JP2009214816A - Hybrid vehicle and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce vibration when cranking an internal combustion engine. <P>SOLUTION: Temporary correction torque set based on suppression torque for canceling torque acting on a drive shaft based on a pressure change inside a cylinder is multiplied by a gain k set to have a tendency to become larger as a crank angle θ that is a stop position of a crankshaft of the engine in a state of stopping operation before start-up is further away from a position just before a compression top dead center (TDC) to set correction torque, and a motor outputting power to the drive shaft is drive-controlled such that torque obtained by adding the correction torque, the torque canceling the torque acting on the drive shaft according to the cranking, and requirement torque required for running will act on the drive shaft. Because the more proper correction torque is set by using the gain k according to the crank angle θ before the start-up, the vibration at time of cranking of the engine can be more properly reduced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  More particularly, the present invention relates to an internal combustion engine, a generator capable of inputting / outputting power, a drive shaft connected to an axle, an output shaft of the internal combustion engine, and a rotating shaft of the generator. Three-axis power input / output means connected to the three axes for inputting / outputting power to / from the remaining shafts based on power input / output to / from any two of the three axes, and input / output power to / from the drive shaft The present invention relates to a hybrid vehicle including an electric motor, a generator, and an electric storage means capable of exchanging electric power with the electric motor, and a control method for such a hybrid vehicle.

Conventionally, this type of hybrid vehicle includes an engine, a planetary gear having a carrier connected to the crankshaft of the engine and a ring gear connected to a drive shaft connected to the axle, and a motor MG1 connected to a sun gear of the planetary gear. In a hybrid vehicle having a motor MG2 connected to the drive shaft, the correction torque corresponding to the crank angle at the time of cranking the engine is output from the motor MG2, thereby acting on the drive shaft when the engine is cranked. The thing which suppresses the torque pulsation to perform is proposed (for example, refer patent document 1). In this hybrid vehicle, the correction torque is set by multiplying the provisional correction torque that is in reverse phase to the torque acting on the drive shaft according to the crank angle during engine cranking by a correction coefficient that decreases as the vehicle speed increases, and is required for driving. Output from the motor MG2 is the sum of the required torque and the torque for canceling the torque acting on the drive shaft accompanying the cranking of the engine and the correction torque. Vibration is suppressed.
JP-A-2005-90307

  Like the above-described hybrid vehicle, by outputting a correction torque having a phase opposite to the torque acting on the drive shaft according to the crank angle when the engine is cranked, vibration at the time of starting the engine can be suppressed. However, the degree of suppression of vibration may vary depending on the crank angle at the start of cranking, that is, the crank angle that is stopped immediately before cranking is started. The amount of air in the initial compression stroke at the time of start differs depending on the crank angle of the stopped engine. As a result, the magnitude of torque pulsation applied to the drive shaft differs, and a correction torque corresponding to the crank angle is simply output. If it is only, variation will arise in the suppression of the vibration accompanying cranking. Further, in the type in which the electric power from the battery is boosted and supplied to the motor, the output of the correction torque that is too large requires the voltage supplied to the motor to be higher than necessary, which may waste power. .

  The main object of the hybrid vehicle and the control method thereof of the present invention is to reduce vibrations when cranking the internal combustion engine.

  The hybrid vehicle and the control method thereof according to the present invention employ the following means in order to achieve at least the above-described main object.

The hybrid vehicle of the present invention
An internal combustion engine, a generator capable of inputting / outputting power, a drive shaft coupled to an axle, an output shaft of the internal combustion engine, and a rotation shaft of the generator, connected to any of the three shafts Three-axis power input / output means for inputting / outputting power to the remaining shafts based on power input / output to / from two shafts, an electric motor for inputting / outputting power to / from the drive shaft, the generator and the electric motor A hybrid vehicle comprising a storage means capable of exchange,
Rotational position detecting means for detecting the rotational position of the output shaft immediately before starting the internal combustion engine;
Gain setting means for setting a gain based on the detected rotational position;
A damping torque setting means for setting a damping torque for suppressing vibration generated in the drive shaft with cranking of the internal combustion engine using the set gain;
A required torque setting means for setting a required torque required for the drive shaft for traveling;
When starting the internal combustion engine, the generator and the internal combustion engine are controlled so that the internal combustion engine is cranked and started, and torque acting on the drive shaft accompanying the cranking of the internal combustion engine is canceled. Control means for controlling the electric motor so that a sum of a cancel torque, a set required torque and the set damping torque is output to the drive shaft;
It is a summary to provide.

  In the hybrid vehicle of the present invention, when starting the internal combustion engine, a gain is set based on the rotational position of the output shaft of the internal combustion engine immediately before starting the internal combustion engine, and the cranking of the internal combustion engine is performed using the set gain. A damping torque is set to suppress vibration generated in the drive shaft, and the generator and the internal combustion engine are controlled so that the internal combustion engine is cranked and started. The electric motor is controlled so that the sum of the cancel torque for canceling the torque acting on the shaft, the required torque required for the drive shaft for traveling and the set damping torque is output to the drive shaft. That is, the internal combustion engine is started by outputting the damping torque obtained using the gain based on the rotational position of the output shaft of the internal combustion engine immediately before starting the internal combustion engine from the electric motor. As a result, the damping torque can be set using a gain corresponding to the amount of air in the first compression stroke at the start of the internal combustion engine, and vibrations when cranking the internal combustion engine can be reduced more appropriately. it can. Further, since the damping torque is set using a gain corresponding to the rotational position of the output shaft of the internal combustion engine immediately before starting the internal combustion engine, regardless of the rotational position of the output shaft of the internal combustion engine immediately before starting the internal combustion engine. Compared with the case where the vibration damping torque is set to the above, the vibration damping torque can be made more appropriate, and the electric power used for vibration damping control can be reduced.

  In such a hybrid vehicle of the present invention, the gain setting means is means for setting the gain so that the detected rotational position tends to increase as the distance from the predetermined rotational position before the top dead center of the internal combustion engine increases. You can also Here, the predetermined rotational position is a rotational position where the air amount in the first compression stroke is relatively small. The reason why the gain is set so as to increase with increasing distance from the predetermined rotational position is based on the fact that the amount of air in the first compression stroke increases as the distance from the predetermined rotational position increases, and torque pulsation at the initial stage of cranking increases. In such an aspect, when the operation of the internal combustion engine is stopped, the control means is a means for controlling the generator and the electric motor so that the internal combustion engine stops at the predetermined rotational position. You can also. In this way, the damping torque can be set using a small gain, and the power used for damping control can be reduced.

  Further, in the hybrid vehicle of the present invention, the damping torque setting means sets, as the damping torque, a torque obtained by multiplying the torque that vibrates in the opposite phase to the torque pulsation generated on the drive shaft by the set gain. It can also be a means to do. The hybrid vehicle of the present invention further includes boosting means for boosting the electric power of the power storage means and supplying the boosted power to the generator and the motor side, and the control means is provided on the generator and motor side of the boosting means. The voltage boosting means may be a means for controlling the boosting means so that the target voltage tends to increase as the torque output from the electric motor increases.

The hybrid vehicle control method of the present invention includes:
An internal combustion engine, a generator capable of inputting / outputting power, a drive shaft coupled to an axle, an output shaft of the internal combustion engine, and a rotation shaft of the generator, connected to any of the three shafts Three-axis power input / output means for inputting / outputting power to the remaining shafts based on power input / output to / from two shafts, an electric motor for inputting / outputting power to / from the drive shaft, the generator and the electric motor A hybrid vehicle control method comprising:
When starting the internal combustion engine, a gain is set based on the rotational position of the output shaft when the operation of the internal combustion engine is stopped, and the drive is performed in accordance with the cranking of the internal combustion engine using the set gain. A damping torque for suppressing vibration generated in the shaft is set, the generator and the internal combustion engine are controlled so that the internal combustion engine is cranked and started, and the cranking of the internal combustion engine is performed. The electric motor is configured so that a sum of a cancel torque for canceling a torque acting on the drive shaft, a required torque required for the drive shaft for traveling and the set damping torque is output to the drive shaft. Control,
It is characterized by that.

  In this hybrid vehicle control method of the present invention, when starting the internal combustion engine, a gain is set based on the rotational position of the output shaft of the internal combustion engine immediately before starting the internal combustion engine, and the internal combustion engine is used using the set gain. The damping torque for suppressing the vibration generated in the drive shaft with the cranking of the engine is set, the generator and the internal combustion engine are controlled so that the internal combustion engine is cranked and started, and the cranking of the internal combustion engine is performed. Along with this, the motor is controlled so that the sum of the cancel torque for canceling the torque acting on the drive shaft, the required torque required for the drive shaft for traveling and the set damping torque is output to the drive shaft. To do. That is, the internal combustion engine is started by outputting the damping torque obtained using the gain based on the rotational position of the output shaft of the internal combustion engine immediately before starting the internal combustion engine from the electric motor. As a result, the damping torque can be set using a gain corresponding to the amount of air in the first compression stroke at the start of the internal combustion engine, and vibrations when cranking the internal combustion engine can be reduced more appropriately. it can. Further, since the damping torque is set using a gain corresponding to the rotational position of the output shaft of the internal combustion engine immediately before starting the internal combustion engine, regardless of the rotational position of the output shaft of the internal combustion engine immediately before starting the internal combustion engine. Compared with the case where the vibration damping torque is set to the above, the vibration damping torque can be made more appropriate, and the electric power used for vibration damping control can be reduced.

  Next, the best mode for carrying out the present invention will be described using examples.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 according to an embodiment of the present invention, and FIG. 2 is a configuration diagram showing an outline of the configuration of an electric drive system including motors MG1 and MG2. As shown in FIG. 1, the hybrid vehicle 20 according to the embodiment includes an engine 22, a three-shaft power distribution and integration mechanism 30 connected to a crankshaft 26 as an output shaft of the engine 22 via a damper 28, A motor MG1 capable of generating electricity connected to the distribution integration mechanism 30, a motor MG2 connected to a ring gear shaft 32a as a drive shaft connected to the power distribution integration mechanism 30 via a reduction gear 35, and a direct current to an alternating current Inverters 41 and 42 that can be converted to and supplied to the motors MG1 and MG2, a booster circuit 55 that converts the voltage of the power from the battery 50 and can be supplied to the inverters 41 and 42, a battery 50 and a booster circuit 55, And a hybrid electronic control unit 70 for controlling the entire vehicle.

  The engine 22 is an internal combustion engine that outputs power using a hydrocarbon-based fuel such as gasoline or light oil. The engine electronic control unit (hereinafter referred to as engine ECU) 24 performs fuel injection control, ignition control, and intake air amount adjustment. Under control of operation such as control. The engine ECU 24 receives signals from various sensors that detect the operating state of the engine 22, for example, a crank angle θ from a crank angle sensor 23 that detects the crank angle of the crankshaft 26 of the engine 22. The engine ECU 24 is in communication with the hybrid electronic control unit 70, controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and, if necessary, transmits data related to the operating state of the engine 22 to the hybrid electronic control. Output to unit 70. The engine ECU 24 also calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22 based on the crank angle θ from the crank angle sensor 23.

  The power distribution and integration mechanism 30 includes an external gear sun gear 31, an internal gear ring gear 32 arranged concentrically with the sun gear 31, a plurality of pinion gears 33 that mesh with the sun gear 31 and mesh with the ring gear 32, A planetary gear mechanism is provided that includes a carrier 34 that holds a plurality of pinion gears 33 so as to rotate and revolve, and that performs differential action using the sun gear 31, the ring gear 32, and the carrier 34 as rotational elements. In the power distribution and integration mechanism 30, the crankshaft 26 of the engine 22 is connected to the carrier 34, the motor MG1 is connected to the sun gear 31, and the reduction gear 35 is connected to the ring gear 32 via the ring gear shaft 32a. When functioning as a generator, power from the engine 22 input from the carrier 34 is distributed according to the gear ratio between the sun gear 31 side and the ring gear 32 side, and when the motor MG1 functions as an electric motor, the engine input from the carrier 34 The power from 22 and the power from the motor MG1 input from the sun gear 31 are integrated and output to the ring gear 32 side. The power output to the ring gear 32 is finally output from the ring gear shaft 32a to the drive wheels 63a and 63b of the vehicle via the gear mechanism 60 and the differential gear 62.

  As shown in FIG. 2, each of the motor MG1 and the motor MG2 is configured as a well-known synchronous generator motor including a rotor having a permanent magnet attached to the outer surface and a stator wound with a three-phase coil. Electric power is exchanged with battery 50 through inverters 41 and 42 and booster circuit 55. In the embodiment, motors MG1 and MG2 and inverters 41 and 42 having rated maximum input voltage Vset (for example, 650 V) are used. The inverters 41 and 42 include six transistors T11 to T16 and T21 to 26, and six diodes D11 to D16 and D21 to D26 connected in parallel to the transistors T11 to T16 and T21 to T26 in the reverse direction. Yes. Two transistors T11 to T16 and T21 to T26 are arranged in pairs so that each of the inverters 41 and 42 serves as a source side and a sink side with respect to the positive electrode bus 54a and the negative electrode bus 54b shared by the power line 54. Each of the three-phase coils (U-phase, V-phase, W-phase) of the motors MG1, MG2 is connected to each connection point between the paired transistors. Therefore, a rotating magnetic field is formed in the three-phase coil by controlling the ratio of the on-time of the transistors T11 to T16 and T21 to T26 that make a pair while a voltage is acting between the positive electrode bus 54a and the negative electrode bus 54b. The motors MG1, MG2 can be driven to rotate. Since the inverters 41 and 42 share the positive bus 54a and the negative bus 54b, the electric power generated by either the motor MG1 or MG2 can be supplied to another motor. A smoothing capacitor 57 is connected to the positive electrode bus 54a and the negative electrode bus 54b. The motors MG1 and MG2 are both driven and controlled by a motor electronic control unit (hereinafter referred to as a motor ECU) 40. The motor ECU 40 detects signals necessary for driving and controlling the motors MG1 and MG2, such as signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and current sensors (not shown). The phase current applied to the motors MG1 and MG2 is input, and the motor ECU 40 outputs switching control signals to the transistors T11 to T16 and T21 to T26 of the inverters 41 and 42. The motor ECU 40 is in communication with the hybrid electronic control unit 70, controls the driving of the motors MG1 and MG2 by a control signal from the hybrid electronic control unit 70, and, if necessary, data on the operating state of the motors MG1 and MG2. Output to the hybrid electronic control unit 70. The motor ECU 40 also calculates the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 based on signals from the rotational position detection sensors 43 and 44.

  As shown in FIG. 2, the booster circuit 55 includes two transistors T31 and T32, two diodes D31 and D32 connected in parallel to the transistors T31 and T32 in the reverse direction, and a reactor L. The two transistors T31 and T32 are connected to the positive bus 54a and the negative bus 54b of the inverters 41 and 42, respectively, and the reactor L is connected to the connection point. Further, the positive terminal and the negative terminal of the battery 50 are connected to the reactor L and the negative bus 54 b via the system main relay 56, respectively. Therefore, by turning on / off the transistors T31 and T32, the voltage of the DC power of the battery 50 is boosted and supplied to the inverters 41 and 42, or the DC voltage acting on the positive bus 54a and the negative bus 54b is lowered. The battery 50 can be charged. A smoothing capacitor 58 is connected to the reactor L and the negative electrode bus 54b. Hereinafter, the power line 54 side of the booster circuit 55 is referred to as a high voltage system, and the battery 50 side of the booster circuit 55 is referred to as a low voltage system.

  The battery 50 is configured as a lithium ion secondary battery with a rated voltage of 200 V, for example, and is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52. The battery ECU 52 is attached to a signal necessary for managing the battery 50, for example, an inter-terminal voltage Vb from the voltage sensor 51a installed between the terminals of the battery 50, and an electric power line connected to the output terminal of the battery 50. The charging / discharging current Ib from the received current sensor 51b, the battery temperature Tb from the temperature sensor 51c attached to the battery 50, and the like are input, and data on the state of the battery 50 is electronically controlled by communication as necessary. Output to unit 70. Further, the battery ECU 52 calculates the remaining capacity SOC based on the integrated value of the charging / discharging current Ib detected by the current sensor 51b in order to manage the battery 50, and sets the input / output limits Win and Wout of the battery 50. It is.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port and communication not shown. And a port. The hybrid electronic control unit 70 includes a temperature Tup of the booster circuit 55 from the temperature sensor 55a (for example, the temperature of the reactor L) and a voltage of the capacitor 57 from the voltage sensor 57a (hereinafter referred to as a high voltage system voltage VH). , The voltage of the capacitor 58 from the voltage sensor 58a, the ignition signal from the ignition switch 80, the shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, and the accelerator pedal position that detects the depression amount of the accelerator pedal 83 The accelerator opening Acc from the sensor 84, the brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the like are input via the input port. From the hybrid electronic control unit 70, a switching control signal to the transistors T31 and T32 of the booster circuit 55, a drive signal to the system main relay 56, and the like are output via an output port. As described above, the hybrid electronic control unit 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52. ing.

  The hybrid vehicle 20 of the embodiment thus configured calculates the required torque to be output to the ring gear shaft 32a as the drive shaft based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal 83 by the driver. Then, the operation of the engine 22, the motor MG1, and the motor MG2 is controlled so that the required power corresponding to the required torque is output to the ring gear shaft 32a. As operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that the power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is the power distribution and integration mechanism 30. Torque conversion operation mode for driving and controlling the motor MG1 and the motor MG2 so that the torque is converted by the motor MG1 and the motor MG2 and output to the ring gear shaft 32a, and the required power and the power required for charging and discharging the battery 50. The engine 22 is operated and controlled so that suitable power is output from the engine 22, and all or part of the power output from the engine 22 with charging / discharging of the battery 50 is the power distribution integration mechanism 30, the motor MG1, and the motor. The required power is converted to the ring gear shaft 32 with torque conversion by MG2. Charge / discharge operation mode in which the motor MG1 and the motor MG2 are driven and controlled so as to be output to each other, and a motor operation mode in which the operation of the engine 22 is stopped and the power corresponding to the required power from the motor MG2 is output to the ring gear shaft 32a. and so on. The torque conversion operation mode and the charge / discharge operation mode are modes in which the engine 22 and the motors MG1, MG2 are controlled so that the required power is output to the ring gear shaft 32a with the operation of the engine 22. Since there is no difference in the control, both are hereinafter referred to as the engine operation mode.

  Next, the operation of the hybrid vehicle 20 of the embodiment configured in this way, particularly the operation when starting the engine 22 will be described. FIG. 3 is a flowchart showing an example of a start-time drive control routine executed by the hybrid electronic control unit 70 of the embodiment when the engine 22 is started. In the embodiment, when the operation of the engine 22 is stopped, the motor MG1 is controlled so that any cylinder of the engine 22 stops at the target stop position immediately before the compression top dead center (TDC). 22 may stop at the target stop position, but may stop at a position deviating from the target stop position.

  When the start-up drive control routine is executed, the CPU 72 of the hybrid electronic control unit 70 first inputs a crank angle θ as a stop position of the crankshaft 26 of the engine 22 that has stopped operating (step S100). A gain k used for vibration suppression control is set based on the crank angle θ (step S110). Here, the crank angle θ is detected by the crank angle sensor 23 when the operation of the engine 22 is stopped, and is stored in a predetermined area of a RAM (not shown) of the engine ECU 24 and is input from the engine ECU 24 by communication. did. As a gain setting map, a relationship between the crank angle θ and the gain k is determined in advance so that the gain k is set to become smaller as it is farther from just before the compression top dead center (TDC) of any cylinder of the engine 22. It is stored in the ROM 74, and is set by deriving the corresponding gain k from the map when the crank angle θ is given. An example of the gain setting map is shown in FIG. When the crank angle θ is immediately before the compression top dead center (TDC) of the engine 22, the first compression stroke when cranking the engine 22 is the stroke up to the top dead center, so the air amount in the first compression stroke Becomes smaller, and it becomes easier to increase the rotational speed by the top dead center in the next compression stroke. For this reason, it is considered that the torque pulsation at the initial stage of cranking becomes relatively small. On the other hand, when the crank angle θ becomes far from just before the compression top dead center (TDC) of the engine 22, the air amount in the first compression stroke increases, and the torque pulsation at the initial stage of cranking increases. The gain k in the embodiment is considered to be the smallest when the torque pulsation at the initial stage of cranking changes based on the crank angle θ and the crank angle θ is just before the compression top dead center (TDC) of the engine 22. It is set based on. When the engine 22 has four cylinders, the compression top dead center (TDC) occurs every 180 degrees, and when the engine 22 has six cylinders, the compression top dead center (TDC) occurs every 120 degrees.

  Next, data necessary for control, such as the accelerator opening degree Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 88, the rotational speed Ne and crank angle θ of the engine 22, and the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2. Is input (step S120). Here, the crank angle θ and the rotational speed Ne of the engine 22 are input from the engine ECU 24 by communication from the crank angle θ detected by the crank angle sensor 23 and the rotational speed Ne calculated based on the crank angle θ. It was. Further, the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 are input from the motor ECU 40 by communication from those calculated based on the rotational positions of the rotors of the motors MG1 and MG2 detected by the rotational position detection sensors 43 and 44. It was supposed to be.

  The required torque Tr * to be output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b as the torque required for the vehicle based on the accelerator opening Acc and the vehicle speed V that are input, and the ring gear shaft 32a. The required power Pr * is set as the driving power to be output to (step S130). In the embodiment, the required torque Tr * is determined in advance by storing the relationship between the accelerator opening Acc, the vehicle speed V, and the required torque Tr * in the ROM 74 as a required torque setting map, and the accelerator opening Acc, the vehicle speed V, , The corresponding required torque Tr * is derived and set from the stored map. FIG. 5 shows an example of the required torque setting map. The required power Pr * can be calculated by multiplying the set required torque Tr * by the rotation speed Nr of the ring gear shaft 32a. The rotation speed Nr of the ring gear shaft 32a can be obtained by multiplying the vehicle speed V by the conversion factor k, or can be obtained by dividing the rotation speed Nm2 of the motor MG2 by the gear ratio Gr of the reduction gear 35.

  Subsequently, the torque command Tm1 * of the motor MG1 is set based on the torque map at the time of starting, the elapsed time t from the start of starting the engine 22, and the rotational speed Ne of the engine 22. (Step S140). FIG. 6 shows an example of a torque map set in the torque command Tm1 * of the motor MG1 when the engine 22 is started and an example of a change in the rotational speed Ne of the engine 22. In the torque map of the embodiment, a relatively large torque is set in the torque command Tm1 * using rate processing immediately after the time t11 when the start instruction of the engine 22 is given, and the rotational speed Ne of the engine 22 is rapidly increased. Torque that allows the engine 22 to be stably motored at the rotation speed Nref or higher at a time t12 after the rotation speed Ne of the engine 22 has passed the resonance rotation speed band or after the time necessary for passing through the resonance rotation speed band. Is set to the torque command Tm1 * to reduce the power consumption and the reaction force on the ring gear shaft 32a as the drive shaft. Then, the torque command Tm1 * is set to 0 using rate processing from the time t13 when the rotational speed Ne of the engine 22 reaches the rotational speed Nref, and the torque for power generation is torqued from the time t15 when the complete explosion of the engine 22 is determined. Set to command Tm1 *. Here, the rotational speed Nref is the rotational speed at which the fuel injection control and the ignition control of the engine 22 are started.

  Next, the temporary correction torque Tαtmp is set based on the crank angle θ (step S150), and the correction torque Tα is set by multiplying the set temporary correction torque Tαtmp by the gain k (step S160). In the embodiment, the temporary correction torque Tαtmp is stored in the ROM 74 as a temporary correction torque setting map by previously setting the relationship between the crank angle θ and the temporary correction torque Tαtmp. The provisional correction torque Tαtmp is derived and set. When the engine 22 is cranked, each cylinder repeats four strokes of intake, compression, expansion, and exhaust. However, since fuel injection and ignition are not performed, the pressure in the cylinder increases during the compression stroke and decreases during the expansion stroke. Become. Such a pressure change in the cylinder acts as a torque on the crankshaft 26 of the engine 22 via the piston. Although a slight pressure change occurs in the cylinder in the intake stroke and the exhaust stroke, it is negligible because the magnitude thereof is small compared to the compression stroke and the expansion stroke. Since the torque acting on the crankshaft 26 acts on the ring gear shaft 32a as a drive shaft via the power distribution and integration mechanism 30, it also appears on the ring gear shaft 32a as a torque pulsation based on a pressure change in the cylinder. FIG. 7 shows an example of the relationship between the torque acting on the ring gear shaft 32a and the crank angle θ based on the pressure change in the cylinder, and the relationship between the suppression torque for canceling the torque acting on the ring gear shaft 32a and the crank angle θ. An example is shown. In the figure, the broken line indicates the relationship between the torque acting on the ring gear shaft 32a and the crank angle θ, and the solid line indicates the relationship between the suppression torque and the crank angle θ. As shown in the figure, the torque acting on the ring gear 32a based on the pressure change in the cylinder ranges from the bottom dead center (−180 ° CA) to the top dead center (0 ° CA) where the target cylinder is in the compression stroke. Then, it acts in the direction of suppressing the rotation of the engine 22, and acts in the direction of promoting the rotation of the engine 22 in the range from the top dead center (0 ° CA) to the bottom dead center (+ 180 ° CA) of the expansion stroke. Therefore, the torque pulsation of the ring gear shaft 32a at the time of cranking can be reduced by applying a suppression torque that cancels this torque to the ring gear shaft 32a. The suppression torque may be changed between plus and minus of the sign of the torque acting on the ring gear 32a based on the pressure change in the cylinder, that is, the engine 22 rotates in the range from the bottom dead center to the top dead center of the compression stroke. The torque may be set as a torque acting in the acceleration direction, and may be set as a torque in a direction to suppress the rotation of the engine 22 in the range from the top dead center to the bottom dead center of the expansion stroke. The torque acting on the ring gear shaft 32a based on the pressure change in the cylinder varies depending on the size and characteristics of the engine 22, such as intake and exhaust valve timings, but can be obtained in advance through experiments. The temporary correction torque setting map of the embodiment can be obtained by superimposing the suppression torque in one cylinder by the number of cylinders of the engine 22, and the torque pulsation generated in the ring gear shaft 32a at the time of cranking is obtained and canceled. Therefore, it can be obtained as a torque to be applied from the motor MG2.

  When the correction torque Tα is set in this way, the deviation from the power consumption (generated power) of the motor MG1 obtained by multiplying the output limit Wout of the battery 50 and the set torque command Tm1 * of the motor MG1 by the current rotational speed Nm1 of the motor MG1. Is divided by the rotational speed Nm2 of the motor MG2 to calculate a torque limit Tmax as an upper limit of the torque that may be output from the motor MG2 by the following equation (1) (step S170), and the correction torque Tα and the required torque Tr * And the torque command Tm1 * and the gear ratio ρ of the power distribution and integration mechanism 30 are used to calculate a temporary motor torque Tm2tmp as a torque to be output from the motor MG2 by the following equation (2) (step S180), and the calculated torque limit Comparing Tmax with the provisional motor torque Tm2tmp, the smaller torque is calculated by the motor MG2. It is set as the torque command Tm2 * (step S190). The above equation (2) is a dynamic relational expression for the rotating element of the power distribution and integration mechanism 30. FIG. 8 shows an example of a collinear diagram showing the dynamic relationship between the rotational speed and torque of each rotary element of the power distribution and integration mechanism 30 during cranking of the engine 22. In the figure, the left S-axis indicates the rotation speed of the sun gear 31 that is the rotation speed Nm1 of the motor MG1, the C-axis indicates the rotation speed of the carrier 34 that is the rotation speed Ne of the engine 22, and the R-axis indicates the rotation speed of the motor MG2. The rotational speed Nr of the ring gear 32 obtained by dividing the number Nm2 by the gear ratio Gr of the reduction gear 35 is shown. Equation (2) can be easily derived by using the alignment chart of FIG. Note that two thick arrows on the R axis in FIG. 8 indicate torque acting on the ring gear shaft 32a as a drive shaft when the torque of the torque command Tm1 * is output from the motor MG1 and the engine 22 is cranked. The torque Tm2 * output from the motor MG2 indicates the torque acting on the ring gear shaft 32a via the reduction gear 35. By setting the torque command Tm2 * of the motor MG2 in this way, when the engine 22 is cranked by the motor MG1, the torque acting on the ring gear shaft 32a as the drive shaft is canceled and the torque pulsation acting on the ring gear shaft 32a Torque corresponding to the required torque Tr * requested by the driver can be output while suppressing the above.

Tmax = (Wout−Tm1 * ・ Nm1) / Nm2 (1)
Tm2tmp = (Tr * + Tm1 * / ρ + Tα) / Gr (2)

  When the torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are thus set, the set torque commands Tm1 * and Tm2 * are transmitted to the motor ECU 40 (step S200). Receiving the torque commands Tm1 * and Tm2 *, the motor ECU 40 controls the switching elements of the inverters 41 and 42 so that the motor MG1 is driven by the torque command Tm1 * and the motor MG2 is driven by the torque command Tm2 *. .

  Next, a smaller voltage is set as the voltage command Vh * between the temporary voltage set based on the torque commands Tm1 * and Tm2 * and the maximum voltage Vmax as the rated value of the booster circuit 55 (step S210). Here, in the embodiment, the temporary voltage has a larger absolute value among the torque commands Tm1 * and Tm2 * as a relationship in which energy efficiency becomes higher when the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *. The relationship with the temporary voltage is obtained in advance and stored in the ROM 74 as a temporary voltage setting map, and when the torque commands Tm1 * and Tm2 * are given, the temporary voltage corresponding to the larger one is derived from the map and set. It was. FIG. 9 shows an example of the temporary voltage setting map. When the voltage command Vh * is set, the hybrid electronic control unit 70 performs switching control of the transistors T31 and T32 of the booster circuit 55 so that the high voltage system becomes the voltage command Vh *.

  Then, it is determined whether or not the rotational speed Ne of the engine 22 is equal to or higher than the rotational speed Nref (step S220). When the rotational speed Ne of the engine 22 is less than the rotational speed Nref, the process returns to step S120 and the processes of steps S120 to S220 are performed. repeat. On the other hand, when the rotational speed Ne of the engine 22 reaches the rotational speed Nref or more, a control signal for starting fuel injection control and ignition control is transmitted to the engine ECU 24 (step S230), and the engine 22 waits for the complete explosion. (Step S240), this routine is finished. The engine ECU 24 that has received the control signal for starting the fuel injection control and the ignition control starts the control of the fuel injection from the fuel injection valve and the control of the ignition by the spark plug.

  According to the hybrid vehicle 20 of the embodiment described above, the crank angle θ, which is the stop position of the crankshaft 26 of the engine 22 in a state where the operation before starting is stopped, is a position immediately before the compression top dead center (TDC). Is corrected by multiplying the gain k, which is set to increase with increasing distance, from the temporary correction torque Tαtmp set based on the suppression torque for canceling the torque acting on the ring gear shaft 32a based on the pressure change in the cylinder. Torque command for the motor MG2 is set so that the sum of the correction torque Tα and the torque that cancels the torque that acts on the ring gear shaft 32a in accordance with the cranking and the required torque Tr * acts on the ring gear shaft 32a. The engine 22 is cranked by setting Tm2 * and controlling the motor MG2. It is possible to suppress the vibration caused by torque pulsation when. In addition, since the gain k is set based on the crank angle θ before starting and the correction torque Tα is set, the correction torque Tα having a magnitude corresponding to the crank angle θ before starting can be obtained. Vibration caused by torque pulsation when cranking the engine 22 more appropriately according to the angle θ can be suppressed. Therefore, since the correction torque Tα that is larger than necessary is not set, the torque command Tm2 * that is larger than necessary is not set. As a result, it is possible to suppress excessive boosting by the booster circuit 55 and to suppress power consumption. Of course, it is possible to travel while outputting the required torque Tr * while the engine 22 is being cranked.

  In the hybrid vehicle 20 of the embodiment, the gain k is set so that the crank angle θ before starting increases as the distance from the position immediately before the compression top dead center (TDC) increases. When the gain k does not tend to increase as the angle θ becomes farther from the position immediately before the compression top dead center (TDC), the gain k is determined based on the relationship between the crank angle θ before starting and the gain k obtained by experiments or the like. May be set.

  In the hybrid vehicle 20 of the embodiment, when the operation of the engine 22 is stopped, the motor MG1 is controlled such that any cylinder of the engine 22 stops at the target stop position immediately before the compression top dead center (TDC). However, the motor MG1 may not be controlled so that the engine 22 stops at the target stop position when the operation of the engine 22 is stopped.

  In the hybrid vehicle 20 of the embodiment, the motor MG2 is attached to the ring gear shaft 32a via the reduction gear 35, but the motor MG2 may be attached to the ring gear shaft 32a via a transmission instead of the reduction gear 35. The motor MG2 may be attached to the ring gear shaft 32a without using the reduction gear 35 or the transmission.

  In the hybrid vehicle 20 of the embodiment, the electric power from the battery 50 is boosted by the booster circuit 55 and supplied to the inverters 41 and 42 that drive the motors MG1 and MG2, but the battery 50 is not provided with such a booster circuit 55. May be supplied to the inverters 41 and 42 that drive the motors MG1 and MG2 without increasing the power from the inverters 41 and 42.

  Here, the correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the engine 22 corresponds to an “internal combustion engine”, the motor MG1 corresponds to a “generator”, the power distribution / integration mechanism 30 corresponds to a “three-axis power input / output unit”, and the motor MG2 corresponds to a “motor”. The battery 50 corresponds to “power storage means”, the crank angle sensor 23 and the engine ECU 24 storing the crank angle θ from the crank angle sensor 23 correspond to “rotational position detection means”, and the crank angle θ Is a hybrid electronic control unit that executes the process of step S110 of the start-time drive control routine of FIG. 3 for setting the gain k used for vibration suppression control so that the distance increases from the position immediately before the compression top dead center (TDC). 70 corresponds to the “gain setting means”, and sets the correction torque Tα by multiplying the provisional correction torque Tαtmp based on the crank angle θ by the gain k, and starts the drive control routine at the time of FIG. The hybrid electronic control unit 70 that executes the processing of steps S150 and S160 of the routine corresponds to the “vibration damping torque setting means”, and sets the required torque Tr * based on the accelerator opening Acc and the vehicle speed V of FIG. The hybrid electronic control unit 70 that executes the process of step S130 of the start-time drive control routine corresponds to “required torque setting means”. Then, the torque command Tm1 * of the motor MG1 is set so that the engine 22 is cranked and started, and the correction torque Tα, the torque that cancels the torque acting on the ring gear shaft 32a due to cranking, and the required torque Tr * are set. The torque command Tm2 * of the motor MG2 is set and transmitted to the motor ECU 40 so that the sum torque acts on the ring gear shaft 32a, and the fuel injection control and the ignition control are performed when the rotational speed Ne of the engine 22 reaches the rotational speed Nref or more. The control signal for starting the engine is transmitted to the engine ECU 24. The hybrid electronic control unit 70 for executing the processes of steps S140 and S170 to S230 of the start time drive control routine of FIG. 3 and the torque commands Tm1 * and Tm2 * are received. Torque corresponding to torque commands Tm1 * and Tm2 * is output. The motor ECU 40 that controls the motors MG1 and MG2 and the engine ECU 24 that receives the control signal for starting the fuel injection control and the ignition control and starts the fuel injection control and the ignition control of the engine 22 are referred to as “control means”. Equivalent to. Further, the booster circuit 55 corresponds to “boosting means”.

  Here, the “internal combustion engine” is not limited to an internal combustion engine that outputs power using a hydrocarbon fuel such as gasoline or light oil, and may be any type of internal combustion engine such as a hydrogen engine. The “generator” is not limited to the motor MG1 configured as a synchronous generator motor, and may be any type of generator such as an induction motor that can input and output power. The “three-axis power input / output means” is not limited to the power distribution / integration mechanism 30 described above, but includes four or more shafts using a double pinion type planetary gear mechanism or a combination of a plurality of planetary gear mechanisms. Predetermined gears on the three axes of the drive shaft connected to the axle, the output shaft of the internal combustion engine, and the rotating shaft of the generator, such as those connected to the shaft and those having a different operation action from the planetary gear such as a differential gear As long as it is connected with a ratio and inputs / outputs power to / from the remaining shafts based on power input / output to / from any two of the three shafts, it does not matter. The “motor” is not limited to the motor MG2 configured as a synchronous generator motor, and may be any type of motor as long as it can input and output power to the drive shaft, such as an induction motor. . The “power storage means” is not limited to the battery 50 as a secondary battery, and may be anything as long as it can exchange electric power with a generator, such as a capacitor. The “rotation position detection means” is not limited to the crank angle sensor 23 and the engine ECU 24 that stores the crank angle θ from the crank angle sensor 23, but the rotation of the output shaft of the internal combustion engine immediately before starting the internal combustion engine. Any device that detects the position may be used. The “gain setting means” is not limited to the one that sets the gain k used for damping control so that the rank angle θ tends to increase as the distance from the position immediately before the compression top dead center (TDC) increases. Any gain may be used as long as the gain is set based on the rotational position of the output shaft of the internal combustion engine immediately before starting the engine. The “damping torque setting means” is not limited to the setting of the correction torque Tα by multiplying the provisional correction torque Tαtmp based on the crank angle θ by the gain k, but the set gain is used to set the correction torque Tα. Any method may be used as long as it sets a damping torque for suppressing vibration generated in the drive shaft in accordance with the ranking. The “required torque setting means” is not limited to the one that sets the required torque Tr * based on the accelerator opening Acc and the vehicle speed V, but sets the required torque based only on the accelerator opening Acc. Or set the required torque required for the drive shaft for driving, such as setting the required torque based on the driving position on the driving route if the driving route is preset. Any object can be used. The “control means” is not limited to the combination of the hybrid electronic control unit 70, the engine ECU 24, and the motor ECU 40, and may be configured by a single electronic control unit. The “control means” controls the motor MG1 and the engine 22 so that the engine 22 is cranked and started when the engine 22 is started, and acts on the ring gear shaft 32a in accordance with the correction torque Tα and cranking. Is not limited to controlling the motor MG2 so that the sum of the torque to cancel the torque to be applied and the required torque Tr * acts on the ring gear shaft 32a. When the internal combustion engine is started, the internal combustion engine is cranked. The sum of the cancel torque, the requested torque, and the damping torque for controlling the generator and the internal combustion engine to be started and canceling the torque acting on the drive shaft accompanying the cranking of the internal combustion engine is Any device can be used as long as it controls the electric motor so that it is output to the drive shaft.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. It is an example for specifically explaining the best mode for doing so, and does not limit the elements of the invention described in the column of means for solving the problem. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  The best mode for carrying out the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention. Of course, it can be implemented in the form.

  The present invention is applicable to the hybrid vehicle manufacturing industry.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 according to an embodiment of the present invention. It is a block diagram which shows the outline of a structure of the electric drive system containing motor MG1, MG2. It is a flowchart which shows an example of the drive control routine at the time of start performed by the hybrid electronic control unit 70 of an Example. It is explanatory drawing which shows an example of the map for gain setting. It is explanatory drawing which shows an example of the map for request | requirement torque setting. It is explanatory drawing which shows an example of the torque map set to the torque command Tm1 * of motor MG1 at the time of engine 22 start, and an example of the mode of the rotation speed Ne of the engine 22. An example of the relationship between the torque acting on the ring gear shaft 32a based on the pressure change in the cylinder and the crank angle θ, and an example of the relationship between the suppression torque for canceling the torque acting on the ring gear shaft 32a and the crank angle θ It is explanatory drawing shown. FIG. 3 is an explanatory diagram showing an example of a collinear diagram showing a dynamic relationship between the rotational speed and torque of each rotary element of the power distribution and integration mechanism 30 during cranking of the engine 22. It is explanatory drawing which shows an example of the temporary voltage setting map.

Explanation of symbols

  20 hybrid vehicle, 22 engine, 23 crank angle sensor, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 power distribution and integration mechanism, 31 sun gear, 32 ring gear, 32a ring gear shaft, 33 pinion gear, 34 Carrier, 35 Reduction gear, 40 Motor electronic control unit (motor ECU), 41, 42 Inverter, 43, 44 Rotation position detection sensor, 50 battery, 51a Voltage sensor, 51b Current sensor, 51c Temperature sensor, 52 Electronic control for battery Unit (battery ECU), 54 power line, 54a positive bus, 54b negative bus, 55 booster circuit, 55a temperature sensor, 56 system main relay, 57, 58 capacitor, 57a, 58a voltage sensor 60, gear mechanism, 62 differential gear, 63a, 63b drive wheel, 70 hybrid electronic control unit, 72 CPU, 74 ROM, 76 RAM, 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 Accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, MG1, MG2 motor, D11-D16, D21-D26, D31, D32 diode, T11-T16, T21-T26, T31, T32 transistor, L reactor.

Claims (6)

An internal combustion engine, a generator capable of inputting / outputting power, a drive shaft coupled to an axle, an output shaft of the internal combustion engine, and a rotation shaft of the generator, connected to any of the three shafts Three-axis power input / output means for inputting / outputting power to the remaining shafts based on power input / output to / from two shafts, an electric motor for inputting / outputting power to / from the drive shaft, the generator and the electric motor A hybrid vehicle comprising a storage means capable of exchange,
Rotational position detecting means for detecting the rotational position of the output shaft immediately before starting the internal combustion engine;
Gain setting means for setting a gain based on the detected rotational position;
A damping torque setting means for setting a damping torque for suppressing vibration generated in the drive shaft with cranking of the internal combustion engine using the set gain;
A required torque setting means for setting a required torque required for the drive shaft for traveling;
When starting the internal combustion engine, the generator and the internal combustion engine are controlled so that the internal combustion engine is cranked and started, and torque acting on the drive shaft accompanying the cranking of the internal combustion engine is canceled. Control means for controlling the electric motor so that a sum of a cancel torque, a set required torque and the set damping torque is output to the drive shaft;
A hybrid car with   2. The hybrid vehicle according to claim 1, wherein the gain setting means is means for setting a gain such that the detected rotational position tends to increase with increasing distance from a predetermined rotational position before the top dead center of the internal combustion engine.   3. The hybrid vehicle according to claim 2, wherein the control means is means for controlling the generator and the electric motor so that the internal combustion engine stops at the predetermined rotational position when the operation of the internal combustion engine is stopped.   4. The damping torque setting means is means for setting, as the damping torque, a torque obtained by multiplying a torque oscillating in a phase opposite to a torque pulsation generated in the drive shaft by the set gain. A hybrid vehicle according to any one of the claims. A hybrid vehicle according to any one of claims 1 to 4,
Boosting means for boosting the power of the power storage means and supplying it to the generator and the motor side;
The control means is means for controlling the boosting means such that the voltage on the generator and motor side of the boosting means becomes a target voltage that tends to increase as the torque output from the motor increases.
Hybrid car. An internal combustion engine, a generator capable of inputting / outputting power, a drive shaft coupled to an axle, an output shaft of the internal combustion engine, and a rotation shaft of the generator, connected to any of the three shafts Three-axis power input / output means for inputting / outputting power to the remaining shafts based on power input / output to / from two shafts, an electric motor for inputting / outputting power to / from the drive shaft, the generator and the electric motor A hybrid vehicle control method comprising:
When starting the internal combustion engine, a gain is set based on the rotational position of the output shaft immediately before the internal combustion engine is started, and the drive shaft is applied to the drive shaft along with cranking of the internal combustion engine using the set gain. A damping torque for suppressing the generated vibration is set, the generator and the internal combustion engine are controlled so that the internal combustion engine is cranked and started, and the drive shaft is driven along with the cranking of the internal combustion engine. The motor is controlled so that a sum of a cancel torque for canceling the torque acting on the drive shaft, a required torque required for the drive shaft for traveling and the set damping torque is output to the drive shaft. ,
A control method for a hybrid vehicle.

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