Abstract:
When reception of engine rotating speed information from an engine control unit is failed, the control unit puts gear positions belonging to a second gear position group in a non-operable and connected state, and then puts a second clutch into a engaged state to convert a rotating speed of a second input shaft detected by a second rotational sensor into a rotating speed of an engine output shaft. The control unit controls so as to fasten a first clutch based on the converted rotating speed of the engine output shaft, thereby enabling a star of a vehicle.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a control apparatus for an automatic transmission communicating with a control unit of an internal-combustion engine to which the automatic transmission for a vehicle is connected. In particular, the present invention relates to a control apparatus for a twin-clutch automatic transmission in which multiple gear positions are divided into two gear position groups, and which is equipped with a first clutch for selecting a gear position in one gear position group, and a second clutch for selecting a gear position in the other gear position group. 
       BACKGROUND ART 
       [0002]    Conventionally, there has been heretofore known a twin-clutch automatic transmission in which multiple gear positions are divided into two gear position groups (odd gear position group and even gear position group), and which is equipped with a first clutch mechanism for selecting a gear position in one gear position group and a second clutch mechanism for selecting a gear position in the other gear position group (e.g., see Patent Document 1). The twin-clutch automatic transmission of this kind is configured such that the other clutch mechanism is put into a disengaged state, while selecting the gear position in the gear position group corresponding to the one clutch mechanism, with the other clutch mechanism engaging. At this time, a gear drive system associated with the gear position corresponding to the other clutch mechanism is in a neutral condition where power is not transmitted. The twin-clutch mechanism is arranged to allow power transmission, through such an operation, with the prescribed gear position selected. The twin-clutch automatic transmission is configured to couple a first input shaft and an engine output shaft together by engaging the first clutch mechanism. Like this, twin-clutch automatic transmission is configured to couple the second input shaft and the engine output shaft together by engaging the second clutch mechanism. The first input shaft or the second input shaft is arranged to transmit a rotation via each driven gear to the output shaft of the twin-clutch automatic transmission. 
         [0003]    An Engine Control Unit (ECU) is connected to an engine to be coupled with the twin-clutch automatic transmission of this sort. Moreover, a Transmission Control Unit (TCU) is also connected to the twin-clutch automatic transmission. The ECU is configured to receive a signal indicative of rotating speed information from an engine speed sensor which detects a engine speed, and a signal indicative of accelerator opening information and brake switch information, etc. By doing so, various decisions are done for engine control. The TCU is configured to receive signals from a first input shaft rotational sensor, a second input shaft rotational sensor, an output shaft rotational sensor, and a shift lever switch. Hereupon, the first input shaft rotational sensor is for detecting a rotating speed of the first input shaft, the second input shaft rotational sensor is for detecting a rotating speed of the second input shaft, and the output shaft rotational sensor is for detecting a rotating speed of an output shaft of the twin-clutch automatic transmission, respectively. The TCU is configured to do various decisions for outputting a control signal to a shift-clutch actuator. Between the ECU and the TCU, communication is made via bidirectional Controller Area Network (CAN) communication. 
         [0004]    As a representative of clutch torque capacity regulation executed in a control apparatus for the twin-clutch automatic transmission on starting a vehicle, an approach is well known to control slip quantity of an engine speed and a clutch speed. In this approach, the torque capacity of the clutch is regulated such that a target engine speed is determined from at least accelerator opening to achieve the target engine rotation. Usually, it is the custom to do clutch torque capacity regulation by synthesizing feed-forward control in response to torque to be input and feedback control in response to a deviation between the target engine speed and an actual engine speed. However, this approach is problematic that a too much feed-forward controlled variable can cause an engine stall due to factors, including engine torque accuracy, feasibility of torque clutch capacity, variations in response lag, and environmental changes such as temperature. Under these circumstances, it is often the case that the feedback control is sometimes regarded as more important than the others. 
       PRIOR ART DOCUMENT 
       [0005]    Patent Document 
         [0006]    Patent Document 1: JP 2009-97648 A 
       SUMMARY OF THE INVENTION 
     Problem to be Solved 
       [0007]    Since the feedback control is a control technique in response to the deviation between the target engine speed and the actual engine speed, as mentioned above, reception of the engine speed information is indispensable as a general rule. The engine speed is received via the CAN communication from the ECU. Thus, in the event of disconnection of a CAM communication line, it falls into a situation where the TCU fails to receive the engine speed information. Hence, even granted that the engine can be operated as usual while the CAN communication line is disconnected, the TCU is allowed only to perform the feed-forward control. In this situation, it could not be denied that it is prone to rev up engine revolutions, with the inability to start a vehicle. For the purpose of preventing such an undesirable event, it may hit on an idea of taking measures of directly receiving a signal from the engine speed sensor and of taking a dual system with the CAN information for striving for a redundant configuration of the system. However, a problem emerges that such measures will invite higher cost. 
         [0008]    Further, in such twin-clutch automatic transmission, the transmission is equipped with plural rotational speed sensors deemed to be necessary from a functional point of view. It is possible to say that improving an operating rate of the equipped parts is desirable utilizing these rotational speed sensors, from the point of view of building an efficient control system. 
         [0009]    The present invention is made focusing on the above-identified problems potentially immanent in the prior art, and its objective is to provide a control unit of a twin-clutch automatic transmission which enables a start of a vehicle in the absence of parameter information to be received via communication between control units, and is able to build a fault tolerant control system, independent of control of a dual system. 
       SOLUTION TO THE PROBLEM 
       [0010]    To solve the above-identified problem, according to one aspect of the present invention, the invention provides a control apparatus for a twin-clutch automatic transmission to be connected to the twin-clutch automatic transmission, wherein the twin-clutch automatic transmission has a plurality of gear positions which are divided into a first gear position group and a second gear position group, and are operatively and connect ably coupled with an engine output shaft of an internal-combustion engine, the twin-clutch automatic transmission comprises a first input shaft for the gear positions belonging to the first gear position group; a first clutch mechanism for connecting the first input shaft to the engine output shaft; a first rotating speed detector for detecting a rotating speed of the first input shaft; a second input shaft for the gear positions belonging to the second gear position group; a second clutch mechanism for connecting the second input shaft to the engine output shaft; and a second rotating speed detector for detecting a rotating speed of the second input shaft, the control apparatus is communicable with an internal-combustion engine control unit to which rotating speed information on the engine output shaft of the internal-combustion engine is input, the control apparatus controls to fasten the first clutch mechanism for a start of a vehicle, based on the rotating speed information received from the internal-combustion engine control unit, when reception of the rotating speed information from the internal-combustion engine control unit is not succeeded, the control apparatus puts the gear positions belonging to the second gear position group into a disengaged state, and then puts the second clutch mechanism into a engaged state, and converts a rotating speed of the second input shaft detected by the second rotating speed detector into to a rotating speed of the engine output shaft, and the control apparatus controls to fasten the first clutch mechanism based on the converted rotating speed of the engine output shaft. 
         [0011]    Further, as the aforesaid aspect, when reception of the rotating speed information from the internal-combustion control unit is failed, the control apparatus calculates abnormal state clutch torque to fasten the first clutch mechanism by synthesizing abnormal state feed-forward control torque set independent of actual torque of the internal-combustion engine and abnormal state feedback control torque calculated based on a deviation between a target rotating speed of the internal-combustion engine and the converted rotating speed of the engine output shaft. 
         [0012]    Further, as the aforesaid aspect, when reception of the rotating speed information from the internal-combustion engine control unit is failed, the control apparatus converts the rotating speed detected by the first rotating speed detector concerning rotation of the first input shaft following the first clutch mechanism in a engaged state into the rotating speed of the engine output shaft, and then controls engaging of the second clutch mechanism for continuous driving so as to implement the engaging based on the converted rotating speed of the engine output shaft, and the control apparatus converts the rotating speed detected by the second rotating speed detector concerning rotation of the second input shaft following the second clutch mechanism in a engaged state into the rotating speed of the engine output shaft, and then controls engaging of the first clutch mechanism for continuous driving so as to implement the engaging based on the converted rotating speed of the engine output shaft. 
         [0013]    ADVANTAGEOUS EFFECT OF THE INVENTION 
         [0014]    According to the present invention, the invention realizes the control apparatus for the twin-clutch automatic transmission which enables a start of the vehicle, even when reception of parameter information via communication between the internal-combustion engine control unit and the control apparatus is failed, minimum driving e.g., retreat running, and ,building of the fault tolerant control system, independent of the dual system. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a skeleton diagram showing a twin-clutch automatic transmission to which a control apparatus for a twin-clutch automatic transmission according to an embodiment of the present invention is applied; 
           [0016]      FIG. 2  is a block diagram showing a configuration including a control apparatus for a twin-clutch automatic transmission according to an embodiment of the present invention; 
           [0017]      FIG. 3  is a graph showing a relationship between accelerator opening and a target engine speed; 
           [0018]      FIG. 4  is a flow chart showing a flow of control on starting a vehicle; 
           [0019]      FIG. 5  is a flow chart showing a flow of control by a control unit according to the present embodiment; 
           [0020]      FIG. 6  is a timing chart in a normal condition on starting a vehicle; and 
           [0021]      FIG. 7  is a timing chart in a CAN abnormal state on starting a vehicle. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0022]    Hereinafter, a description will be made to the details of a control apparatus for a twin-clutch automatic transmission according to an embodiment of the present invention with reference to the accompanying drawings. 
         [0023]    Firstly, an explanation will be made to the twin-clutch automatic transmission  100  to be used for in the present embodiment, referring to a skeleton diagrams shown in  FIG. 1 . As shown in  FIG. 1 , the twin-clutch automatic transmission  100  is provided with a plurality of gear positions synthesizing a first gear position group (odd gear position group)  1  and a second gear position group (even gear position group)  2 . Further, the twin-clutch automatic transmission  100  is provided with a first clutch C 1 , as a first clutch mechanism, for selecting a gear position belonging to the first gear position group  1 , and a second clutch C 2 , as a second clutch mechanism, for selecting a gear position belonging to the second gear position group  2 . 
         [0024]    While engaging one clutch out of the first clutch C 1  and the second clutch C 2 , and selecting a prescribed gear position in the corresponding gear position group, the other clutch is put into a disengaged state. At the same time, a corresponding gear transmission system is put into a neutral condition where power is not transmitted, thus capacitating the transmitter  100  to do power transmission in a condition where the prescribed gear position is selected. 
         [0025]    As shown in  FIG. 1 , the first clutch C 1  and the second clutch C 2  are coupled to an engine output shaft  3 , as an engine output shaft, of the internal-combustion engine. An output from the first clutch C 1  is coupled to a hollow input shaft  4 , and transmitted via respective gears  5 , 6 , and  7  to the first input shaft  8 . In the meanwhile, an output from the second clutch C 2  is connected to the second input shaft  9 . 
         [0026]    The first input shaft  8  is provided with a first-speed drive gear  11 , a third-speed drive gear  13 , and a fifth-speed drive gear  15 . Meanwhile, the second input shaft  9  is provided with a second-speed drive gear  12 , a fourth-speed drive gear  14 , a sixth-speed drive gear  16 , and a reverse drive gear  17 . 
         [0027]    The twin-clutch automatic transmission  100  includes a transmission output shaft  10 . The transmission output shaft  10  is provided with a first-second-speed driven gear  18 , a third-fourth-speed driven gear  19 , a fifth-sixth-speed driven gear  20 , and a reverse driven gear  21 . 
         [0028]    The first input shaft  8  is provided with a first-third-speed synchronous mechanism  22  for switching among a neutral position, a first-speed gear drive gear selecting position, and a third-speed gear drive gear selecting position, and a fifth-speed synchronous mechanism  23  for switching between a neutral position and a fifth-speed drive gear selecting position. Meanwhile, the second input shaft  9  is provided with a second-fourth-speed synchronous mechanism  24  for switching among a neutral position, a second-speed gear drive gear selecting position, and a fourth-speed drive gear selecting position, and a sixth-R-speed synchronous mechanism  25  for changing among a neutral position, a six-speed drive gear selecting position, and a reverse drive gear selecting position. 
         [0029]    The twin-clutch automatic transmission  100  is provided with a shift-clutch actuator  101  for actuating these synchronous mechanisms  22 ,  23 ,  24  and  25 , and the first clutch C 1  and the second clutch C 2  (see  FIG. 2 ). In this connection, a final gear (not shown) is provided in the transmission output shaft  10  to transmit power to a driving wheel (not shown). 
         [0030]    The twin-clutch automatic transmission  100  is provided with a first rotational sensor  27 , as a first rotating speed detector, for detecting a rotating speed of the first input shaft  8 , a second rotational sensor  28 , as a second rotating speed detector, for detecting a rotating speed of the second input shaft  9 , and a third rotational sensor  29 , as a third rotating speed detector, for detecting a rotating speed of the transmission output shaft  10 . 
         [0031]    An explanation will then be made to a configuration of a Transmission Control Unit (hereafter referred to merely as TCU)  400  for the twin-clutch automatic transmission according to the present embodiment, referring to a control system block diagram shown in  FIG. 2 . As shown in  FIG. 2 , an engine  200  is coupled with the twin-clutch automatic transmission  100 . In passing, the engine output shaft  3  is coupled with the clutches C 1 , C 2 , as mentioned above. Further, the engine  200  is provided with an engine speed sensor  201  for detecting an engine speed. 
         [0032]    As shown in  FIG. 2 , an Engine Control Unit (hereinafter, referred to merely as ECU)  300 , as an internal-combustion engine control unit, is connected to the engine  200 . The above engine speed sensor  201 , an accelerator  301 , and a brake switch  302  are connected to the engine  200  to make various decisions for control of the engine  200 . 
         [0033]    The TCU  400 , as a control unit, is connected to a shift-clutch actuator  101  of the twin-clutch automatic transmission  100 . As shown in  FIG. 2 , a shift lever switch  401  is connected to the TCU  400  to receive switching positional information of the shift lever. Moreover, the aforesaid first rotational sensor  27 , the second rotational sensor  28 , and the third rotational sensor  29  are connected to the TCU  400  to receive a data signal representative of a rotating speed of the first input shaft  8 , a rotating speed of the second input shaft  9 , and a rotating speed of the transmission output shaft  10 , respectively. 
         [0034]    Further, the ECU  300  and the TCU  400  are configured to be connected in a transmittable and receivable manner via CAN communication for allowing communication there between. The TCU  400  is configured to do various determinations based on information of these data signals via the shift lever switch  401 , the first rotational sensor  27 , the second rotational sensor  28 , the third rotational sensor  29  and the CAN communication, and to output a control signal to the shift-clutch actuator  101 . 
         [0035]    Then, an explanation will be made to an operation of the twin-clutch automatic transmission  100 . As shown in  FIG. 2 , the TCU  400  selects a gear position, suited for a current driving condition, from values detected by the shift lever switch  401 , the first rotational sensor  27 , the second rotational sensor  28 , the third rotational sensor  29 , and the accelerator opening, the engine speed, and the brake switch information, etc. sent from ECU  300  via the CAN communication, and actuates the shift-clutch actuator  101  in such a manner as to implement this gear position. 
         [0036]    The shift-clutch actuator  101  is connected to a shifting fork (not shown) and the shifting fork is configured to fit to sleeves provided in the first-third-speed synchronous mechanism  22 , the fifth-speed synchronous mechanism  23 , the second-fourth-speed synchronous mechanism  24 , and the sixth-R-speed synchronous mechanism  25 . The shifting fork is configured to move by actuating the shift-clutch actuator  101 , and to shift to a gear position selected by these synchronous mechanisms  22  to  25 . The shift-clutch actuator  101  is actuated to fasten to one clutch out of the first clutch C 1  and the second clutch C 2  belonging to the selected gear position groups (first gear position group  1  and second gear position group  2 ), and to release the other clutch. This transmits driving power output from the engine  200 . 
         [0037]    Where the shift lever switch  401  is in a neutral condition, the first clutch C 1  and the second clutch C 2  are both released, and all the synchronous mechanisms  22  to  25  are controlled to come to a neutral position. Where a driver changes a shift lever to a drive range, the first clutch C 1  and the second clutch C 2  are both held in a released state, and the shift-clutch actuator  101  is actuated in order for the first-third-speed synchronous mechanism  22  to shift to the first-speed selecting position. After the change of the first-third-speed synchronous mechanism  22  is completed, the system detects a driver&#39;s intention of what for a vehicle is started from the brake switch information of the brake switch  302  and the accelerator opening information of the accelerator to regulate torque capacity of the first clutch C 1  by means of the shift-clutch actuator  101  for a smooth start of the vehicle. 
         [0038]    What is used for clutch torque capacity regulation on starting the vehicle is a technique of controlling slip quantity of the engine speed and the clutch rotating speed. The technique introduced here determines a target engine speed, based on previously prepared results, inherent to the vehicle indicating a relationship between the accelerator opening and the target engine speed, as shown e.g., in  FIG. 3 , at least from the accelerator opening, and regulates torque capacity of the first clutch C 1  so as to achieve the target engine speed. Typically, it is the custom to perform clutch torque capacity regulation, by synthesizing feed-forward control in response to torque to be input, and feedback control in response to a deviation between the target engine speed and an actual engine speed. However, it is liable that a too much feed-forward controlled variable can cause an engine stall due to factors, including engine torque accuracy, feasibility of torque capacity, variations in response lag, and environmental changes such as temperature. Under these circumstances, it is often the case that the feedback control is sometimes regarded as more important than feed-forward control. 
         [0039]    As state above, since the feedback control is a control mode in response to the deviation between the target engine speed and the actual engine speed, reception of the engine speed information is indispensable. Usually, because the engine speed information is information to be received via the CAN communication from the ECU  300 , once disconnection of a CAN communication line is occurred, for any reason, the TCU  400  falls into a situation where the TCU  400  is unable to receive information from the ECU  300 . 
         [0040]    In the present embodiment, in case of failure to receive the engine speed information by the TCU  400  e.g., due to disconnection of the CAN communication line, TCU  400  fastens the second clutch C 2 , after the second-fourth-speed synchronous mechanism  24  and the sixth-R-speed synchronous mechanism  25  are both shifted to a neutral position to receive the engine speed information by the second rotational sensor  28 . In this way, the TCU  400  is one intended to receive the engine speed information from the second rotational sensor  28  for allowing control of the first clutch C 1  on a start of the vehicle. In this way, as long as the second-fourth-speed synchronous mechanism  24  and the sixth-R-speed synchronous mechanism  25  are both in the neutral position, power will not be transmitted even though the second clutch C 2  is engaged. As a rotating speed of the second input shaft  9  coincides with the engine speed because of the engaging of the second clutch C 2 , it becomes possible to receive the engine speed information from a value detected by the second rotational sensor  28 . 
         [0041]    An explanation will next be made to control by the control apparatus for the twin-clutch automatic transmission according to the present embodiment referring to  FIG. 4 .  FIG. 4  is a flow chart showing control executed by the control apparatus for the twin-clutch automatic transmission on starting the vehicle. 
         [0042]    Initially, it is determined whether a shift range position detected by the shift lever switch  401  is within a driving range (step S 1 ). Here, the driving range signifies a forward driving range and a backward driving range. 
         [0043]    In step S 1 , if it is determined not to be within the driving range, all the synchronous mechanisms  22  to  25  are shifted to the neutral position (step S 12 ), and clutch torque is in turn set to 0 (step S 13 ). 
         [0044]    Next, a control value of the clutch actuator in the shift-clutch actuator  101  is calculated (step S 9 ). In this connection, as a clutch actuator, a solenoid of oil pressure control valve may e.g., be available. In this case, a current value to be flown to the hydraulic solenoid is calculated based on the clutch torque. Control can be made to actuate the clutch by applying the current value thus calculated as above to the hydraulic solenoid (step S 10 ). 
         [0045]    In step S 1 , if it is determined that the shift range position is within the driving range, then it is determined whether the CAN communication is in an abnormal state due to disconnection (step S 2 ). Herein, whether the CAN communication is in the abnormal state can be determined relying upon whether there exists a case where communication from the ECU  300  is unable to receive over a predetermined period of time, or a case where transmission notifying that the engine rotation information of the ECU  300  is invalid is received. In step S 2 , if it is determined that the CAN communication is normal, then the process proceeds to step S 11  where control of a normal state control step is executed by the TCU  400 . 
         [0046]    An explanation will be made here to control in a normal condition to be executed in step S 11  referring to a flow chart shown in  FIG. 5 . Firstly, it is determined in step S 101  that a gear-in of a gear position (normally, first-speed) to be used on starting the vehicle is already completed. It should be noted that whether the gear-in is completed can be determined e.g., by providing a sensor for detecting a moving position of a shifting fork (not shown) and a position of the shifting fork is in a gear-in position. If it is determined in step S 101  that the gear-in is not yet completed, then the process proceeds to step S 102  where control will be done so as to change to a target gear position. 
         [0047]    If it is determined in step S 101  that the gear-in is already completed, then a target engine speed is calculated based on the accelerator opening(step S 103 ),In passing, the target engine speed is determined e.g., from a relationship between the accelerator opening and the target engine speed, as shown in  FIG. 3 . 
         [0048]    In step S 104 , clutch feed-forward control torque (i.e., FF clutch torque) is calculated from input torque. In this instance, the clutch feed-forward control torque is calculated e.g., by multiplying a given factor and the input torque together, within the limits where there is no fear of occurring an engine stall, incidental to an increased feed-forward control variable, due to factors, including engine torque accuracy, feasibility of torque clutch capacity, variations in response lag, and environmental changes such as temperature. 
         [0049]    Then, in step S 105 , the clutch feedback control torque (i.e., FB clutch torque) is calculated. The clutch feedback control torque is torque which is calculated by (Proportional/Integral) PI control based e.g., on the deviation between the target engine speed and the actual engine speed. 
         [0050]    Subsequently, in step S 106 , the clutch torque is calculated by synthesizing the clutch feed-forward control torque and the clutch feedback control torque. Incidentally, after step S 106 , the aforesaid process in steps S 9 , S 10 , shown in  FIG. 4 , will be performed. 
         [0051]      FIG. 6  is a timing chart where the CAN communication is in the normal condition on starting the vehicle. As shown in  FIG. 6 , when the shift range is changed from a neutral (N) range to a drive (D) range, the shift actuator in the sift clutch actuator  101  is first actuated, and then the first-third-speed synchronous mechanism  22  is shifted from the neutral position to the first-speed gear-in position. By a first-third-speed shifting fork positional sensor (not shown), and then the shift actuator is deactivated. Thereafter, when the accelerator is pressed, a target engine speed is set in accordance with the accelerator opening, and the clutch torque is controlled so that the actual engine speed runs up to the target engine speed, thus starting the vehicle. 
         [0052]    An explanation will next be made to a flow of control executed in an abnormal state control step governed by the TCU  400  when the CAN communication is in the abnormal state, returning again back to  FIG. 4 . 
         [0053]    As shown in  FIG. 4 , if it is determined in step S 2  that the CAN communication is in the abnormal state, the process proceeds to step S 3  where all gears of the even shaft are shifted to the neutral position. Then, in step S 4 , the second clutch C 2  that is an even clutch is engaged. After that, in step S 5 , a target engine speed is calculated when a CAN communication error is occurred. Because when the CAN communication is disconnected, reception of the accelerator opening information from the ECU300 fails, calculation is made, in such an eventuality, by assuming the accelerator opening to be a fixed value, in spite of the accelerator opening. 
         [0054]    Subsequently, in step S 6 , the clutch feed-forward control torque (CAN abnormal state FF clutch torque) is calculated when the CAN communication is in the abnormal state. Likewise, because when the CAN communication is in the abnormal state, the engine torque information also cannot be received from the ECU300, calculation is made, in such an eventuality, by assuming the engine torque to be a fixed value, in spite of the engine torque. 
         [0055]    Then, in step S 7 , the clutch feedback control torque (CAN abnormal state FB clutch torque) is calculated when the CAN communication is in the abnormal state. In this case, as with the normal condition, calculation is made by Proportional Integral (PI) control based on the deviation between the target engine speed and the actual engine speed (i.e. , second input shaft rotating speed). 
         [0056]    Afterward, in step S 8 , the CAN abnormal state clutch torque is calculated as the sum of the CAN abnormal state FF clutch torque and the CAN abnormal state FB clutch torque. Subsequent processes are executed in step S 9  and step S 10 , as stated above. 
         [0057]      FIG. 7  is a timing chart when the CAN communication is in the abnormal state on starting the vehicle. As shown in  FIG. 7 , it is similar, as with the normal condition, in that the first gear-in is done after the shift range is changed from the neutral (N) range to the drive (D) range. In case of abnormal state of the CAN communication, the even clutch actuator is actuated in parallel with this, and the second clutch C 2  is engaged. Hereupon, a process to change a gear of the even shaft to the neutral position is omitted. This is because the shift range is originally N, and thus all the gears are changed to the neutral position in neutral. Once the second clutch C 2  is engaged, rotation of the second input shaft  9  runs up from 0 until it matches with the engine speed. Afterward, the clutch torque capacity is regulated, as with the normal condition, so as to run up to the target engine speed, which enables a start of the vehicle. 
         [0058]    As can be seen from the foregoing descriptions, with the control apparatus for the twin-clutch automatic transmission according to the present embodiment, the apparatus allows a start of the vehicle, even in situations where reception of the engine rotation information from the ECU 300 is failed. 
         [0059]    Further, in the control apparatus for the twin-clutch automatic transmission according to the present embodiment, one could imagine circumstances where when a driver presses the accelerator to take the engine to full power and a throttle is opened to full throttle, it would eventuate in precluding a smooth start of the vehicle. Nonetheless, in the present embodiment, there is provided one, in addition to the aforesaid arrangement, allowing detection of the occurrence of abnormal state, even at the ECU 300 side, where it will be impossible to do the ECU communication. Hence, the apparatus may implement a smoother start of the vehicle, in the situation by controlling an electric throttle at the ECU 300 side, so as not to generate torque exceeding a predetermined one, regardless of the accelerator opening. 
         [0060]    It should be noted that as for a case where the CAN communication becomes abnormal, either the clutch C 1  or the clutch C 2  is being engaged during traveling, and it satisfies inequality of rotating speed of the shaft in engaging=engine speed. Therefore, substituting the rotating speed of the shaft in engaging for the engine speed allows continuous driving of the vehicle. A clutch change in the first clutch C 1  and the second clutch C 2  in gear shifting is possible by performing feed-forward control of the each clutch, admitting that it leads to a deteriorated gear shift shock. That is, in the present embodiment, it enables gear shift of shift up and shift down, which allows, to some extent, long distance travelling and speed-up traveling. Accordingly, it enables retreat running and vehicle movement to a service facility, even when the CAM communication is failed. 
         [0061]    In the control apparatus for the twin-clutch automatic transmission according to the present embodiment, the transmission is configured to take an arrangement where redundancy is avoided, such as to be a dual system with the CAN information, without directly inputting a signal from the engine rotational sensor to the TCU  400 . This eliminates a possibility of becoming higher cost. In the present embodiment, notwithstanding, the twin-clutch automatic transmission  100  is provided with a plurality of rotational sensors  27 ,  28  deemed to be indispensable, from the functional perspective, they are instrumental to raise an operating ratio of parts equipped therein by taking advantage of these sensors, which builds an efficient control system. 
         [0062]    In the control apparatus for the twin-clutch automatic transmission according to the present embodiment, the apparatus enables a start of the vehicle, even when reception of the parameter information via the CAN communication between control units (ECU  300  and TCU  400 ) is failed. This allows building of a fault tolerant control system for communicating information there between, independent of the dual system. 
         [0063]    While in the above, the descriptions are made of the embodiment of the present invention, it should not be construed that the statements and the drawings that form part of the disclosures of the present embodiment are ones made with the intention of limiting the present invention. It would have been obvious to a person skilled in the art, from the above disclosures, to contrive a variety of alternative embodiments, examples, and operation technologies. 
         [0064]    For example, whereas in the forgoing present embodiment, the descriptions are made by giving an example where communications to communicate information between the control units are conducted via the CAN communication, not necessarily limited thereto, another system may, of course, be adopted in which various in-vehicle LANs are installed, except for the CAN communication. 
         [0065]    Reference Signs List
   C 1 : first clutch   C 2 : second clutch     1 : first gear position group     2 : second gear position group     3 : engine output shaft     8 : first input shaft     9 : second input shaft     10 : transmission output shaft     22 : first-third-speed synchronous mechanism     23 : fifth-speed synchronous mechanism     24 : second-fourth-speed synchronous mechanism     25 : sixth-R-speed synchronous mechanism     27 : first rotational sensor (first rotating speed detector)     28 : second rotational sensor (second rotating speed detector)     29 : third rotational sensor     100 : twin-clutch automatic transmission     101 : shift-clutch actuator     200 : engine (internal-combustion engine)     201 : engine rotational sensor     300 : engine control unit (ECU)     301 : accelerator     302 : brake switch     400 : transmission control unit (TCU)     401 : shift lever switch