JP2013107511A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the following performance of an engine rotation number with respect to an abrupt change of required torque while further suppressing the hunting of the engine rotation number.SOLUTION: When an engine first temporary target rotation number Ne1* and an engine second temporary target rotation number Ne2* are target rotation numbers in such a way that change directions of an engine target rotation number Ne* become the same (YES in S380 or S390), a value obtained by adding the previous Ne* and a value larger in absolute value out of target rotation number change amounts ΔNe1*, ΔNe2* which are adjusted so as not to exceed a first upper limit value Ne1ref (S320 to S370) is set as the engine target rotation number Ne* (S400, S410). In the case other than this (NO in S390), a value obtained by adding the previous Ne* and the target rotation number chamber amount ΔNe2* which is adjusted so as not exceed a second upper limit value Ne2ref (<first upper limit value Ne1ref) (S350 to S370) is set as the engine target rotation number Ne* (S400, S410).

Description

  The present invention relates to a hybrid vehicle including an engine capable of outputting power to a drive shaft, a motor capable of outputting power to the drive shaft, and a battery capable of charging / discharging electric power between the motors.

  Conventionally, this type of hybrid vehicle includes an engine, a first motor, a planetary gear connected to the engine output shaft, the motor output shaft and the axle, a second motor capable of outputting power to the axle, One having a main battery that exchanges electric power with one motor and a second motor has been proposed (see, for example, Patent Document 1). In this hybrid vehicle, the target rotational speed is set according to the state of charge of the battery, and the control amount of the throttle valve is feedback controlled so that the actual rotational speed converges to the target rotational speed. As a result, the engine speed is accurately controlled to the target speed to suppress the battery from being insufficiently charged or from being overdischarged.

Japanese Patent Laid-Open No. 11-022501

  By the way, when the engine speed is controlled by feedback control according to the state of charge of the battery, the actual engine speed may be difficult to change due to, for example, inertia. In such a case, the deviation between the actual rotational speed and the target rotational speed continues to occur, so that the control amount by the feedback control becomes too large, and the target rotational speed of the engine may be hunted. On the other hand, for example, if the gain of feedback control is reduced in order to suppress hunting, the actual rotational speed is difficult to increase when the required torque changes suddenly, such as during acceleration, and the followability of the engine rotational speed decreases. There was a problem.

  The main purpose of the hybrid vehicle of the present invention is to ensure the followability of the engine speed to a sudden change in required torque while further suppressing the hunting of the engine speed.

  The hybrid vehicle of the present invention employs the following means in order to achieve the main object described above.

The hybrid vehicle of the present invention
An engine capable of outputting power to the drive shaft, a motor capable of outputting power to the drive shaft, a battery capable of charging / discharging power between the motors, and charge / discharge required power to charge / discharge the battery Charge / discharge target power setting means for setting the charge / discharge target power by feedback control so that the deviation between the charge / discharge power for charging / discharging the battery is canceled, the travel required power required for travel, and the charge / discharge target power A hybrid vehicle comprising: control means for controlling the engine and the motor so that the engine is driven at a driving torque required for driving while the engine is operated at an operation point based on an engine target rotational speed;
The first engine temporary target rotational speed at the operating point based on the travel required power and the second engine temporary target rotational speed at the operating point based on the travel required power and the charge / discharge target power are the engine target rotational speeds. When the target rotational speed is such that the change directions are the same, the engine target rotational speed is set in a range in which the absolute value of the change amount of the engine target rotational speed does not exceed a predetermined first upper limit value, When the first engine temporary target rotational speed and the second engine temporary target rotational speed are not the target rotational speeds so that the engine target rotational speed changes in the same direction, the engine target rotational speed change amount Target engine speed setting means for setting the engine target engine speed in a range in which an absolute value does not exceed a second upper limit value that is smaller than the first upper limit value;
The main point is that

  In the hybrid vehicle of the present invention, the charge / discharge target power is set by feedback control so that the deviation between the charge / discharge required power for charging / discharging the battery and the charge / discharge power for charging / discharging the battery is canceled, and required for running. The engine and the motor are controlled so that the engine is driven at the operation point based on the required travel power, the charge / discharge target power, and the target engine speed and the required torque required for the travel. The first engine temporary target rotational speed at the operating point based on the second engine temporary target rotational speed at the operating point based on the travel required power and the charge / discharge target power is the same in the direction of change of the engine target rotational speed. When the target engine speed is such that the absolute value of the change amount of the engine target engine speed is Setting the target engine rotational speed within a range that does not exceed the first upper limit value of the constant. When the first engine temporary target rotational speed and the second engine temporary target rotational speed are not the target rotational speeds in which the engine target rotational speed changes in the same direction, the absolute amount of change in the engine target rotational speed is absolute. The engine target speed is set in a range in which the value does not exceed the second upper limit value that is smaller than the first upper limit value. Thus, the first engine temporary target rotational speed based on the travel required power and the second engine temporary target rotational speed based on the travel required power and the charge / discharge target power are both in the same direction. When the target engine speed is the target engine speed, the engine target engine speed is set in the range of the first upper limit value that is larger than the second upper limit value. The followability of the engine speed with respect to a sudden change in required torque can be ensured. On the other hand, when the first engine temporary target rotational speed and the second engine temporary target rotational speed are not the target rotational speed in which the direction of change of the engine target rotational speed is the same, the value is larger than the first upper limit value. Since the engine target speed is set within the range of the small second upper limit value, hunting of the engine speed can be further suppressed as compared with the case where it is set within the range of the first upper limit value. In this way, it is possible to ensure the followability of the engine speed with respect to a sudden change in the required torque while further suppressing the hunting of the engine speed. Here, “when the first engine temporary target rotational speed and the second engine temporary target rotational speed are target rotational speeds such that the changing direction of the engine target rotational speed is the same direction” means that the first engine temporary target rotational speed is the same. When the target rotational speed and the second engine temporary target rotational speed are both the target rotational speed in the direction of increasing the engine target rotational speed, or both the first engine temporary target rotational speed and the second engine temporary target rotational speed are the engine. This is when the target rotational speed is in the direction of decreasing the target rotational speed. The “operation point” refers to a point made up of the rotational speed and torque.

  In such a hybrid vehicle of the present invention, the target rotational speed setting means is such that the first engine temporary target rotational speed and the second engine temporary target rotational speed have the same direction of change in the engine target rotational speed. When the target engine speed is such that the absolute value of the change amount of the engine target engine speed does not exceed the first upper limit value, the first engine temporary target engine speed, the second engine temporary target engine speed, Of these, the one with the larger absolute value of the change amount of the engine target speed may be set as the engine target speed. By doing this, the absolute value of the change amount of the engine target speed can be set to a larger value, and the followability of the engine speed to the change of the required torque can be further ensured.

  In such a hybrid vehicle of the present invention, the target rotational speed setting means is such that the first engine temporary target rotational speed and the second engine temporary target rotational speed have the same direction of change in the engine target rotational speed. When the target engine speed is not such a value, the second engine temporary target engine speed is set to the engine target engine speed within a range where the absolute value of the change amount of the engine target engine speed does not exceed the second upper limit value. Also good. In this way, when the hunting of the engine speed is further suppressed, the second engine temporary target speed based on the required travel power and the charge / discharge target power is set as the target speed, so that a more appropriate value is set to the engine target. The rotation speed can be set.

  Such a hybrid vehicle of the present invention is connected to the first motor and the second motor as the motor capable of outputting power to the drive shaft, the output shaft of the engine, the rotation shaft of the first motor, and the drive shaft. It is good also as a thing provided with the made planetary gear. Further, the hybrid vehicle of the present invention may include a continuously variable transmission that transmits power from the engine to the drive shaft.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. 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 relationship between battery temperature Tb and 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. FIG. 4 is a collinear diagram showing the dynamic relationship between the rotational speed and torque of each rotating element of planetary gear 30 when operating with power output from engine 22; It is a flowchart which shows an example of an engine target rotation speed setting process. 4 is an explanatory diagram showing an example of an operation line of an engine 22. FIG. It is a flowchart which shows an example of the engine target rotation speed setting process of a modification. 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.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. As shown in FIG. 1, the hybrid vehicle 20 of the embodiment includes a planetary gear 30 in which a carrier 34 that connects a plurality of pinion gears 33 to a crankshaft 26 as an output shaft of the engine 22 via dampers 28 is connected. For example, a motor MG1 configured as a known synchronous generator motor and connected to the sun gear 31 of the planetary gear 30 and a ring gear as a drive shaft connected to the ring gear 32 of the planetary gear 30 configured as a known synchronous generator motor Motor MG2 connected to shaft 32a via reduction gear 35, inverters 41 and 42 capable of converting a direct current into an alternating current and supplying it to motors MG1 and MG2, and an inverter 41 configured as, for example, a lithium ion secondary battery , 42 and motors MG1, MG2 and It includes a battery 50 for exchanging power, and a hybrid electronic control unit 70 that controls the entire vehicle. The ring gear shaft 32a is connected to drive wheels 63a and 63b of the vehicle via a gear mechanism 60 and a differential gear 62.

  The engine 22 is an internal combustion engine that outputs power using a hydrocarbon-based fuel such as gasoline or light oil. The engine electronic control unit (hereinafter referred to as engine ECU) 24 performs fuel injection control, ignition control, and intake air amount adjustment. Under control of operation such as control. The engine ECU 24 receives signals from various sensors that detect the operating state of the engine 22, for example, a crank position from a crank position sensor (not shown) that detects the crank angle of the crankshaft 26 of the engine 22. The engine ECU 24 is in communication with the hybrid electronic control unit 70, controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and, if necessary, transmits data related to the operating state of the engine 22 to the hybrid electronic control. Output to unit 70. The engine ECU 24 also calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22, based on a crank position from a crank position sensor (not shown).

  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 currents applied to the motors MG1 and MG2 are input. The motor ECU 40 outputs a switching control signal to the switching elements of the inverters 41 and 42. The motor ECU 40 is in communication with the hybrid electronic control unit 70, controls the driving of the motors MG1 and MG2 by a control signal from the hybrid electronic control unit 70, and, if necessary, data on the operating state of the motors MG1 and MG2. Output to the hybrid electronic control unit 70. The motor ECU 40 also calculates the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 based on signals from the rotational position detection sensors 43 and 44.

  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, such as a voltage Vb between terminals from a voltage sensor 53a installed between terminals of the battery 50, and a current sensor 53b connected to an output terminal of the battery 50. The charging / discharging current Ib, the battery temperature Tb from the temperature sensor 51b attached to the battery 50, and the like are input, and data relating to the state of the battery 50 is output to the hybrid electronic control unit 70 by communication as necessary. Further, the battery ECU 52 determines a storage ratio SOC, which is a ratio of the storage amount stored in the battery 50 based on the integrated value of the charge / discharge current Ib detected by the current sensor 53b in order to manage the battery 50. Or the charge / discharge power Pb for charging / discharging the battery 50 based on the product of the battery voltage Vb from the voltage sensor 53a and the charge / discharge current Ib from the current sensor 53b, or the remaining capacity (SOC) from the threshold S1 The charge / discharge required power Pb1 * is set so that the battery 50 is charged with a larger amount of power as the remaining capacity (SOC) becomes smaller, or the battery 50 is charged / discharged based on the calculated storage ratio SOC and the battery temperature Tb. The input / output limits Win and Wout, which are the maximum allowable power, may be calculated. 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 limiting limit are set based on the storage ratio SOC of the battery 50. It can be set by setting a correction coefficient and multiplying the basic value of the set input / output limits Win and Wout by the correction coefficient. The charge / discharge current Ib is positive on the discharge side and negative on the charge side.

  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 the operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is 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 transmitted to the planetary gear 30 and the motor MG1. And the motor MG2 convert the torque to be output to the ring gear shaft 32a. The torque conversion operation mode for driving and controlling the motor MG1 and the motor MG2 and the power suitable for the sum of the required power and the power required for charging and discharging the battery 50 are obtained. The operation of the engine 22 is controlled so as to be output from the engine 22, and all or a part of the power output from the engine 22 with charging / discharging of the battery 50 is converted by the planetary gear 30, the motor MG1, and the motor MG2. As a result, the required power is applied to the ring gear shaft 32a. Charge / discharge operation mode in which the motor MG1 and the motor MG2 are driven and controlled so as to be powered, motor operation mode in which the operation of the engine 22 is stopped and operation corresponding to the power required by the motor MG2 is output to the ring gear shaft 32a. There is.

  Next, the operation of the hybrid vehicle 20 configured as described above will be described. FIG. 2 is a flowchart illustrating an example of a drive control routine executed by the hybrid electronic control unit 70 according to the embodiment. This routine is repeatedly executed every predetermined time (for example, several milliseconds).

  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, charge / discharge required power Pb1 *, charge / discharge power Pb, input / output limits Win, Wout of the battery 50, and the like are input (step S100). Here, the rotational speed Ne of the engine 22 is calculated based on the rotational position of the crankshaft 26 detected by the crank position sensor, 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 Pb1 * is set based on the remaining capacity (SOC) and is input from the battery ECU 52 by communication. The charge / discharge power Pb is set based on the battery voltage Vb and the charge / discharge current Ib and is input from the battery ECU 52 by communication. Input and output limits Win and Wout of the battery 50 are input from the battery ECU 52 by communication from the battery temperature Tb detected by the temperature sensor 51b and the remaining capacity (SOC) of the battery 50. It was. 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.

  When the data is input in this way, the charge / discharge target power Pb2 * obtained by adjusting the charge / discharge request power Pb1 * so that the deviation between the input charge / discharge request power Pb1 * and the charge / discharge power Pb is canceled out is fed back by the following equation (1). It derives from the relational expression of control (PI control) (step S110). In Equation (1), “kb1” in the second term on the right side is the gain of the proportional term, and “kb2” in the third term on the right side is the gain of the integral term.

  Pb2 * ← Pb1 * + kb1 ・ (Pb1 * -Pb) + kb2∫ (Pb1 * -Pb) dt (1)

  Subsequently, the required torque Tr * to be output to the ring gear shaft 32a as the drive shaft is set based on the accelerator opening Acc and the vehicle speed V, and the travel request required for traveling based on the set required torque Tr *. The power Pr * is set, and the required power Pe * required for the engine 22 is set (step S120). In this embodiment, the required torque Tr * is stored in the ROM 74 as a required torque setting map by predetermining the relationship between the accelerator opening Acc, the vehicle speed V, and the required torque Tr *. When the vehicle speed V is given, the corresponding required torque Tr * is derived from the map. An example of the required torque setting map is shown in FIG. The travel required power Pr * can be calculated as the required torque Tr * multiplied by the rotational speed Nr of the ring gear shaft 32a. The rotational speed Nr of the ring gear shaft 32a is obtained by multiplying the vehicle speed V by the 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). The required power Pe * can be calculated by subtracting the charge / discharge target power (negative on the charging side) from the travel required power Pr * and adding a loss (loss).

  Subsequently, an engine target speed setting process for setting the engine target speed Ne * is executed (step S130). Based on the set engine target speed Ne * and the required power Pe * set in step S120, the engine target speed Ne * is set. The target torque Te * is derived from the relationship Pe * = Ne * × Te * (step S140). The engine target speed setting process in step S130 will be described later.

  When the engine target speed Ne * and the engine target torque Te * are set, the motor MG1 is expressed by the following equation (2) based on the engine target speed Ne *, the speed Nr of the ring gear shaft 32a, and the gear ratio ρ of the planetary gear 30. And a torque command that is a torque to be output from the motor MG1 by the following equation (3) based on the deviation between the calculated target rotation speed Nm1 * and the current rotation speed Nm1 of the motor MG1. Tm1 * is calculated (step S150). Here, Expression (2) is a dynamic relational expression for the rotating element of the planetary gear 30. FIG. 6 is a collinear diagram showing a dynamic relationship between the rotational speed and torque of the rotating element of the planetary gear 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 (2) 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. Here, the torque that the torque Tm1 output from the motor MG1 acts on the ring gear shaft 32a can be considered as the torque that the motor MG1 receives the reaction force of the engine torque and the engine torque is directly transmitted to the ring gear shaft 32a. Therefore, this torque is also called direct torque. Expression (3) is a relational expression in feedback control for rotating the motor MG1 at the target rotational speed Nm1 *. In Expression (3), “k1” in the second term on the right side is a gain of the 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 (2)
Tm1 * = ρ ・ Te * / (1 + ρ) + k1 (Nm1 * -Nm1) + k2∫ (Nm1 * -Nm1) dt (3)

  Then, the torque command Tm1 * set to the required torque Tr * is divided by the gear ratio ρ of the planetary gear 30 and further divided by the gear ratio Gr of the reduction gear 35 to be a temporary value of torque to be output from the motor MG2. Is calculated by the following equation (4) (step S160) and obtained by multiplying the torque command Tm1 * set by the input / output limits Win and Wout of the battery 50 by the current rotational speed Nm1 of the motor MG1. The torque limits Tm2min and Tm2max as the upper and lower limits of the torque that may be output from the motor MG2 by dividing the deviation from the power consumption (generated power) of the motor MG1 by the rotational speed Nm2 of the motor MG2 Calculation is performed using equation (6) (step S170), and the set temporary torque Tm2tmp is calculated using equation (7). Limited Tm2min, and limited by Tm2max to set a torque command Tm2 * of the motor MG2 (step S180). Here, equation (4) can be easily derived from the alignment chart of FIG.

Tm2tmp = (T * + Tm1 * / ρ) / Gr (4)
Tm2min = (Win-Tm1 * ・ Nm1) / Nm2 (5)
Tm2max = (Wout-Tm1 * ・ Nm1) / Nm2 (6)
Tm2 * = max (min (Tm2tmp, Tm2max), Tm2min) (7)

  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. 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.

  Next, engine target speed setting processing will be described. FIG. 7 is a flowchart showing an example of engine target speed setting processing executed by the hybrid electronic control unit 70. When the engine target speed setting process is executed, the CPU 72 of the hybrid electronic control unit 70 derives the first engine temporary target speed Ne1 * and the second engine temporary target speed Ne2 * (step S300). . Here, the first engine temporary target rotational speed Ne1 * is derived as the engine rotational speed at the operating point based on the required travel power Pr * set in step S120 of the drive control routine. The first engine temporary target rotational speed Ne1 * is derived based on an operation line for operating the engine 22 efficiently. An example of the operation line of the engine 22 is shown in FIG. As shown in the figure, since the operating point based on the travel required power Pr * can be determined as the intersection of the operation line and the travel required power Pr * with a constant curve, the engine speed Ne at this operating point is determined as the first engine temporary. Derived as the target rotational speed Ne1 *. The second engine temporary target rotational speed Ne2 * is derived as the engine rotational speed at the operating point based on the required power Pe * set in step S120 from the travel required power Pr * and the charge / discharge target power Pb2 *. This second engine temporary target rotational speed Ne2 * is similar to the first engine temporary target rotational speed Ne1 * by using a curve with a constant required power Pe * instead of the travel required power Pr * in FIG. The engine speed Ne at the operation point determined as the intersection of the operation line and the curve with the required power Pe * is derived as the second engine temporary target speed Ne2 *.

  Subsequently, the target rotational speed that is the difference between the derived first engine temporary target rotational speed Ne1 * and the previous Ne * that is the engine target rotational speed Ne * when the engine target rotational speed setting process of FIG. The numerical change amount ΔNe1 * is derived, and the target rotational speed change amount ΔNe2 *, which is the difference between the derived second engine temporary target rotational speed Ne2 * and the previous Ne *, is derived (step S310). When the target rotational speed change amount ΔNe1 * is 0 or a positive value, the target rotational speed change amount ΔNe1 * is adjusted by the following equation (8), and when the target rotational speed change amount ΔNe1 * is a negative value: The target rotational speed change amount ΔNe1 * is adjusted by the following equation (9) (steps S320 to S340). By the processes in steps S320 to S340, the absolute value of the target rotational speed change amount ΔNe1 * is adjusted so as not to exceed the first upper limit value ΔNe1ref (> 0). The first upper limit value ΔNe1ref defines the range of the absolute value of the amount of change in the engine target speed Ne * (the difference between the previous Ne * and the engine target speed Ne * that is set this time). It is a value (for example, 18 rpm / 8 msec, 20 rpm / 8 msec, 22 rpm / 8 msec, etc.) determined so as to further ensure the followability of the engine speed Ne to the change in the required torque Tr *. This target rotational speed change amount ΔNe1ref can be determined in advance through experiments, for example.

ΔNe1 * ← min (ΔNe1 *, ΔNe1ref) (8)
ΔNe1 * ← max (ΔNe1 *,-ΔNe1ref) (9)

  Subsequently, when the target rotational speed change amount ΔNe2 * is 0 or a positive value, ΔNe2 * is adjusted by the following formula (10), and when the target rotational speed change amount ΔNe2 * is a negative value, the following formula (11 ) To adjust ΔNe2 * (steps S350 to 370). By the processes in steps S350 to S370, the absolute value of the target rotational speed change amount ΔNe2 * is adjusted so as not to exceed the second upper limit value ΔNe2ref (> 0). The second upper limit value ΔNe2ref defines the range of the absolute value of the change amount of the engine target speed Ne * (difference between the previous Ne * and the engine target speed Ne * set this time). It is a value (for example, 1 rpm / 8 msec, 2 rpm / 8 msec, 3 rpm / 8 msec) determined as a value smaller than the first upper limit value ΔNe1ref so that hunting of several Ne can be further suppressed. This ΔNe2ref can be determined in advance by experiments, for example.

ΔNe1 * ← min (ΔNe2 *, ΔNe2ref) (10)
ΔNe1 * ← max (ΔNe2 *,-ΔNe2ref) (11)

  Then, it is determined whether or not the target rotational speed change amounts ΔNe1 * and ΔNe2 * are both positive values (step S380). If both are positive values, the engine target rotational speed Ne * is determined by the following equation (12). After setting (step S400), the engine target speed setting process is terminated. If any of the target rotational speed changes ΔNe1 * and ΔNe2 * is not a positive value in step S380, it is determined whether or not both of the target rotational speed changes ΔNe1 * and ΔNe2 * are negative values (step S380). In S390), when both are negative values, the engine target speed Ne * is set by the following equation (13) (step S410), and the engine target speed setting process is terminated. By the process of step S400 or step S410, a value obtained by adding the previous Ne * and the target rotational speed change amount ΔNe1 *, ΔNe2 *, whichever has the larger absolute value, is set as the engine target rotational speed Ne *. At this time, since the target rotational speed change amounts ΔNe1 * and ΔNe2 * are both adjusted so that the absolute value does not exceed the first upper limit value Ne1ref, the engine target rotational speed Ne * is equal to the engine target rotational speed Ne *. The absolute value of the change amount is set in a range that does not exceed the first upper limit value Ne1ref. Here, in step S380, the target engine speed change amounts ΔNe1 * and ΔNe2 * are both positive values. Both the first engine temporary target engine speed Ne1 * and the second engine temporary target engine speed Ne2 * are engine targets. This means that the rotational speed Ne * is the target rotational speed in the direction of increasing from the previous Ne *. In addition, in step S390, the target engine speed change amounts ΔNe1 * and ΔNe2 * are both negative values, indicating that both the first engine temporary target engine speed Ne1 * and the second engine temporary target engine speed Ne2 * are engine target engine speeds. This means that the target rotational speed is a direction in which the number Ne * is lowered from the previous Ne *. Thus, in the engine target speed setting process, the first engine temporary target speed Ne1 * and the second engine temporary target speed Ne2 * are such that the direction of change of the engine target speed Ne * is the same. When the target engine speed is the target engine speed Ne *, the engine target engine speed Ne * is set in a range in which the absolute value of the change amount of the engine target engine speed Ne * does not exceed the first upper limit value Ne1ref.

Ne * ← Previous Ne * + max (ΔNe1 *, ΔNe2 *) (12)
Ne * ← Previous Ne * + min (ΔNe1 *, ΔNe2 *) (13)

  On the other hand, if any of the target rotational speed changes ΔNe1 * and Ne2 * is not a positive value in step S380 and any of the target rotational speed changes ΔNe1 * and Ne2 * is not a negative value in step S390, that is, When the target rotational speed change amounts ΔNe1 * and Ne2 * are opposite or when either of them is 0, the engine target rotational speed Ne * is set by the following equation (14) (step S420), and the engine target rotational speed is set. The number setting process ends. By the process of step S420, a value obtained by adding the previous Ne * and the target rotational speed change amount ΔNe2 * is set as the engine target rotational speed Ne *. Since the target rotational speed change amount ΔNe2 * is adjusted so that the absolute value does not exceed the second upper limit value Ne2ref, the engine target rotational speed Ne * is the absolute value of the change amount of the engine target rotational speed Ne *. The second upper limit value Ne2ref is set in a range not exceeding. Thus, in the engine target speed setting process, the first engine temporary target speed Ne1 * and the second engine temporary target speed Ne2 * are such that the direction of change of the engine target speed Ne * is the same. When the engine speed is not the target speed, the engine target speed Ne * is set in a range where the absolute value of the change amount of the engine target speed Ne * does not exceed the second upper limit value Ne2ref.

  Ne * ← Previous Ne * + ΔNe2 * (14)

  When the engine target speed setting process is executed in this manner and the process of step S400 or step S410 is performed, the absolute value of the change amount of the engine target speed Ne * is larger than the second upper limit value Ne2ref. Since the engine target speed Ne * is set within a range that does not exceed the large first upper limit value Ne1ref, it is possible to further ensure the followability of the engine speed Ne with respect to a sudden change in the required torque Tr *. On the other hand, when the process of step S420 is performed, the engine target is within a range where the absolute value of the change amount of the engine target rotational speed Ne * does not exceed the second upper limit value Ne2ref which is smaller than the first upper limit value Ne1ref. Since the rotational speed Ne * is set, hunting of the engine rotational speed Ne can be further suppressed.

  According to the hybrid vehicle 20 of the embodiment described above, the first engine temporary target rotational speed Ne1 * and the second engine temporary target rotational speed Ne2 * are both in the same direction of change of the engine target rotational speed Ne *. If the target engine speed is such that the absolute value of the change amount of the engine target engine speed does not exceed the first upper limit value Ne1ref, the engine target engine speed Ne * is set so as to respond to a sudden change in the required torque Tr *. Ensures engine speed tracking. On the other hand, when the first engine temporary target rotational speed Ne1 * and the second engine temporary target rotational speed Ne2 * are not the target rotational speeds in which the change directions of the engine target rotational speed Ne * are both the same direction, the engine target The engine target speed Ne * is set in a range where the absolute value of the change amount of the rotational speed does not exceed the second upper limit value ne2ref, which is smaller than the first upper limit value Ne1ref, and hunting of the engine speed Ne is further suppressed. To do. As a result, it is possible to ensure followability of the engine speed Ne to a sudden change in the required torque Tr * while further suppressing hunting of the engine speed Ne.

  In addition, when the first engine temporary target rotational speed Ne1 * and the second engine temporary target rotational speed Ne2 * are the target rotational speeds in which the change directions of the engine target rotational speed Ne * are both the same direction, The larger of the absolute value of Ne * and the target rotational speed change amount ΔNe1 * adjusted so as not to exceed the first upper limit value Ne1ref and the target rotational speed change amount ΔNe2 * adjusted so as not to exceed the second upper limit value Ne2ref And the value obtained by adding the value to the engine target rotational speed Ne *. For this reason, either one of the target rotational speed changes ΔNe1 * and ΔNe2 * is appropriately selected so that the absolute value of the engine rotational speed Ne * becomes larger, and the engine rotational speed with respect to the change in the required torque is selected. Followability can be further ensured.

  Further, when the first engine temporary target rotational speed Ne1 * and the second engine temporary target rotational speed Ne2 * are not the target rotational speeds in which the changing directions of the engine target rotational speed Ne * are both the same direction, the engine target The second engine provisional target rotational speed Ne2 * is set to the engine target rotational speed Ne * in a range where the absolute value of the change amount of the rotational speed Ne * does not exceed the second upper limit value Ne2ref. Thus, when the hunting of the engine speed Ne * is further suppressed, the second engine temporary target speed Ne2 * based on the travel required power Pr * and the charge / discharge target power Pb2 * is set as the engine target speed Ne *. Therefore, a more appropriate value can be set as the engine target speed Ne *.

  In the hybrid vehicle 20 of the embodiment, the target rotational speeds ΔNe1 * and ΔNe2 * are adjusted so as not to exceed the first upper limit value Ne1ref and the second upper limit value Ne2ref in the engine target rotational speed setting process of FIG. Steps S320 to S340, Steps S350 to S370), the first engine temporary target rotational speed Ne1 * and the second engine temporary target rotational speed Ne2 * are targets in which the changing direction of the engine target rotational speed Ne * is the same. It is assumed that the engine speed is determined (steps S380 and S390), but the first engine temporary target speed Ne1 * and the second engine temporary target speed Ne2 * are equal to the engine target speed Ne *. It may be determined first whether or not the target rotational speed is such that the changing directions are the same. FIG. 9 is a flowchart illustrating an example of a target engine speed setting process according to a modification. In FIG. 9, the same step number is assigned to the same process as the engine target speed setting process of FIG. 7, and detailed description thereof is omitted. When the engine target rotational speed setting process of this modification is executed, the CPU 72 of the hybrid electronic control unit 70 performs the processes of steps S300 and S310. Subsequently, the process of step S380 is performed. When the target rotational speed change amounts ΔNe1 * and ΔNe2 * are both positive values in step S380, the engine target rotational speed Ne * is set according to the following equation (15) (step 380). S400a), the target engine speed setting process is terminated. If any of the target rotational speed changes ΔNe1 * and ΔNe2 * is not a positive value in step S380, the process of step S390 is performed, and in step S390, the target rotational speed changes ΔNe1 * and ΔNe2 * are both negative values. If this is the case, the engine target speed Ne * is set by the following equation (16) (step S410a), and the engine target speed setting process is terminated. By the processing of step S400 or S410, the target rotational speed change amounts ΔNe1 * and ΔNe2 * are within a range in which the absolute value of the target rotational speed change amounts ΔNe1 * and ΔNe2 * does not exceed the first upper limit value ΔNe1ref with respect to the previous Ne *. A value obtained by adding the larger one of the absolute values is set as the engine target speed Ne *. That is, the engine target of the first engine temporary target rotational speed Ne1 * and the second engine temporary target rotational speed Ne2 * is within a range where the absolute value of the change amount of the engine target rotational speed Ne * does not exceed the first upper limit value ΔNeref1. The one where the absolute value of the change amount of the rotational speed Ne * becomes larger is set as the engine target rotational speed Ne *. By setting the engine target speed in this manner, the absolute value of the change amount of the engine target speed Ne * is set to a larger value, and the followability of the engine speed Ne * with respect to the change in the required torque Tr * is further ensured. be able to. Further, when any of the target rotational speed change amounts ΔNe1 * and ΔNe2 * is not a negative value in step S390, the process of step S350 is performed. If ΔNe2 * is 0 or a positive value in step S350, the engine target speed Ne * is set by the following equation (17) (step S420a), and the engine target speed setting process is terminated. On the other hand, when ΔNe2 * is a negative value in step S350, the engine target speed Ne * is set by the following equation (18) (step S420b), and the engine target speed setting process is ended. As a result of the processing of step S420a or S420b, the second engine temporary target rotational speed Ne2 is within a range in which the absolute value of the change amount of the engine target rotational speed Ne * does not exceed the second upper limit value Ne2ref, as in step S420 of the embodiment. * Is set to the engine target speed Ne *. Even in the engine target speed setting process of this modification, it is possible to ensure the followability of the engine speed with respect to a sudden change in the required torque Tr * while further suppressing the hunting of the engine speed Ne.

Ne * ← Previous Ne * + min (max (ΔNe1 *, ΔNe2 *), ΔNe1ref) (15)
Ne * ← Previous Ne * + max (min (ΔNe1 *, ΔNe2 *),-ΔNe1ref) (16)
Ne * ← Previous Ne * + min (ΔNe2 *, ΔNe2ref) (17)
Ne * ← Previous Ne * + max (ΔNe2 *,-ΔNe2ref) (18)

  In the hybrid vehicle 20 of the embodiment, the charge / discharge target power Pb2 * is derived by PI control using the equation (1) in step S110 of the drive control routine of FIG. The charge / discharge target power Pb2 * may be set by feedback control so as to cancel the deviation between the charge / discharge power Pb and the charge / discharge target power Pb2 * is set using feedback control different from the embodiment, such as PID control. It may be set.

  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. 10) 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).

  A hybrid vehicle to which the present invention is applied may include a continuously variable transmission (CVT) 65 like a hybrid vehicle 220 according to a modification shown in FIG. A hybrid vehicle 220 according to the modification shown in FIG. 11 is connected to the crankshaft of the engine 22 and can exchange electric power with the battery 50 via the inverter 41, and the rotor (rotary shaft) of the motor MG1 and the drive. A mechanical (for example, belt type or toroidal) continuously variable transmission 65 connected to a drive shaft connected to the wheels 63a, 63b, a drive shaft connected to the wheels 64a, 64b, and an inverter 42 are connected. And a motor MG2 capable of exchanging electric power with the battery 50. Also in the hybrid vehicle 220 configured as described above, it is possible to secure the followability of the engine speed Ne to a sudden change in the required torque Tr * while further suppressing the hunting of the engine speed Ne by applying the present invention. it can. In hybrid vehicle 220, motor MG1 and inverter 41 may be omitted, and continuously variable transmission 65 may be connected to the crankshaft of engine 22. In hybrid vehicle 220, motor MG2 and inverter 42 may be omitted. In hybrid vehicle 220, engine 22 (and motor MG1) is connected to a drive shaft connected to wheels 64a and 64b via continuously variable transmission 65, and motor MG2 is connected to drive wheels 63a and 63b. It may be connected to the shaft.

  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 “engine”, the motor MG1 corresponds to “first motor” and “motor”, the motor MG2 corresponds to “second motor” and “motor”, and the planetary gear 30 corresponds to “ 2 corresponds to “planetary gear”, the battery 50 corresponds to “battery”, and the hybrid electronic control unit 70 that executes the process of step S120 of the drive control routine of FIG. 2 corresponds to “charge / discharge target power setting means”. The hybrid electronic control unit 70 that executes the processing of steps S120 and S140 to S190 of the control routine, the engine ECU 24 that controls the operation of the engine 22, and the motor ECU 40 that controls the driving of the motors MG1 and MG2 correspond to “control means”. The hybrid electronic control unit for executing the engine target speed setting process of FIG. 0 corresponds to the "target rotational speed setting means".

  Here, the “engine” is not limited to an engine that outputs power using a hydrocarbon fuel such as gasoline or light oil, and may be any type of engine such as a hydrogen engine. The “first motor” is not limited to the motor MG1 configured as a synchronous motor, and any type of motor such as an induction motor that outputs power to the drive shaft may be used. The “second motor” is not limited to the motor MG2 configured as a synchronous motor, and may be any type of motor as long as it outputs power to the drive wheels, such as an induction motor. The “battery” is not limited to the battery 50 configured as a lithium ion battery, but may be any type of battery such as a nickel metal hydride battery.

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

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

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

  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, 51b temperature sensor, 52 battery electronic control unit (battery ECU), 53a voltage sensor 53b Current sensor, 60 gear mechanism, 62 differential gear, 63a, 63b drive wheel, 64a, 64b wheel, 65 continuously variable transmission (CVT), 70 hybrid electronic control unit, 72 CPU, 7 ROM, 76 RAM, 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 an accelerator pedal position sensor, 85 brake pedal, 86 a brake pedal position sensor, 88 vehicle speed sensor, MG1, MG2, MG motor.

Claims (5)

An engine capable of outputting power to the drive shaft, a motor capable of outputting power to the drive shaft, a battery capable of charging / discharging power between the motors, and charge / discharge required power to charge / discharge the battery Charge / discharge target power setting means for setting the charge / discharge target power by feedback control so that the deviation between the charge / discharge power for charging / discharging the battery is canceled, the travel required power required for travel, and the charge / discharge target power A hybrid vehicle comprising: control means for controlling the engine and the motor so that the engine is driven at a driving torque required for driving while the engine is operated at an operation point based on an engine target rotational speed;
The first engine temporary target rotational speed at the operating point based on the travel required power and the second engine temporary target rotational speed at the operating point based on the travel required power and the charge / discharge target power are the engine target rotational speeds. When the target rotational speed is such that the change directions are the same, the engine target rotational speed is set in a range in which the absolute value of the change amount of the engine target rotational speed does not exceed a predetermined first upper limit value, When the first engine temporary target rotational speed and the second engine temporary target rotational speed are not the target rotational speeds so that the engine target rotational speed changes in the same direction, the engine target rotational speed change amount Target engine speed setting means for setting the engine target engine speed in a range in which an absolute value does not exceed a second upper limit value that is smaller than the first upper limit value;
A hybrid car equipped with When the target engine speed setting means is such that the first engine temporary target engine speed and the second engine temporary target engine speed are both the same direction of change of the engine target engine speed. The absolute value of the amount of change in the engine target speed does not exceed the first upper limit value, and the engine target speed of the first engine temporary target speed and the second engine temporary target speed is within the range. A means for setting the engine having a larger absolute value of the change amount as the engine target speed;
The hybrid vehicle according to claim 1. The target engine speed setting means is configured such that when the first engine temporary target engine speed and the second engine temporary target engine speed are not the target engine speeds such that the change directions of the engine target engine speed are both the same direction, Means for setting the second engine temporary target engine speed to the engine target engine speed within a range where the absolute value of the change amount of the engine target engine speed does not exceed the second upper limit value;
The hybrid vehicle according to claim 1 or 2. It is a hybrid car given in any 1 paragraph of Claims 1-3,
A first motor and a second motor as the motor capable of outputting power to the drive shaft;
A planetary gear connected to the output shaft of the engine, the rotary shaft of the first motor, and the drive shaft;
A hybrid car equipped with It is a hybrid car given in any 1 paragraph of Claims 1-3,
A continuously variable transmission that transmits power from the engine to the drive shaft;
A hybrid car equipped with