JP4301252B2 - POWER OUTPUT DEVICE, ITS CONTROL METHOD, AND VEHICLE - Google Patents

Description

  The present invention relates to a power output apparatus, a control method therefor, and a vehicle.

Conventionally, as this type of power output device, an engine, a planetary gear in which a carrier is connected to the output shaft of the engine and a ring gear is connected to a drive shaft, a first motor that inputs and outputs power to the sun gear of the planetary gear, A second motor that inputs and outputs power to the drive shaft, and a battery that can exchange power with the first motor and the second motor, and is mounted on an automobile has been proposed (see, for example, Patent Document 1). ). In this device, when the accelerator is turned off, the first temporary engine speed based on the target power required for the engine, the required torque required for the drive shaft, and the speed required for making the battery charge limit compatible. The larger of the second temporary engine speeds is set as the target engine speed, and the engine and the two motors are controlled so that the engine is operated at the target speed and the required torque is output to the drive shaft. Thus, the braking force request due to the accelerator off is dealt with while considering the charging limit of the battery.
Japanese Patent Laid-Open No. 2005-2898

  By the way, in such a power output device, when the accelerator pedal is greatly depressed by the driver, when the engine speed is increased in order to increase the output from the engine, the system including the engine due to the increase in the engine speed is used. Inertia acts on the drive shaft as a force in the direction of decelerating the vehicle. At this time, if the upper limit of the torque that can be output from the second motor to the drive shaft using the electric power from the battery is greatly limited, the torque that takes into account the force in the direction of decelerating the vehicle acting on the drive shaft is set to the second torque. Output from the motor to the drive shaft may not be sufficient, and output response may be reduced.

  The power output device, the control method thereof, and the vehicle according to the present invention are intended to suppress a decrease in output responsiveness. Another object of the vehicle of the present invention is to prevent the driver from feeling mottled.

  The power output device, the control method thereof, and the vehicle of the present invention employ the following means in order to achieve at least a part of the above-described object.

The power output apparatus of the present invention is
A power output device that outputs power to a drive shaft,
An internal combustion engine capable of outputting power to the drive shaft;
An electric motor capable of outputting power to the drive shaft;
Power storage means capable of exchanging electric power with the electric motor;
Required driving force setting means for setting required driving force required for the drive shaft;
Lower limit speed setting means for setting a lower limit speed of the internal combustion engine based on the state of the power storage means;
A temporary rotational speed of the internal combustion engine is set on the basis of the set required driving force and a predetermined constraint, and the set temporary rotational speed is limited by the set lower limit rotational speed to achieve a target rotational speed of the internal combustion engine Target speed setting means for setting the number;
Control means for controlling the internal combustion engine and the electric motor so that the internal combustion engine is operated at the set target rotational speed and a drive force based on the set required drive force is output to the drive shaft;
It is a summary to provide.

  In the power output apparatus of the present invention, the temporary rotational speed of the internal combustion engine is set based on the required driving force required for the drive shaft and predetermined restrictions, and the lower limit rotational speed of the internal combustion engine is set based on the state of the power storage means. The target rotational speed of the internal combustion engine is set by limiting the set temporary rotational speed with the lower limit rotational speed, and the internal combustion engine is operated at the target rotational speed and the driving force based on the requested driving force is output to the drive shaft. And controlling the internal combustion engine and the electric motor. Therefore, since the internal combustion engine is operated at a rotational speed equal to or higher than the lower limit rotational speed based on the state of the power storage means, the target of the internal combustion engine that is set based on the required driving force and predetermined restrictions when the required driving force increases rapidly. The degree of increase in the rotational speed can be suppressed according to the state of the power storage means. Thereby, the inertia of the system including the internal combustion engine due to the increase in the rotation speed of the internal combustion engine can be suppressed, and the force in the direction of reducing the rotation speed of the drive shaft acting on the drive shaft due to the inertia can be suppressed. Thus, it is possible to suppress a decrease in output responsiveness. Here, the “predetermined constraint” includes a constraint for the internal combustion engine to operate efficiently.

  In such a power output apparatus of the present invention, the lower limit rotational speed setting means may be means for setting the lower limit rotational speed so as to increase as the output restriction of the power storage means is largely restricted. Further, the lower limit rotational speed setting means may be means for setting the lower limit rotational speed so that the lower the rotational speed, the larger the amount of power stored, which is the amount of power that can be discharged from the power storage means. In these cases, the lower limit rotational speed can be set more appropriately.

  Further, in the power output apparatus of the present invention, the lower limit rotational speed setting means includes a first rotational speed based on the output limit of the power storage means and a second power quantity based on a power storage amount that can be discharged from the power storage means. It can also be means for setting the larger number of rotations among the rotation numbers as the lower limit rotation number. By so doing, when the required driving force increases rapidly, the degree of increase in the rotational speed of the internal combustion engine can be further suppressed based on the output limit of the power storage means and the amount of power stored.

  Further, in the power output device of the present invention, the power output device of the internal combustion engine is connected to the output shaft and the drive shaft and can exchange power with the power storage means, and the power output from the internal combustion engine is accompanied by input and output of power and power. Power motive power input / output means for outputting at least part of the power to the drive shaft is provided, and the control means is means for controlling the internal combustion engine, the electric motor, and the power motive power input / output means. it can. In this case, the electric power drive input / output means is connected to the three shafts of the output shaft of the internal combustion engine, the drive shaft, and the rotary shaft, and is based on the power input / output to any two of the three shafts. It may be a means provided with a three-shaft power input / output means for inputting / outputting power to the remaining shaft and a generator capable of inputting / outputting power to / from the rotating shaft.

  The vehicle of the present invention is the power output device of the present invention according to any one of the above-described aspects, that is, basically a power output device that outputs power to the drive shaft, and can output power to the drive shaft. An internal combustion engine, an electric motor capable of outputting power to the drive shaft, power storage means capable of exchanging electric power with the motor, required drive force setting means for setting a required drive force required for the drive shaft, and the power storage A lower limit rotational speed setting means for setting a lower limit rotational speed of the internal combustion engine based on the state of the means, a temporary rotational speed of the internal combustion engine is set based on the set required driving force and a predetermined constraint, and Target rotational speed setting means for setting the target rotational speed of the internal combustion engine by limiting the set temporary rotational speed by the set lower limit rotational speed, and the internal combustion engine is operated at the set target rotational speed The set required driving force And a control means for controlling the internal combustion engine and the electric motor so that a driving force based on the driving shaft is output to the driving shaft. The power output device is mounted, and the axle is connected to the driving shaft. .

  Since the vehicle according to the present invention is equipped with the power output device of the present invention according to any one of the aspects described above, the effect exhibited by the power output device of the present invention, for example, the effect of suppressing a decrease in output responsiveness, etc. The same effect can be achieved. In addition, by suppressing the decrease in output responsiveness, it is possible to suppress the driver from feeling mottled and to suppress the deterioration of drivability.

The method for controlling the power output apparatus of the present invention includes:
A control method of a power output device comprising: an internal combustion engine capable of outputting power to a drive shaft; an electric motor capable of outputting power to the drive shaft; and an electric storage means capable of exchanging electric power with the motor;
The temporary rotational speed of the internal combustion engine is set based on the required driving force required for the drive shaft and a predetermined constraint, and the lower limit rotational speed of the internal combustion engine is set based on the state of the power storage means. The target rotational speed of the internal combustion engine is set by limiting the provisional rotational speed with the set lower limit rotational speed, and the internal combustion engine is operated at the set target rotational speed and the driving force based on the required driving force is The gist is to control the internal combustion engine and the electric motor so as to be output to the drive shaft.

  According to the control method of the power output apparatus of the present invention, the temporary rotational speed of the internal combustion engine is set based on the required driving force required for the drive shaft and the predetermined constraint, and the internal combustion engine is set based on the state of the power storage means. The target rotational speed of the internal combustion engine is set by limiting the set temporary rotational speed with the lower rotational speed, the internal combustion engine is operated at the target rotational speed, and the driving force based on the required driving force is The internal combustion engine and the electric motor are controlled so as to be output to the drive shaft. Therefore, since the internal combustion engine is operated at a rotational speed equal to or higher than the lower limit rotational speed based on the state of the power storage means, the target of the internal combustion engine that is set based on the required driving force and predetermined restrictions when the required driving force increases rapidly. The degree of increase in the rotational speed can be suppressed according to the state of the power storage means. Thereby, the inertia of the system including the internal combustion engine due to the increase in the rotation speed of the internal combustion engine can be suppressed, and the force in the direction of reducing the rotation speed of the drive shaft acting on the drive shaft due to the inertia can be suppressed. Thus, it is possible to suppress a decrease in output responsiveness. Here, the “predetermined constraint” includes a constraint for the internal combustion engine to operate efficiently.

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

  FIG. 1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 equipped with a power output apparatus according to an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22, a three-shaft power distribution / integration mechanism 30 connected to a crankshaft 26 as an output shaft of the engine 22 via a damper 28, and power distribution / integration. A motor MG1 capable of generating electricity connected to the mechanism 30, a reduction gear 35 attached to a ring gear shaft 32a as a drive shaft connected to the power distribution and integration mechanism 30, a motor MG2 connected to the reduction gear 35, And a hybrid electronic control unit 70 for controlling the entire power output apparatus.

  The engine 22 is an internal combustion engine that outputs power using a hydrocarbon-based fuel such as gasoline or light oil, and an engine electronic control unit (hereinafter referred to as an engine ECU) that receives signals from various sensors that detect the operating state of the engine 22. ) 24 is subjected to operation control such as fuel injection control, ignition control, intake air amount adjustment control and the like. The engine ECU 24 is in communication with the hybrid electronic control unit 70, controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and, if necessary, transmits data related to the operating state of the engine 22 to the hybrid electronic control. Output to unit 70.

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

  The motor MG1 and the motor MG2 are both configured as well-known synchronous generator motors that can be driven as generators and can be driven as motors, and exchange power with the battery 50 via inverters 41 and 42. The power line 54 connecting the inverters 41 and 42 and the battery 50 is configured as a positive electrode bus and a negative electrode bus shared by the inverters 41 and 42, and the electric power generated by one of the motors MG1 and MG2 It can be consumed by a motor. Therefore, battery 50 is charged / discharged by electric power generated from one of motors MG1 and MG2 or insufficient electric power. If the balance of electric power is balanced by the motors MG1 and MG2, the battery 50 is not charged / discharged. The motors MG1 and MG2 are both driven and controlled by a motor electronic control unit (hereinafter referred to as a motor ECU) 40. The motor ECU 40 detects signals necessary for driving and controlling the motors MG1 and MG2, such as signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and current sensors (not shown). The phase current applied to the motors MG1 and MG2 to be applied is input, and a switching control signal to the inverters 41 and 42 is output from the motor ECU 40. The motor ECU 40 is in communication with the hybrid electronic control unit 70, controls the driving of the motors MG1 and MG2 by a control signal from the hybrid electronic control unit 70, and, if necessary, data on the operating state of the motors MG1 and MG2. Output to the hybrid electronic control unit 70.

  The battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52. The battery ECU 52 receives signals necessary for managing the battery 50, for example, an inter-terminal voltage Vb from the voltage sensor 51 a 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 Ib from the attached current sensor 51b, the battery temperature Tb from the temperature sensor 51c attached to the battery 50, and the like are input. Output to the control unit 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 51b in order to manage the battery 50.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72. In addition to the CPU 72, a ROM 74 that stores processing programs, a RAM 76 that temporarily stores data, an input / output port and communication (not shown), and the like. 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 opening Acc from the vehicle, the brake pedal position BP from the brake pedal position sensor 86 for detecting the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the like are input via the input port. As described above, the hybrid electronic control unit 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52. ing.

  The hybrid vehicle 20 of the embodiment thus configured calculates the required torque to be output to the ring gear shaft 32a as the drive shaft based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal 83 by the driver. Then, the operation of the engine 22, the motor MG1, and the motor MG2 is controlled so that the required power corresponding to the required torque is output to the ring gear shaft 32a. As operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is the power distribution and integration mechanism 30. Torque conversion operation mode for driving and controlling the motor MG1 and the motor MG2 so that the torque is converted by the motor MG1 and the motor MG2 and output to the ring gear shaft 32a, and the required power and the power required for charging and discharging the battery 50. The engine 22 is operated and controlled so that suitable power is output from the engine 22, and all or part of the power output from the engine 22 with charging / discharging of the battery 50 is the power distribution and integration mechanism 30, the motor MG1, and the motor. The required power is converted to the ring gear shaft 32 with torque conversion by MG2. Charge / discharge operation mode in which the motor MG1 and the motor MG2 are driven and controlled to be output to each other, and a motor operation mode in which the operation of the engine 22 is stopped and the power corresponding to the required power from the motor MG2 is output to the ring gear shaft 32a. and so on.

  Next, the operation of the thus configured hybrid vehicle 20 of the embodiment 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 repeatedly executed every predetermined time (for example, every several msec).

  When the drive control routine is executed, first, the CPU 72 of the hybrid electronic control unit 70 first determines the accelerator opening Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 88, the rotational speed Nm1, of the motors MG1, MG2. A process of inputting data necessary for control, such as Nm2, the remaining capacity SOC of the battery 50, the input / output limits Win and Wout of the battery 50, is executed (step S100). Here, 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. To do. Further, the remaining capacity SOC of the battery 50 is calculated from the integrated value of the charge / discharge current of the battery 50 detected by the current sensor 51b, and is input from the battery ECU 52 by communication. Further, the input / output restrictions Win and Wout of the battery 50 are set based on the battery temperature Tb of the battery 50 detected by the temperature sensor 51 and the remaining capacity SOC of the battery 50 and are input from the battery ECU 52 by communication. It was. The input / output limits Win and Wout of the battery 50 are set to basic values of the input / output limits Win and Wout based on the battery temperature Tb, and the output limit correction coefficient and the input limit are set based on the remaining capacity 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. 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 thus input, the required torque Tr * to be output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b as the torque required for the vehicle based on the input accelerator opening Acc and the vehicle speed V. And the required power Pe * required for the engine 22 is set (step S110). In the embodiment, the required torque Tr * is determined in advance by storing the relationship between the accelerator opening Acc, the vehicle speed V, and the required torque Tr * in the ROM 74 as a required torque setting map, and the accelerator opening Acc, the vehicle speed V, , The corresponding required torque Tr * is derived and set from the stored map. FIG. 5 shows an example of the required torque setting map. The required power Pe * can be calculated as the sum of the set required torque Tr * multiplied by the rotational speed Nr of the ring gear shaft 32a and the charge / discharge required power Pb * required by the battery 50 and the loss Loss. The rotation speed Nr of the ring gear shaft 32a can be obtained by multiplying the vehicle speed V by the conversion factor k, or can be obtained by dividing the rotation speed Nm2 of the motor MG2 by the gear ratio Gr of the reduction gear 35.

  Subsequently, the temporary engine speed Nettmp and the temporary engine torque Tempmp are set based on the set required power Pe * (step S120). This setting is performed based on an operation line for efficiently operating the engine 22 and the required power Pe *. FIG. 6 shows an example of the operation line of the engine 22 and how the temporary engine speed Nettmp and the temporary engine torque Tentmp are set. As shown in the figure, the temporary engine speed Nettmp and the temporary engine torque Tentmp can be obtained from the intersection of the operation line and a curve with a constant required power Pe * (Netmp × Tempp).

  Next, the temporary lower limit rotational speed Nemin1 of the engine 22 is set based on the output limit Wout of the battery 50 (step S130), and the temporary lower limit rotational speed Nemin2 of the engine 22 is set based on the remaining capacity SOC of the battery 50 ( Step S140), the larger one of the set provisional lower limit rotation speed Nemin1 and provisional lower limit rotation speed Nemin2 is set as the lower limit rotation speed Nemin of the engine 22 (step S150). Here, the provisional lower limit rotation speed Nemin1 is obtained by preliminarily determining the relationship between the output limit Wout of the battery 50 and the provisional lower limit rotation speed Nemin1 by an experiment or the like and storing it as a map in the embodiment. The corresponding provisional lower limit rotational speed Nemin1 is derived from the stored map and set. An example of the relationship between the output limit Wout of the battery 50 and the temporary lower limit rotation speed Nemin1 is shown in FIG. As shown in the figure, the provisional lower limit rotation speed Nemin1 is set to be constant when the output limit Wout of the battery 50 is equal to or greater than a predetermined value W1, and the output limit Wout is greatly limited when the output limit Wout is less than the predetermined value W1. The tendency to become larger was set. Here, the predetermined value W1 is equal to the torque output from the engine 22 to the ring gear shaft 32a via the power distribution integration mechanism 30 when the required torque Tr * increases rapidly, such as when the accelerator pedal 83 is greatly depressed, and the motor MG2. Can be set near the lower limit of the output limit Wout of the battery 50 that can sufficiently cope with the driver's request by the torque output to the ring gear shaft 32a, and is determined by the characteristics of the battery 50 and the like. Therefore, the provisional lower limit rotational speed Nemin1 is set to increase as the upper limit of the torque that can be output from the motor MG2 to the ring gear shaft 32a using the electric power from the battery 50 is greatly limited. Further, in the embodiment, the temporary lower limit rotation speed Nemin2 is stored as a map in which the relationship between the remaining capacity SOC of the battery 50 and the temporary lower limit rotation speed Nemin2 is determined in advance through experiments or the like, and stored when the remaining capacity SOC is given. The corresponding provisional lower limit rotation speed Nemin2 is derived from the map and set. An example of the relationship between the output limit Wout of the battery 50 and the temporary lower limit rotation speed Nemin2 is shown in FIG. As shown in the figure, the temporary lower limit Nemin2 is set to be constant when the remaining capacity SOC of the battery 50 is greater than or equal to the predetermined remaining capacity S1, and the remaining capacity SOC is smaller when the remaining capacity SOC of the battery 50 is less than the predetermined remaining capacity S1. The smaller the value, the larger the tendency. Here, the predetermined remaining capacity S1 is the torque and motor that are output from the engine 22 to the ring gear shaft 32a via the power distribution and integration mechanism 30 when the required torque Tr * increases rapidly, such as when the accelerator pedal 83 is greatly depressed. The torque output from the MG2 to the ring gear shaft 32a can be set near the lower limit of the remaining capacity SOC of the battery 50 that can sufficiently cope with the driver's request, and is determined by the characteristics of the battery 50, for example, 35%, 40%, 45%, etc. Accordingly, the temporary lower limit rotational speed Nemin2 is set to increase as the upper limit of the torque that can be output from the motor MG2 to the ring gear shaft 32a using the electric power from the battery 50 is limited, similarly to the temporary lower limit rotational speed Nemin1. Will be. The reason why the temporary lower limit rotation speed Nemin1 and the temporary lower limit rotation speed Nemin2 are set as described above will be described later.

  When the lower limit rotational speed Nemin is set in this way, the temporary engine rotational speed Netmp is compared with the lower limit rotational speed Nemin (step S160). The temporary engine torque Tempmp is set as the target torque Te * of the engine 22 (step S170). When the temporary engine speed Netmp is less than the lower limit speed Nemin, the lower limit speed Nemin is set as the target of the engine 22. The target torque Te * of the engine 22 is set by setting the rotational speed Ne * and dividing the required power Pe * by the target rotational speed Ne * (step S180). That is, the target rotational speed Ne * is set as the rotational speed equal to or higher than the lower limit rotational speed Nemin set based on the output limit Wout of the battery 50 and the remaining capacity SOC.

  When the target rotational speed Ne * and the target torque Te * of the engine 22 are set, the set target rotational speed Ne *, 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 are used. Then, the target rotational speed Nm1 * of the motor MG1 is calculated by the following equation (1), and the target torque Te *, the gear ratio ρ of the power distribution and integration mechanism 30, the target rotational speed Nm1 * of the motor MG1 and the current rotational speed Nm1. Based on the equation (2), a torque command Tm1 * for the motor MG1 is calculated (step S190). Here, Expression (1) is a dynamic relational expression for the rotating element of the power distribution and integration mechanism 30. FIG. 9 is a collinear diagram showing a dynamic relationship between the number of rotations and torque in 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 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. The two thick arrows on the R axis indicate that the torque Tm1 output from the motor MG1 acts on the ring gear shaft 32a and the torque Tm2 output from the motor MG2 acts on the ring gear shaft 32a via the reduction gear 35. Torque. Expression (1) can be easily derived by using this alignment chart. Equation (2) is a torque for balancing the torque output from the engine 22 and acting on the sun gear 31, and a torque for canceling the difference between the target rotational speed Nm1 * of the motor MG1 and the rotational speed Nm1. The torque command Tm1 * of the motor MG1 is set as the sum of the torque considering the inertia Ti of the system including the engine 22 and the motor MG1. In the formula (2), the first term on the right side can be easily derived from the alignment chart of FIG. Further, the second term and the third term on the right side are feedback control terms for rotating the motor MG1 at the target rotational speed Nm1 *, the second term “k1” on the right side is the gain of the proportional term, and the third term on the right side. The term “k2” is the gain of the integral term. Further, the fourth term on the right side can be calculated using the moment of inertia of the system including the engine 22 and the motor MG1 and the time derivative of the rotational speed Nm1 of the motor MG1.

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

  When the target rotational speed Nm1 * and the torque command Tm1 * of the motor MG1 are thus calculated, the input / output limits Win and Wout of the battery 50 and the calculated torque command Tm1 * of the motor MG1 are multiplied by the current rotational speed Nm1 of the motor MG1. Torque limits Tmin and Tmax as upper and lower limits of the torque that may be output from the motor MG2 by dividing the deviation from the obtained power consumption (generated power) of the motor MG1 by the rotational speed Nm2 of the motor MG2 is expressed by the following equation (3). In addition, the temporary motor torque Tm2tmp as the torque to be output from the motor MG2 is calculated using the required torque Tr *, the torque command Tm1 *, and the gear ratio ρ of the power distribution and integration mechanism 30 (step S200). Calculated by equation (5) (step S210), and with the calculated torque limits Tmin and Tmax Setting the torque command Tm2 * of the motor MG2 as a value obtained by limiting the motor torque Tm2tmp (step S220). By setting the torque command Tm2 * of the motor MG2 in this way, the required torque Tr * output to the ring gear shaft 32a as the drive shaft is set as a torque limited within the range of the input / output limits Win and Wout of the battery 50. can do. Equation (5) can be easily derived from the collinear diagram of FIG. 9 described above. In the formula (5), the torque command Tm1 * is a torque that takes into account the inertia of the system including the engine 22 and the motor MG1, and therefore, the torque output to the ring gear shaft 32a as the drive shaft also takes into account the inertia. It will be.

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

  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. The torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are transmitted to the motor ECU 40 (step S230), and the drive control routine is terminated. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * performs fuel injection control in the engine 22 such that the engine 22 is operated at an operating point indicated by the target rotational speed Ne * and the target torque Te *. Controls such as 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.

  Now, when the output limit Wout of the battery 50 is greatly limited or when the remaining capacity SOC of the battery 50 is small, the upper limit of the torque that can be output from the motor MG2 to the ring gear shaft 32a as the drive shaft using the power from the battery 50 Let us consider a case where the accelerator pedal 83 is greatly depressed when is small. When the accelerator pedal 83 is depressed greatly, the required torque Tr * increases rapidly, and the required power Pe * based on the required torque Tr * increases rapidly. Therefore, when the rotational speed Ne of the engine 22 is small, an attempt is made to increase it. At this time, since the inertia of the system including the engine 22 caused by increasing the rotational speed Ne acts on the ring gear shaft 32a as a force in the direction of decelerating the vehicle, it is necessary to output torque taking this into account from the motor MG2. In some cases, the output responsiveness with respect to the driver's request is reduced, and the driver feels mottled. In the embodiment, when the output speed limit Wout is largely limited by setting the target speed Ne * of the engine 22 as the speed equal to or higher than the lower limit speed Nemin based on the output limit Wout of the battery 50 and the remaining capacity SOC. Alternatively, when the accelerator pedal 83 is largely depressed by the driver when the remaining capacity SOC is small, the degree of increase in the rotational speed Ne of the engine 22 can be suppressed. Thereby, the force acting on the ring gear shaft 32a as the force in the direction in which the inertia of the system including the engine 22 decelerates the vehicle can be suppressed, and the decrease in output response can be suppressed. As a result, it is possible to suppress the driver from feeling mottled and to suppress the deterioration of drivability. Moreover, when setting the target rotational speed Ne * of the engine 22, the larger value of the temporary lower limit rotational speed Nemin1 based on the output limit Wout of the battery 50 and the temporary lower limit rotational speed Nemin2 based on the remaining capacity SOC of the battery 50. Is used as the lower limit rotational speed Nemin, the degree of increase in the rotational speed Ne of the engine 22 when the required torque Tr * increases rapidly can be further suppressed, and the decrease in output responsiveness can be further suppressed.

  According to the hybrid vehicle 20 of the embodiment described above, the engine 22 is operated at the target rotational speed Ne * set as the rotational speed equal to or higher than the lower limit rotational speed Nemin based on the output limit Wout of the battery 50 and the remaining capacity SOC. The degree of increase in the rotational speed Ne of the engine 22 when the required torque Tr * increases rapidly, such as when the driver depresses the accelerator pedal 83 greatly, can be suppressed. As a result, when the upper limit of the torque that can be output from the motor MG2 using the power from the battery 50 to the ring gear shaft 32a is greatly limited, the inertia of the system including the engine 22 is greatly increased in the ring gear shaft 32a as the drive shaft. It is possible to suppress a decrease in output responsiveness due to the action, and to prevent the driver from feeling mottled. As a result, it is possible to suppress deterioration of drivability.

  In the hybrid vehicle 20 of the embodiment, the larger one of the temporary lower limit rotation speed Nemin1 based on the output limit Wout of the battery 50 and the temporary lower limit rotation speed Nemin2 based on the remaining capacity SOC of the battery 50 is set as the lower limit rotation speed Nemin. However, the smaller one may be set as the lower limit rotational speed Nemin. Further, in the hybrid vehicle 20 of the embodiment, the lower limit rotation speed Nemin is set based on the output limit Wout of the battery 50 and the remaining capacity SOC, but only the output limit Wout without using the remaining capacity SOC of the battery 50. The lower limit rotational speed Nemin may be set based on the above, or the lower limit rotational speed Nemin may be set based only on the remaining capacity SOC without using the output limit Wout.

  In the hybrid vehicle 20 of the embodiment, as shown in FIG. 7, the provisional lower limit rotational speed tends to increase linearly as the output limit Wout is greatly limited in the region where the output limit Wout of the battery 50 is less than the predetermined value W1. Although Nemin1 is set, the provisional lower limit rotation speed Nemin1 may be set so that the lower the output limit Wout in the region where the output limit Wout is less than the predetermined value W1, the larger the curve becomes, and the output limit Wout may be set. The provisional lower limit rotation speed Nemin1 may be set so that the smaller the output limit Wout is in a region where the value is less than the predetermined value W1, the number of steps becomes one step or more. Further, the provisional lower limit rotation speed Nemin1 may be set such that the output limit Wout of the battery 50 tends to increase as the output limit Wout decreases, regardless of whether the output limit Wout is less than the predetermined value W1.

  In the hybrid vehicle 20 of the embodiment, as shown in FIG. 8, the provisional lower limit rotational speed Nemin2 tends to increase linearly as the remaining capacity SOC decreases in a region where the remaining capacity SOC of the battery 50 is less than the predetermined remaining capacity S1. However, the provisional lower limit rotational speed Nemin2 may be set such that the lower the remaining capacity SOC is, the smaller the remaining capacity SOC is in a region where the remaining capacity SOC is less than the predetermined remaining capacity S1. The provisional lower limit rotation speed Nemin2 may be set such that the smaller the remaining capacity SOC in the region less than the predetermined remaining capacity S1, the larger the number of steps is, and the remaining capacity SOC is less than the predetermined remaining capacity S1. Regardless of whether or not this region is, the provisional lower limit rotational speed Nemin2 may be set so that the smaller the remaining capacity SOC is, the larger the tendency is.

  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).

  In the hybrid vehicle 20 of the embodiment, the power from the engine 22 is output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b via the power distribution and integration mechanism 30, but the modification of FIG. As illustrated in the example hybrid vehicle 220, the engine 22 includes an inner rotor 232 connected to the crankshaft 26 of the engine 22 and an outer rotor 234 connected to a drive shaft that outputs power to the drive wheels 63a and 63b. It is good also as what is provided with the counterrotor motor 230 which transmits a part of motive power of 22 to a drive shaft, and converts the remaining motive power into electric power.

  In the hybrid vehicle 20 of the embodiment, the power from the engine 22 is output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b via the power distribution and integration mechanism 30, and the power from the motor MG2 is output to the ring gear shaft. However, any vehicle that travels using the power from the engine and the power from the motor may be used.

  Moreover, it is not limited to what is applied to such a hybrid vehicle, It is good also as a form of the power output device mounted in vehicles other than a motor vehicle, a ship, an aircraft, etc. Furthermore, it is good also as a form of the control method of such a power output device.

  The embodiments of the present invention have been described using the embodiments. However, the present invention is not limited to these embodiments, and can be implemented in various forms without departing from the gist of the present invention. Of course you get.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 according to an embodiment of the present invention. It is a flowchart which shows an example of the drive control routine performed by the hybrid electronic control unit 70 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 a mode that an example of the operation line of the engine 22, and temporary engine speed Nettmp and temporary engine torque Tentmp are set. It is explanatory drawing which shows an example of the relationship between the output limitation Wout of the battery 50, and provisional minimum rotation speed Nemin1. It is explanatory drawing which shows an example of the relationship between the remaining capacity SOC of the battery 50, and provisional minimum rotation speed Nemin2. FIG. 4 is an explanatory diagram showing an example of a collinear diagram for dynamically explaining rotational elements of a power distribution and integration mechanism 30; FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 220 of a modified example.

Explanation of symbols

20, 120, 220 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 power distribution integration mechanism, 31 sun gear, 32 ring gear, 32a ring gear shaft, 33 pinion gear, 34 carrier 35, reduction gear, 40 motor electronic control unit (motor ECU), 41, 42 inverter, 43, 44 rotational position detection sensor, 50 battery, 51a voltage sensor, 51b current sensor, 51c temperature sensor, 52 electronic control unit for battery (Battery ECU), 54 power line, 60 gear mechanism, 62 differential gear, 63a, 63b driving wheel, 64a, 64b wheel, 70 hybrid electronic control unit, 72 CPU, 74 ROM, 76 RAM, 80 Ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, 230 counter rotor motor, 232 inner rotor 234 outer rotor, MG1 , MG2 motor.

Claims (7)

A power output device that outputs power to a drive shaft,
An internal combustion engine capable of outputting power to the drive shaft;
An electric motor capable of outputting power to the drive shaft;
Power storage means capable of exchanging electric power with the electric motor;
Required driving force setting means for setting required driving force required for the drive shaft;
Of the first rotation speed based on the output limit of the power storage means and the second rotation speed based on the power storage amount that is the amount of power that can be discharged from the power storage means, the larger rotation speed is the lower limit rotation speed of the internal combustion engine. and the lower limit rotation speed setting means for setting as,
A temporary rotational speed of the internal combustion engine is set on the basis of the set required driving force and a predetermined constraint, and the set temporary rotational speed is limited by the set lower limit rotational speed to achieve a target rotational speed of the internal combustion engine Target speed setting means for setting the number;
Control means for controlling the internal combustion engine and the electric motor so that the internal combustion engine is operated at the set target rotational speed and a drive force based on the set required drive force is output to the drive shaft;
A power output device comprising:   The power output apparatus according to claim 1, wherein the lower limit rotational speed setting means is a means for setting the lower limit rotational speed such that the lower limit rotational speed tends to increase as the output limit of the power storage means is largely limited.   3. The power output apparatus according to claim 1, wherein the lower limit rotational speed setting means is a means for setting the lower limit rotational speed such that the lower limit rotational speed tends to increase as the power storage amount, which is the amount of power that can be discharged from the power storage device, decreases. The power output device according to any one of claims 1 to 3 ,
Connected to the output shaft of the internal combustion engine and the drive shaft and capable of exchanging electric power with the power storage means, and at least part of the power from the internal combustion engine with the input and output of electric power and power is the drive shaft Power power input / output means to output to
The control means is a means for controlling the internal combustion engine, the electric motor, and the power power input / output means. The electric power drive input / output means is connected to the three shafts of the output shaft of the internal combustion engine, the drive shaft, and the rotary shaft, and the remaining shaft based on the power input / output to / from any two of the three shafts 5. The power output apparatus according to claim 4 , wherein the power output device comprises: a three-axis power input / output means for inputting / outputting power to / from the power generator; and a generator capable of inputting / outputting power to / from the rotating shaft. A vehicle comprising the power output device according to any one of claims 1 to 5 and an axle connected to the drive shaft. A control method of a power output device comprising: an internal combustion engine capable of outputting power to a drive shaft; an electric motor capable of outputting power to the drive shaft; and an electric storage means capable of exchanging electric power with the motor;
The temporary rotational speed of the internal combustion engine is set based on the required driving force required for the drive shaft and a predetermined constraint, and the first rotational speed based on the output limit of the power storage means can be discharged from the power storage means The larger rotation speed of the second rotation speed based on the amount of stored electric power is set as the lower limit rotation speed of the internal combustion engine, and the set temporary rotation speed is limited by the set lower limit rotation speed. The internal combustion engine and the electric motor are set such that a target rotational speed of the internal combustion engine is set, the internal combustion engine is operated at the set target rotational speed, and a driving force based on the required driving force is output to the driving shaft. Control method for power output device.

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