JP4241710B2 - Vehicle and control method thereof - Google Patents

Description

  The present invention relates to a vehicle and a vehicle control method for controlling the vehicle.

Conventionally, as this type of vehicle, an engine output shaft, a generator and a planetary gear mechanism having three rotating elements connected to the drive output shaft, an electric motor connected to the drive output shaft, a generator and an electric motor, A hybrid vehicle including a battery that exchanges electric power is known (see, for example, Patent Document 1). During steady running of the vehicle, the engine is controlled so that power corresponding to the required power is output, and all of the power output from the engine is torque-converted by the planetary gear mechanism, the generator, and the motor to drive the drive output shaft. The generator and the motor are controlled so as to be output to each other.
JP-A-10-295003

  By the way, in the vehicle as described above, it is possible to drive the engine at an arbitrary driving point. Therefore, while the driving force for driving the vehicle to the drive output shaft is being output, By adjusting the power (torque) output to the output shaft of the engine and changing the engine speed, the driver feels like a shift in a vehicle with a stepped automatic transmission. can do. However, if the power output from the generator is reduced to increase the engine speed, the generated power of the generator is reduced, so that part of the power consumed by the motor is compensated for by the power storage device. It is necessary to cover the discharge. At this time, depending on the state of the power storage device, sufficient power may not be supplied from the power storage device to the motor, and a driving force corresponding to the required driving force may not be obtained.

  Therefore, a vehicle and a control method thereof according to the present invention are for causing a vehicle to travel when the rotational speed of an internal combustion engine is changed while the vehicle is traveling by a driving force based on a required driving force required for traveling. One of the purposes is to suppress a decrease in driving force. Another object of the vehicle and the control method thereof according to the present invention is to suppress charging / discharging due to excessive electric power of the power storage device when the rotational speed of the internal combustion engine is changed.

  The vehicle and the control method thereof according to the present invention employ the following means in order to achieve at least one of the above objects.

The vehicle according to the present invention is
An internal combustion engine;
An electric power input unit that is connected to a first axle as one of the axles of the vehicle and an output shaft of the internal combustion engine and that can input and output power to and from the first axle and the output shaft with input and output of electric power and power. Output means;
An electric motor capable of inputting / outputting power to / from a second axle that is either the first axle or an axle different from the first axle;
Power storage means capable of exchanging power between the power drive input / output means and the electric motor;
An input / output limit setting means for setting an input / output limit of power for the power storage means based on the state of the power storage means;
A required driving force setting means for setting a required driving force required for traveling;
When the rotational speed of the internal combustion engine is changed by the electric power input means according to the establishment of a predetermined change condition during traveling by the driving force based on the set required driving force, until a predetermined release condition is satisfied, A driving force based on the set required driving force within a range of the corrected input / output limit while the rotational speed of the internal combustion engine is changed with a correction to expand the set input / output limit of the power storage unit Control means for controlling the internal combustion engine, the power drive input / output means and the electric motor so that
Is provided.

  In this vehicle, the power input / output restriction for the power storage means is set based on the state of the power storage means, the required driving force required for traveling is set, and the driving force based on the set required driving force is used. When the rotational speed of the internal combustion engine is changed by the electric power input means in response to the establishment of a predetermined change condition during traveling, there is a correction that expands the set input / output limit of the power storage means until the predetermined release condition is satisfied. Then, the internal combustion engine, the power drive input / output means, and the electric motor are controlled so that the rotational speed of the internal combustion engine is changed and the driving force based on the required driving force is output within the corrected input / output limit range. As described above, when the rotational speed of the internal combustion engine is changed by the power power input / output means during traveling of the vehicle based on the driving force based on the required driving force, the input / output limit of the power storage means is expanded until a predetermined release condition is satisfied. If correction is performed, even if the power output from the power drive input / output means changes, it is possible to supply sufficient power from the power storage means to the electric motor to suppress a decrease in driving force. In this vehicle, the correction for expanding the input / output range of the power storage means is limited to the time from when the predetermined change condition is satisfied until the predetermined release condition is satisfied. Can be suppressed.

  Further, the release condition may be that the change of the rotational speed of the internal combustion engine is substantially completed. As a result, from the establishment of the predetermined change condition until the change of the rotational speed of the internal combustion engine is almost completed, the input / output limit of the power storage output stage is expanded to suppress a decrease in driving force for driving the vehicle. Is possible.

  Further, the release condition may be that a predetermined time elapses after the change condition is satisfied. In this way, regardless of whether or not the change of the rotational speed of the internal combustion engine is almost completed, the input / output limit of the storage output stage is increased until a predetermined time elapses after the change condition is satisfied, thereby It is possible to suppress deterioration of the power storage means by suppressing charging / discharging by the necessary electric power to a necessary minimum.

  The vehicle according to the present invention may further include shift setting means for setting a shift position for determining a relationship between a vehicle speed of the internal combustion engine and a rotation speed of the internal combustion engine, and the change condition is the shift setting. Different shift positions may be set depending on the means. As a result, when the rotational speed of the internal combustion engine is changed so as to give the driver a sense of shift according to the change of the shift position, it is possible to suppress a decrease in driving force for running the vehicle.

  In this case, the change condition may be that a shift position is set on the downshift side by the shift setting means. As a result, when the rotational speed of the internal combustion engine is increased in response to a downshift, even if the power output from the power drive input / output means decreases, sufficient power is supplied from the power storage means to the motor to reduce the driving force. Can be suppressed.

  The shift setting means may set the shift position in accordance with a driver's shift operation. Thereby, when changing the rotation speed of an internal combustion engine according to a driver | operator's downshift request | requirement, it becomes possible to suppress the fall of the driving force for making a vehicle drive | work.

  The power power input / output means is connected to the first axle, the output shaft of the internal combustion engine, and a rotatable third shaft, and is used for power input / output to any two of these three shafts. There may be provided three-axis power input / output means for inputting / outputting power determined on the basis of the remaining shaft, and a generator capable of inputting / outputting power to / from the third shaft.

The vehicle control method according to the present invention includes an internal combustion engine, a first axle that is one of the axles of the vehicle, and an output shaft of the internal combustion engine. Electric power input / output means capable of inputting / outputting power to / from the output shaft; an electric motor capable of inputting / outputting power to / from a second axle which is either the first axle or an axle different from the first axle; A vehicle control method comprising power input / output means and power storage means capable of exchanging electric power with the electric motor,
(A) setting power input / output restrictions for the power storage means based on the state of the power storage means;
(B) The rotational speed of the internal combustion engine is changed by the electric power input means according to the establishment of a predetermined change condition while the vehicle is running with a driving force based on the required driving force required for running. In some cases, the rotational speed of the internal combustion engine is changed with a correction that expands the set input / output limit of the power storage unit until a predetermined release condition is satisfied, and within the corrected input / output limit range. Controlling the internal combustion engine, the power drive input / output means, and the electric motor so that a driving force based on a set required driving force is output;
Is included.

  According to this vehicle control method, the power input / output limit for the power storage means is set based on the state of the power storage means, and the vehicle travels with the driving force based on the required driving force required for traveling. When changing the rotational speed of the internal combustion engine by the electric power input means in response to the establishment of the predetermined change condition, the correction for expanding the input / output limit of the power storage means is performed until the predetermined release condition is satisfied. The internal combustion engine, the power power input / output means, and the electric motor so that a driving force based on the set required driving force is output within a range of the corrected input / output restriction while the rotational speed of the internal combustion engine is changed And are controlled. As a result, even when the power output from the power power input / output means changes when the rotational speed of the internal combustion engine is changed by the power power input / output means, sufficient power is supplied from the power storage means to the motor to drive the driving force. Can be suppressed. Further, since the correction for expanding the input / output range of the power storage means is limited to the time from when the predetermined change condition is satisfied until the predetermined release condition is satisfied, charging / discharging due to excessive electric power of the power storage device is suppressed. Can do.

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

  FIG. 1 is a schematic configuration diagram 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 (hereinafter referred to as “hybrid ECU”) 70 for controlling the entire power output apparatus.

  The engine 22 is an internal combustion engine that outputs power using hydrocarbon fuel such as gasoline or light oil, and an engine electronic control unit (hereinafter referred to as “engine ECU”) that inputs signals from various sensors that detect the operating state of the engine 22. ) 24) is under operation control such as fuel injection control, ignition control, and intake air amount adjustment control. The engine ECU 24 communicates with the hybrid ECU 70, controls the operation of the engine 22 by a control signal from the hybrid ECU 70, and outputs data related to the operation state of the engine 22 to the hybrid ECU 70 as necessary.

  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. 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. The power distribution and integration mechanism 30 includes the motor MG1. 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.

  Both the motor MG1 and the motor MG2 are configured as well-known synchronous generator motors that can operate as a generator and operate as an electric motor, 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 bus and a negative bus shared by the inverters 41 and 42, and the power generated by any one of the motors MG 1 and MG 2 It can be consumed by a motor. Therefore, the battery 50 is charged / discharged by electric power generated from one of the 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 “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 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 ECU 70, controls the driving of the motors MG1, MG2 by a control signal from the hybrid ECU 70, and outputs data related to the operating state of the motors MG1, MG2 to the hybrid ECU 70 as necessary.

  The battery 50 is managed by a battery electronic control unit (hereinafter referred to as “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 the 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, and the battery ECU 52 communicates data regarding the state of the battery 50 as necessary. Is output to the hybrid ECU 70. The battery ECU 52 also calculates the remaining capacity (SOC) based on the integrated value of the charge / discharge current detected by the current sensor in order to manage the battery 50.

  The hybrid ECU 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 that stores a processing program, a RAM 76 that temporarily stores data, and a timer that executes a timing process in response to a timing command. 78, and an input / output port and a communication port (not shown). The hybrid ECU 70 includes an ignition signal from the ignition switch 80, a shift position SP from the shift position sensor 82 that detects the shift position SP that is the operation position of the shift lever 81, and an accelerator pedal position sensor that detects the amount of depression of the accelerator pedal 83. The accelerator opening Acc from 84, 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 ECU 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.

  Here, in the hybrid vehicle 20 of the present embodiment, as the shift position SP of the shift lever 81, the parking position used during parking, the reverse position for reverse travel, the neutral position for neutral travel, the normal D position for forward travel, the 3rd position 2nd position and 1st position are prepared. In the hybrid vehicle 20 of this embodiment, when the D position is selected as the shift position SP, driving control is performed so that the engine 22 is efficiently operated, and the 3rd, 2nd, or 1st position is selected as the shift position SP. In some cases, a configuration simulating so-called sequential shift is adopted in which drive control is performed so that the engine 22 rotates at a rotational speed corresponding to the vehicle speed V and the shift position SP. Thus, for example, when the shift lever 81 is operated by the driver to downshift from the 3rd position to the 2nd position, the rotation speed Ne of the engine 22 is adjusted by adjusting the torque Tm1 output from the motor MG1. Thus, it is possible to give the driving feeling similar to a downshift feeling as a shift feeling in a vehicle equipped with a stepped automatic transmission. For example, when the driver operates the shift lever 81 to upshift from the 2nd position to the 3rd position, the rotational speed Ne of the engine 22 is decreased by increasing the torque Tm1 output from the motor MG1. Thus, it is possible to give the driving feeling similar to an upshift feeling as a shift feeling in a vehicle equipped with a stepped automatic transmission to the drivers. When the accelerator opening is 10% or less and the accelerator is off, the fuel-cut engine 22 is motored by the motor MG1 to forcibly rotate and drive at a rotational speed corresponding to the shift position SP and the vehicle speed V. If the system torque is output to the ring gear shaft 32a as a shaft, a driving feeling similar to a so-called engine brake can be provided to the drivers.

  The hybrid vehicle 20 of the embodiment configured as described above is a request 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. The engine 22, the motor MG <b> 1, and the motor MG <b> 2 are controlled so that the torque is calculated and the required power corresponding to the required torque is output to the ring gear shaft 32 a. As the operation control mode of the engine 22, the motor MG1, and the motor MG2, the engine 22 is operated and controlled so that power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is a power distribution integration mechanism. 30, a 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, the required power and the power required for charging and discharging the battery 50 The operation of the engine 22 is controlled so that the power corresponding to the sum of the 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 and the motor. The required power is ringed with torque conversion by MG1 and motor MG2. Charge / discharge operation mode for driving and controlling the motor MG1 and the motor MG2 to be output to the gear shaft 32a, and the operation to stop the operation of the engine 22 and output the power corresponding to the required power from the motor MG2 to the ring gear shaft 32a. There are motor operation modes to be controlled.

  Next, the operation of the hybrid vehicle 20 of the embodiment, particularly the operation when the shift lever 81 is changed by the driver operating the shift lever 81 will be described. FIG. 2 is a flowchart showing an example of a drive control routine executed by the hybrid electronic control unit 70. This routine is executed every predetermined time (for example, every several msec) when the 3rd, 2nd, or 1st position is selected as the shift position SP by the driver.

  When the drive control routine of FIG. 2 is started, first, the CPU 72 of the hybrid ECU 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, and so on. Input processing of data necessary for control such as the rotational speed Nm1, Nm2 of MG2, the shift position SP from the shift position sensor 82, the charge / discharge required power Pb * to be charged / discharged by the battery 50, and the input / output limits Win, Wout of the battery 50 Is executed (step S100). Here, the rotation speed Ne of the engine 22 is calculated based on a signal from a crank position sensor (not shown) attached to the crankshaft 26 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. The charge / discharge required power Pb * is set based on the remaining capacity (SOC) of the battery 50 and the like, and is input from the battery ECU 52 by communication. Input / output restrictions Win and Wout of the battery 50 are input from the battery ECU 52 by communication from the battery temperature Tb of the battery 50 detected by the temperature sensor 51 and the remaining capacity (SOC) of the battery 50. It was. 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. The limiting correction coefficient is set, and the input / output limits Win and Wout can be set by multiplying the basic value of the set input / output limits Win and Wout by the correction coefficient. FIG. 3 shows an example of the relationship between the battery temperature Tb and the input / output limits Win, Wout, and FIG. 4 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.

  After the data input process in step S100, the required torque Tr * to be output to the ring gear shaft 32a connected to the drive wheels 39a and 39b via the axle 36 based on the input accelerator opening Acc and the vehicle speed V and the engine 22 Is set to the required power Pe * (step S110). In the embodiment, the relationship between the accelerator opening Acc, the vehicle speed V, and the required torque Tr * is determined in advance and stored in the ROM 74 as a required torque setting map. When the accelerator opening Acc and the vehicle speed V are given, the map is displayed. From this, the required torque Tr * corresponding to both is derived and set. An example of the required torque setting map is shown in FIG. In the embodiment, the required power Pe * is set as the sum of the required torque Tr * multiplied by the rotational speed Nr of the ring gear shaft 32a and the charge / discharge required power Pb * to be charged / discharged by the battery 50 and the loss Loss. It was supposed to be. The rotational speed Nr of the ring gear shaft 32a can be obtained by dividing the rotational speed Nm2 of the motor MG2 by the gear ratio Gr of the reduction gear 35, as shown in the figure, or by multiplying the vehicle speed V by the conversion factor k.

  Next, the target rotational speed Ne * of the engine 22 is set based on the shift position SP and the vehicle speed V input in step S100, and the target torque Te * of the engine 22 is set based on the set target rotational speed Ne *. (Step S120). In this embodiment, the relationship between the shift position SP, the vehicle speed V, and the target rotational speed Ne * of the engine 22 is determined in advance and stored in the ROM 74 as a target rotational speed setting map, and the shift position SP and the vehicle speed V are given. If so, the target rotational speed Ne * of the engine 22 corresponding to both is derived from the map and set. An example of the relationship among the shift position SP, the vehicle speed V, and the target rotational speed Ne * is shown in FIG. As shown in the figure, if the vehicle speed V is constant, the rotational speed of the engine 22 is increased as the shift position SP is changed to the downshift side. In the present embodiment, the target torque Te * of the engine 22 is set based on the set target rotational speed Ne * and the required power Pe * set in step S110. If the required power for the engine 22 is constant, the rotational speed and torque of the engine 22 show a correlation as illustrated in FIG. 7, and therefore, in step S120, the required power Pe * (= Ne * × Te *) is constant. The torque value corresponding to the target rotational speed Ne * is set as the target torque Te * from the curve indicating that the

  Subsequently, it is determined whether or not the process accompanying the change of the shift position SP to the downshift side should be executed (steps S130 and S140). In the embodiment, it is determined whether or not the process associated with the downshift can be executed based on the value of the flag F and whether or not the shift position SP is changed to the downshift side (steps S130 and S140). The flag F indicates whether or not processing associated with downshifting is being performed. A value 0 is set as an initial value, and a value 1 is set when the processing is being performed. Further, whether or not a downshift (for example, a change from the 3rd position to the 2nd position) has been made is determined by comparing the current value of the input shift position SP with the previous value. When the flag F is 0 and no downshift has been performed, it is determined that it is not necessary to execute the process associated with the downshift, and the output limit Wout of the battery 50 input in step S100 is determined as the control output limit Wout. * Is set (step S150).

  Further, based on the target rotational speed Ne * set in step S120, the rotational speed Nr (= Nm2 / Gr) of the ring gear shaft 32a, and the gear ratio ρ of the power distribution and integration mechanism 30, the calculation using the following equation (1) is performed. The target rotational speed Nm1 * of the motor MG1 is set, and the torque command Tm1 * of the motor MG1 is set by calculation using the following equation (2) based on the set target rotational speed Nm1 * and the current rotational speed Nm1. (Step S160). Expression (1) is a dynamic relational expression related to the rotating elements of the power distribution and integration mechanism 30. FIG. 8 is a collinear diagram showing a dynamic relationship between the rotational speed and torque for the rotating elements of the power distribution and integration mechanism 30. 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 ring gear 32 (ring gear). The rotational speed Nr of the shaft 32a) is shown. The target rotational speed Nm1 * of the motor MG1 can be easily derived by using the rotational speed relationship in this alignment chart. Accordingly, the engine 22 is rotated at the target rotational speed Ne * by setting the torque command Tm1 * so that the motor MG1 rotates at the target rotational speed Nm1 * obtained from the equation (1) and drivingly controlling the motor MG1. Can do. Expression (2) is a relational expression in the feedback control for rotating the motor MG1 at the target rotational speed Nm1 *. In the expression (2), “k1” in the second term on the right side is the gain of the proportional term, and the right side The third term “k2” is the gain of the integral term. Note that the two bold arrows pointing upward on the R axis in FIG. 8 indicate the torque that is directly transmitted from the engine 22 to the ring gear shaft 32a when the engine 22 is operated at the operation point of the target rotational speed Ne * and the target torque Te *. (−1 / ρ · Tm1 *) and torque Tm2 * · Gr applied from the motor MG2 to the ring gear shaft 32a via the reduction gear 35.

Nm1 * ＝ Ne * ・ (1 + ρ) / ρ−Nm2 / (Gr ・ ρ) (1)
Tm1 * = previous Tm1 * + k1 (Nm1 * −Nm1) + k2∫ (Nm1 * −Nm1) dt (2)

  When the target rotational speed Nm1 * and the torque command Tm1 * of the motor MG1 are set, the control output limit Wout * for the battery 50 set so far and the input limit Win of the battery 50 input in step S100 and the set motor MG1 May be output from the motor MG2 by dividing the deviation from the power consumption (generated power) of the motor MG1 obtained by multiplying the current torque command Tm1 * by the current rotational speed Nm1 of the motor MG1 by the rotational speed Nm2 of the motor MG2. Torque limits Tm2max and Tm2min as upper and lower torque limits are calculated using the following equations (3) and (4) (step S170). Further, a temporary motor torque Tm2tmp as a torque to be output from the motor MG2 is calculated using the required torque Tr *, the torque command Tm1 *, the gear ratio ρ of the power distribution and integration mechanism 30 and the gear ratio Gr of the reduction gear 35. ) (Step S180), and the torque command Tm2 * of the motor MG2 is set by limiting the calculated temporary motor torque Tm2tmp with the torque limits Tm2max and Tm2min (step S190). By setting the torque command Tm2 * of the motor MG2 in this way, the required torque Tr * output to the ring gear shaft 32a is basically set as a torque that is limited within the range of the input / output limits Win and Wout of the battery 50. be able to. Equation (5) can be easily derived from the alignment chart of FIG.

Tmax = (Wout * −Tm1 * ・ Nm1) / Nm2 (3)
Tmin = (Win−Tm1 * ・ Nm1) / Nm2 (4)
Tm2tmp = (Tr * + Tm1 * / ρ) / Gr (5)

  When the target rotational speed Ne * and target torque Te * of the engine 22 and the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are set, the target rotational speed Ne * and the target torque Te * of the engine 22 are sent to the engine ECU 24 and the motor MG1. , MG2 torque commands Tm1 * and Tm2 * are respectively transmitted to the motor ECU 40 (step S200), and the drive control routine is ended once. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * performs fuel injection control on the engine 22 such that the engine 22 is operated at an operating point determined by the target rotational speed Ne * and the target torque Te *. Ignition control etc. are executed. The motor ECU 40 that has received the torque commands Tm1 * and Tm2 * switches the switching elements of the inverters 41 and 42 so that the motor MG1 is driven according to the torque command Tm1 * and the motor MG2 is driven according to the torque command Tm2 *. Take control.

  On the other hand, when it is determined in step S130 that the flag F has a value of 0 and downshift has been performed in step S140, the flag F is set to 1 (step S210) and the engine 22 set in step S120 is set. A deviation ΔNe between the target rotational speed Ne * (current value) and the current rotational speed Ne of the engine 22 input in step S100 is calculated (step S220), and the calculated deviation ΔNe is less than a predetermined threshold value α. It is determined whether or not there is (step S230). The threshold value α used in step S230 is for determining whether or not the rotational speed of the engine 22 that is increased according to the downshift has substantially reached the target rotational speed Ne *, and is a relatively small positive value. Is done. If it is determined in step S230 that the deviation ΔNe is not less than or equal to the predetermined threshold value α, it is determined whether or not a predetermined time t has elapsed since the driver operated the shift lever 81 and downshifted. (Step S240). If it is determined in step S240 that the predetermined time t has not elapsed since the downshift was performed, the output limit Wout of the battery 50 input in step S100 is set in advance as shown in the following equation (6). A value obtained by adding the determined correction value ΔW is set as a control output limit Wout * (step S250), and the processes after step S160 are executed. In the embodiment, the time measurement by the timer 78 is started when a downshift is performed by the driver via the shift lever 81, and the time measurement value by the timer 78 is read in step S240. The time t in step S240 is determined in consideration of the magnitude of the correction value ΔW, the durability of the battery 50, and the like. Similarly, the correction value ΔW in step S250 is determined in consideration of the characteristics of the battery 50, the durability of the battery 50, and the like. The predetermined time t and the correction value ΔW may be fixed values or may be changed according to the vehicle speed V or the like.

  Wout * = Wout + ΔW (6)

  As described above, when the downshift is performed by the driver, the torque limit as the upper and lower limits of the torque that may be output from the motor MG2 using the control output limit Wout * (= Wout + ΔW) set in S250. Tm2min and Tm2max are set (step S170), and the torque command Tm2 * for the motor MG2 is limited using the set torque limits Tm2min and Tm2max. Thus, when the driver downshifts, the value obtained by adding the correction value ΔW to the output limit Wout of the battery 50 is set as the control output limit Wout * for the following reason. That is, when a downshift is performed, the torque from the motor MG1 is reduced to increase the number of revolutions of the engine 22 to give the driver a sense of downshift. However, the torque Tm1 from the motor MG1 is reduced. If the power is reduced, the generated power (Tm1 × Nm1) of the motor MG1 is also reduced, so that it is necessary to cover part of the power consumed by the motor MG2 by discharging the battery 50 in order to compensate for this. At this time, depending on the state of the battery 50, that is, the value of the output limit Wout of the battery 50, sufficient power cannot be supplied from the battery 50 to the motor MG2, and the driving force based on the required torque Tr * set in step S110 is changed to the ring gear shaft. There is a possibility that it cannot be output to 32a. For this reason, when downshifting is performed, the correction value ΔW is added to the output limit Wout of the battery 50 input in step S100 to increase the input / output limit of the battery 50, so that the ranges of the torque limits Tm2min and Tm2max Thus, sufficient electric power can be supplied to the motor MG2. As a result, a downshift is performed while the vehicle is driven by the driving force based on the required torque Tr *, and is output from the motor MG1 when the motor MG1 increases the rotational speed of the engine 22 to give the driver a sense of downshift. Even if the torque decreases, it is possible to supply sufficient power from the battery 50 to the motor MG2 to increase the torque from the motor MG2, thereby suppressing a decrease in driving force.

  If the flag is set to 1 in step S210 due to the downshift being performed by the driver, the next time the drive control routine of FIG. 2 is executed, the downshift is performed in step S130. It is determined that the accompanying process should be executed. In this case, a deviation ΔNe between the target engine speed Ne * (current value) set in step S120 and the current engine speed Ne input in step S100 is calculated (step S220). It is determined whether or not the deviation ΔNe is equal to or less than the threshold value α (step S230). If it is determined that the deviation ΔNe is equal to or less than the threshold value α and the change in the rotational speed of the engine 22 due to the downshift is substantially completed, the flag F is set to 0 (step S260). The output limit Wout of the battery 50 input in step S100 is set as the control output limit Wout * (step S150). In other words, in the embodiment, the correction for expanding the input / output limit of the battery 50 is the maximum, the rotation speed of the engine 22 corresponding to the downshift from the downshift by the driver as a condition for changing the rotation speed of the engine 22. It is limited until the change is almost completed, and during that time, the input / output restriction of the battery 50 can be expanded to suppress the decrease in driving force for running the hybrid vehicle 20.

  Further, when the drive control routine of FIG. 2 is executed, after it is determined in step S130 that the process associated with the downshift should be executed, the target rotational speed Ne * (current value) of the engine 22 and the previous value are determined. Even if it is determined that the deviation ΔNe exceeds the threshold value α, if the predetermined time t has elapsed since the time when the downshift was performed by the driver, the flag F is set to 0 (step S260), The output limit Wout of the battery 50 input in step S100 is set as the control output limit Wout * (step S150). That is, in the embodiment, the correction for expanding the input / output limit of the battery 50 is performed until a predetermined time t elapses from the time of the downshift by the driver regardless of whether or not the change in the rotation speed of the engine 22 is almost completed. It is limited between. As a result, charging / discharging due to excessive power of the battery 50 can be suppressed to the minimum necessary, and deterioration of the battery 50 can be suppressed.

  As described above, in the hybrid vehicle 20 of the embodiment, when the rotational speed of the engine 22 is changed by the motor MG1 in accordance with the downshift by the driver as the change condition during traveling by the driving force based on the required torque Tr *. Further, the rotational speed of the engine 22 is changed with a correction for expanding the input / output limit of the battery 50, and the driving force based on the required driving force is output within the corrected input / output limit range of the battery 50. The engine 22 and the motors MG1, MG2 are controlled. Thus, the torque output from the motor MG1 is reduced by correcting the input / output restriction of the battery 50 when the motor MG1 changes the rotational speed of the engine 22 to give the driver a sense of shift. Even so, it is possible to supply sufficient electric power from the battery 50 to the motor MG2 to suppress a decrease in driving force. And since the correction which expands the input / output range of the battery 50 is limited until the change of the rotational speed of the engine 22 is almost completed after the downshift by the driver or until a predetermined time elapses. Charging / discharging due to excessive power of the battery 50 can be suppressed.

  In the above-described embodiment, the correction for expanding the input / output range of the battery 50 is limited until the change of the rotation speed of the engine 22 is almost completed after the downshift by the driver or until a predetermined time elapses. However, it is not limited to this. That is, the condition for canceling the correction for expanding the input / output range of the battery 50 is that the change in the rotational speed of the internal combustion engine is generally completed after the downshift, and is predetermined after the downshift. It may be either one of the passage of time.

  Further, in the above-described embodiment, the processing in the case where the rotation speed of the engine 22 is changed in accordance with the downshift by the driver has been described. However, the driver can upshift while driving with the driving force based on the required torque Tr *. Accordingly, when the rotation speed of the engine 22 is changed by the motor MG1, the same process as described above may be executed. When such an upshift is performed, the torque from the motor MG1 is increased to reduce the rotational speed of the engine 22, thereby giving the driver a sense of upshifting. When Tm1 is increased, the generated power (Tm1 × Nm1) of the motor MG1 is also increased. Therefore, surplus power that cannot be consumed by the motor MG2 among the generated power of the motor MG1 is charged in the battery 50. At this time, depending on the state of the battery 50, that is, the value of the input limit Win of the battery 50, the battery 50 cannot be charged with surplus power, and surplus power is supplied to the motor MG2, and excessive driving force is applied to the ring gear shaft 32a. There is a possibility that the driver will not be given an upshift feeling. For this reason, when an upshift is performed by the driver during traveling using the driving force based on the required torque Tr *, the correction value ΔW ′ is subtracted from the input limit Win of the battery 50 input in step S100 to input / output the battery 50. By enlarging the limit, the battery 50 may be charged with surplus power. However, if control different from such control, for example, control for canceling excess driving force by supplying surplus power to the motor MG2 by braking force by the brake device, such input / output limitation of the battery 50 is performed. There is no need to make corrections to enlarge the image.

  Further, the present invention is not limited to the case where the driver performs a shift operation, and may be applied when the rotational speed of the engine 22 is suddenly changed due to a factor other than the change of the shift position SP.

  As mentioned above, although the embodiment of the present invention has been described using the examples, the present invention is not limited to the above-described examples at all, and various modifications are made without departing from the gist of the present invention. Needless to say, you get.

  That is, in the hybrid vehicle 20 of the above embodiment, the ring gear shaft 32a as the drive shaft and the motor MG2 are connected via the reduction gear 35 that reduces the rotational speed of the motor MG2 and transmits it to the ring gear shaft 32a. Instead of the reduction gear 35, for example, a transmission that has two or three shift stages of Hi and Lo and shifts the rotation speed of the motor MG2 and transmits it to the ring gear shaft 32a may be adopted. Good.

  Further, in the hybrid vehicles 20 and 20B of the above embodiment, the power of the motor MG2 is decelerated by the reduction gear 35 and output to the ring gear shaft 32a, but like the hybrid vehicle 120 as a modified example shown in FIG. An axle (an axle connected to wheels 39c and 39d in FIG. 9) different from an axle (an axle to which driving wheels 39a and 39b are connected) to which the power of motor MG2 is changed by transmission 65 and ring gear shaft 32a is connected. You may make it transmit to.

  Furthermore, the hybrid vehicles 20 and 20B of each of the above embodiments output the power of the engine 22 to the ring gear shaft 32a as the drive shaft connected to the drive wheels 39a and 39b via the power distribution and integration mechanism 30. Like the modified hybrid vehicle 220 shown in FIG. 10, 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 39a and 39b And a counter-rotor motor 230 that transmits a part of the power of the engine 22 to the drive shaft and converts the remaining power into electric power.

1 is a schematic configuration diagram of a hybrid vehicle 20 that is an embodiment of the present invention. It is a flowchart which shows an example of the drive control routine performed by hybrid ECU70 of an Example. 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 explanatory drawing which shows an example of the map for request | requirement torque setting. It is explanatory drawing which shows an example of the relationship between shift position SP, vehicle speed V, and target rotational speed Ne *. It is explanatory drawing which illustrates the correlation with the rotation speed of an engine 22, and a torque. 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 the power distribution and integration mechanism 30. FIG. It is a schematic block diagram of the hybrid vehicle 120 of the modification. FIG. 11 is a schematic configuration diagram of a hybrid vehicle 220 of a modification 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, 36 axle, 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 driving wheel, 65 transmission, 70 electronic control unit for hybrid (hybrid ECU), 72 CPU, 74 ROM, 76 RAM, 8 timer, 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 counter rotor motor, 232 inner rotor 234 outer Rotor, MG1, MG2 motor.

Claims (7)

An internal combustion engine;
An electric power input unit that is connected to a first axle as one of the axles of the vehicle and an output shaft of the internal combustion engine and that can input and output power to and from the first axle and the output shaft with input and output of electric power and power. Output means;
An electric motor capable of inputting / outputting power to / from a second axle that is either the first axle or an axle different from the first axle;
Power storage means capable of exchanging power between the power drive input / output means and the electric motor;
An input / output limit setting means for setting an input / output limit of power for the power storage means based on the state of the power storage means;
A required driving force setting means for setting a required driving force required for traveling;
When the rotational speed of the internal combustion engine is changed by the electric power input means according to the establishment of a predetermined change condition during traveling by the driving force based on the set required driving force, until a predetermined release condition is satisfied, A driving force based on the set required driving force within a range of the corrected input / output limit while the rotational speed of the internal combustion engine is changed with a correction to expand the set input / output limit of the power storage unit Control means for controlling the internal combustion engine, the power drive input / output means and the electric motor so that
A vehicle comprising:   The vehicle according to claim 1, wherein the release condition is that a change in the rotational speed of the internal combustion engine is substantially completed.   The vehicle according to claim 1, wherein the release condition is that a predetermined time elapses from the establishment of the change condition. A vehicle according to any one of claims 1 to 3,
Shift setting means for setting a shift position for determining the relationship between the vehicle speed of the internal combustion engine and the rotational speed of the internal combustion engine;
The change condition is that a shift position different from that is set by the shift setting means.
vehicle.   The vehicle according to claim 4, wherein the change condition is that a shift position is set on the downshift side by the shift setting means.   The vehicle according to claim 4 or 5, wherein the shift setting means sets the shift position in accordance with a driver's shift operation. The power power input / output means is connected to the first axle, the output shaft of the internal combustion engine, and a rotatable third shaft, and based on power input / output to any two of these three shafts. The vehicle according to any one of claims 1 to 6, further comprising: a three-axis power input / output unit that inputs / outputs a fixed power to / from a remaining shaft; and a generator capable of inputting / outputting power to / from the third shaft.

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