Abstract:
15  A method and an assembly  61  for use with a vehicle  10  having a high voltage battery  42  and an internal combustion engine  12  of the type having a selectively rotatable crankshaft  13  After the high voltage battery  42  receives a donor charge, the assembly  61  causes the crankshaft  13  to be rotated at a slow speed for a predetermined period of time before electrical energy is transferred to the internal combustion engine  12  and before combustion occurs within the engine  12.

Description:
BACKGROUND OF INVENTION 
     (1) Field of the Invention 
     The present invention generally relates to a method and an apparatus for selectively rotating the crankshaft of an engine at a predetermined speed after electrical charge has been transferred to a vehicular battery during a jumpstart operation, thereby reducing the amount of electrical energy needed to start the engine, and to a vehicle which incorporates the method and more particularly, to a method and an apparatus which detects the occurrence of a transfer of charge to a vehicular battery and which, in response to the detected charge transfer, causes the vehicular engine to start at a relatively low speed and to ramp up slowly. 
     (2) Background of the Invention 
     A hybrid electric vehicle typically includes a high voltage and a low voltage battery which cooperatively provide energy which allow the vehicle to be operated in a desired manner. By way of example and without limitation, the high voltage battery is typically used to provide energy to and receive energy from at least one motor and/or a motor and generator assembly which are used to provide torque to the wheels of the vehicle, thereby allowing the hybrid electric vehicle to be selectively propelled and maneuvered. The low voltage battery provides energy for the various other vehicular components (e.g., such as a radio). 
     In the event that the high voltage battery becomes discharged or contains an amount of charge below which the battery cannot operate the at least one motor or the motor/generator assembly, the high voltage battery must be recharged, thereby allowing the hybrid vehicle to be started and operated. 
     Moreover, it is desirable to quickly charge the high voltage battery to a level in which the hybrid vehicle may be started in order to reduce the overall time in which the vehicle is disabled. Many of the currently utilized jumpstart strategies (e.g., a jumpstart or jumpstart operation may be defined as a selective transfer of electrical charge from a donor vehicle or battery to the high voltage vehicular battery and the use of the transferred charge to start the vehicle or operate an engine) do not allow the high voltage vehicular battery to be quickly charged and/or require the use of relatively large and expensive conductors or charging assemblies to communicate a relatively large charge to the high voltage battery. 
     SUMMARY OF INVENTION 
     A method and apparatus is provided for controlling the starting speed of an engine, after a vehicle has received a donor charge, in a manner which overcomes some or all of the previously delineated drawbacks of prior strategies and which, by way of example and without limitation, reduces the amount of electrical energy needed to startably operate the engine. 
     In accordance with another aspect of the present invention, an apparatus for rotating a crankshaft of an internal combustion engine after a donor charge has been communicated to a battery is provided. Particularly, the apparatus includes a first assembly which senses the transfer of the donor charge to the battery; and a second assembly which is coupled to the crankshaft and to the first assembly and which rotates the engine at a predetermined speed after the transfer of the donor charge is completed and before combustion occurs within the engine. 
     In accordance with yet another aspect of the present invention, a vehicle is provided having an internal combustion engine including a selectively rotatable crankshaft, a battery which is coupled to the engine, which supplies electrical energy to the engine, and which has a predetermined amount of electrical charge; and an assembly which is coupled to the engine and to the battery, which senses the occurrence of a predetermined loss of charge of the battery, which allows electrical charge to be communicated to the battery, and which rotates the crankshaft at a predetermined speed after the electrical charge has been communicated to the battery and before electrical energy is supplied to the engine. 
     In accordance with still another aspect of the present invention, a method is provided for operating a vehicle of the type having an internal combustion engine. Particularly, the method includes the steps of detecting a transfer of donor charge to a battery, and causing the engine to rotate at a predetermined speed before combustion occurs within the engine. 
     These and other features, aspects, and advantages of the present invention a vehicle is provided. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1 is a block diagram of a vehicle which operates in accordance with the teachings of the preferred embodiment of the invention. 
    
    
     DETAILED DESCRIPTION 
     Referring now to FIG. 1, there is shown a vehicle  10  which is made in accordance with the teachings of the preferred embodiment of the invention. Particularly, vehicle  10  includes a first torque generator  12 , such as and without limitation an internal combustion engine, and a second torque generator  14 , such as and without limitation an electric motor/generator, one electric motor, or several cooperatively interconnected electrical motors. Particularly, the first torque generator (e.g., the internal combustion engine)  12  includes a selectively movable crankshaft  13  and the second torque generator  14  includes a selectively movable output shaft  15 . The rotating crankshaft  13  and the output shaft  15  provide the torque necessary to selectively propel the vehicle  10 . 
     As shown, the vehicle  10  further includes a planetary gear assembly  16  which is coupled to the crankshaft  13  and the output shaft  15 , a selectively movable member  20  which is coupled to the planetary gear assembly  16 , and a differential assembly  22  which is coupled to the selectively movable member  20 . The differential assembly  22  is coupled to a pair of wheels  28 ,  30  by the respective use of axles or half-shafts  32 ,  34 . 
     Further, as shown, the vehicle  10  includes an inverter assembly  40  which is coupled to the second torque generator  14 , a high voltage battery  42  which is coupled to the inverter assembly  40 , a direct current to direct current converter  48  which is coupled to the high voltage battery  42 , and a low voltage battery  50  which is coupled to the direct current to direct current converter  48 . Particularly, in one embodiment, the inverter assembly  40 , the second torque generator  14 , and the planetary gear assembly  16  cooperatively form a transaxle assembly. 
     The vehicle  10  further includes a controller assembly  60  (e.g., a powertrain controller assembly or module) which is operable under stored program control and which is coupled to the first torque generator or internal combustion engine  12 , a traction battery controller assembly or module  90 , and an electrical current sensor  54  which resides within and/or is operatively coupled to the high voltage battery  42  and which is coupled to the traction controller assembly  90  by the use of bus  71 . Particularly, the sensor  54  senses the amount of electric current which is communicated to and/or which emanates from the high voltage battery  42 . This information is communicated to the controller assembly  90  by the bus  71 . Particularly, a state of charge estimator (not shown) resides with the traction battery controller assembly  90  and uses the information generated by the sensor  54  to continually determine the amount of electrical charge which is then currently present within the high voltage battery  42  (e.g., since the amount of electrical charge fluctuates within the high voltage battery  42 , the controller assembly  90  must continually monitor this state of electrical charge in order to continually determine whether the high voltage battery  42  is being discharged). The controller assembly  60  is coupled to the torque generator  12  by the use of bus  80  and bus  70  provides a communication channel between the controllers  60 ,  90  and the inverter assembly  40 . It should be appreciated that only the relevant portions of the vehicle  10  are shown in FIG.  1  and that the present invention is not limited to a particular type of vehicle. Rather, the present invention may be used with a wide variety of vehicles, including but not limited to non-hybrid vehicles or various dissimilar vehicular configurations. Further, it should be appreciated that the controller assembly  60  may include several operatively interconnected controllers or sensors and that nothing in this description is meant to limit the present invention to a particular type of vehicle or to a particular number of controllers and that controller assembly  60  and  90  in combination with sensor  54  cooperatively comprise an assembly  61  which performs the preferred method of the present invention as illustrated in FIG.  1  and which may be used within a hybrid vehicle in a retrofit or original equipment manner. 
     In normal operation, the controller assembly  60 , by the use of bus  70  and  80 , selects one or both of the torque generators  12 ,  14  to become operable. The torque which is produced by these torque generators  12 ,  14  is transferred to the planetary gear assembly  16  where it is transferred to the differential assembly  22  by the use of the output shaft or member  20 . The differential assembly  22  distributes the received torque to the axles or half-shafts  32 ,  34  and the distributed torque is then communicated to the wheels  28 ,  30 , thereby allowing the vehicle  10  to be selectively propelled and maneuvered. 
     The electrical current sensor  54  in conjunction with the state of charge estimator (not shown) which may be embodied within software, firmware, and/or hardware which is operatively located within controller  90  detects when the high voltage battery  42  has become discharged or has an insufficient amount of electrical charge to operate the second torque generator  14 . This information is transmitted to the controller assembly  90  and the assembly  90  communicates this information to the controller assembly  60 . The controller assembly  60  then causes the battery  50  (or allows a donor battery) to provide electrical charge to the high voltage battery  42 . After the high voltage battery  42  has been given a relatively small amount of electrical charge the controller assembly  90 , by use of the current sensor  54  and/or the charge estimator senses this occurrence and a signal or “flag” is sent to the controller assembly  60  by the controller assembly  90 . The controller assembly  60  then commands the inverter assembly  40 , by the use of bus  70 , to operate the second torque generator  14  in order to spin or rotate the engine  12  (i.e., spin or selectively rotate the crankshaft  13 ) at a relatively low rate of speed, such as and without limitation a rate of speed of about two hundred revolutions per minute, for about one second to about ten seconds. After this rotation is accomplished, electrical energy may be communicated the engine  12 , from the battery  42  (or from the battery  50 ), in order to allow combustion to occur within the engine  12  and to allow the engine  12  to be combustibly started. Thus, the foregoing allows the internal combustion engine  12  to be started with a significantly lower amount of power or energy than the internal combustion engine  12  normally uses during a “fast starting” or “normal starting” event, thereby allowing the high voltage battery  42  to use less energy to start the internal combustion engine  12  and concomitantly reducing the amount of energy or electrical charge required by the high voltage battery  42  to start the internal combustion engine  12  and to jumpstart the vehicle  10 . Such a reduction in the amount of required energy reduces the time to charge the high voltage battery  42  (allows the battery  42  to be only partially changed) and obviates the need for costly cables and charging assemblies while reducing the likelihood of battery damage and reducing the total amount of time in which the vehicle  10  is disabled. Further, the present invention, by reducing the amount of electrical current which is transferred to the high voltage battery  42  during the charging process, extends the operating life of the battery and obviates the need for cooling fans and other cooling assemblies. 
     It is to be understood that the invention is not limited to the exact construction and method which has been illustrated above, but that various changes and modifications may be made without departing from the spirit and the scope of the inventions as are delineated in the following claims.