIG. 12  show the anomaly case with a temporary stuck, and the views of  FIG. 13  show the anomaly case with a complete stuck; 
         FIG. 14  is a view for showing, by way of example, an anomaly-cause specifying model; 
         FIG. 15  is a flow chart showing a main part of a control routine executed by a vehicle anomaly analysis apparatus, namely, a control routine that is executed for specifying cause of an anomaly in the shift control operation executed in the step-variable transmission portion, with an improved accuracy; and 
         FIG. 16  is a view for showing, by way of example, an anomaly-cause specifying model in an embodiment of the present invention, which is other than an embodiment shown in  FIG. 14 . 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     In the embodiment of the present invention, a gear ratio in the vehicle transmission is defined as “rotational speed of input-side rotary member/rotational speed of output-side rotary member”. A running speed of the vehicle could be lower as the gear ratio is higher, and could be higher as the gear ratio is lower. The highest gear ratio can be expressed also as a lowest-speed gear ratio. 
     The drive force source is an internal combustion engine such as gasoline engine and diesel engine, which is configured to generate a drive force by combustion of a fuel. Further, the vehicle may include, for example, an electric motor as another drive force source in addition to or in place of the internal combustion engine. The electric motor is broadly interpreted as a kind of an engine. 
     Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. 
     First Embodiment 
       FIG. 1  is a view schematically showing a construction of a drive-force transmitting device  12  provided in a vehicle  10  to which the present invention is applied, for explaining major portions of control functions and control systems that are provided to perform various control operations in the vehicle  10 . As shown in  FIG. 1 , the vehicle  10  includes an engine  14  and first and second rotating machines MG 1 , MG 2 . The drive-force transmitting device  12  includes a non-rotary member in the form of a transmission casing  16  that is attached to a body of the vehicle  10 , an electrically-operated continuously-variable transmission portion  18  and a mechanically-operated step-variable transmission portion  20 . The continuously-variable transmission portion  18  and the step-variable transmission portion  20  are provided within the casing  16 , and are arranged in a series on a common axis. The continuously-variable transmission portion  18  is connected to the engine  14  directly or indirectly through, for example, a damper (not shown). The step-variable transmission portion  20  is connected to an output rotary member of the continuously-variable transmission portion  18 . The drive-force transmitting device  12  further includes a differential gear device  24  connected to an output shaft  22  that is an output rotary member of the step-variable transmission portion  20 , and a pair of axles  26  connected to the differential gear device  24 . In the drive-force transmitting device  12 , a drive force outputted from the engine  14  or the second rotating machine MG 2  is transmitted to the step-variable transmission portion  20 , and is then transmitted from the step-variable transmission portion  20  through the differential gear device  24  to drive wheels  28  of the vehicle  10 , for example. The drive force is synonymous with a drive torque or a drive power unless otherwise distinguished from them. It is noted that the drive-force transmitting device  12  including the continuously-variable transmission portion  18  and the step-variable transmission portion  20  is constructed substantially symmetrically about its axis corresponding to the above-described common axis, so that a lower half of the drive-force transmitting device  12  is not shown in  FIG. 1 . The above-described common axis corresponds to axes of a crank shaft of the engine  14  and a connecting shaft  34  that is described below. 
     The engine  14  is a known internal combustion engine such as gasoline engine and diesel engine, which serves as a drive force source capable of generating a drive torque. The vehicle  10  is provided with an engine control device  50  that includes a throttle actuator, a fuel injection device and an ignition device. With the engine control device  50  being controlled by an electronic control apparatus  90  that is described below, an engine torque Te, which is an output torque of the engine  14 , is controlled. In the present embodiment, the engine  14  is connected to the continuously-variable transmission portion  18 , without a fluid transmitting device (such as a torque converter and a fluid coupling device) disposed therebetween. 
     Each of the first and second rotating machines MG 1 , MG 2  is a rotating electric machine having a function serving as an electric motor and a function serving as a generator. That is, each of the first and second rotating machines MG 1 , MG 2  is a so-called “motor generator”. The first and second rotating machines MG 1 , MG 2  are connected to an electric storage device in the form of a battery  54  provided in the vehicle  10 , through an inverter  52  provided in the vehicle  10 . The inverter  52  is controlled by the electronic control apparatus  90  whereby an MG 1  torque Tg and an MG 2  torque Tm as output torques of the respective first and second rotating machines MG 1 , MG 2  are controlled. The output torque of each of the first and second rotating machines MG 1 , MG 2  serves as a power running torque when acting as a positive torque for acceleration, with the each of the first and second rotating machines MG 1 , MG 2  being rotated in a forward direction. The output torque of each of the first and second rotating machines MG 1 , MG 2  serves as a regenerative torque when acting as a negative torque for deceleration, with the each of the first and second rotating machines MG 1 , MG 2  being rotated in the forward direction. The battery  54  is the electric storage device to and from which an electric power is supplied from and to the first rotating machine MG 1  and the second rotating machine MG 2 . 
     The continuously-variable transmission portion  18  is provided with: the above-described first rotating machine (first motor/generator) MG 1 ; a differential mechanism  32  serving as a drive-force distributing device to mechanically distribute the drive force of the engine  14  to the first rotating machine MG 1  and to an intermediate transmitting member  30  that is an output rotary member of the continuously-variable transmission portion  18 ; and a second rotating machine (second motor/generator) MG 2  connected to the intermediate transmitting member  30  in a drive-force transmittable manner. The continuously-variable transmission portion  18  is an electrically-controlled continuously-variable transmission wherein a differential state of the differential mechanism  32  is controllable by controlling an operation state of the first rotating machine MG 1 . The first rotating machine MG 1  serves as a differential rotating machine capable of controlling an engine rotational speed Ne that is a rotational speed of the engine  14 . The second rotating machine MG 2  serves as a vehicle-driving rotating machine, i.e., a drive force source capable of generating a drive torque driving the vehicle  10 . The vehicle  10  is a hybrid vehicle provided with the drive force sources in the form of the engine  14  and the second rotating machine MG 2 . The drive force of each of the drive forces is to be transmitted to the drive wheels  28  through the drive-force transmitting device  12 . It is noted that an operation of the first rotating machine MG 1  is controlled by controlling an operation state of the first rotating machine MG 1 . 
     The differential mechanism  32  is a planetary gear device of a single-pinion type having a sun gear S 0 , a carrier CA 0  and a ring gear R 0 . The carrier CA 0  is connected to the engine  14  through the connecting shaft  34  in a drive-force transmittable manner, and the sun gear S 0  is connected to the first rotating machine MG 1  in a drive-force transmittable manner, while the ring gear R 0  is connected to the second rotating machine MG 2  in a drive-force transmittable manner. In the differential mechanism  32 , the carrier CA 0  serves as an input rotary element, and the sun gear S 0  serves as a reaction rotary element, while the ring gear R 0  serves as an output rotary element. 
     The step-variable transmission portion  20  is a mechanically-operated transmission mechanism which constitutes a part of a drive-force transmission path between the intermediate transmitting member  30  and the drive wheels  28 , namely, constitutes a part of a drive-force transmission path between the continuously-variable transmission portion  18  and the drive wheels  28 . The intermediate transmitting member  30  also serves as an input rotary member of the step-variable transmission portion  20 . The step-variable transmission portion  20  is considered to also as a vehicle transmission constituting a part of a drive-force transmission path between the drive force source (second rotating machine MG 2  or engine  14 ) and the drive wheels  28 , since the second rotating machine MG 2  is connected to the intermediate transmitting member  30  such that the intermediate transmitting member  30  is rotated together with the second rotating machine MG 2 , or since the engine  14  is connected to an input rotary member of the continuously-variable transmission portion  18 . The intermediate transmitting member  30  is a transmitting member through which the drive force of the drive force source is to be transmitted to the drive wheels  28 . The step-variable transmission portion  20  is a known automatic transmission of a planetary gear type which is provided with a plurality of planetary gear devices in the form of a first planetary gear device  36  and a second planetary gear device  38 , and a plurality of engagement devices including a clutch C 1 , a clutch C 2 , a brake B 1  and a brake B 2 . Hereinafter, the clutch C 1 , clutch C 2 , brake B 1  and brake B 2  will be referred to as engagement devices CB unless otherwise specified. 
     Each of the engagement devices CB is a hydraulically-operated frictional engagement device in the form of a multiple-disc type or a single-disc type clutch or brake that is to be pressed by a hydraulic actuator, or a band brake that is to be tightened by a hydraulic actuator. A torque capacity of each of the engagement devices CB is to be changed by an engaging pressure Pcb in the form of a corresponding one of hydraulic pressures Pc 1 , Pc 2 , Pb 1 , Pb 2  (see  FIG. 4 ) as regulated pressures supplied from a hydraulic control unit (hydraulic control circuit)  56  provided in the vehicle  10 , whereby an operation state of each of the engagement devices CB is to be switched among engaged, slipped and released states, for example. 
     In the step-variable transmission portion  20 , selected ones of rotary elements of the first and second planetary gear devices  36 ,  38  are connected to each other or to the intermediate transmitting member  30 , casing  16  or output shaft  22 , either directly or indirectly (selectively) through the engagement devices CB or a one-way clutch F 1 . The rotary elements of the first planetary gear device  36  are a sun gear S 1 , a carrier CA 1  and a ring gear R 1 . The rotary elements of the second planetary gear device  38  are a sun gear S 2 , a carrier CA 2  and a ring gear R 2 . 
     The step-variable transmission portion  20  is shifted to a selected one of a plurality of AT gear positions (speed positions) by engaging actions of selected ones of the engagement devices CB. The plurality of AT gear positions have respective different gear ratios (speed ratios) γat (=AT input rotational speed Ni/output rotational speed No). Namely, the step-variable transmission portion  20  is shifted up and down from one gear position to another by placing selected ones of the engagement devices in the engaged state. The step-variable transmission portion  20  is a step-variable automatic transmission configured to establish a selected one a plurality of gear positions. In the following description of the present embodiment, the gear position established in the step-variable transmission portion  20  will be referred to as AT gear position. The AT input rotational speed Ni is an input rotational speed of the step-variable transmission portion  20  that is a rotational speed of the input rotary member of the step-variable transmission portion  20 , which is equal to a rotational speed of the intermediate transmitting member  30 , and which is equal to an MG 2  rotational speed Nm that is an rotational speed of the second rotating machine MG 2 . Thus, the AT input rotational speed Ni can be represented by the MG 2  rotational speed Nm. The output rotational speed No is a rotational speed of the output shaft  22  that is an output rotational speed of the step-variable transmission portion  20 , which is considered to be an output speed of a transmission device (composite transmission)  40  which consists of the continuously-variable transmission portion  18  and the step-variable transmission portion  20 . The transmission device  40  is a transmission that constitutes a part of a drive-force transmission path between the engine  14  and the drive wheels  28 . 
     As shown in a table of  FIG. 2 , the step-variable transmission portion  20  is configured to establish a selected one of a plurality of AT gear positions in the form of four forward AT gear positions and a reverse AT gear position. The four forward AT gear positions consist of a first speed AT gear position, a second speed AT gear position, a third speed AT gear position and a fourth speed AT gear position, which are represented by “1st”, “2nd”, “3rd” and “4th” in the table of  FIG. 2 . The first speed AT gear position is the lowest-speed gear position having a highest gear ratio γat, while the fourth speed AT gear position is the highest-speed gear position having a lowest gear ratio γat. The gear ratio γat decreases in the direction from the first speed AT gear position (lowest-speed gear position) toward the fourth speed AT gear position (highest-speed gear position). The reverse AT gear position is represented by “Rev” in the table of  FIG. 2 , and is established by, for example, engagements of the clutch C 1  and the brake B 2 . That is, when the vehicle  10  is to run in reverse direction, the first speed AT gear position is established, for example, as described below. The table of  FIG. 2  indicates a relationship between each of the AT gear positions of the step-variable transmission portion  20  and operation states of the respective engagement devices CB of the step-variable transmission portion  20 , namely, a relationship between each of the AT gear positions and a combination of ones of the engagement devices CB, which are to be placed in theirs engaged states to establish the each of the AT gear positions. In the table of  FIG. 2 , “O” indicates the engaged state of the engagement devices CB, “A” indicates the engaged state of the brake B 2  during application of an engine brake to the vehicle  10  or during a coasting shift-down action of the step-variable transmission portion  20 , and the blank indicates the released state of the engagement devices CB. 
     The step-variable transmission portion  20  is configured to switch from one of the AT gear positions to another one of the AT gear positions, namely, to establish one of the AT gear positions which is selected, by the electronic control apparatus  90 , according to, for example, an accelerating operation made by a vehicle driver (operator) and the vehicle running speed V. The step-variable transmission portion  20  is shifted up or down from one of the AT gear positions to another, for example, by so-called “clutch-to-clutch” shifting operation that is made by releasing and engaging actions of selected two of the engagement devices CB, namely, by a releasing action of one of the engagement devices CB and an engaging action of another one of the engagement devices CB. In the following description of the present embodiment, a shift down action from the second speed AT gear position to the first speed AT gear position will be referred to as shift down action from 2nd to 1st. The other shift down and up actions will be referred in the same way. 
     The vehicle  10  further includes an MOP  57  that is a mechanically-operated oil pump and an EOP  58  that is an electrically-operated oil pump. The MOP  57  is connected to the connecting shaft  34 , and is to be rotated together with rotation of the engine  14 , so as to output a working fluid OIL that is to be used in the drive-force transmitting device  12 . The EOP  58  is to be orated by a motor  59  which is provided in the vehicle  10  and which serves exclusively for the EOP  58 , so as to output the working fluid OIL. The working fluid OIL outputted by the MOP  57  and the EOP  58  is used for switching the operation state of each of the engagement devices CB in the step-variable transmission portion  20 . 
       FIG. 3  is a collinear chart representative of a relative relationship of rotational speeds of the rotary elements in the continuously-variable transmission portion  18  and the step-variable transmission portion  20 . In  FIG. 3 , three vertical lines Y 1 , Y 2 , Y 3  corresponding to the three rotary elements of the differential mechanism  32  constituting the continuously-variable transmission portion  18  are a g-axis representative of the rotational speed of the sun gear S 0  corresponding to a second rotary element RE 2 , an e-axis representative of the rotational speed of the carrier CA 0  corresponding to a first rotary element RE 1 , and an m-axis representative of the rotational speed of the ring gear R 0  corresponding to a third rotary element RE 3  (i.e., the input rotational speed of the step-variable transmission portion  20 ) in order from the left side. Four vertical lines Y 4 , Y 5 , Y 6 , Y 7  of the step-variable transmission portion  20  are axes respectively representative of the rotational speed of the sun gear S 2  corresponding to a fourth rotary element RE 4 , the rotational speed of the ring gear R 1  and the carrier CA 2  connected to each other and corresponding to a fifth rotary element RE 5  (i.e., the rotational speed of the output shaft  22 ), the rotational speed of the carrier CA 1  and the ring gear R 2  connected to each other and corresponding to a sixth rotary element RE 6 , and the rotational speed of the sun gear S 1  corresponding to a seventh rotary element RE 7  in order from the left. An interval between the vertical lines Y 1 , Y 2 , Y 3  is determined in accordance with a gear ratio ρ 0  of the differential mechanism  32 . An interval between the vertical lines Y 4 , Y 5 , Y 6 , Y 7  is determined in accordance with gear ratios ρ 1 , ρ 2  of the first and second planetary gear devices  36 ,  38 . When an interval between the sun gear and the carrier is set to an interval corresponding to “1” in the relationship between the vertical axes of the collinear chart, an interval corresponding to the gear ratio ρ (=the number Zs of teeth of the sun gear/the number Zr of teeth of the ring gear) of the planetary gear device is set between the carrier and the ring gear. 
     In representation using the collinear chart of  FIG. 3 , in the differential mechanism  32  of the continuously-variable transmission portion  18 , the engine  14  (see “ENG” in  FIG. 3 ) is connected to the first rotary element RE 1 ; the first rotating machine MG 1  (see “MG 1 ” in  FIG. 3 ) is connected to the second rotary element RE 2 ; the second rotating machine MG 2  (see “MG 2 ” in  FIG. 3 ) is connected to the third rotary element RE 3  that is to be rotated integrally with the intermediate transmitting member  30 ; and therefore, the rotation of the engine  14  is transmitted via the intermediate transmitting member  30  to the step-variable transmission portion  20 . In the continuously-variable transmission portion  18 , the relationship between the rotational speed of the sun gear S 0  and the rotational speed of the ring gear R 0  is indicated by straight lines L 0  and L 0 R crossing the vertical line Y 2 . 
     In the step-variable transmission portion  20 , the fourth rotary element RE 4  is selectively connected through the clutch C 1  to the intermediate transmitting member  30 ; the fifth rotary element RE 5  is connected to the output shaft  22 ; the sixth rotary element RE 6  is selectively connected through the clutch C 2  to the intermediate transmitting member  30  and selectively connected through the brake B 2  to the casing  16 ; and the seventh rotary element RE 7  is selectively connected through the brake B 1  to the casing  16 . In the step-variable transmission portion  20 , the rotational speeds of “1st”, “2nd”, “3rd”, “4th”, and “Rev” of the output shaft  22  are indicated by respective straight lines L 1 , L 2 , L 3 , L 4 , LR crossing the vertical line Y 5  in accordance with engagement/release control of the engagement devices CB. 
     The straight line L 0  and the straight lines L 1 , L 2 , L 3 , L 4  indicated by solid lines in  FIG. 3  indicate the relative speeds of the rotary elements during forward running in a hybrid running mode enabling a hybrid running in which at least the engine  14  is used as the drive force source for driving the vehicle  10 . In this hybrid running mode, when a reaction torque, i.e., a negative torque from the first rotating machine MG 1 , is inputted in positive rotation to the sun gear S 0  with respect to the engine torque Te inputted to the carrier CA 0  in the differential mechanism  32 , an engine direct transmission torque Td [=Te/(1+ρ 0 )=ρ(1/ρ 0 )×Tg] appears in the ring gear R 0  as a positive torque in positive rotation. A combined torque of the engine direct transmission torque Td and the MG 2  torque Tm is transmitted as the drive torque of the vehicle  10  in the forward direction depending on a required drive force to the drive wheels  28  through the step-variable transmission portion  20  having any AT gear position formed out of the AT first to AT fourth gear positions. In this case, the first rotating machine MG 1  functions as an electric generator generating a negative torque in positive rotation. A generated electric power Wg of the first rotating machine MG 1  is stored in the battery  54  or consumed by the second rotating machine MG 2 . The second rotating machine MG 2  outputs the MG 2  torque Tm by using all or a part of the generated electric power Wg or using the electric power from the battery  54  in addition to the generated electric power Wg. 
     In the differential mechanism  32  during a motor drive mode in which the vehicle  10  is driven with a drive force generated by the second motor/generator MG 2  operated as a drive power source while the engine  14  is stopped (held at rest), the carrier CA 0  is held stationary while the MG 2  torque Tm that is a positive torque is applied to the ring gear R 0  and rotating the ring gear R 0  in the positive direction. The state of the differential mechanism  32  in this motor drive mode is not shown in the collinear chart of  FIG. 3 . At this time, the first motor/generator MG 1  connected to the sun gear S 0  is placed in a non-load state and freely rotatable in the negative direction. Namely, in the motor drive mode, the engine  14  is held in its non-operated state, so that a rotational speed Ne of the engine  14  (engine rotational speed Ne) is kept zero, and the vehicle  10  is driven in the forward direction with the MG 2  torque Tm (positive forward driving torque), which is transmitted as a forward drive torque to the drive wheels  28  through the step-variable transmission portion  20  placed in one of the first through fourth speed AT gear positions. During the forward running in the motor running mode, the MG 2  torque Tm is a power running torque that is a positive torque in positive rotation. 
     The straight lines L 0 R and LR indicated by broken lines in  FIG. 3  indicate the relative speeds of the rotary elements in reverse running in the motor running mode. During reverse running in this motor running mode, the MG 2  torque Tm is inputted to the ring gear R 0  as a negative torque in negative rotation, and the MG 2  torque Tm is transmitted as the drive torque of the vehicle  10  in a reverse direction to the drive wheels  28  through the step-variable transmission portion  20  in which the AT first gear position is established. The vehicle  10  can perform the reverse running when the electronic control apparatus  90  causes the second rotating machine MG 2  to output a reverse MG 2  torque Tm having a positive/negative sign opposite to a forward MG 2  torque Tm during forward running while a forward low-side AT gear position, for example, the AT first gear position, is established as one the plurality of AT gear positions. During the reverse running in the motor running mode, the MG 2  torque Tm is a power running torque that is a negative torque in negative rotation. In this case, the forward MG 2  torque Tm is a power running torque that is a positive torque in positive direction, and the reverse MG 2  torque Tm is a power running torque that is a negative torque in negative direction. In this way, the vehicle  10  performs the reverse running by inverting positiveness/negativeness of the MG 2  torque Tm with the forward AT gear position. Using the forward AT gear position means using the same AT gear position as when the forward running is performed. Even in the hybrid running mode, the reverse running can be performed as in the motor running mode since the second rotating machine MG 2  can be rotated in negative direction as indicated by the straight line L 0 R. 
     In the drive-force transmitting device  12 , the continuously-variable transmission portion  18  constitutes an electric transmission mechanism that includes the differential mechanism  32  having three rotary elements, wherein the three rotary elements consist of the first rotary element RE 1  in the form of the carrier CA 0  to which the engine  14  is connected in a drive-force transmittable manner, the second rotary element RE 2  in the form of the sun gear S 0  to which the first rotating machine MG 1  is connected in a drive-force transmittable manner, and the third rotary element RE 3  in the form of the ring gear R 0  to which the intermediate transmitting member  30  is connected, and wherein the differential state of the differential mechanism  32  is controlled by controlling the operation state of the first rotating machine MG 1 . From another viewpoint, the third rotary element RE 3  having the intermediate transmitting member  30  connected thereto is the third rotary element RE 3  to which the second rotating machine MG 2  is connected in a drive-force transmittable manner. That is, in the drive-force transmitting device  12 , the continuously-variable transmission portion  18  has the differential mechanism  32  to which the engine  14  is connected in a drive-force transmittable manner and the first rotating machine MG 1  connected to the differential mechanism  32  in a drive-force transmittable manner, such that the differential state of the differential mechanism  32  is controlled by controlling the operation state of the first rotating machine MG 1 . The continuously-variable transmission portion  18  is operated as an electric continuously variable transmission driven to change a gear ratio γ 0  (=Ne/Nm) that is a ratio of the engine rotational speed Ne to the MG 2  rotational speed Nm, wherein the engine rotational speed Ne is equal to the rotational speed of the connecting shaft  34  serving as an input rotary member of the continuously-variable transmission portion  18  while the MG 2  rotational speed Nm is equal to the rotational speed of the intermediate transmitting member  30  serving as an output rotating member of the continuously-variable transmission portion  18 . 
     For example, in the hybrid running mode, when the rotational speed of the sun gear S 0  is increased or reduced by controlling the rotational speed of the first rotating machine MG 1  relative to the rotational speed of the ring gear R 0  that is restrained by the rotation of the drive wheels  28  since one of the AT gear positions is established in the step-variable transmission portion  20 , the rotational speed of the carrier CA 0 , i.e., the engine rotational speed Ne, is increased or reduced. Therefore, in the hybrid running, the engine  14  can be operated at an efficient operating point. Thus, a continuously variable transmission can be constituted by cooperation of the step-variable transmission portion  20  having one of the AT gear position is established therein and the continuously-variable transmission portion  18  operated as a continuously variable transmission, as the whole of the transmission device  40  in which the continuously-variable transmission portion  18  and the step-variable transmission portion  20  are arranged in series. 
     Alternatively, since a shifting operation can be performed in the continuously-variable transmission portion  18  as in a step-variable transmission, a shifting operation can be performed as in a step-variable transmission by using the step-variable transmission portion  20  having one of the AT gear positions established therein and the continuously-variable transmission portion  18  in which a shifting operation is performed as in a step-variable transmission, as the whole of the transmission device  40 . In other words, in the transmission device  40 , the step-variable transmission portion  20  and the continuously-variable transmission portion  18  can be controlled so as to selectively establish a plurality of gear positions that are different in the gear ratio γt (=Ne/No) indicative of the ratio of the engine rotational speed Ne to the output rotational speed No. In the present embodiment, the gear position established in the transmission device  40  is referred to as an overall gear position (although it may be referred also to as a conceptual gear position). The gear ratio γt is an overall gear ratio of the transmission device  40  consisting of the continuously-variable transmission portion  18  and the step-variable transmission portion  20  which are disposed in series with each other. The overall gear ratio γt is equal to a product of the gear ratio γ 0  of the continuously-variable transmission portion  18  and the gear ratio γat of the step-variable transmission portion  20 , namely, γt=γ 0 ×γat. 
     For example, the overall gear position is assigned such that one or more types are established for each of the AT gear positions of the step-variable transmission portion  20  by combining the AT gear positions of the step-variable transmission portion  20  with one or more types of the gear ratio γ 0  of the continuously-variable transmission portion  18 . For example, the overall gear position is defined in advance such that first through third overall gear positions are established for the first speed AT gear position, the fourth through sixth overall gear positions are established for the second speed AT gear position, seventh through ninth overall gear positions are established for the third speed AT gear position, and the tenth overall gear position is established for the fourth speed AT gear position. In the transmission device  40 , the continuously-variable transmission portion  18  is controlled to attain the engine rotational speed Ne by which a desired gear ratio γt is established for the output rotational speed No, so that different gear positions are established with a certain AT gear position being established in the step-variable transmission portion  20 . Further, in the transmission device  40 , the continuously-variable transmission portion  18  is controlled with switching of the AT gear position in the step-variable transmission portion  20  whereby the overall gear position is switched. 
     Referring back to  FIG. 1 , the vehicle  10  is provided with the electronic control apparatus  90  as a controller including the control apparatus which is constructed according to present invention and which is configured to control, for example, the engine  14 , continuously-variable transmission portion  18  and step-variable transmission portion  20 .  FIG. 1  is a view showing an input/output system of the electronic control apparatus  90 , and is a functional block diagram for explaining major control functions and control portions if the electronic control apparatus  90 . For example, the electronic control apparatus  90  includes a so-called microcomputer incorporating a CPU, a ROM, a RAM and an input-output interface. The CPU performs control operations of the vehicle  10 , by processing various input signals, according to control programs stored in the ROM, while utilizing a temporary data storage function of the RAM. The electronic control apparatus  90  may be constituted by two or more control units exclusively assigned to perform different control operations such as the engine control operation and the hydraulic-pressure control operation. 
     The electronic control apparatus  90  receives various input signals based on values detected by respective sensors provided in the vehicle  10 . Specifically, the electronic control apparatus  90  receives: an output signal of an engine speed sensor  60  indicative of an engine rotational speed Ne which is a rotational speed of the engine  14 ; an output signal of an output speed sensor  62  indicative of an output-shaft rotational speed No which is a rotational speed of the output shaft  22  and which corresponds to the running speed V of the vehicle  10 ; an output signal of a MG 1  speed sensor  64  indicative of an MG 1  rotational speed Ng which is a rotational speed of the first rotating machine MG 1 ; an output signal of a MG 2  speed sensor  66  indicative of an MG 2  rotational speed Nm which is a rotational speed of the second rotating machine MG 2  and which corresponds to an AT input rotational speed Ni; an output signal of an accelerator-opening degree sensor  68  indicative of an acceleration opening degree θacc representing an amount of accelerating operation made by the vehicle driver; an output signal of a throttle-opening degree sensor  70  indicative of a throttle opening degree θth; an output signal of a brake pedal sensor  71  indicative of a brake-ON signal Bon representing a state of depression of a brake pedal by the vehicle driver to operate wheel brakes and also a braking operation amount Bra representing an amount of depression of the brake pedal by the vehicle driver corresponding to a depressing force applied to the brake pedal; an output signal of a steering sensor  72  indicative of a steering angle θsw and a steering direction Dsw of a steering wheel provided in the vehicle  10  and also a steering ON signal SWon representing a state in which the steering wheel is being held by the vehicle driver; an output signal of a driver condition sensor  73  indicative of a driver condition signal Drv representing a condition of the vehicle driver; an output signal of a G senor  74  indicative of a longitudinal acceleration Gx and a lateral acceleration Gy of the vehicle  10 ; an output signal of a yaw rate sensor  76  indicative of a yaw rate Ryaw that is an angular speed around a vertical axis of the vehicle  10 ; an output signal of a battery sensor  77  indicative of a battery temperature THba, a charging/discharging electric current Ibat and a voltage Vbat of the battery  54 ; output signals of respective hydraulic pressure sensors (hydraulic pressure sensor set)  78  indicative of engaging pressures Pcb that are hydraulic pressures of the working fluid OIL for switching the operation states of the respective engagement devices CB; an output signal of a fluid temperature sensor  79  indicative of a working fluid temperature THoil that is a temperature of the working fluid OIL; an output signal of a vehicle-area information sensor  80  indicative of vehicle area information Iard; an output signal of a vehicle location sensor  81  indicative of location information Ivp; an output signal of an external-network communication antenna  82  indicative of an communication signal Scom; an output signal of a navigation system  83  indicative of navigation information Inavi; output signals of drive-assist setting switches  84  indicative of drive-assist setting signals Sset representing a setting made by the vehicle driver for execution of a drive-assist control such as automatic drive control and a cruise control; and an output signal of a shift position sensor  85  indicative of an operation position POSsh of a shift lever provided in the vehicle  10 . 
     The engaging pressures Pcb are the hydraulic pressures Pc 1 , Pc 2 , Pb 1 , Pb 2  that are output pressures outputted from respective solenoid valves SL 1 -SL 4  and supplied to the respective engagement devices CB (see  FIG. 4 ). The hydraulic pressure sensors  78  include hydraulic pressure sensors configured to detect the hydraulic pressures Pc 1 , Pc 2 , Pb 1 , Pb 2  outputted from the respective solenoid valves SL 1 -SL 4 . 
     The amount of accelerating operation made by the vehicle driver is, for example, an amount of operation of an acceleration operating member such as an accelerator pedal, and corresponds to a required output amount that is an amount of output of the vehicle  10  required by the vehicle driver. As the required output amount required by the vehicle driver, the throttle opening degree θth can be used in addition to or in place of the accelerator operation degree θacc, for example. 
     The driver condition sensor  73  includes a camera configured to photograph, for example, a facial expression and pupils of eyes of the vehicle driver and/or a biometric information sensor configured to detect biometric information of the vehicle driver, so as to detect or obtain directions of his or her eyes and face, movements of his or her eye balls and face and condition of his or her heartbeat, for example. 
     The vehicle-area information sensor  80  includes a lidar (Light Detection and Ranging), a radar (Radio Detection and Ranging) and/or an onboard camera, for example, so as to directly obtain information relating to a road on which the vehicle  10  is running and information relating to an object or objects present around the vehicle  10 . The lidar is constituted by, for example, a plurality of lidar units configured to detect objects present in the respective front, lateral and rear sides of the vehicle  10 , or a single lidar unit configured to detect objects present all around the vehicle  10 . The lidar is configured to output, as the vehicle area information Iard, object information that is information relating to the detected object or objects. The radar is constituted by, for example, a plurality of radar units configured to detect objects present in the respective front, front vicinity and rear vicinity of the vehicle  10 , and to output, as the vehicle area information lard, object information that is information relating to the detected object or objects. The objected information outputted as the vehicle area information lard by the lidar and the radar includes a distance and a direction of each of the detected objects from the vehicle  10 . The onboard camera is, for example, a monocular camera or a stereo camera configured to capture images of front and rear sides of the vehicle  10 , and to output, as the vehicle area information Iard, captured image information that is information relating to the captured images. The captured image information outputted as the vehicle area information Iard by the onboard camera includes information relating to lanes of a running road, signs and parking spaces present on the running road, and at least one other vehicle (that is other than the vehicle  10 ), pedestrians and obstacles present on the running road. 
     The vehicle location sensor  81  includes a GPS antenna. The location information Ivp outputted by the vehicle location sensor  81  includes own-vehicle location information indicating a location of the vehicle  10  on the earth&#39;s surface or a map based on, for example, GPS signals (Orbit signals) transmitted by GPS (Global Positioning System) satellites. 
     The navigation system  83  is a known navigation system including a display and a speaker, and is configured to specify a location of the vehicle  10  on pre-stored map data, based on the location information Ivp, and to indicate the location of the vehicle  10  on the map displayed on the display. The navigation system  83  receives a destination point inputted thereto, calculates a running route from a departure point to the destination point, and informs, as instructions, the vehicle driver of the running route, for example, through the display and the speaker. The navigation information Inavi includes map information such as road information and facility information that are based on the map data pre-stored in the navigation system  83 . The road information includes information relating to types of roads (such as urban roads, suburban roads, mountain roads and highway load), branching and merging of roads, road gradients, and running speed limits. The facility information includes information of types, locations, names of sites such as supermarkets, shops, restaurants, parking lots, parks, places for repairing the vehicle  10 , a home of vehicle&#39;s owner and service areas located on the highway load. The service areas are sites which are located on, for example, the highway load, and in which there are facilities for parking, eating, and refueling. 
     The drive-assist setting switches  84  include an automatic-drive selecting switch for executing the automatic drive control, a cruise switch for executing the cruise control, a switch for setting the vehicle running speed in execution of the cruise control, a switch for setting a distance from another vehicle preceding the vehicle  10  in execution of the cruise control, and a switch for executing a lane keeping control for keeping the vehicle  10  to run within a selected road lane. 
     The communication signal Scom includes road traffic information that is transmitted and received to and from a center that is an external device such as a road traffic information communication system, and/or inter-vehicle communication information that is directly transmitted and received to and from the at least one other vehicle present in the vicinity of the vehicle  10  without via the center. The road traffic information includes information relating to traffic jams, accidents, road constructions, required travel times, and parking lots on roads. The inter-vehicle communication information includes vehicle information, running information, traffic environment information. The vehicle information includes information indicative of a vehicle type of the at least one other vehicle such as passenger vehicle, truck, and two-wheel vehicle. The running information includes information relating to the at least one other vehicle such as information indicative of the vehicle speed V, location information, brake-pedal operation information, turn-signal-lamp blinking information, and hazard-lamp blinking information. The traffic environment information includes information relating to traffic jams and road constructions. 
     The electronic control apparatus  90  generates various output signals to the various devices provided in the vehicle  10 , such as: an engine control command signal Se that is to be supplied to the engine control device  50  for controlling the engine  14 , rotating-machine control command signals Smg that are to be supplied to the inverter  52  for controlling the first and second rotating machines MG 1 , MG 2 ; hydraulic control command signal Sat that is to be supplied to the hydraulic control unit  56  for controlling the operation states of the engagement devices CB; an EOP control command signal Seop that is to be supplied to the motor  59  for controlling operation of the EOP  58 ; the communication signal Scom that is to be supplied to the external-network communication antenna  82 ; a brake-control command signal Sbra that is supplied to a wheel brake device  86 , for controlling a braking torque generated by the wheel brake device  86 ; a steering-control command signal Sste that is to be supplied to a steering device  87 , for controlling steering of wheels (especially, front wheels) of the vehicle  10 ; and an information-notification-control command signal Sinf that is to be supplied to an information notification device  88 , for warning and notifying information to the vehicle driver. 
     The hydraulic control command signal Sat serves also as hydraulic control command signals for controlling shifting actions of the step-variable transmission portion  20 , wherein the hydraulic control command signals are provided, for example, for operating the solenoid valves SL 1 -SL 4  (see  FIG. 4 ) configured to regulate the respective hydraulic pressures Pc 1 , Pc 2 , Pb 1 , Pb 2  that are to be supplied to hydraulic actuators of the respective engagement devices CB. The electronic control apparatus  90  includes a drive unit (drive circuit)  89  configured to drive valves such as the solenoid valves SL 1 -SL 4 . The electronic control apparatus  90  is configured to set hydraulic-pressure command values corresponding to the respective hydraulic pressures Pc 1 , Pc 2 , Pb 1 , Pb 2 , and to supply drive currents or drive voltages corresponding to the respective hydraulic-pressure command values, to the hydraulic control unit  56  through the drive unit  89 . 
     The wheel brake device  86  is a brake device including wheel brakes each of which is configured to apply a braking torque to a corresponding one of the wheels that include the drive wheels  28  and driven wheels (not shown). The wheel brake device  86  supplies a brake hydraulic pressure to a wheel cylinder provided in each of the wheel brakes in response to a depressing operation of the brake pedal by the vehicle driver, for example. In the wheel brake device  86 , normally, a brake master cylinder is configured to generate a master-cylinder hydraulic pressure whose magnitude corresponds to the braking operation amount Bra, and the generated master-cylinder hydraulic pressure is supplied as the brake hydraulic pressure to the wheel cylinder. On the other hand, in the wheel brake device  86 , for example, during execution of an ABS control, an anti-skid control, a vehicle-running-speed control or an automatic drive control, the brake hydraulic pressure required for execution of such a control is supplied to the wheel cylinder for enabling the wheel cylinder to generate the required braking torque. 
     The steering device  87  is configured to apply an assist torque to a steering system of the vehicle  10  in accordance with the vehicle running speed V, steering angle θsw, steering direction Dsw and yaw rate Ryaw, for example. For example, during execution of the automatic driving control, the steering device  87  applies a torque for controlling the steering of the front wheels, to the steering system of the vehicle  10 . 
     The information notification device  88  is configured to give a warning or notification to the vehicle driver in even of a failure in some components involved in the running of the vehicle  10  or deterioration in the functions of the components, for example. The information notification device  88  is constituted by, for example, a display device such as a monitor, a display and an alarm lamp, and/or a sound output device such as a speaker and a buzzer. The display device is configured to visually give a warning or notification to the vehicle driver. The sound output device is configured to aurally give a warning or notification to the vehicle driver. 
       FIG. 4  is a view for explaining the hydraulic control unit  56  and a hydraulic source that is configured to supply the working fluid OIL to the hydraulic control unit  56 . As shown in  FIG. 4 , the MOP  57  and the EOP  58  are provided in parallel with each other in a hydraulic circuit in which the working fluid OIL is caused to flow. The MOP  57  and EOP  58  are configured to output the working fluid OIL serving as original hydraulic pressures for switching an operation state of each of the engagement devices CB and as lubricant fluids for lubricating various parts of the drive-force transmitting device  12 . The MOP  57  and EOP  58  pump up the working fluid OIL returned into an oil pan  100  that is disposed in a lower portion of the casing  16 , through a strainer  102  as an inlet port that is common to the MOP  57  and EOP  58 , and supply the working fluid OIL to respective fluid delivery passages  104 ,  106 . The fluid delivery passages  104 ,  106  are connected to a fluid passage of the hydraulic control unit  56 , for example, connected to a line-pressure fluid passage  108  through which a line pressure PL is caused to flow. The fluid delivery passage  104 , to which the working fluid OIL is to be supplied from the MOP  57 , is connected to the line-pressure fluid passage  108  through an MOP check valve  110  that is provided in the hydraulic control unit  56 . The fluid delivery passage  106 , to which the working fluid OIL is to be supplied from the EOP  58 , is connected to the line-pressure fluid passage  108  through an EOP check valve  112  that is provided in the hydraulic control unit  56 . The MOP  57  generates a working hydraulic pressure by being rotated together with rotation of the engine  14 . The EOP  58  generates a working hydraulic pressure by being rotated by the motor  59 , and is capable of generating the working hydraulic pressure, irrespective whether the engine  14  is rotated or not. The EOP  58  is operated to generate the working hydraulic pressure, for example, when the vehicle  10  runs in the motor running mode. 
     The hydraulic control unit  56  includes, in addition to the above-described line-pressure fluid passage  108 , MOP check valve  110 , EOP check valve  112  and solenoid valves SL 1 -SL 4 , a regulator valve  114 , a switch valve  116 , a fluid supply passage  118 , a fluid discharge passage  120  and solenoid valves SLT, S 1 , S 2 . 
     The regulator valve  114  regulates the line pressure PL that is the working fluid OIL supplied from at least one of the MOP  57  and EOP  58 . The solenoid valve SLT, which is a linear solenoid valve, for example, is controlled by the electronic control apparatus  90 , so as to supply, to the regulator valve  114 , a pilot pressure Pslt that is dependent on, for example, the input torque applied to the step-variable transmission portion  20 , whereby the line pressure PL is controlled to a pressure value dependent on, for example, the input torque applied to the step-variable transmission portion  20 . The solenoid valve SLT is configured to receive an original pressure in the form of a modulator pressure PM having a certain pressure value, for example, to which the line pressure PL as an original pressure is regulated by a modulator valve (not shown). 
     The switch valve  116  is configured to establish one of fluid passages that is selected based on the hydraulic pressures supplied from the solenoid valves S 1 , S 2 . Each of the solenoid valves S 1 , S 2  is, for example, an ON-OFF solenoid valve, and is controlled by the electronic control apparatus  90 , so as to supply the hydraulic pressure to the switch valve  116 . When the hydraulic pressure is supplied from the solenoid valve S 2  without the hydraulic pressure being supplied from the solenoid valve S 1 , the switch valve  116  establishes a fluid passage that connects between the line-pressure fluid passage  108  and the fluid supply passage  118 . When the hydraulic pressures are supplied from both of the solenoid valve S 1  and the solenoid valve S 2  or supplied from neither the solenoid valve S 1  nor the solenoid valve S 2 , or when the hydraulic pressure is supplied from the solenoid valve S 1  without the hydraulic pressure being supplied from the solenoid valve S 2 , the switch valve  116  establishes a fluid passage that connects between the fluid discharge passage  120  and the fluid supply passage  118  while blocking the fluid passage between the line-pressure fluid passage  108  and the fluid supply passage  118 . The fluid supply passage  118  is a fluid passage through which the hydraulic pressure inputted to each of the solenoid valves SL 2 , SL 3  is caused to flow. The fluid discharge passage  120  is an atmosphere-opening passage through which the working fluid OIL is discharged from the hydraulic control unit  56  toward outside the hydraulic control unit  56 , namely, through which the working fluid OIL is returned to the oil pan  100 . When the operation position POSsh is a D position selecting a forward running position of the transmission device  40  that enables a forward running of the vehicle  10 , for example, the electronic control apparatus  90  supplies, to the hydraulic control unit  56 , the hydraulic control command signal Sat which causes the solenoid valve S 2  to output the hydraulic pressure and which causes the solenoid valve S 1  not to output the hydraulic pressure. When the operation position POSsh is a R position selecting a reverse running position of the transmission device  40  that enables a reverse running of the vehicle  10 , for example, the electronic control apparatus  90  supplies, to the hydraulic control unit  56 , the hydraulic control command signal Sat which causes the solenoid valves S 1 , S 2  to output the hydraulic pressures. 
     Each of the solenoid valves SL 1 -SL 4  is, for example, a linear solenoid valve that is controlled by the electronic control apparatus  90 , so as to output a corresponding one of the hydraulic pressures Pc 1 , Pc 2 , Pb 1 , Pb 2  to a corresponding one of the engagement devices CB. The solenoid valves SL 1 -SL 4  are control valves configured to regulate the engaging pressures Pcb of the respective engagement devices CB. The solenoid valve SL 1  receives the line pressure PL as the original pressure and regulates the C 1  hydraulic pressure Pc 1  that is supplied to the hydraulic actuator of the clutch C 1 . The solenoid valve SL 2  receives the line pressure PL as the original pressure through the switch valve  116  and regulates the C 2  hydraulic pressure Pc 2  that is supplied to the hydraulic actuator of the clutch C 2 . The solenoid valve SL 3  receives the line pressure PL as the original pressure through the switch valve  116  and regulates the B 1  hydraulic pressure Pb 1  that is supplied to the hydraulic actuator of the brake B 1 . The solenoid valve SL 4  receives the line pressure PL as the original pressure and regulates the hydraulic pressure Pb 2  that is supplied to the hydraulic actuator of the brake B 2 . 
       FIG. 5  is a cross sectional view for explaining a construction of each of the solenoid valves SL 1 -SL 4 .  FIG. 5  shows, by way of example, the solenoid valve SL 1  as one of the solenoid valves SL 1 -SL 4  that are substantially identical in construction with one another. The solenoid valve SL 1  includes a solenoid  122  configured, when being energized, to covert an electric energy into a drive force, and a regulator portion  124  configured, when being driven by the solenoid  122 , to regulate the line pressure PL so as to generate the C 1  hydraulic pressure Pc 1 . The solenoid  122  includes a cylindrical-tubular-shaped winding core  126 , a coil  128  constituted by a conductor cable wound on a periphery of the winding core  126 , a core  130  provided to be axially movable inside the winding core  126 , a plunger  132  fixed to one of axially opposite end portions of the core  130  which is remote from the regulator portion  124 , a casing  134  storing therein the winding core  126 , coil  128 , core  130  and plunger  132 , and a cover  136  fitted in an opening of the casing  134 . The regulator portion  124  includes a sleeve  138  fitted in the casing  134 , a spool valve element  140  provided to be axially movable inside the sleeve  138 , and a spring  142  constantly forces or biases the spool valve element  140  toward the solenoid  122 . The spool valve element  140  is in contact, at one of axially opposite end portions which is on a side of the solenoid  122 , with the other of the above-described axially opposite end portions of the core  130 , namely, one of the above-described axially opposite end portions of the core  130 , which is on a side of the regulator portion  124 . In the solenoid valve SL 1  constructed as described above, with the drive current being applied to the coil  128 , the plunger  132  is moved by a distance that is dependent on an amount of the applied electric current, in an axial direction of the plunger  132 , core  130  and spool valve element  140  that are coaxial with one another, and the core  130  and the spool valve element  140  are moved together with the plunger  132  in the axial direction. With the axial movement of the spool valve element  140 , a rate of flow of the working fluid OIL introduced through an inlet port  144  and a rate of flow of the working fluid OIL discharged through a drain port  146  are adjusted, so that the line pressure PL inputted through the inlet port  144  is regulated in accordance with the valve characteristic of the linear solenoid valve SL 1 , which is a predetermined relationship, as shown in  FIG. 6  by way of example, between the drive current and an output pressure that corresponds to the C 1  hydraulic pressure Pc 1  to which the line pressure PL is regulated. The C 1  hydraulic pressure Pc 1  as the output pressure is outputted through an outlet port  148 . 
       FIG. 7  is a view for explaining, by way of example, the drive current in accordance with the hydraulic-pressure command value, which is applied to the solenoid valve SL configured to regulate the hydraulic pressure of an engaging-side frictional engagement device as one of the engagement devices CB that is to be engaged in a shift control operation executed in the step-variable transmission portion  20 , in process of engagement of the engaging-side frictional engagement device. In  FIG. 7 , a time point t 1   a  indicates a point of time at which output of the hydraulic control command signal Sat is started for the engaging-side frictional engagement device in the shift control operation executed in the step-variable transmission portion  20 . In a quick apply period from the start of the output of the hydraulic control command signal Sat until a time point t 2   a,  the drive current is drastically increased. Then, in a constant-pressure stand-by period until a time point t 3 , the drive current is kept substantially at a constant value by which the engaging pressure Pcb of the engaging-side frictional engagement device becomes a constant stand-by pressure for placing the engaging-side frictional engagement device in a pre-engaged state that is a state shortly before the engagement. Then, in a sweep period until a synchronization determination is made, namely, until it is determined that the MG 2  rotational speed Nm or the engine rotational speed Ne becomes synchronized with a rotational speed that is dependent on a gear ratio established upon completion of a shifting action executed in the step-variable transmission portion  20 , the drive current is controlled to be gradually increased such that the engaging pressure Pcb of the engaging-side frictional engagement device is slowly increased (see point time t 3   a  to point time t 4   a ). When the synchronization determination has been made, the drive current is increased to a maximum value (see point time t 4   a ). 
     Referring back to  FIG. 1 , the vehicle  10  further includes a transceiver  150 , a first gateway ECU  152 , a second gateway ECU  154  and a connector  156 . 
     The transceiver  150  is a device configured to communicate with a server  200  as an external device which is present apart from the vehicle  10  and is provided outside the vehicle  10 . The server  200  is a system present on a network outside the vehicle  10 , and is configured to receive, process, analyze, store and supply various information such as vehicle state information and vehicle phenomenon information. The server  200  transmits and receives the various information to and from the above-described at least one other vehicle as well as to and from the vehicle  10 . However, the transceiver  150  may have a function for directly communicating with the at least one other vehicle present in the vicinity of the vehicle  10  without via the server  200 . The vehicle state information represents, for example, an operation or driving state relating to driving of the vehicle  10 , which is detected by the various sensors or the like. This driving state is represented, for example, by the accelerator operation degree θacc and the vehicle running speed V. The vehicle phenomenon information represents, for example, phenomenons caused in the vehicle  10 . These phenomenons are, for example, an acoustic pressure, i.e., a sound or noise inside the vehicle  10 , which is detected by a microphone (not shown) and a vibration felt by the vehicle driver and passengers in the vehicle  10 , which is detected by the G sensor  74 . It is noted that the transceiver  150  may communicate with the server  200  via the external-network communication antenna  82  by a radio or wireless communication. 
     Each of the first and second gateway ECUs  152 ,  154  has substantially the same hardware construction as the electronic control apparatus  90 , and is constituted by, for example, a relay device provided to rewrite programs and/or data stored in a rewritable ROM included in the electronic control apparatus  90 . The first gateway ECU  152  is connected to the transceiver  150 , and is configured to rewrite the programs stored in the ROM, for example, through the wireless communication between transceiver  150  and the server  200 . The server  200  serves as a software distribution center configured to distribute programs for the rewriting. The second gateway ECU  154  is mechanically connectable through the connector  156  to an external rewriting device  210  as an external device that is present apart from the vehicle  10 , and is configured to rewrite the programs stored in the ROM provided in the electronic control apparatus  90 , for example, through the external rewriting device  210 . 
     For performing various control operations in the vehicle  10 , the electronic control apparatus  90  includes an AT shift control means or portion in the form of an AT shift control portion  92 , a hybrid control means or portion in the form of a hybrid control portion  94  and a driving control means or portion in the form of a driving control portion  96 . 
     The AT shift control portion  92  is configured to determine a shifting action of the step-variable transmission portion  20 , by using, for example, an AT gear position shift map as shown in  FIG. 8 , which is a relationship obtained by experimentation or determined by an appropriate design theory, and outputs the hydraulic control command signal Sat supplied to the hydraulic control unit  56 , so as to execute the shift control operation in the step-variable transmission portion  20  as needed. The AT gear position shifting map is a predetermined relationship between two variables in the form of the vehicle running speed V and the required drive force Frdem, for example, which relationship is used to determine a shifting action of the step-variable transmission portion  20  and is represented by shifting lines in two-dimensional coordinates in which the running speed V and the required drive force Frdem are taken along respective two axes. It is noted that one of the two variables may be the output rotational speed No in place of the vehicle running speed V and that the other of the two variables may be the required drive torque Trdem, accelerator opening degree θacc or throttle valve opening degree θth in place of the required drive force Frdem. The shifting lines in the AT gear position shifting map consist of shift-up lines (indicated by solid lines in  FIG. 8 ) for determining a shift-up action of the step-variable transmission portion  20 , and shift-down lines (indicated by broken lines in  FIG. 8 ) for determining a shift-down action of the step-variable transmission portion  20 . 
     The hybrid control portion  94  has a function serving as an engine control means or portion for controlling the operation of the engine  14  and a function serving as a rotating machine control means or portion for controlling the operations of the first rotating machine MG 1  and the second rotating machine MG 2  via the inverter  52 , and executes a hybrid drive control, for example, using the engine  14 , the first rotating machine MG 1  and the second rotating machine MG 2  through these control functions. The hybrid control portion  94  calculates a drive request amount in the form of the required drive force Frdem that is to be applied to the drive wheels  28 , by applying the accelerator opening degree θacc and the vehicle running speed V to, for example, a drive request amount map that is a predetermined relationship. The required drive torque Trdem [Nm] applied to the drive wheels  28 , a required drive power Prdem [W] applied to the drive wheels  28 , a required AT output torque applied to the output shaft  22 , etc. can be used as the drive request amount, in addition to the required drive force Frdem [N]. 
     The hybrid control portion  94  outputs the engine control command signal Se for controlling the engine  14  and the rotating-machine control command signals Smg for controlling the first and second rotating machines MG 1 , MG 2 , by taking account of a maximum charging amount Win of electric power that can be charged to the battery  54 , and a maximum discharging amount Wout of electric power that can be discharged from the battery  54 , such that the required drive power Prdem based on the required drive torque Trdem and the vehicle running speed V is obtained. The engine control command signal Se is, for example, a command value of an engine power Pe that is the power of the engine  14  outputting the engine torque Te at the current engine rotation speed Ne. The rotating-machine control command signal Smg is, for example, a command value of the generated electric power Wg of the first rotating machine MG 1  outputting the MG 1  torque Tg as the reaction torque of the engine torque Te at the MG 1  rotation speed Ng which is the MG 1  rotation speed Ng at the time of command signal Smg output, and is a command value of a consumed electric power Wm of the second rotating machine MG 2  outputting the MG 2  torque Tm at the MG 2  rotation speed Nm which is the MG 2  rotation speed Nm at the time of command signal Smg output. 
     The maximum charging amount Win of the battery  54  is a maximum amount of the electric power that can be charged to the battery  54 , while the maximum discharging amount Wout of the battery  54  is a maximum amount of the electric power that can be discharged from the battery  54 . That is, the maximum charging and discharging amounts Win, Wout of the battery  54   d  define a range of an electric power Pbat of the battery  54  that can be used. The maximum charging and discharging amounts Win, Wout are calculated by the electronic control apparatus  90 , for example, based on a battery temperature THbat and a charged state value SOC [%] of the battery  54 . The charged state value SOC of the battery  54  is a value indicative of a charged state of the battery  54 , i.e., an amount of the electric power stored in the battery  54 , and is calculated by the electronic control apparatus  90 , for example, based on the charging/discharging electric current Ibat and the voltage Vbat of the battery  54 . 
     For example, when the transmission device  40  is operated as a continuously variable transmission as a whole by operating the continuously variable transmission portion  18  as a continuously variable transmission, the hybrid control portion  94  controls the engine  14  and controls the generated electric power Wg of the first rotating machine MG 1  so as to attain the engine rotational speed Ne and the engine torque Te at which the engine power Pe achieving the required drive power Prdem is acquired in consideration of an engine optimum fuel consumption point etc., and thereby provides the continuously variable shift control of the continuously variable transmission portion  18  to change the gear ratio γ 0  of the continuously variable transmission portion  18 . As a result of this control, the gear ratio γt of the transmission device  40  is controlled in the case of operating the transmission device  40  as a continuously variable transmission. 
     For example, when the transmission device  40  is operated as a step-variable transmission as a whole by operating the continuously variable transmission portion  18  as in a step-variable transmission, the hybrid control portion  94  uses a predetermined relationship, for example, an overall gear position shift map, to determine a shifting action of the transmission device  40  and provides the shift control of the continuously variable transmission portion  18  so as to selectively establish the plurality of overall gear positions in coordination with the shift control of the AT gear position of the step-variable transmission portion  20  by the AT shift control portion  92 . The plurality of overall gear positions can be established by controlling the engine rotational speed Ne by the first rotating machine MG 1  in accordance with the vehicle speed V so as to maintain the respective gear ratios γt. The gear ratio γt of each of the overall gear positions may not necessarily be a constant value over the entire region of the vehicle speed V and may be changed in a predetermined region or may be limited by an upper limit, a lower limit, etc. of the rotational speed of each rotary member or element. As described above, the hybrid control portion  94  can provide the shift control in which the engine rotational speed Ne is changed as in a step-variable shift. An overall step-variable shift control of causing the transmission device  40  to perform a shift as in a step-variable transmission as a whole may be provided only in priority to the continuously variable shift control of operating the transmission device  40  as a continuously variable transmission as a whole in the case that, for example, the vehicle driver selects a running mode placing emphasis on running performance such as a sports running mode etc. or the required drive torque Trdem is relatively large; however, the overall step-variable shift control may basically be provided except when a predetermined restriction is placed on provision. 
     The hybrid control portion  94  selectively establishes the motor running mode or the hybrid running mode as the running mode depending on a driving state, so as to cause the vehicle  10  to run in a selected one of the running modes. For example, the hybrid control portion  94  establishes the motor running mode when the required drive power Prdem is in a motor running region smaller than a predetermined threshold value, and establishes the hybrid running mode when the required drive power Prdem is in a hybrid running region equal to or greater than the predetermined threshold value. In  FIG. 8 , one-dot chain line A is a boundary line for switching the drive force source for driving the vehicle  10  between at least the engine  14  and only the second rotating machine MG 2 . That is, the one-dot chain line A of  FIG. 8  is a boundary line between the hybrid running region and the motor running region for switching between the hybrid running and the motor running. A predetermined relationship having the boundary line as indicated by the one-dot chain line A of  FIG. 8  is an example of a drive-force source switching map defined by the two-dimensional coordinates of variables in the form of the vehicle running speed V and the required drive force Frdem. It is noted that, in  FIG. 8 , the drive-force source switching map is shown together with AT gear position shift map, for convenience of the description. 
     The hybrid control portion  94  establishes the motor running mode when the required drive power Prdem is in the motor running region, and establishes the hybrid running mode when the required drive power Prdem is in the hybrid running region. However, even when the required drive power Prdem is in the motor running region, the hybrid control portion  94  establishes the hybrid running mode if the charged state value SOC of the battery  54  is less than a predetermined engine-start threshold value. The motor running mode is a driving state in which the vehicle  10  is caused to run by the driving torque generated by the second rotating machine MG 2 , with the engine  14  being stopped. The hybrid running mode is a driving state in which the vehicle  10  is caused to run with the engine  14  being operated. The engine-start threshold value is a predetermined threshold value for determining that the state-of-charge value SOC reaches a level at which the engine  14  must forcibly be started for charging the battery  54 . 
     When establishing the hybrid running mode upon stop of operation of the engine  14 , the hybrid control portion  94  executes a control for staring the engine  14 . For staring the engine  14 , the hybrid control portion  94  increases the engine rotational speed Ne by the first rotating machine MG 1 , and starts the engine  14 , by igniting when the engine rotational speed Ne becomes at least a certain speed value that is an ignitable speed value. That is, the hybrid control portion  94  starts the engine  14  by cranking the engine  14  by the first rotating machine MG 1 . 
     The driving control portion  96  is capable of executing, as a drive control for driving the vehicle  10 , a selected one of a manual drive control for driving the vehicle  10  in accordance with driving operations made by the vehicle driver and a drive assist control for driving the vehicle  10  without depending on the driving operations made by the vehicle driver. The manual drive control is for causing the vehicle  10  to run by manual operations, i.e., the driving operation manually made by the vehicle driver. The manual drive control is a driving method for casing the vehicle  10  to run by the vehicle driver&#39;s driving operations such as an accelerating operation, a barking operation and a steering operation. The drive assist control is for causing the vehicle  10  to run, for example, with a drive assist by which the driving operations are automatically assisted. The drive assist is a driving method for causing the vehicle  10  to run, for example, by automatically accelerating, decelerating and braking the vehicle  10 , by controls executed by the electronic control apparatus  90 , based on the signals and information supplied from the various sensors, without depending on the driving operations made by the vehicle driver, namely, without depending on intentions of the vehicle driver. The drive assist control is, for example, the automatic drive control in which the vehicle  10  is accelerated, decelerated, braked and steered, depending on a target driving state that is automatically determined based on, for example, the map information and the destination point inputted by the vehicle driver. It is noted that the drive assist control may be broadly interpreted to encompass the cruise control in which some of the driving operations such as the steering operation are executed by the vehicle driver while the other driving operations such as the accelerating, decelerating and braking operations are automatically executed. 
     When a drive-assist mode is not selected with the automatic-drive selecting switch and the cruise switch of the drive-assist setting switches  84  being placed in OFF, the driving control portion  96  establishes a manual drive mode so as to execute the manual drive control. The driving control portion  96  executes the manual drive control by outputting commands for controlling the step-variable transmission portion  20 , engine  14  and first and second rotating machines MG 1 , MG 2 , wherein the commands are supplied to the AT shift control portion  92  and the hybrid control portion  94 . 
     When an automatic drive mode is selected with the automatic-drive selecting switch of the drive-assist setting switches  84  being placed in ON by the vehicle driver, the driving control portion  96  establishes the automatic drive mode so as to execute the automatic drive control. Specifically, the driving control portion  96  automatically sets a target driving state that is dependent on, for example, the destination point inputted by the vehicle driver, the own-vehicle location information based on the location information Ivp, the map information based on the navigation information Inavi and various information relating to the running road and based on the vehicle area information Iard. The driving control portion  96  executes the automatic drive control for automatically accelerating, decelerating and steering the vehicle  10 , based on the set target driving state. To this end, the driving control portion  96  outputs the commands for controlling the step-variable transmission portion  20 , engine  14  and rotating machines MG 1 , MG 2 , and the outputted commands are supplied to the AT shift control portion  92  and the hybrid control portion  94 . Further, in this instance, the driving control portion  96  outputs the brake-control command signal Sbra for obtaining the required braking torque, and the steering-control command signal Sste for controlling steering of the front wheels, wherein the outputted brake-control command signal Sbra and steering-control command signal Sste are supplied to the wheel brake device  86  and the steering device  87 , respectively. 
     By the way, in the vehicle  10 , there is a possibility that an anomaly could occur in the shift control operation executed in the step-variable transmission portion  20 . The anomaly in the shift control operation executed in the step-variable transmission portion  20  is, for example, shifting malfunction of the step-variable transmission portion  20 . 
       FIG. 9  is a time chart for explaining, by way of example, shifting malfunction of the step-variable transmission portion  20 . In  FIG. 9 , a period from a time point t 1   b  to a time point t 3   b  corresponds to a process of the shift control operation executed in the step-variable transmission portion  20  by which a 2→3 shift-up action of the step-variable transmission portion  20  is executed. In the process of the shift control operation executed in the step-variable transmission portion  20 , a learning control operation is executed so as to converge a racing (blowing-up) of a rotational speed Nfx of a rotary member. That is, in the process of the clutch-to-clutch shifting operation of the step-variable transmission portion  20 , the learning control operation is executed such that a racing amount ΔNf of the rotational speed Nfx is converged within a predetermined racing amount range RngNf, and the hydraulic-pressure command value is corrected. The rotational speed Nfx is a rotational speed that is to be changed in the process of the shift control operation executed in the step-variable transmission portion  20 , and is, for example, the MG 2  rotational speed Nm. The above-described racing is a phenomenon that the rotational speed Nfx is increased relative to a reference rotational speed Nref that is based on the gear ratio γat and the output rotational speed No of the step-variable transmission portion  20 , in the process of the shift control operation executed in the step-variable transmission portion  20 . The racing amount ΔNf is an amount of increase of the rotational speed Nfx upon occurrence of the above-described racing. Where the rotational speed Nfx is the MG 2  rotational speed Nm, a racing amount ΔNfm of the MG 2  rotational speed Nm is an amount of increase of the MG 2  rotational speed Nm relative to a reference rotational speed Nrefm (=γat×No). The predetermined racing amount range RngNf is a normal range of the racing amount ΔNf, which is determined as a small racing amount range in which, for example, a shock or the like is suppressed in the process of the shift control operation executed in the step-variable transmission portion  20 . Where the transmission device (composite transmission)  40  is operated as a step-variable transmission as a whole, as described above, a shift control operation is executed in cooperation with the shift control operation executed in the step-variable transmission portion  20  such that a selected one of the overall gear positions is established in the transmission device  40 . Therefore, there is a possibility that the racing could occur also in the engine rotational speed Ne that is an input rotational speed of the transmission device  40 . In this case, the rotational speed Nfx is, for example, the engine rotational speed Ne that is to be changed in the process of the shift control operation executed in step-variable transmission portion  20 . Where the rotational speed Nfx is the engine rotational speed Ne, a racing amount ΔNfe of the engine rotational speed Ne is an amount of increase of the engine rotational speed Ne relative to a reference rotational speed Nrefe (=γ 0 ×γat×No=γt×No). 
     Specifically described, when the racing amount ΔNf is larger than the predetermined racing amount range RngNf upon occurrence of the racing of the engine rotational speed Ne or the MG 2  rotational speed Nm (see vicinity of the time point t 2   b ), an initial pressure value of the C 2  hydraulic pressure supplied to the engaging-side frictional engagement device is increased in the next execution of the 2→3 shift-up action. On the other hand, when the racing amount ΔNf is smaller than the predetermined racing amount range RngNf, the initial pressure value of the C 2  hydraulic pressure is reduced in the next execution of the 2→3 shift-up action. The initial pressure value is, for example, the hydraulic-pressure command value in the quick apply period (see period from the time point t 1   a  to the time point t 2   a  in  FIG. 7 ) or the hydraulic-pressure command value in the constant-pressure stand-by stage (see period from the time point t 2   a  to the time point t 3   a  in  FIG. 7 ). When the racing amount ΔNf of the engine rotational speed Ne or the MG 2  rotational speed Nm is converged within the predetermined racing amount range RngNf by correction of the hydraulic-pressure command value, the learning control operation is completed. 
     After completion of the learning control operation described above, in case of occurrence of a racing amount anomaly in which the racing amount ΔNf becomes not smaller than a racing-anomaly determination value ΔNffx, it is determined that the shifting malfunction of the step-variable transmission portion  20  has occurred. The racing-anomaly determination value ΔNffx is, for example, a predetermined threshold value which is larger than the predetermined racing amount range RngNf and which is determined for determining that a large degree of racing that causes the shifting malfunction of the step-variable transmission portion  20  has occurred. Further, after completion of the learning control operation described above, in case of occurrence of a tie-up in which the racing amount ΔNf becomes not larger than a tie-up determination value ΔNftu, too, it is determined that the shifting malfunction of the step-variable transmission portion  20  has occurred. The tie-up determination value ΔNftu is, for example, a predetermined threshold value which is smaller than the predetermined racing amount range RngNf and which is determined for determining that the tie-up that causes the racing amount ΔNf to be zero or extremely small has occurred. It is noted that, in the above-described learning control operation, the hydraulic-pressure command value may be corrected such that a racing time in place of the racing amount ΔNf is held within a predetermined length of time. The racing time is a length of time for which the racing continues upon occurrence of the racing of the rotational speed Nfx. 
     There is a case in which a shifting shock is generated when the racing amount anomaly or the tie-up occurs. After completion of the learning control operation executed in the shift control operation for the step-variable transmission portion  20 , in case of generation of the shifting shock causing the longitudinal acceleration Gx to be not lower than a predetermined acceleration value, it is determined that the shifting malfunction of the step-variable transmission portion  20  has occurred. The predetermined acceleration value is, for example, a predetermined threshold value that is determined for determining that the longitudinal acceleration Gx has been increased to a high acceleration value causing the shifting malfunction of the step-variable transmission portion  20 . 
     A vehicle anomaly analysis apparatus  300  (see  FIG. 1 ), which is an external apparatus provided apart from the vehicle  10 , is configured, when an anomaly has occurred in the shift control operation executed in the step-variable transmission portion  20 , to analyze the anomaly by using the rotational speed Nfx, particularly, determine or specify cause of the anomaly. It can be considered that the vehicle anomaly analysis apparatus  300  cooperates with the electronic control device  90  of the vehicle  10 , or with the server  200  and the electronic control device  90  of the vehicle  10 , to constitute a vehicle anomaly analysis system for analyzing the anomaly having occurred in the shift control operation executed in the step-variable transmission portion  20 . 
     As described above, after the learning control operation executed in the shift control operation of the step-variable transmission portion  20  has been completed, it is possible to detect occurrence of the shifting malfunction of the step-variable transmission portion  20 , by seeing an indication that the racing amount ΔNf of the rotational speed Nfx has become deviated from the predetermined racing amount range RngNf and has become not smaller than the racing-anomaly determination value ΔNffx or not larger than the tie-up determination value ΔNftu. However, the cause of the anomaly is not necessarily easy to be specified by only seeing an indication that the racing amount ΔNf becomes an abnormal value. 
       FIGS. 10, 11, 12 and 13  are views for showing, by way of examples, a normal case and anomaly cases, in an arrangement in which the hydraulic pressures Pc 1 , Pc 2 , Pb 1 , Pb 2  are controlled directly by the respective solenoid valves S 11 , SL 2 , SL 3 , SL 4 . In a lower one of the views of each of  FIGS. 10, 11, 12 and 13 , a manner of chronological change of the racing amount ΔNfe of the engine rotational speed Ne, for example, in process of the 2→3 shift-up action executed in the step-variable transmission portion  20  is shown by way of example. The views of  FIG. 10  show the normal case, the views of  FIG. 11  show the anomaly case with a suction of air by the oil pump, the views of  FIG. 12  show the anomaly case with a temporary stuck of the solenoid valve SL 2 , and the views of  FIG. 13  show the anomaly case with a complete stuck of the solenoid valve SL 2 . The above-described suction of air by the oil pump is a phenomenon that the oil pump sucks the air when sucking the working fluid OIL from the oil pan  100 . The above-described temporary or complete stuck of the solenoid valve SL is a phenomenon that a valve spool is stuck and not moved in the solenoid valve SL, for example, due to entrance of foreign substances. The malfunction of any one of the solenoid valves SL 1 -SL 4  due to the suction of the air by the MOP  57  and/or MOP  58  or the occurrence of the stuck of the corresponding solenoid valve is the cause of the shifting malfunction of the step-variable transmission portion  20 . With only an indication that the racing amount ΔNfe has become the abnormal value, it is difficult to specify the cause of the shifting malfunction of the step-variable transmission portion  20 . However, the cause of the shifting malfunction of the step-variable transmission portion  20  can be easily specified by seeing the manner of the chronological change of the racing amount ΔNfe as shown in  FIGS. 10, 11, 12 and 13 . 
     Referring back to  FIG. 1 , the vehicle anomaly analysis apparatus  300  includes an anomaly-cause specifying model  310  that is prepared to indicate a relationship between the manner of the chronological change of the racing amount ΔNf of the rotational speed Nfx and the cause of the anomaly in the shift control operation of the step-variable transmission portion  20 . The vehicle anomaly analysis apparatus  300  determines or specifies the cause of the anomaly in the shift control operation of the step-variable transmission portion  20 , by applying the anomaly-cause specifying model  310  to the manner of the chronological change of the racing amount ΔNf upon occurrence of the anomaly in the shift control operation of the step-variable transmission portion  20 . The vehicle anomaly analysis apparatus  300  is connected to the server  200  and/or the vehicle  10 , for example, via a wireless communication. The vehicle anomaly analysis apparatus  300  obtains the manner of the chronological change of the racing amount ΔNf from the server  200  and/or the vehicle  10 . The vehicle  10  memorizes the manner of the chronological change of the racing amount ΔNf, and transmits the manner of the chronological change of the racing amount ΔNf, to the server  200  and/or the vehicle anomaly analysis apparatus  300 , as needed. The server  200  memorizes the manner of the chronological change of the racing amount ΔNf as big data. The anomaly-cause specifying model  310  is determined or prepared, for example, by using at least one prototype vehicle  400  (see  FIG. 1 ) that is the vehicle  10  in a prototype stage. The anomaly-cause specifying model  310  is established or realized, for example, by a supervised learning that is a machine learning using, as teaching data, the manner of the chronological change of the racing amount ΔNf upon the occurrence of the anomaly in the shift control operation of the step-variable transmission portion  20  and the cause of the anomaly in the shift control operation. of the step-variable transmission portion  20 . Each of the at least one prototype vehicle  400  has basically the same construction as the vehicle  10  that is a mass-produced vehicle. 
     There will be described a process of constructing the anomaly-cause specifying model  310 , by way of example. 
     The manner of the chronological change of the racing amount ΔNf of the rotational speed Nfx does not directly reflect the suction of air by the MOP  57  and/or the EOP  58 , the malfunction of the solenoid valves SL 1 -SL 4  and the like. Therefore, a certain length of time and a certain number of personnel are required to construct the anomaly-cause specifying model  310 , if the anomaly-cause specifying model  310  is intended to be constructed by specifying the cause of the anomaly in the shift control operation of the step-variable transmission portion  20 , from the manner of the chronological change of the racing amount ΔNf of the rotational speed Nfx. 
     The anomaly-cause specifying model  310  indicates the relationship between the manner of the chronological change of the racing amount ΔNf of the rotational speed Nfx and, as the cause of the anomaly in the shift control operation of the step-variable transmission portion  20 , a cause that is predetermined based on an operation-state representing value representing an operation state of the vehicle  10 , wherein the cause of the anomaly in the shift control operation of the step-variable transmission portion  20  can be specified by the operation-state representing value, easier than by the rotational speed Nfx (particularly, the manner of the chronological change of the racing amount ΔNf of the rotational speed Nfx). 
     Referring back to  FIGS. 10, 11, 12 and 13 , their views show, in addition to the manner of the chronological change of the racing amount ΔNfe of the engine rotational speed Ne, a manner of chronological change of an actual pressure value (see “ACTUAL HYDRAULIC PRESSURE” in  FIGS. 10, 11, 12 and 13 ) of the C 2  hydraulic pressure Pc 2  in the process of the 2→3 shift-up action of the step-variable transmission portion  20 , by way of examples. In  FIG. 11 , “BOOST GENERATION” indicates a phenomenon that is caused as a result of entrance of air into the solenoid valve SL 2  due to suction of the air by the MOP  57  and/or EOP  58 . As is apparent from  FIGS. 10, 11, 12 and 13 , the cause of the shifting malfunction of the step-variable transmission portion  20  can be determined or specified easier by using the actual pressure value of the C 2  hydraulic pressure Pc 2 , than by using the racing amount ΔNfe of the engine rotational speed Ne. 
     That is, the engaging pressures Pcb, which are output pressures of the respective solenoid valves SL 1 -SL 4 , more precisely reflect the malfunction of the solenoid valves SL 1 -SL 4  and the like, than the manner of the chronological change of the racing amount ΔNf of the rotational speed Nfx. Therefore, the cause of the anomaly in the shift control operation of the step-variable transmission portion  20  can be specified easier by seeing the engaging pressures Pcb, than by seeing the manner of the chronological change of the racing amount ΔNf of the rotational speed Nfx. The above-described operation-state representing value is a value of each of the engaging pressure Pcb. As the cause of the shifting malfunction of the step-variable transmission portion  20 , there is also an anomaly of the drive unit  89  such as a short-circuit in the drive unit  89 . Since the operation state of each of the solenoid valves SL 1 -SL 4  can be easily known by seeing a corresponding one of the engaging pressures Pcb, the cause of the shifting malfunction of the step-variable transmission portion  20  that includes the anomaly of the drive unit  89  can be easily specified by seeing the value of each of the engaging pressures Pcb as the above-described operation-state representing value. 
     There is a case in which the hydraulic pressure sensors  78  are not installed in the vehicle  10 , for example, due to a cost limitation. In such a case, too, the anomaly-cause specifying model  310  can be appropriately constructed by detecting the engaging pressures Pcb through hydraulic pressure sensors (hydraulic pressure sensor set)  402  which are installed in each of the at least one prototype vehicle  400  and which are equivalent to the hydraulic pressure sensors  78 . This method for constructing the anomaly-cause specifying model  310  is useful in the case in which the hydraulic pressure sensors  78  are not installed in the vehicle  10 . For convenience of the following description, sensors, which are installed in each of the at least one prototype vehicle  400  and which are equivalent to various sensors installed in the vehicle  10  and other than the hydraulic pressure sensors  78 , will be referred to as “other sensors  404 ”, so as to be distinguished from the hydraulic pressure sensors  402 . 
     The vehicle  10  is provided with some kinds of sensors such as the engine speed sensor  60 , output speed sensor  62 , MG 2  speed sensor  66 , accelerator-opening degree sensor  68  and G sensor  74 , although these are limited kinds of sensors. The supervised learning as the machine learning is executed, with data of detected values of the other sensors  404  (that are equivalent to the various sensors installed in the vehicle  10 ) upon occurrence of the anomaly in the shift control operation of the step-variable transmission portion  20  being inputted, and with the cause of the anomaly in the shift control operation being outputted. 
     Referring back to  FIG. 1 , the vehicle anomaly analysis apparatus  300  includes a so-called microcomputer incorporating a CPU, a ROM, a RAM and an input-output interface. The CPU performs various control operations, by processing various input signals, according to control programs stored in the ROM, while utilizing a temporary data storage function of the RAM. The vehicle anomaly analysis apparatus  300  includes a calculation portion  302  and an indication portion  304 . The calculation portion  302  is an artificial intelligence including a database portion  306  configured to store data and an inference portion  308  configured to infer a conclusion from the stored data. The anomaly-cause specifying model  310  is realized by the supervised learning executed by the calculation portion  302 . The indication portion  304  is an output device such as a display, a printer and the like, which is configured to indicate, for example, result of the calculation or processing made by the calculation portion  302 . 
       FIG. 14  is a view showing the anomaly-cause specifying model  310  by way of example. The anomaly-cause specifying model  310  shown in  FIG. 14  is a neutral network based on kinds of the detected values of the sensors provided in the vehicle  10 . The anomaly-cause specifying model  310  is a model that can be constituted by simulating a nerve cell group of a living body, through software by computer program or hardware consisting of combination of electronic elements. The anomaly-cause specifying model  310  is a multi-layer structure consisting of an input layer constituted by i pieces of nerve cell elements (=neurons) Pi 1  (P 11 -Pi 1 ), an intermediate layer constituted by j pieces of nerve cell elements Pj 2  (P 12 -Pj 2 ) and an output layer constituted by k pieces of nerve cell elements Pk 3  (P 13 -Pk 3 ). The intermediate layer may be a multi-layer structure. For transmitting states of the nerve cell elements from the input layer to the output layer, the anomaly-cause specifying model  310  is provided with transfer elements Dij for coupling the i pieces of nerve cell elements Pi 1  and the j pieces of nerve cell elements Pj 2  through coupling coefficients, i.e., weighted values Wij, and transfer elements Dik for coupling the j pieces of nerve cell elements Pj 2  and the k pieces of nerve cell elements Pk 3  through weighted values Wik. 
     The anomaly-cause specifying model  310  is an anomaly analysis system in which the weighted values Wij, Wjk are subjected to the machine learning through a predetermined algorithm. In the supervised learning for the anomaly-cause specifying model  310 , teaching data, i.e., teaching signals obtained in the at least one prototype vehicle  400  are used. The data of the detected values of the other sensors  404  upon occurrence of the anomaly in the shift control operation of the step-variable transmission portion  20  in each of the at least one prototype vehicle  400  are provided as the teaching signal to the input layer (see “X 11 -Xi 1 ” in  FIG. 14 ). Meanwhile, the causes of the anomaly in the shift control operation of the step-variable transmission portion  20 , which are obtained based on the detected values of the hydraulic pressure sensors  402  in each of the at least one prototype vehicle  400 , are provided as the teaching signals to the output layer (see “Y 13 -Yk 3 ” in  FIG. 14 ). In examples shown in  FIGS. 10, 11, 12 and 13 , for example, there is a strong correlation between each of the manners of the chronological change of the racing amount ΔNfe of the engine rotational speed Ne in the process of the shift control operation executed in the step-variable transmission portion  20  and a corresponding one of the causes of the anomaly in the shift control operation of the step-variable transmission portion  20 , so that large weighted values Wij, Wjk are given to such a correlation. In the analysis using the artificial intelligence, at least the correlation must be known. Regarding the data of the detected values of the other sensors  404 , the cause of the anomaly can be easily specified by using the detected values changed chronologically, than by using data at a certain point of time, as shown in  FIGS. 10, 11, 12 and 13  by way of example. The detected values of the other sensors  404  that are chronologically changed are provided as teaching signals to the input layer. As described above, the anomaly-cause specifying model  310  is a learning model that indicates relationships between detected values of the other sensors  404  upon occurrence of anomalies in the at least one prototype vehicle  400  and causes of the anomalies specified based on detected values of the hydraulic pressure sensors  402  in the at least one prototype vehicle  400 , wherein the relationships are predetermined by using the at least one prototype vehicle  400 . 
     The vehicle anomaly analysis apparatus  300  includes a state determining means or portion in the form of a state determining portion  312  and an anomaly-cause specifying means of portion in the form of an anomaly-cause specifying portion  314 , for performing a control function for improving accuracy in specifying the cause of the anomaly in the shift control operation of the step-variable transmission portion  20 . 
     The state determining portion  312  is configured to make determination as to whether an anomaly has occurred or not, in the shift control operation of the step-variable transmission portion  20  of each of the vehicles  10  in market or field. The state determining portion  312  makes this determination, depending on whether the electronic control apparatus  90  of each of the vehicles  10  determines that the anomaly has occurred or not, in the shift control operation of the step-variable transmission portion  20  of the each of the vehicles  10 . The electronic control apparatus  90  is configured to determine whether the anomaly has occurred or not, in the shift control operation of the step-variable transmission portion  20 , depending on the detected values of the various sensors which are other than the hydraulic pressure sensors  78  and which represent the operation state of each of the vehicles  10 . Alternatively, the state determining portion  312  may make the above determination, depending on the detected values of the various sensors which are other than the hydraulic pressure sensors  78  and which are provided in each of the vehicles  10 , wherein the detected values are obtained from the server  200 . Described specifically, where the anomaly occurring in the shift control operation of the step-variable transmission portion  20  of each of the vehicles  10  is the shifting malfunction of the step-variable transmission portion  20 , it is determined whether the shifting malfunction of the step-variable transmission portion  20  has occurred or not, depending on whether the racing amount ΔNf of the rotational speed Nfx has become not smaller than the racing-anomaly determination value ΔNffx or not, in the process of the shift control operation, after completion of the learning control operation executed in the shift control operation of the step-variable transmission portion  20 , and/or depending on whether the racing amount ΔNf of the rotational speed Nfx has become not larger than the tie-up determination value ΔNftu or not, in the process of the shift control operation, after completion of the learning control operation executed in the shift control operation of the step-variable transmission portion  20 . Alternatively, it is determined whether the shifting malfunction of the step-variable transmission portion  20  has occurred or not, depending on whether the shifting shock causing the longitudinal acceleration Gx to be not lower than the above-described predetermined acceleration value has been generated or not, in the process of the shift control operation, after completion of the learning control operation executed in the shift control operation of the step-variable transmission portion  20 . Thus, the vehicle anomaly analysis apparatus  300  makes the determination as to whether the anomaly has occurred or not, in the shift control operation of the step-variable transmission portion  20  of each of the vehicles  10 , based on the detected values of the various sensors which are other than the hydraulic pressure sensors  78  and which are provided in each of the vehicles  10 . 
     The anomaly-cause specifying portion  314  is configured, when it is determined by the state determining portion  312  that the anomaly has occurred in the shift control operation of the step-variable transmission portion  20  in at least one of the vehicles  10 , to obtain, from the at least one of the vehicles  10  via a certain network, the big data of the at least one of the vehicles  10  upon occurrence of the anomaly in the shift control operation. The big data of the at least one of the vehicles  10  obtained from the at least one of the vehicles  10  are, for example, big data of the at least one of the vehicles  10  transmitted directly from the at least one of the vehicles  10  and/or big data of the at least one of the vehicles  10  transmitted indirectly from the at least one of the vehicles  10  via the server  200 . The indirectly transmitted big data of the at least one of the vehicles  10  are, for example, big data of the at least one of the vehicles  10  transmitted via only the server  200  or big data of the at least one of the vehicles  10  transmitted from the at least one of the vehicles  10  to the server  200  and stored in the server  200 . As described above, the data of the detected values of the other sensors  404 , which are chronologically changed, are provided as teaching signals to the input layer of the anomaly-cause specifying model  310 , and the big data of the at least one of the vehicles  10  are data representing the manner of the chronological change of each of the detected values of the various sensors that are other than the hydraulic pressure sensors  78 , wherein the data are stored in each of the at least one of the vehicles  10 . Therefore, the manner of the chronological change of each of the detected values of the various sensors other than the hydraulic pressure sensors  78  is used for specifying the cause of the anomaly in the shift control operation. 
     The anomaly-cause specifying portion  314  is configured to analyze the cause of the anomaly having occurred in the shift control operation of the step-variable transmission portion  20  of each of the at least one of the vehicles  10 , by using the obtained big data of the at least one of the vehicles  10  and the anomaly-cause specifying model  310 . That is, the anomaly-cause specifying portion  314  inputs the obtained big data of the at least one of the vehicles  10  into the anomaly-cause specifying model  310 , and analyzes the cause of the anomaly in the shift control operation of the step-variable transmission portion  20 . 
     Further, the anomaly-cause specifying portion  314  determines whether the cause of the anomaly in the shift control operation of the step-variable transmission portion  20  could have been specified or not. When determining that the cause of the anomaly in the shift control operation could have been specified, the anomaly-cause specifying portion  314  indicates the specified cause of the anomaly in the indication portion  304  or the like. It is ideal that the specified cause of the anomaly in the shift control operation is limited to a single cause. However, in a case in which there are a plurality of possible candidates of the cause of the anomaly, the candidates of the cause are arranged in an order of probability of each of the candidates, which is obtained through analysis of the anomaly. When determining that the cause of the anomaly in the shift control operation cannot be specified, the anomaly-cause specifying portion  314  indicates that the cause of the anomaly is unknown or unspecified in the indication portion  304  or the like. 
       FIG. 15  is a flow chart showing a main part of a control routine executed by the vehicle anomaly analysis apparatus  300 , namely, a control routine that is executed for specifying the cause of the anomaly in the shift control operation executed in the step-variable transmission portion  200 , with an improved accuracy in specifying cause of the anomaly. This control routine is executed, for example, in a repeated manner. 
     As shown in  FIG. 15 , the control routine is initiated with step S 10  corresponding to function of the state determining portion  312 , which is implemented to determine whether the anomaly has occurred in the shift control operation of the step-variable transmission portion  20  of at least one of the vehicles  10  in market or field. When a negative determination is made at step S 10 , one cycle of execution of the control routine is completed. When an affirmative determination is made at step S 10 , step S 20  corresponding to function of the anomaly-cause specifying portion  314  is implemented to obtain the big data of the least one of the vehicles  10  upon occurrence of the anomaly in the shift control operation via the network. Step S 20  is followed by step S 30  corresponding to function of the anomaly-cause specifying portion  314 , which is implemented to input the obtained big data of the at least one of the vehicles  10 , into the anomaly-cause specifying model  310  as the anomaly analysis system, and then to analyze the cause of the anomaly in the shift control operation in the anomaly-cause specifying model  310 . Step S 30  is followed by step S 40  corresponding to function of the anomaly-cause specifying portion  314 , which is implemented to determine whether the cause of the anomaly in the shift control operation has been specified or not. When an affirmative determination is made at step S 40 , step S 50  corresponding to function of the anomaly-cause specifying portion  314  is implemented to indicate the specified cause of the anomaly in the shift control operation. When a negative determination is made at step S 40 , the control flow goes to step S 60  corresponding to function of the anomaly-cause specifying portion  314 , which is implemented to indicate that the cause of the anomaly is unspecified. 
     As described above, in the present embodiment, the cause of the anomaly in the shift control operation of the step-variable transmission portion  20  is determined or specified, by applying the predetermined anomaly-cause specifying model  310  that indicates the relationship between the manner of the chronological change of the racing amount ΔNf of the rotational speed Nfx and the cause of the anomaly in the shift control operation of the step-variable transmission portion  20 , to the manner of the chronological change of the racing amount ΔNf of the rotational speed Nfx upon occurrence of the anomaly in the shift control operation of the step-variable transmission portion  20 , so that it is possible to improve accuracy in specifying the cause of the anomaly in the shift control operation of the step-variable transmission portion  20 . 
     In the present embodiment, the anomaly-cause specifying model  310  is realized by the supervised learning that is the machine learning using, as the teaching data, the manner of the chronological change of the racing amount ΔNf of the rotational speed Nfx upon the occurrence of the anomaly in the shift control operation of the step-variable transmission portion  20  and the cause of the anomaly in the shift control operation of the step-variable transmission portion  20 , so that it is possible to construct a learning model by which the cause of the anomaly in the shift control operation of the step-variable transmission portion  20  can be specified with an improved accuracy. 
     In the present embodiment, the anomaly in the shift control operation of the step-variable transmission portion  20  is the shifting malfunction of the step-variable transmission portion  20 , so that the cause of the shifting malfunction of the step-variable transmission portion  20  can be specified with an improved accuracy by using the anomaly-cause specifying model  310 . 
     In the present embodiment, the cause of the anomaly in the shift control operation of the step-variable transmission portion  20  is the suction of the air by the MOP  57  and/or the EOP  58 , the malfunction of the solenoid valves SL 1 -SL 4 , and/or the malfunction of the drive unit  89 . Therefore, even in event of occurrence of the anomaly in the shift control operation of the step-variable transmission portion  20 , which causes the racing amount ΔNf of the rotational speed Nfx to become an abnormal value, the cause of the anomaly can be specified with an improved accuracy by using the anomaly-cause specifying model  310 . 
     In the present embodiment, the anomaly-cause specifying model  310  indicates the relationship between the manner of the chronological change of the racing amount ΔNf of the rotational speed Nfx and, as the cause of the anomaly in the shift control operation of the step-variable transmission portion  20 , the cause that is predetermined based on the operation-state representing value, wherein the cause of the anomaly in the shift control operation of the step-variable transmission portion  20  can be specified by the operation-state representing value, easier than by the rotational speed Nfx. Therefore, the cause of the anomaly in the shift control operation of the step-variable transmission portion  20  can be specified with an improved accuracy in the anomaly-cause specifying model  310 . 
     In the present embodiment, the above-described operation-state representing value is the value of the engaging pressure Pcb, so that the cause of the anomaly in the shift control operation of the step-variable transmission portion  20  can be appropriately specified in the anomaly-cause specifying model  310 . 
     There will be described another embodiment of this invention. The same reference signs as used in the above-described first embodiment will be used in the following second embodiment, to identify the functionally corresponding elements, and descriptions thereof are not provided. 
     Second Embodiment 
     In the above-described first embodiment, the suction of the air by the MOP  57  and/or the EOP  58 , the malfunction of the solenoid valves SL 1 -SL 4  and the anomaly of the drive unit  89  have been described, by way of example, as the cause of the anomaly in the shift control operation of the step-variable transmission portion  20 . In the following description of this second embodiment, there will be described reduction of durability of the step-variable transmission portion  20  as the cause of the anomaly in the shift control operation of the step-variable transmission portion  20 . The reduction of the durability of the step-variable transmission portion  20  is, for example, reduction of durability of friction members of the engagement devices CB and temporary malfunctions of the engagement devices CB due to, for example, increased temperatures of the friction members of the engagement devices CB. The reduction of the durability of the step-variable transmission portion  20  highly correlates with, for example, the number of occurrences of the anomaly in the shift control operation of the step-variable transmission portion  20 , which is determined by the state determining portion  312 . 
     In this second embodiment, the vehicle anomaly analysis apparatus  300  includes an anomaly-cause specifying model  320  shown in  FIG. 16 , in addition to or in place of the above-described anomaly-cause specifying model  310 . The anomaly-cause specifying model  320  further indicates a relationship between the number of occurrences of the anomaly in the shift control operation of the step-variable transmission portion  20  and the cause of the anomaly in the shift control operation of the step-variable transmission portion  20 . The anomaly-cause specifying model  320  is established or realized, for example, by the supervised learning that is the machine learning using, as the teaching data, the manner of the chronological change of the racing amount ΔNf upon the occurrence of the anomaly in the shift control operation of the step-variable transmission portion  20 , the number of occurrences of the anomaly in the shift control operation of the step-variable transmission portion  20  and the reduction of the durability of the step-variable transmission portion  20 . The reduction of the durability of the step-variable transmission portion  20  is represented, for example, by a degree or size of damage on the friction member of each of the engagement devices CB. In principle, the racing amount ΔNf is increased with increase of the damage, and the racing occurs at increased frequency with increase of the damage. 
     The anomaly-cause specifying model  320  shown in  FIG. 16  is a neutral network as the above-described anomaly-cause specifying model  310 . The anomaly-cause specifying model  320  is a multi-layer structure consisting of an input layer constituted by f pieces of nerve cell elements Pf 1  (P 11 -Pf 1 ), an intermediate layer constituted by g pieces of nerve cell elements Pg 2  (P 12 -Pg 2 ) and an output layer constituted by h pieces of nerve cell elements Ph 3  (P 13 -Ph 3 ). Further, the anomaly-cause specifying model  320  is provided with transfer elements Dfg for coupling the f pieces of nerve cell elements Pf 1  and the g pieces of nerve cell elements Pg 2  through weighted values Wfg, and transfer elements Dgh for coupling the g pieces of nerve cell elements Pg 2  and the h pieces of nerve cell elements Ph 3  through weighted values Wgh. 
     The anomaly-cause specifying model  320  is an anomaly analysis system in which the weighted values Wfg, Wgh are subjected to the machine learning through a predetermined algorithm. In the supervised learning for the anomaly-cause specifying model  310 , teaching data, i.e., teaching signals obtained in the at least one prototype vehicle  400  are used. The data of the detected values of the other sensors  404  upon occurrence of the anomaly in the shift control operation of the step-variable transmission portion  20  in each of the at least one prototype vehicle  400  and also the number of occurrences of the anomaly in the shift control operation of the step-variable transmission portion  20  in each of the at least one prototype vehicle  400  are provided as the teaching signal to the input layer (see “X 11 -Xf 1 ” in  FIG. 16 ). Meanwhile, the causes of the anomaly in the shift control operation of the step-variable transmission portion  20 , which are obtained based on the detected values of the hydraulic pressure sensors  402  in each of the at least one prototype vehicle  400 , are provided as the teaching signals to the output layer (see “Z 13 -Zh 3 ” in  FIG. 16 ). There is a strong correlation between each of the manners of the chronological change of the racing amount ΔNfe of the engine rotational speed Ne in the process of the shift control operation executed in the step-variable transmission portion  20  and a corresponding degree of reduction of the durability of the step-variable transmission portion  20 , and also a strong correlation between each number of the occurrences of the anomaly in the shift control operation of the step-variable transmission portion  20  and a corresponding degree of reduction of the durability of the step-variable transmission portion  20 , so that so that large weighted values Wij, Wjk are given to such correlations. 
     As described above, as in the above-described first embodiment, in the present second embodiment, it is possible to improve the accuracy in specifying the cause of the anomaly in the shift control operation of the step-variable transmission portion  20 . 
     In the present second embodiment, the anomaly-cause specifying model  320  further indicates the relationship between the number of occurrences of the anomaly in the shift control operation of the step-variable transmission portion  20  and the reduction of the durability of the step-variable transmission portion  20 . Therefore, even where the cause of the anomaly in the shift control operation of the step-variable transmission portion  20  is the reduction of the durability of the step-variable transmission portion  20 , the cause of the anomaly can be specified with an improved accuracy by using the anomaly-cause specifying model  320 . 
     In the present second embodiment, the anomaly-cause specifying model  320  is realized by the supervised learning that is the machine learning using, as the teaching data, the manner of chronological change of the racing amount ΔNf of the rotational speed Nfx upon the occurrence of the anomaly in the shift control operation of the step-variable transmission portion  20 , the number of occurrences of the anomaly in the shift control operation of the step-variable transmission portion  20  and the reduction of the durability of the step-variable transmission portion  20 . Therefore, it is possible to construct a learning model by which the cause of the anomaly in the shift control operation of the step-variable transmission portion  20  can be specified with an improved accuracy. 
     While the preferred embodiments of this invention have been described in detail by reference to the drawings, it is to be understood that the invention may be otherwise embodied. 
     For example, in the above-described embodiments, the vehicle anomaly analysis apparatus  300  is an external apparatus provided apart from the vehicle  10 . However, this is not essential. For example, a part or an entirety of the function for the specifying the cause of the anomaly in the shift control operation of the step-variable transmission portion  20 , which is provided in the vehicle anomaly analysis apparatus  300  in the above-described embodiments, may be provided in the server  200 , or in the vehicle  10  (particularly, in the electronic control apparatus  90 ). Further, the content of the cause of the anomaly in the shift control operation of the step-variable transmission portion  20  may be indicated or displayed in a monitor or the like that is provided apart from the vehicle anomaly analysis apparatus  300 , or in a monitor or the like of a personal computer connected to the server  200  through a certain network. Further, the content of the cause of the anomaly may be indicated or displayed in the information notification device  88  or the like provided in the vehicle  10 . It is noted that the vehicle anomaly analysis apparatus  300  is used, for example, when the vehicle  10  is brought to a maintenance workshop, or is used in a manufacturer of the vehicle  10 . 
     In the above-described embodiments, the anomaly-cause specifying models  310 ,  320  are realized in the calculation portion  302  as the artificial intelligence. However, this is not essential. For example, each of the anomaly-cause specifying models  310 ,  320  can be realized by a computer or the like that is not based on a neutral network. 
     In the above-described embodiments, the vehicle  10  including the transmission device  40  has been described as an example of the vehicle in which the anomaly could occur in the shift control operation of the step-variable transmission portion  20 . However, the present invention is applicable not only to the vehicle  10  but also to any other vehicle in which an anomaly could occur in a shift control operation of an automatic transmission included in the vehicle. 
     It is to be understood that the embodiments described above are given for illustrative purpose only, and that the present invention may be embodied with various modifications and improvements which may occur to those skilled in the art. 
     NOMENCLATURE OF ELEMENTS 
     
         
           10 : vehicle 
           14 : engine (drive force source) 
           20 : mechanically-operated step-variable transmission portion (automatic transmission) 
           28 : drive wheels 
           40 : transmission device (automatic transmission) 
           57 : MOP (oil pump) 
           58 : EOP (oil pump) 
           89 : drive unit 
           300 : vehicle anomaly analysis apparatus 
           310 : anomaly-cause specifying model 
           320 : anomaly-cause specifying model 
         CB: engagement devices (frictional engagement devices) 
         MG 2 : second rotating machine (drive force source) 
         SL 1 -SL 4 : solenoid valves (control valves)