JP2009137401A - Hybrid vehicle and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the start and stop of the operation of an engine from frequently occurring while suppressing deterioration of the fuel economy due to continuous engine operation in an inefficient area. <P>SOLUTION: When a request power Pe* requested by a vehicle becomes not less than a threshold value for start determination Pstart to determine start of the engine, and then the engine is started, a value P1 with a larger hysteresis to the threshold value for start determination Pstart is set as a threshold value for stop determination Pstop to determinate stop of the engine based on the request power Pe*. A value becoming larger toward a value P2 so as to make the hysteresis smaller for the threshold value for start determination Pstart as the elapsed time after starting the engine becomes longer is set as the threshold value for stop determination Pstop. The value P2 whose hysteresis is the smallest for the threshold value for start determination Pstart when the elapsed time is a predetermined time Tref or longer is set as the threshold value for stop determination Pstop. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is connected to an internal combustion engine and a drive shaft connected to an axle, and is connected to an output shaft of the internal combustion engine so as to be rotatable independently of the rotation of the drive shaft. The present invention relates to a hybrid vehicle including an electric power drive input / output means capable of inputting / outputting torque to / from an output shaft and the drive shaft, and an electric motor capable of inputting / outputting power to / from the drive shaft, and a control method thereof.

Conventionally, as this type of hybrid vehicle, a hybrid vehicle capable of intermittent engine operation has been proposed in which determination of engine start and operation stop is performed with hysteresis (see, for example, Patent Document 1). In this hybrid vehicle, the engine is started when the engine required power exceeds the engine start determination value with the engine stopped, and the engine required power is higher than the engine start determination value with the engine being operated. The engine is stopped when it falls below the small engine stop judgment value.
JP 2005-42561 A

  In the hybrid vehicle described above, if the hysteresis (difference between the engine start determination value and the engine stop determination value) used for determination of engine start and operation stop is set large, engine start and operation stop frequently occur. However, depending on the engine power requirement, the engine operation may be continued at an operation point with a low efficiency, resulting in a decrease in energy efficiency of the entire vehicle. On the other hand, if the hysteresis is set to a small value, it is possible to avoid a state in which the engine operation continues for a long time at an inefficient operation point, but the engine stop and the operation stop with respect to the change in the engine required power. Will occur relatively frequently.

  The main object of the hybrid vehicle and the control method thereof of the present invention is to suppress frequent start and stop of the internal combustion engine and further improve the energy efficiency of the vehicle.

  The hybrid vehicle of the present invention and its control method employ the following means in order to achieve the main object described above.

The hybrid vehicle of the present invention
An internal combustion engine;
Connected to the drive shaft connected to the axle and connected to the output shaft of the internal combustion engine so as to be rotatable independently of the rotation of the drive shaft, and the output shaft and the drive shaft by input and output of electric power and power Power input / output means capable of inputting and outputting torque to
An electric motor capable of inputting and outputting power to the drive shaft;
Requested torque setting means for setting a requested torque required for the drive shaft;
Operation stop determination means for determining operation and operation stop of the internal combustion engine with hysteresis;
A hysteresis setting means for setting the hysteresis so that the longer the elapsed time from the start until the internal combustion engine is next stopped when the internal combustion engine that has been stopped is started,
When it is determined that the internal combustion engine is in operation, the internal combustion engine, the power power input / output means, and the electric motor are output so that a torque based on the set required torque is output to the drive shaft along with the operation of the internal combustion engine. When the internal combustion engine is determined to stop operating, the internal combustion engine is stopped and the power input / output to / from the internal combustion engine is output so that torque based on the set required torque is output to the drive shaft. Control means for controlling the means and the motor;
It is a summary to provide.

  In the hybrid vehicle of the present invention, the required torque required for the drive shaft is set, the operation and stop of the internal combustion engine are determined with hysteresis, and when the internal combustion engine that is stopped is started, The hysteresis is set so that the longer the elapsed time from start until the operation is stopped, the smaller the hysteresis, and when it is determined that the internal combustion engine is operating, the torque based on the required torque is output to the drive shaft with the operation of the internal combustion engine. The internal combustion engine, the power input / output means, and the motor are controlled so that the internal combustion engine is stopped when it is determined that the internal combustion engine is stopped, and the torque based on the required torque is output to the drive shaft. The power input / output means and the electric motor are controlled. Therefore, it is possible to suppress the frequent start and stop of the internal combustion engine and to suppress the decrease in the vehicle energy efficiency due to the continued operation of the internal combustion engine.

  In such a hybrid vehicle of the present invention, when the internal combustion engine being operated is stopped, the hysteresis setting means tends to become smaller as the elapsed time from the operation stop becomes longer until the internal combustion engine is started next. It may be a means for setting hysteresis. In this way, it is possible to more reliably suppress the frequent start and stop of the internal combustion engine and to suppress the reduction in vehicle energy efficiency caused by the continued operation of the internal combustion engine.

  In the hybrid vehicle of the present invention, the hysteresis setting means may be means for setting the hysteresis so that the hysteresis time gradually decreases as the elapsed time increases.

  Furthermore, the hybrid vehicle of the present invention further includes required power setting means for setting required power required for the vehicle based on the set required torque, wherein the operation stop determining means is based on the set required power. The control means determines the operation and stop of the internal combustion engine with hysteresis, and the control means outputs the set required power from the internal combustion engine when it is determined that the internal combustion engine is operating. The internal combustion engine, the power drive input / output means, and the electric motor are controlled so that torque based on the set required torque is output to the drive shaft, and when it is determined that the internal combustion engine is stopped, the internal combustion engine is The internal combustion engine and the electric power are input so that a torque based on the set required torque is output to the drive shaft while the operation is stopped. It may be assumed to be a means for controlling the power means and the electric motor. In this way, it is possible to determine whether the internal combustion engine is operating or stopped based on the required power required for the vehicle. In the hybrid vehicle of this aspect of the present invention, the operation stop determination means determines that the internal combustion engine is in operation when the set required power becomes equal to or greater than a first threshold while the internal combustion engine is stopped. Means for determining that the internal combustion engine has stopped operating when the set required power becomes less than a second threshold value smaller than the first threshold value during operation of the internal combustion engine, and the hysteresis setting means May be means for setting the first threshold and / or the second threshold.

  Further, in the hybrid vehicle of the present invention, the power driving input / output means is connected to three axes of a generator capable of inputting / outputting power, an output shaft of the internal combustion engine, a rotating shaft of the generator, and the axle side. Further, it may be a means provided with a three-axis power input / output means for inputting / outputting power to / from the remaining one axis based on power input / output to / from any two of the three axes. .

The hybrid vehicle control method of the present invention includes:
An internal combustion engine is connected to a drive shaft connected to an axle and is connected to an output shaft of the internal combustion engine so as to be rotatable independently of the rotation of the drive shaft. A control method for a hybrid vehicle comprising: electric power input / output means capable of inputting / outputting torque to / from a drive shaft; and an electric motor capable of inputting / outputting power to / from the drive shaft,
(A) setting a required torque required for the drive shaft;
(B) determining operation and shutdown of the internal combustion engine with hysteresis;
(C) When the internal combustion engine that has been stopped is started, the hysteresis is set so that the longer the elapsed time from the start until the internal combustion engine is next stopped, the smaller the hysteresis is;
(D) when it is determined that the internal combustion engine is in operation, the internal combustion engine and the power power input / output means so that a torque based on the set required torque is output to the drive shaft along with the operation of the internal combustion engine. The internal combustion engine and the electric power are controlled so that the internal combustion engine is stopped when it is determined that the operation of the internal combustion engine is stopped, and the torque based on the set required torque is output to the drive shaft. The gist is to control the power input / output means and the electric motor.

  According to this hybrid vehicle control method of the present invention, the required torque required for the drive shaft is set, the operation and stop of the internal combustion engine are determined with hysteresis, and the stopped internal combustion engine is started. Hysteresis is set so that the elapsed time from the start becomes longer until the internal combustion engine is next stopped, and when it is determined that the internal combustion engine is operating, the torque based on the required torque is accompanied by the operation of the internal combustion engine. The internal combustion engine, the power input / output means and the motor are controlled so as to be output to the drive shaft, and when it is determined that the operation of the internal combustion engine is stopped, the internal combustion engine is stopped and torque based on the required torque is output to the drive shaft. The internal combustion engine, the power drive input / output means and the motor are controlled. Therefore, it is possible to suppress the frequent start and stop of the internal combustion engine and to suppress the decrease in the vehicle energy efficiency due to the continued operation of the internal combustion engine.

  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. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22, a three-shaft power distribution / integration mechanism 30 connected to a crankshaft 26 as an output shaft of the engine 22 via a damper 28, and power distribution / integration. A motor MG1 capable of generating electricity connected to the mechanism 30, a reduction gear 35 attached to a ring gear shaft 32a as a drive shaft connected to the power distribution and integration mechanism 30, a motor MG2 connected to the reduction gear 35, And a hybrid electronic control unit 70 for controlling the entire drive system of the vehicle.

  The engine 22 is an internal combustion engine that outputs power using a hydrocarbon-based fuel such as gasoline or light oil, and an engine electronic control unit (hereinafter referred to as an engine ECU) that receives signals from various sensors that detect the operating state of the engine 22. ) 24 is subjected to operation control such as fuel injection control, ignition control, intake air amount adjustment control and the like. 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 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.

  The motor MG1 and the motor MG2 are both configured as well-known synchronous generator motors that can be driven as generators and can be driven as motors, and exchange power with the battery 50 via inverters 41 and 42. The power line 54 connecting the inverters 41 and 42 and the battery 50 is configured as a positive electrode bus and a negative electrode bus shared by the inverters 41 and 42, and the electric power generated by one of the motors MG1 and MG2 It can be consumed by a motor. Therefore, battery 50 is charged / discharged by electric power generated from one of motors MG1 and MG2 or insufficient electric power. If the balance of electric power is balanced by the motors MG1 and MG2, the battery 50 is not charged / discharged. 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 to be applied is input, and a switching control signal to the inverters 41 and 42 is output from the motor ECU 40. 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.

  The battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52. The battery ECU 52 receives signals necessary for managing the battery 50, for example, a voltage between terminals from a voltage sensor (not shown) installed between terminals of the battery 50, and a power line 54 connected to the output terminal of the battery 50. The charging / discharging current from the attached current sensor (not shown), the battery temperature Tb from the temperature sensor 51 attached to the battery 50, and the like are input. Output to the control unit 70. Further, the battery ECU 52 calculates the remaining capacity (SOC) based on the integrated value of the charging / discharging current detected by the current sensor in order to manage the battery 50, and calculates the remaining capacity (SOC) and the battery temperature Tb. The input / output limits Win and Wout, which are the maximum allowable power that may charge / discharge the battery 50, are calculated based on the above. The input / output limits Win and Wout of the battery 50 are set to the basic values of the input / output limits Win and Wout based on the battery temperature Tb, and the output limiting correction coefficient and the input are set based on the remaining capacity (SOC) of the battery 50. It can be set by setting a correction coefficient for restriction and multiplying the basic value of the set input / output restrictions Win and Wout by the correction coefficient. FIG. 2 shows an example of the relationship between the battery temperature Tb and the input / output limits Win, Wout, and FIG. 3 shows an example of the relationship between the remaining capacity (SOC) of the battery 50 and the correction coefficients of the input / output limits Win, Wout.

  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 an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. The accelerator pedal opening Acc from the vehicle, the brake pedal position BP from the brake pedal position sensor 86 for detecting 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. 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.

  Next, the operation of the hybrid vehicle 20 of the embodiment configured as described above, particularly the operation accompanying the intermittent operation of the engine 22 will be described. FIG. 4 is a flowchart showing an example of a drive control routine executed by the hybrid electronic control unit 70. This routine is repeatedly executed every predetermined time (for example, every several msec).

  When the drive control routine is executed, first, the CPU 72 of the hybrid electronic control unit 70 first determines the accelerator opening Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 88, the rotational speed Ne of the engine 22, the motor MG1. , MG2 rotation speeds Nm1, Nm2, and input / output limits Win, Wout of the battery 50, etc. are input (step S100). Here, the rotation speed Ne of the engine 22 is calculated based on a signal from a crank position sensor (not shown) and is input from the engine ECU 24 by communication. 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. Further, the input / output limits Win and Wout of the battery 50 are set based on the battery temperature Tb of the battery 50 and the remaining capacity (SOC) of the battery 50 and input from the battery ECU 52 by communication.

  When the data is thus input, 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 input accelerator opening Acc and the vehicle speed V. And the required power Pe * required for the vehicle is set (step S110). 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 Pe * can be calculated as the sum of the set required torque Tr * multiplied by the rotational speed Nr of the ring gear shaft 32a and the charge / discharge required power Pb * required by the battery 50 and the loss Loss. The rotational speed Nr of the ring gear shaft 32a is obtained by multiplying the vehicle speed V by a conversion factor k (Nr = k · V), or the rotational speed Nm2 of the motor MG2 is divided by the gear ratio Gr of the reduction gear 35 (Nr = Nm2 / Gr).

  Subsequently, it is determined whether or not the engine 22 is in operation (step S120). When the engine 22 is in operation, whether the set required power Pe * is less than a stop determination threshold value Pstop for stopping the operation of the engine 22 or not. It is determined whether or not (step S130). Here, the stop determination threshold value Pstop is set as a value in the vicinity of the lower limit value of the power region in which the engine 22 can be operated relatively efficiently by a stop determination threshold setting routine described later.

  When the required power Pe * is equal to or greater than the stop determination threshold value Pstop, it is determined that the operation of the engine 22 should be continued, and the target rotation as an operation point at which the engine 22 should be operated based on the set required power Pe * of the engine 22 A number Ne * and a target torque Te * are set (step S140). This setting is performed based on an operation line for efficiently operating the engine 22 and the required power Pe *. FIG. 6 shows an example of the operation line of the engine 22 and how the target rotational speed Ne * and the target torque Te * are set. As shown in the figure, the target rotational speed Ne * and the target torque Te * can be obtained from the intersection of the operation line and a curve with a constant required power Pe * (Ne * × Te *).

  Next, the target rotational speed Nm1 * of the motor MG1 is calculated by the following equation (1) using the target rotational speed Ne * of the engine 22, the rotational speed Nm2 of the motor MG2, and the gear ratio ρ of the power distribution and integration mechanism 30. Based on the calculated target rotational speed Nm1 * and the input rotational speed Nm1 of the motor MG1, a torque command Tm1 * to be output from the motor MG1 is calculated by the equation (2) (step S150). Here, Expression (1) is a dynamic relational expression for the rotating element of the power distribution and integration mechanism 30. FIG. 7 is a collinear diagram showing a dynamic relationship between the rotational speed and torque in the rotating elements of the power distribution and integration mechanism 30 when traveling with the power output from 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 (1) can be easily derived by using this alignment chart. The two thick arrows on the R axis indicate that the torque Tm1 output from the motor MG1 acts on the ring gear shaft 32a and the torque Tm2 output from the motor MG2 acts on the ring gear shaft 32a via the reduction gear 35. Torque. Expression (2) is a relational expression in feedback control for rotating the motor MG1 at the target rotational speed Nm1 *. In Expression (2), “k1” in the second term on the right side is a gain of a proportional term. “K2” in the third term on the right side is the gain of the integral term.

Nm1 * = Ne * ・ (1 + ρ) / ρ-Nm2 / ρ (1)
Tm1 * = ρ ・ Te * / (1 + ρ) + k1 (Nm1 * -Nm1) + k2∫ (Nm1 * -Nm1) dt (2)

  Then, by adding the torque command Tm1 * divided by the gear ratio ρ of the power distribution and integration mechanism 30 to the required torque Tr *, a temporary torque Tm2tmp that is a temporary value of the torque to be output from the motor MG2 is expressed by the following equation (3). (Step S160), and deviation from the power consumption (generated power) of the motor MG1 obtained by multiplying the input / output limits Win, Wout of the battery 50 and the set torque command Tm1 * by the current rotational speed Nm1 of the motor MG1. Is divided by the number of rotations Nm2 of the motor MG2 to calculate torque limits Tm2min and Tm2max as upper and lower limits of the torque that may be output from the motor MG2 by the following equations (4) and (5) (step S170). The set temporary torque Tm2tmp is limited by the torque limits Tm2min and Tm2max by the equation (6), and the motor M 2 to set the torque command Tm2 * (step S180). Here, Expression (3) can be easily derived from the alignment chart of FIG.

Tm2tmp = (Tr * + Tm1 * / ρ) / Gr (3)
Tm2min = (Win-Tm1 * ・ Nm1) / Nm2 (4)
Tm2max = (Wout-Tm1 * ・ Nm1) / Nm2 (5)
Tm2 * = max (min (Tm2tmp, Tm2max), Tm2min) (6)

  Thus, when the target engine speed Ne *, the target torque Te *, and the torque commands Tm1 *, Tm2 * of the motors MG1, MG2 are set, the target engine speed Ne * and the target torque Te * of the engine 22 are set in the engine ECU 24. Torque commands Tm1 * and Tm2 * for motors MG1 and MG2 are transmitted to motor ECU 40 (step S190), and the drive control routine is terminated. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * controls the intake air amount in the engine 22 so that the engine 22 is operated at the operating point indicated by the target rotational speed Ne * and the target torque Te *. Controls such as fuel injection control and ignition control. Further, the motor ECU 40 that has received the torque commands Tm1 * and Tm2 * 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 *. To do. By such control, the engine 22 can be efficiently operated within the range of the input / output limits Win and Wout of the battery 50, and the required torque Tr * can be output to the ring gear shaft 32a as a drive shaft to travel.

  When it is determined in step S130 that the required power Pe * is less than the stop determination threshold value Pstop, it is determined that the operation of the engine 22 should be stopped, the fuel injection control and the ignition control are stopped, and the operation of the engine 22 is stopped. A control signal is transmitted to the engine ECU 24 to stop the engine 22 (step S200), and a value 0 is set to the torque command Tm1 * of the motor MG1 (step S210). Then, a value obtained by dividing the required torque Tr * by the gear ratio Gr of the reduction gear 35 is set as a temporary torque Tm2tmp which is a temporary value of torque to be output from the motor MG2 (step S220), and a torque command Tm1 * having a value of 0 is set. Is substituted into the above formulas (4) and (5) to calculate the torque limits Tm2min and Tm2max of the motor MG2 (step S230), and the temporary torque Tm2tmp is limited by the torque limits Tm2min and Tm2max according to the formula (6). The torque command Tm2 * of the motor MG2 is set (step S240), the set torque commands Tm1 * and Tm2 * are transmitted to the motor ECU 40 (step S250), and this routine is finished. By such control, the operation of the engine 22 is stopped, and the required torque Tr * can be output to the ring gear shaft 32a as the drive shaft within the range of the input / output limits Win and Wout of the battery 50 from the motor MG2.

  If it is determined in step S120 that the engine 22 is not operating, that is, the engine 22 is stopped, whether or not the engine 22 is being started (step S260) and the required power Pe * is to start the engine 22. It is determined whether or not the start determination threshold value Pstart is greater than or equal to (step S270). Here, as the start determination threshold value Pstart, a value in the vicinity of the lower limit value of the power region in which the engine 22 can be operated relatively efficiently can be used. However, frequent start and stop of the engine 22 occur. A value larger than the stop determination threshold value Pstop for stopping the operation of the engine 22 is used so as not to be present. When the engine 22 is not being started and the required power Pe * is less than the start determination threshold value Pstart, it is determined that the operation stop state of the engine 22 should be continued, and the above-described steps S210 to S250 are executed.

  When it is determined in step S120 that the engine 22 has been stopped, in step S260 it is determined that the engine 22 is not being started, and in step S270 it is determined that the required power Pe * is greater than or equal to the start determination threshold value Pstart. 22 is determined to be started, and a torque command Tm1 * of the motor MG1 is set based on a torque map at the time of starting and an elapsed time t from the start of starting of the engine 22. (Step S280). FIG. 8 shows an example of a torque map that is set in the torque command Tm1 * of the motor MG1 when the engine 22 is started, and an example of how the rotational speed Ne of the engine 22 changes. 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. Since the time when the engine 22 is started is considered, a torque value Tm1 * for the motor MG1 is set with a rate value used for rate processing.

  When the torque command Tm1 * of the motor MG1 is set in this way, the torque TOR to be output from the motor MG2 by adding the torque command Tm1 * of the motor MG1 divided by the gear ratio ρ of the power distribution and integration mechanism 30 to the required torque Tr *. The temporary torque Tm2tmp which is the value of the motor MG2 is calculated by the above equation (3) (step S290), and the torque limits Tm2min and Tm2max of the motor MG2 are calculated using the above equations (4) and (5) (step S290). S300), the temporary torque Tm2tmp is limited by the torque limits Tm2min and Tm2max according to the above-described equation (6), and the torque command Tm2 * of the motor MG2 is set (step S310). (Step S320).

  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 for starting the fuel injection control and the ignition control (step S330). Since the start of the engine 22 is now considered, the rotational speed Ne of the engine 22 is small and has not reached the rotational speed Nref. For this reason, a negative conclusion is made in this determination, and this routine is terminated without starting the fuel injection control and the ignition control.

  When the engine 22 is started, it is determined in step S260 that the engine 22 is being started. Therefore, the processes in steps S280 to S320 described above are executed, and the rotational speed Ne of the engine 22 is controlled by fuel injection control or ignition. After waiting for the engine speed Nref to be reached to start the control (step S330), a control signal is transmitted to the engine ECU 24 so that the fuel injection control and the ignition control are started (step S340). With this control, the engine 22 that is stopped can be driven to output the required torque Tr * to the ring gear shaft 32a as the drive shaft within the range of the input / output limits Win and Wout of the battery 50 from the motor MG2. it can. FIG. 9 shows an example of a collinear diagram showing the dynamic relationship between the rotational speed and torque in the rotating elements of the power distribution and integration mechanism 30 when the engine 22 is running while being motored.

  Next, processing for setting the stop determination threshold value Pstop for stopping the operation of the engine 22 will be described. FIG. 10 is a flowchart illustrating an example of a stop determination threshold value setting routine executed in parallel with the drive control routine described above by the hybrid electronic control unit 70 according to the embodiment. This routine is repeatedly executed every predetermined time (for example, every several msec).

  When the stop determination threshold setting routine is executed, the CPU 72 of the hybrid electronic control unit 70 first determines whether or not the engine 22 is in operation (step S400), and determines that the engine 22 is not in operation. When it is done, the value of the flag F is checked (step S410). When the engine 22 is not in operation and the flag F has a value 1, it is determined that the engine 22 has just been stopped, the flag F is set to a value 0 (step S420), and the timer T is reset (step S430). . After resetting the timer T or when the flag F has a value of 0, the stop determination threshold value Pstop is set to the value P1 (step S440), and this routine is terminated. Here, the value P1 is set to a sufficiently small value with respect to the start determination threshold value Pstart so that the engine 22 is not frequently started and stopped due to a slight change in the required power Pe *.

  When it is determined in step S400 that the engine 22 is in operation, the value of the flag F is checked (step S450). When the flag F is 0, it is determined that the engine 22 has just started, and the flag F is set to the value 1 (Step S460) and the timer T is started (step S470). After the timer T is started or when the flag F is determined to be 1 in step S450, the value of the timer T is compared with the threshold value Tref (step S480), and when the timer T is less than the threshold value Tref, the value of the timer T is set. Based on this, the stop determination threshold value Pstop is set (step S490), and this routine is terminated. When the timer T is equal to or greater than the threshold value Tref, the stop determination threshold value Pstop is set to a value P2 (step S500). finish. Here, as the stop determination threshold value Pstop when the engine 22 is in operation and the value of the timer T is less than the threshold value Tref, the relationship between the timer T value and the stop determination threshold value Pstop is obtained in advance and stored in the ROM 74 as a map. The stored stop determination threshold value Pstop is derived from the map when the value of the timer T is given and set. An example of this map is shown in FIG. As shown in the figure, the stop determination threshold value Pstop is set so as to increase as the timer T value increases from immediately after the engine 22 is started until the timer T value becomes equal to or greater than the threshold value Tref, that is, to the start determination threshold value Pstart. Approached. As described above, since the start determination threshold value Pstart and the stop determination threshold value Pstop are set so that the start and stop of the engine 22 with respect to the required power Pe * have hysteresis, the slight change in the required power Pe * is set. Therefore, the engine 22 is not frequently started and stopped. However, such hysteresis does not stop the operation of the engine 22 depending on the required power Pe *, and continues the operation of the engine 22 in an inefficient region, resulting in a deterioration in fuel consumption. Therefore, immediately after the engine 22 is started, the hysteresis is increased to make it difficult to stop the engine 22 so that the start and stop of the engine 22 are not repeated in a short time. When a relatively long time has elapsed, the hysteresis is reduced to facilitate the operation stop of the engine 22 so that the operation of the engine 22 is continued in an inefficient region for a long time so that the fuel consumption is not deteriorated. It is doing so.

  FIG. 12 shows how the engine state, the start determination threshold value Pstart, and the stop determination threshold value Pstop change with time. As shown in the figure, when the required power Pe * becomes equal to or greater than the start determination threshold value Pstart while the engine 22 is stopped, the engine 22 starts to be started (time t12), and when the engine 22 starts. (Time t22), the stop determination threshold value Pstop is set to a value P1 having the largest hysteresis with respect to the start determination threshold value Pstart. As a result, immediately after the engine 22 is started, it is difficult for the engine 22 to stop operating due to a slight change in the required power Pe *. When the start of the engine 22 is completed, the timer T starts, and the stop determination threshold value Pstop gradually increases as the value of the timer T increases. When the value of the timer T becomes equal to or greater than the threshold value Tref (time t23), It is set to a value P2 with the smallest hysteresis with respect to the start determination threshold value Pstart. When the requested power Pe * becomes less than the stop determination threshold value Pstop (time t24), the engine 22 stop process is started and the engine 22 is stopped. As described above, when a relatively long time has elapsed since the engine 22 was started, the engine 22 is likely to be stopped. Therefore, the fuel consumption is deteriorated due to the engine 22 being operated in an inefficient region for a long time. Can be suppressed.

  According to the hybrid vehicle 20 of the embodiment described above, the stop for stopping the operation of the engine 22 immediately after the required power Pe * becomes equal to or greater than the start determination threshold value Pstart for starting the engine 22 and the engine 22 is started. The time after the engine 22 is started by making the determination threshold value Pstop set to a value P1 with increased hysteresis with respect to the start determination threshold value Pstart to make it difficult for the engine 22 to be shut down in response to a change in the required power Pe *. Since the stop determination threshold value Pstop is set so that the hysteresis becomes smaller with respect to the start determination threshold value Pstart with the elapse of time so that the engine 22 can be easily stopped, the engine 22 is not frequently started and stopped. At the same time, the deterioration of fuel consumption caused by the continued operation of the engine 22 in the inefficient area It is possible to win.

  In the hybrid vehicle 20 of the embodiment, as shown in FIG. 11, when the required power Pe * is equal to or greater than the start determination threshold value Pstart and the engine 22 is started, the value increases linearly with the passage of time from the start. The stop determination threshold value Pstop is set so that the value increases, but it is not always necessary to set the stop determination threshold value Pstop so that the value increases linearly, and the stop determination threshold value Pstop is set so that the value increases in a curve. The stop determination threshold value Pstop may be set so that the value increases stepwise, or the stop determination is performed so that the value increases at a time when the timer T becomes equal to or greater than the threshold value Tref. The threshold value Pstop for use may be set.

  In the hybrid vehicle 20 of the embodiment, when the required power Pe * is equal to or greater than the start determination threshold value Pstart and the engine 22 is started, the stop determination is made so that the hysteresis becomes smaller with respect to the start determination threshold value Pstart with the passage of time from the start. The threshold value Pstop is set. However, in addition to the setting of the stop determination threshold value Pstop, when the required power Pe * is less than the stop determination threshold value Pstop and the operation of the engine 22 is stopped, the time elapsed from the stoppage of operation. At the same time, the start determination threshold value Pstart may be set so that the hysteresis becomes smaller than the stop determination threshold value Pstop. In this case, the start determination threshold value Pstart may be set so that the value decreases linearly as time elapses from the stop of operation, or the start determination threshold value Pstart is set so that the value decreases in a curve. Alternatively, the start determination threshold value Pstart may be set so that the value decreases stepwise, or the start determination threshold value Pstart is set so that the value decreases at a time when the elapsed time exceeds a predetermined time. It may be set.

  In the hybrid vehicle 20 of the embodiment, the present invention is applied to the determination of the start and stop of the engine 22 with hysteresis based on the required power Pe *, but the start and operation of the engine 22 with hysteresis based on the vehicle speed V. It is good also as what applies to what determines a stop.

  In the hybrid vehicle 20 of the embodiment, the motor MG2 is attached to the ring gear shaft 32a as the drive shaft via the reduction gear 35. However, the motor MG2 may be directly attached to the ring gear shaft 32a, or Instead, the motor MG2 may be attached to the ring gear shaft 32a via a transmission such as a 2-speed, 3-speed, or 4-speed.

  In the hybrid vehicle 20 of the embodiment, the power of the motor MG2 is changed by the reduction gear 35 and output to the ring gear shaft 32a. However, as illustrated in the hybrid vehicle 120 of the modification of FIG. May be connected to an axle (an axle connected to the wheels 64a and 64b in FIG. 13) different from an axle to which the ring gear shaft 32a is connected (an axle to which the drive wheels 63a and 63b are connected).

  In the hybrid vehicle 20 of the embodiment, the power of the engine 22 is output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b via the power distribution and integration mechanism 30, but the modified example of FIG. The hybrid vehicle 220 includes an inner rotor 232 connected to the crankshaft 26 of the engine 22 and an outer rotor 234 connected to a drive shaft that outputs power to the drive wheels 63a and 63b. A counter-rotor motor 230 that transmits a part of the power to the drive shaft and converts the remaining power into electric power may be provided.

  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 combination of the motor MG1 and the power distribution and integration mechanism 30 corresponds to “power power input / output means”, the motor MG2 corresponds to “electric motor”, and the accelerator is opened. The hybrid electronic control unit 70 that executes step S110 of the drive control routine of FIG. 4 for setting the required torque Tr * based on the degree Acc and the vehicle speed V corresponds to “required torque setting means”, and the engine 22 is in operation. 4 is compared with the threshold value Pstart for starting determination to determine whether or not to stop the operation of the engine 22. Steps S120 and S130 of the drive control routine of FIG. Steps S260 and S270 for determining whether or not to start the engine 22 by comparing * and the stop determination threshold value Pstop are executed. The hybrid electronic control unit 70 that corresponds to the “operation stop determination means” and the hybrid electronic control unit 70 that executes the stop determination threshold setting routine of FIG. 10 for setting the stop determination threshold Pstop is the “hysteresis setting means”. When the engine 22 is operated, the required power Pe * is output from the engine 22 and the required torque Tr * is output to the ring gear shaft 32a, and the target rotational speed Ne * and target torque Te * of the engine 22 and the motor Torque commands Tm1 * and Tm2 * of MG1 and MG2 are set and transmitted to the engine ECU 24 and the motor ECU 40. When the engine 22 is stopped, the engine 22 is stopped and the required torque Tr * is output to the ring gear shaft 32a. Set torque commands Tm1 * and Tm2 * A motor ECU40 for controlling the motor MG1, MG2 based engine ECU24 and the torque command Tm1 *, the Tm2 * of controlling the hybrid electronic control unit 70 and the engine 22 to be transmitted to the motor ECU40 Te corresponds to a "control unit". Further, step S110 of the drive control routine of FIG. 4 sets the required power Pe * required for the engine 22 based on the required torque Tr *, the rotation speed Nr of the ring gear shaft 32a, and the charge / discharge required power Pb * of the battery 50. The hybrid electronic control unit 70 that executes is equivalent to “required power setting means”. The motor MG1 corresponds to a “generator”, and the power distribution and integration mechanism 30 corresponds to a “three-axis power input / output unit”. Further, the counter-rotor motor 230 also corresponds to “power power input / output 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 “power power input / output means” is not limited to the combination of the power distribution and integration mechanism 30 and the motor MG1 or the anti-rotor motor 230, but includes an output shaft of the internal combustion engine and a drive shaft connected to the axle. As long as the torque can be input / output to / from the output shaft of the internal combustion engine by the input / output of electric power and power using the reaction force on the driving shaft side. 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 “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. In the case where the travel route is preset, the required torque is set based on the travel position on the travel route, as long as the required torque required for the drive shaft is set. Absent. As the “operation stop determination means”, when the engine 22 is operating and the required power Pe * is less than the stop determination threshold Pstop, the engine 22 is determined to stop operating, and the engine 22 is stopped and the required power Pe * is started. The engine 22 is not limited to determining whether to start the engine 22 when it is equal to or higher than the determination threshold value Pstart. When the engine is operating and the vehicle speed is less than the stop determination threshold value, the engine is stopped and the engine is stopped. Among them, any method may be used as long as it determines the operation and stop of the internal combustion engine with hysteresis, such as determining the operation of the engine when the vehicle speed is equal to or higher than the start determination threshold value. The “hysteresis setting means” is limited to the one that sets the stop determination threshold value Pstop so that the elapsed time (timer T) from when the engine 22 is started increases and gradually increases from the value P1 toward the value P2. If the hysteresis is set so as to decrease as the elapsed time from the start becomes longer until the internal combustion engine is stopped next time I do not care. 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. In addition, as the “control means”, when the engine 22 is operated, the required power Pe * is output from the engine 22 and the required torque Tr * is output to the ring gear shaft 32a. When the torque Te * and the torque commands Tm1 *, Tm2 * of the motors MG1, MG2 are set to control the engine 22 and the motors MG1, MG2 to stop the engine 22, the engine 22 is stopped and the required torque Tr * is The torque commands Tm1 * and Tm2 * are set so as to be output to the ring gear shaft 32a, and the motors MG1 and MG2 are not limited to those controlled. When it is determined that the internal combustion engine is operating, the internal combustion engine is operated. The internal combustion engine and electric power so that a torque based on the set required torque is output to the drive shaft. The internal combustion engine and electric power drive input / output means are controlled so that when the output means and the motor are controlled and the internal combustion engine is determined to be stopped, the internal combustion engine is stopped and torque based on the set required torque is output to the drive shaft. As long as it controls the motor and the electric motor, it may be anything. As the “required power setting means”, the required power Pe * required for the engine 22 is set based on the required torque Tr *, the rotational speed Nr of the ring gear shaft 32a, and the charge / discharge required power Pb * of the battery 50. The present invention is not limited, and any configuration may be used as long as the required power required for the vehicle is set based on the required torque. 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. Connected to the three shafts such as the one connected to the shaft or the differential gear, or the like having a different operation from the planetary gear, such as the drive shaft, the output shaft, and the rotating shaft of the generator. As long as the power is input / output to / from the remaining shafts based on the power input / output to / from the power source, any method may be used. 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 automobile 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 explanatory drawing which shows an example of the relationship between the battery temperature Tb in the battery 50, and the input / output restrictions Win and Wout. It is explanatory drawing which shows an example of the relationship between the remaining capacity (SOC) of the battery 50, and the correction coefficient of input / output restrictions Win and Wout. It is a flowchart which shows an example of the drive control routine performed by the electronic control unit for hybrids 70 of an Example. It is explanatory drawing which shows an example of the map for request | requirement torque setting. It is explanatory drawing which shows a mode that an example of the operating line of the engine 22, the target rotational speed Ne *, and the target torque Te * are set. FIG. 3 is an explanatory diagram showing an example of a collinear diagram showing a dynamic relationship between the number of rotations and torque in a rotating element of a power distribution and integration mechanism 30 when traveling with power output from an engine 22; 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. It is explanatory drawing which shows an example of the collinear diagram which shows the dynamic relationship between the rotation speed and torque in the rotation element of the power distribution integration mechanism 30 when drive | working in the state which is motoring the engine 22. FIG. It is a flowchart which shows an example of the threshold value setting routine for a stop determination performed by the hybrid electronic control unit 70 of an Example. It is explanatory drawing which shows an example of the threshold value setting map for a stop determination. It is explanatory drawing which shows the mode of a time change of the engine state, the threshold value Pstart for start determination, and the threshold value Pstop for stop determination. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 220 of a modified example.

Explanation of symbols

  20, 120, 220 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 power distribution 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 rotational position detection sensor, 50 battery, 51 temperature sensor, 52 battery electronic control unit (battery ECU), 54 power line , 60 gear mechanism, 62 differential gear, 63a, 63b drive wheel, 64a, 64b wheel, 70 electronic control unit for hybrid, 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, 230 rotor motor, 232 inner rotor 234 outer rotor, MG1, MG2 motor .

Claims (7)

An internal combustion engine;
Connected to the drive shaft connected to the axle and connected to the output shaft of the internal combustion engine so as to be rotatable independently of the rotation of the drive shaft, and the output shaft and the drive shaft by input and output of electric power and power Power input / output means capable of inputting and outputting torque to
An electric motor capable of inputting and outputting power to the drive shaft;
Requested torque setting means for setting a requested torque required for the drive shaft;
Operation stop determination means for determining operation and operation stop of the internal combustion engine with hysteresis;
A hysteresis setting means for setting the hysteresis so that the longer the elapsed time from the start until the internal combustion engine is next stopped when the internal combustion engine that has been stopped is started,
When it is determined that the internal combustion engine is in operation, the internal combustion engine, the power power input / output means, and the electric motor are output so that a torque based on the set required torque is output to the drive shaft along with the operation of the internal combustion engine. When the internal combustion engine is determined to stop operating, the internal combustion engine is stopped and the power input / output to / from the internal combustion engine is output so that torque based on the set required torque is output to the drive shaft. Control means for controlling the means and the motor;
A hybrid car with   The hysteresis setting means is means for setting the hysteresis such that when the operating internal combustion engine is stopped, the hysteresis tends to decrease as the elapsed time from the stop of the operation becomes longer until the internal combustion engine is started next time. Item 1. The hybrid vehicle according to item 1.   The hybrid vehicle according to claim 1, wherein the hysteresis setting means is means for setting the hysteresis so that the hysteresis gradually decreases as the elapsed time increases. A hybrid vehicle according to any one of claims 1 to 3,
A required power setting means for setting a required power required for the vehicle based on the set required torque,
The operation stop determination means is means for determining operation and operation stop of the internal combustion engine with hysteresis based on the set required power.
When it is determined that the internal combustion engine is operating, the control means outputs the set required power from the internal combustion engine and outputs a torque based on the set required torque to the drive shaft. The engine, the power power input / output means and the motor are controlled, and when it is determined that the operation of the internal combustion engine is stopped, the internal combustion engine is stopped and torque based on the set required torque is output to the drive shaft. A hybrid vehicle which is means for controlling the internal combustion engine, the electric power drive input / output means and the electric motor. The hybrid vehicle according to claim 4,
The operation stop determination means determines that the internal combustion engine is operating when the set required power becomes equal to or greater than a first threshold while the internal combustion engine is stopped, and the setting is performed while the internal combustion engine is operating. Means for determining that the internal combustion engine has stopped operating when the requested power is less than a second threshold value that is smaller than the first threshold value;
The hysteresis setting means is means for setting the first threshold and / or the second threshold. Hybrid vehicle.   The electric power drive input / output means is connected to three axes of a generator capable of inputting / outputting power, an output shaft of the internal combustion engine, a rotating shaft of the generator and the axle side, and any of the three shafts The hybrid vehicle according to any one of claims 1 to 5, wherein the hybrid vehicle includes means for inputting / outputting power to the remaining one shaft based on power input / output to / from the two shafts. An internal combustion engine is connected to a drive shaft connected to an axle and is connected to an output shaft of the internal combustion engine so as to be rotatable independently of the rotation of the drive shaft. A control method for a hybrid vehicle comprising: electric power input / output means capable of inputting / outputting torque to / from a drive shaft; and an electric motor capable of inputting / outputting power to / from the drive shaft,
(A) setting a required torque required for the drive shaft;
(B) determining operation and shutdown of the internal combustion engine with hysteresis;
(C) When the internal combustion engine that has been stopped is started, the hysteresis is set so that the longer the elapsed time from the start until the internal combustion engine is next stopped, the smaller the hysteresis is;
(D) when it is determined that the internal combustion engine is in operation, the internal combustion engine and the power power input / output means so that a torque based on the set required torque is output to the drive shaft along with the operation of the internal combustion engine. The internal combustion engine and the electric power are controlled so that the internal combustion engine is stopped when it is determined that the operation of the internal combustion engine is stopped, and the torque based on the set required torque is output to the drive shaft. A hybrid vehicle control method for controlling power input / output means and the electric motor.

Images