JP2007223403A - Power output device, its control method, and vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To much more properly cope with an environment, and to suppress to cause any feeling of incompatibility to a driver. <P>SOLUTION: A request torque limit Trmax is set by using a temporary request torque limit Trmaxtump as the upper limit of torque which can be requested to a driving shaft and a correction coefficient α based on an atmospheric pressure Pa or air intake temperature Ta on which the air density of an engine is reflected and a correction value β based on an output limit Wout of a battery (S120 to S150), and execution torque T* is set by limiting request torque Tr* requested to the driving shaft by using the request torque limit Trmax (S160), and the engine and motors MG1 and MG2 are controlled so that the execution torque T* can be output to the driving shaft (S170 to S230). Thus, when the air density is low, or the output limit Wout is small, it is possible to suppress the fluctuation of torque to be output to the driving shaft based on whether or not inertia accompanied with the rotation fluctuation of the engine or the motor MG1 acts on the driving shaft, and to suppress causing feeling of incompatibility to a driver. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

Conventionally, this type of power output apparatus includes an engine, a planetary gear having a carrier connected to the output shaft of the engine and a ring gear connected to the axle, a first motor that inputs and outputs power to the planetary gear, and an axle side. There has been proposed a battery that includes a second motor that inputs and outputs power, and a battery that can exchange power with the first motor and the second motor (see, for example, Patent Document 1). In this device, the torque command value to be output to the ring gear is set based on the depression amount of the accelerator pedal and the rotation speed of the ring gear, and the engine and the two motors are controlled so that the set torque command value is output to the ring gear. To do.
JP-A-9-308012

  In the power output apparatus described above, the environment is good when the environment is in a normal state (for example, the atmospheric pressure is 1 atm and the outside air temperature is 25 degrees). However, for example, in a high altitude environment, the atmospheric pressure is low and the air density is small. The upper limit of the power that can be output from the engine is smaller than that in the lowland environment, and the upper limit of the torque that can be constantly output to the ring gear is reduced. When the air density is low, the torque command value to be output to the ring gear is set in the same way as in the normal state and the engine and the two motors are controlled so that this torque command value is output to the ring gear. When the torque command value is larger than the upper limit of the torque that can be output to the engine, the torque output to the ring gear fluctuates depending on whether or not the inertia accompanying the rotation fluctuation of the engine or the first motor acts on the ring gear. May feel uncomfortable.

  The power output device, the control method thereof, and the vehicle according to the present invention are intended to deal with the environment more appropriately. Another object of the power output device, the control method thereof, and the vehicle of the present invention is to suppress the driver from feeling uncomfortable.

  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;
An air density related physical quantity detecting means for detecting an air density related physical quantity related to the density of air sucked into the internal combustion engine;
Target driving force setting means for setting a target driving force to be output to the driving shaft based on the required driving force required for the driving shaft and the detected air density-related physical quantity;
Control means for controlling the internal combustion engine and the electric motor so that the set target driving force is output to the driving shaft;
A power output device comprising:
It is a summary to provide.

  In the power output apparatus of the present invention, the target driving force to be output to the drive shaft is set based on the required driving force required for the drive shaft and the air density related physical quantity related to the density of air sucked into the internal combustion engine. Then, the internal combustion engine and the electric motor are controlled so that the set target driving force is output to the driving shaft. That is, the target driving force is set and controlled in consideration of the air density related physical quantity. Thereby, it can control more appropriately according to an air density related physical quantity. As a result, it is possible to deal with the environment more appropriately.

  In such a power output apparatus of the present invention, the target driving force setting means generates a limiting driving force based on an upper limit driving force that is an upper limit of a driving force that can be requested to the drive shaft and the detected air density related physical quantity. It is also possible to set the driving force obtained by setting and limiting the required driving force using the set limiting driving force as the target driving force. By so doing, it is possible to set the target driving force using the limited driving force set more appropriately according to the air density related physical quantity. Here, the “upper limit driving force” refers to whether or not the driving force below the upper limit of the driving force that can be constantly output to the driving shaft, that is, whether or not the inertia accompanying the rotational fluctuation of the system including the internal combustion engine acts on the driving shaft. Regardless, the driving force can be less than the upper limit of the driving force that can be output to the drive shaft.

  In the power output apparatus of the present invention, the air density related physical quantity detection means may be means including atmospheric pressure detection means for detecting atmospheric pressure. Here, in setting the target driving force using the limiting driving force, the target driving force setting means is a means for setting the limiting driving force so as to decrease as the detected atmospheric pressure decreases. It can also be. In this way, the target driving force can be set more appropriately according to the atmospheric pressure. As a result, when the atmospheric pressure is low and the air density is small, the drive that is output to the drive shaft based on whether or not the inertia acts on the drive shaft as compared with the one that sets the target drive force regardless of the atmospheric pressure The fluctuation of force can be suppressed, and the driver can be prevented from feeling uncomfortable.

  Furthermore, in the power output apparatus of the present invention, the air density related physical quantity detecting means may be means including temperature detecting means for detecting an intake air temperature which is a temperature of air sucked into the internal combustion engine. it can. Here, in the setting of the target driving force using the limiting driving force, the target driving force setting means is a means for setting the limiting driving force so as to decrease as the detected intake air temperature increases. It can also be. In this way, the target driving force can be set more appropriately according to the intake air temperature. As a result, when the intake air temperature is high and the air density is low, it is output to the drive shaft based on whether or not the inertia acts on the drive shaft as compared with the case where the target drive force is set regardless of the intake air temperature. Torque can be suppressed, and the driver can be prevented from feeling uncomfortable.

  Alternatively, in the power output apparatus of the present invention, the target driving force setting means sets the target driving force based on the required driving force, the detected air density related physical quantity, and an output limit of the power storage means. It can also be assumed. In this way, it is possible to set the target driving force more appropriately in consideration of the output limitation of the power storage means. In this case, the target driving force setting means becomes smaller based on the upper limit driving force, the detected air density related physical quantity, and the output limit of the power storage means, as the output limit of the power storage means is largely limited. The limiting driving force may be set in a tendency, and the driving force that limits the required driving force using the set limiting driving force may be set as the target driving force. In this way, when the output limit of the power storage means is greatly limited and the upper limit of the drive force that can be output from the motor is greatly limited, the target drive force is set regardless of the output limit of the power storage means. Thus, fluctuations in torque output to the drive shaft based on whether the inertia acts on the drive shaft can be suppressed, and the driver can be prevented from feeling uncomfortable.

  In the power output apparatus of the present invention, the power output from the internal combustion engine is connected to the output shaft and the drive shaft of the internal combustion engine and can exchange power with the power storage means, and the power from the internal combustion engine is input and output with power and power. Electric power power input / output means for outputting at least part of the power to the drive shaft, and the control means outputs the internal combustion engine, the electric motor, and the power power so that the set target drive power is output to the drive shaft. It can also be a means for controlling the input / output means. 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, an electric storage means capable of exchanging electric power with the electric motor, and an air density for detecting an air density-related physical quantity related to the density of air sucked into the internal combustion engine Related physical quantity detection means; target drive force setting means for setting a target drive force to be output to the drive shaft based on the required drive force required for the drive shaft and the detected air density related physical quantity; and A power output device including a control means for controlling the internal combustion engine and the electric motor so that a set target driving force is output to the driving shaft, and an axle is connected to the driving shaft. Abstract

  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 above-described aspects, it can be controlled more appropriately according to the effects exhibited by the power output device of the present invention, for example, the air density related physical quantity. It is possible to achieve the same effects as those capable of dealing with the environment more appropriately.

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;
A target driving force to be output to the driving shaft is set based on a required driving force required for the driving shaft and an air density related physical quantity related to the density of air sucked into the internal combustion engine, and the set target The gist is to control the internal combustion engine and the electric motor so that a driving force is output to the driving shaft.

  According to the control method of the power output apparatus of the present invention, the output should be output to the drive shaft based on the required drive force required for the drive shaft and the air density related physical quantity related to the density of the air sucked into the internal combustion engine. A target driving force is set, and the internal combustion engine and the electric motor are controlled so that the set target driving force is output to the drive shaft. That is, the target driving force is set and controlled in consideration of the air density related physical quantity. Thereby, it can control more appropriately according to an air density related physical quantity. As a result, it is possible to deal with the environment more appropriately.

  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 configured as an internal combustion engine capable of outputting power using a hydrocarbon-based fuel such as gasoline or light oil, and the air purified by an air cleaner 122 is passed through a throttle valve 124 as shown in FIG. Inhaled and gasoline is injected from the fuel injection valve 126 to mix the sucked air and gasoline, and this mixture is sucked into the fuel chamber through the intake valve 128 and explosively burned by an electric spark from the spark plug 130. Thus, the reciprocating motion of the piston 132 pushed down by the energy is converted into the rotational motion of the crankshaft 23. Exhaust gas from the engine 22 is discharged to the outside air through a purification device (three-way catalyst) 134 that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx).

  The engine 22 is controlled by an engine electronic control unit (hereinafter referred to as an engine ECU) 24. The engine ECU 24 is configured as a microprocessor centered on the CPU 24a, and includes a ROM 24b that stores a processing program, a RAM 24c that temporarily stores data, an input / output port and a communication port (not shown), in addition to the CPU 24a. . The engine ECU 24 includes signals from various sensors that detect the state of the engine 22, a crank position from the crank position sensor 140 that detects the rotational position of the crankshaft 23, and a water temperature sensor 142 that detects the temperature of cooling water in the engine 22. From the cooling water temperature from the combustion chamber, the in-cylinder pressure Pin from the pressure sensor 143 installed in the combustion chamber, the intake valve 128 that performs intake and exhaust to the combustion chamber, and the cam position sensor 144 that detects the rotational position of the camshaft that opens and closes the exhaust valve Cam position, throttle position from throttle valve position sensor 146 for detecting the position of throttle valve 124, air flow meter signal AF from air flow meter 148 attached to the intake pipe, and temperature sensor also attached to the intake pipe Intake air temperature Ta from 49, the air-fuel ratio from an air-fuel ratio sensor 135a, such as oxygen signal from an oxygen sensor 135b is input via the input port. The engine ECU 24 also integrates various control signals for driving the engine 22, such as a drive signal to the fuel injection valve 126, a drive signal to the throttle motor 136 that adjusts the position of the throttle valve 124, and an igniter. The control signal to the ignition coil 138 and the control signal to the variable valve timing mechanism 150 that can change the opening / closing timing of the intake valve 128 are output via the output port. 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 outputs data related to the operation state of the engine 22 as necessary. .

  The power distribution and integration mechanism 30 includes an external gear sun gear 31, an internal gear ring gear 32 arranged concentrically with the sun gear 31, a plurality of pinion gears 33 that mesh with the sun gear 31 and mesh with the ring gear 32, A planetary gear mechanism is provided that includes a carrier 34 that holds a plurality of pinion gears 33 so as to rotate and revolve, and that performs differential action using the sun gear 31, the ring gear 32, and the carrier 34 as rotational elements. 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, a voltage between terminals from a voltage sensor (not shown) installed between terminals of the battery 50, and a power line 54 connected to the output terminal of the battery 50. The charging / discharging current from the attached current sensor (not shown), the battery temperature Tb from the temperature sensor 51 attached to the battery 50, and the like are input. Output to the control unit 70. The battery ECU 52 also calculates the remaining capacity (SOC) based on the integrated value of the charge / discharge current detected by the current sensor in order to manage the battery 50.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port and communication not shown. And a port. The hybrid electronic control unit 70 includes an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. The accelerator pedal opening Acc from the vehicle, the brake pedal position BP from the brake pedal position sensor 86 for detecting the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the like are input via the input port. As described above, the hybrid electronic control unit 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52. ing.

  The hybrid vehicle 20 of the embodiment thus configured calculates the required torque to be output to the ring gear shaft 32a as the drive shaft based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal 83 by the driver. Then, the operation of the engine 22, the motor MG1, and the motor MG2 is controlled so that the required power corresponding to the required torque is output to the ring gear shaft 32a. As operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that 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. 3 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, the CPU 72 of the hybrid electronic control unit 70 firstly opens the accelerator opening Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 88, and the atmospheric pressure Pa from the atmospheric pressure sensor 89. , A process of inputting data necessary for control, such as intake air temperature Ta, motor speeds Nm1, Nm2, and input / output limits Win, Wout of the battery 50 (step S100). Here, as the intake air temperature Ta, the intake air temperature Ta detected by the temperature sensor 149 is input from the engine ECU 24 by communication. Further, the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 are input from the motor ECU 40 by communication from those calculated based on the rotational positions of the rotors of the motors MG1 and MG2 detected by the rotational position detection sensors 43 and 44. It was supposed to be. Further, the input / output limits Win and Wout of the battery 50 are set based on the battery temperature Tb of the battery 50 detected by the temperature sensor 51 and the remaining capacity (SOC) of the battery 50 from the battery ECU 52 by communication. To do. The input / output limits Win and Wout of the battery 50 are set to the basic values of the input / output limits Win and Wout based on the battery temperature Tb, and the output limiting correction coefficient and the input are set based on the remaining capacity (SOC) of the battery 50. It can be set by setting a correction coefficient for restriction and multiplying the basic value of the set input / output restrictions Win and Wout by the correction coefficient. FIG. 4 shows an example of the relationship between the battery temperature Tb and the input / output limits Win, Wout, and FIG. 5 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. Is set (step S110), and the required torque Tr * when the accelerator opening Acc at the input vehicle speed V is 100% is set as the temporary required torque limit Trmaxtmp (step S120). 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. 6 shows an example of the required torque setting map. In FIG. 6, the required torque Tr * when the accelerator opening degree Acc is 100% is the maximum that can be output to the ring gear shaft 32a in the normal state (for example, the atmospheric pressure Pa is 1 atm and the intake air temperature Ta is 25 degrees). Although it can be set as a torque equal to or less than the torque, in the embodiment, for the sake of simplicity, the maximum torque that can be steadily output to the ring gear shaft 32a in the normal state is set. Here, the maximum torque that can be steadily output to the ring gear shaft 32a in the normal state is whether or not the inertia accompanying the rotation fluctuation of the system including the engine 22 and the motor MG1 acts on the ring gear shaft 32a as the drive shaft. Regardless, the upper limit of the torque that can be output to the ring gear shaft 32a can be set based on the ratings of the engine 22 and the motors MG1, MG2. The temporary required torque limit Trmaxtmp can be set in the same manner as the required torque Tr * using the required torque setting map of FIG.

  Subsequently, the correction coefficient α is set based on the atmospheric pressure Pa reflecting the density of the intake air sucked into the engine 22 and the intake air temperature Ta (step S130), and the correction value based on the output limit Wout of the battery 50. β is set (step S140), and the upper limit of the torque that can be constantly output to the ring gear shaft 32a by subtracting the correction value β from the product of the temporary required torque limit Trmaxtmp multiplied by the correction coefficient α, that is, from the engine 22 and the motor MG1. A required torque limit Trmax, which is the upper limit of the torque that can be output to the ring gear shaft 32a, is set regardless of whether or not the inertia accompanying the rotation fluctuation of the system acts on the ring gear shaft 32a (step S150), and the set required torque limit Ring gear shaft as drive shaft by limiting required torque Tr * with Trmax 2a to set the actual torque T * to be output (step S160). Here, when the required torque limit Trmax is calculated, the correction coefficient α reflecting the intake air density is output from the engine 22 depending on the intake air density even at the same rotation speed and the same throttle opening. This is because the upper limit of the torque that can be output from the engine 22 to the ring gear shaft 32a as the drive shaft via the power distribution and integration mechanism 30 (hereinafter, this torque is referred to as the upper limit direct torque) is different due to the difference in power. In the embodiment, the relationship between the density of the intake air and the required torque limit Trmax is determined in advance by experiments or the like, and the correction coefficient α is set so as to satisfy this relationship. The correction coefficient α is set by setting the correction coefficient αp based on the atmospheric pressure Pa, setting the correction coefficient αt based on the intake air temperature Ta, and multiplying the set correction coefficient αp and the correction coefficient αt. . FIG. 7 shows the relationship between the atmospheric pressure Pa and the correction coefficient αp, and FIG. 8 shows the relationship between the intake air temperature Ta and the correction coefficient αt. In the example of FIG. 7, when the atmospheric pressure Pa falls within the range from the pressure P1 including the standard pressure (for example, 1 atm) Pset to the pressure P2, the value 1.0 is set to the correction coefficient αp, and the atmospheric pressure is lower than the pressure P1. In some cases, the correction coefficient αp is set so as to decrease as the atmospheric pressure Pa decreases, and conversely, when the atmospheric pressure Pa is higher than the pressure P2, the correction coefficient αp is set so as to increase as the atmospheric pressure Pa increases. That is, the pressure P1 to the pressure P2 are pressures that set a dead zone that holds the correction coefficient αp at the standard pressure Pset. In the embodiment, the lower the atmospheric pressure Pa is, the smaller the air density is, and the upper limit direct torque from the engine 22 is smaller. Therefore, the correction coefficient αp is set so that the lower the atmospheric pressure Pa is, the smaller the required torque limit Trmax is. It was used for calculation. By providing the dead zone, it is possible to suppress excessive correction by the atmospheric pressure Pa when the atmospheric pressure Pa is in the vicinity of the standard pressure Pset. In the example of FIG. 8, when the intake air temperature Ta falls within the range from the temperature T1 including the standard temperature (for example, 25 ° C.) Tset to the temperature T2, the correction coefficient αt is set to 1.0, and the intake air temperature Ta is lower than the temperature T1. In some cases, the correction coefficient αt is set so as to increase as the intake air temperature Ta decreases, and conversely, when the intake air temperature Ta is higher than the temperature T2, the correction coefficient αt is set to increase as the intake air temperature Ta increases. That is, the temperature T1 to the temperature T2 are temperatures for setting a dead zone that holds the correction coefficient αt at the standard temperature Tset. In the embodiment, the higher the intake air temperature Ta, the smaller the air density and the lower the upper limit direct torque from the engine 22. Therefore, the correction coefficient αt is set so that the higher the intake air temperature Ta, the smaller the required torque limit Trmax. It was used for calculation. By providing the dead zone, it is possible to suppress excessive correction by the intake air temperature Ta when the intake air temperature Ta is near the standard temperature Tset. When calculating the required torque limit Trmax, the correction value β based on the output limit Wout of the battery 50 is different from the upper limit of the torque that can be output from the motor MG2 according to the output limit Wout of the battery 50. This is because the upper limit of the torque that can be output to the ring gear shaft 32a is different. In the embodiment, the relationship between the output limit Wout of the battery 50 and the required torque limit Trmax is determined in advance by experiments and the correction value β is set so as to satisfy this relationship. FIG. 9 shows the relationship between the output limit Wout of the battery 50 and the correction value β. In the example of FIG. 9, the correction value β tends to increase as the output limit Wout of the battery 50 decreases. This is because when the output limit Wout of the battery 50 is relatively large, that is, when the electric power that can be discharged from the battery 50 is largely limited, the upper limit of the torque that can be output from the motor MG2 is greatly limited. This is because the upper limit of the torque that can be output to 32a is greatly limited. By setting the correction value α and the correction value β in this manner, the required torque limit Trmax is set to be smaller as the atmospheric pressure Pa is lower, and is set to be smaller as the intake air temperature Ta is higher. The output limit Wout is set so as to decrease as the output limit Wout is greatly limited.

  Next, the required power Pe * required by the engine 22 as the sum of the set execution torque T * 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. (Step S170), and based on the calculated required power Pe *, the target rotational speed Ne * and the target torque Te * of the engine 22 are set (step S180). Here, the rotational speed Nr of the ring gear shaft 32a can be obtained by multiplying the vehicle speed V by the conversion factor k, or by dividing the rotational speed Nm2 of the motor MG2 by the gear ratio Gr of the reduction gear 35. The target rotational speed Ne * and the target torque Te * are set based on the operation line for efficiently operating the engine 22 and the required power Pe *. FIG. 10 shows an example of the operation line of the engine 22 and how the target rotational speed Ne * and the target torque Te * are set. As shown in the figure, the target rotational speed Ne * and the target torque Te * can be obtained from the intersection of the operation line and a curve with a constant required power Pe * (Ne * × Te *).

  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. 11 is a collinear diagram showing a dynamic relationship between the rotational speed and torque in the rotary element 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 including 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 motor MG2 outputs the torque using the execution torque T *, the torque command Tm1 *, the gear ratio ρ of the power distribution and integration mechanism 30, and the gear ratio Gr of the reduction gear 35. The temporary motor torque Tm2tmp as the power torque is calculated by the equation (5) (step S210), and the calculated torque Restriction Tmin, set the torque command Tm2 * of the motor MG2 limits the tentative motor torque Tm2tmp at Tmax (step S220). By setting the torque command Tm2 * of the motor MG2 in this way, the effective torque T * 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. 11 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 that is output to the ring gear shaft 32a as the drive shaft is also taken into account. It will be.

Tmin = (Win-Tm1 * ・ Nm1) / Nm2 (3)
Tmax = (Wout-Tm1 * ・ Nm1) / Nm2 (4)
Tm2tmp = (T * + 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 * 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.

  Now, when the atmospheric pressure Pa is low and the air density is low, or when the intake air temperature Ta is high and the air density is low, and the output limit Wout of the battery 50 is relatively small, the driver sets the accelerator opening Acc relatively. Consider when you are stepping in a lot. When the air density is low, the upper limit direct torque from the engine 22 is smaller than when the standard pressure Pset is the standard temperature Tset. Further, when the output limit Wout of the battery 50 is greatly limited, the upper limit of the torque that can be output from the motor MG2 to the ring gear shaft 32a is smaller than when the output limit Wout is not so limited. When the engine 22 and the motors MG1 and MG2 are controlled such that the required torque Tr * is output to the ring gear shaft 32a when the air density is low and the output limit Wout of the battery 50 is small, the ring gear shaft 32a is steadily operated. When the required torque Tr * is larger than the upper limit of the torque that can be output (required torque limit Trmax), whether the inertia accompanying the rotational fluctuation of the system including the engine 22 and the motor MG1 acts on the ring gear shaft 32a as the drive shaft The torque output to the ring gear shaft 32a may fluctuate depending on whether or not the driver may feel uncomfortable. On the other hand, as in the embodiment, a request is made by correcting the temporary required torque limit Trmaxtmp using the correction coefficient α based on the atmospheric pressure Pa reflecting the air density and the intake air temperature Ta and the correction value β based on the output limit Wout of the battery 50. The torque limit Trmax is set and the required torque Tr * is set using the set required torque limit Trmax to set the execution torque T * to be output to the ring gear shaft 32a. The execution torque T * is output to the ring gear shaft 32a. If the engine 22 and the motors MG1 and MG2 are controlled in such a manner, fluctuations in the torque output to the ring gear shaft 32a depending on whether or not the inertia accompanying the rotation fluctuation of the system including the engine 22 and the motor MG1 acts on the ring gear shaft 32a. Can be suppressed, and the driver can be prevented from feeling uncomfortable.

  According to the hybrid vehicle 20 of the embodiment described above, the correction coefficient α based on the atmospheric pressure Pa and the intake air temperature Ta reflecting the intake air density of the engine 22, the correction value β based on the output limit Wout of the battery 50, and the ring gear shaft. The required torque Tr * required for the ring gear shaft 32a is limited using the required torque limit Trmax that is set using the temporary required torque limit that is the upper limit of the torque that can be requested to 32a, and the execution torque T * is set. Since the engine 22 and the motors MG1 and MG2 are controlled so that the execution torque T * set together with the ring gear shaft 32a is output, the engine is operated when the air density is low or the output limit Wout of the battery 50 is greatly limited. Whether inertia caused by the rotational fluctuation of the system including the motor 22 and the motor MG1 acts on the ring gear shaft 32a. The fluctuation of the torque output to the ring gear shaft 32a can be suppressed, and the driver can be prevented from feeling uncomfortable. That is, it is possible to deal with the environment more appropriately.

  In the hybrid vehicle 20 of the embodiment, the correction coefficient α is set using the atmospheric pressure Pa and the intake air temperature Ta as reflecting the density of the intake air, but only the atmospheric pressure Pa is used without using the intake air temperature Ta. May be used to set the correction coefficient α, or the correction coefficient α may be set using only the intake air temperature Ta without using the atmospheric pressure Pa. Alternatively, the correction coefficient α may be set using the directly detected intake air density or the intake air density estimated based on the atmospheric pressure Pa, the intake air temperature Ta, or the like.

  In the hybrid vehicle 20 of the embodiment, the correction coefficient α based on the atmospheric pressure Pa and the intake air temperature Ta, the correction value β based on the output limit Wout of the battery 50, and the temporary required torque limit Trmaxtmp that is the upper limit of the torque that can be requested to the ring gear shaft 32a. However, the required torque limit Trmax may be set using only the correction coefficient α and the temporary required torque limit Trmaxtmp without using the correction value β.

  In the hybrid vehicle 20 of the embodiment, the required torque limit Trmax is set using the temporary required torque limit Trmaxtmp, the correction coefficient α based on the atmospheric pressure Pa and the intake air temperature Ta, and the correction value β based on the output limit Wout of the battery 50. Although the execution torque T * is set by limiting the request torque Tr * using the set request torque limit Trmax, the request torque Tr * and the atmospheric pressure Pa or intake air are set without setting the request torque limit Trmax. The execution torque T * may be directly set using the temperature Ta and the output limit Wout of the battery 50 or using the required torque Tr * and the atmospheric pressure Pa or the intake air temperature Ta.

  In the hybrid vehicle 20 of the embodiment, the power of the motor MG2 is shifted by the reduction gear 35 and output to the ring gear shaft 32a. However, as illustrated in the hybrid vehicle 120 of the modified example of FIG. May be connected to an axle (an axle connected to the wheels 64a and 64b in FIG. 12) different from the axle to which the ring gear shaft 32a is connected (the axle to which the drive wheels 63a and 63b are connected).

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

  In the hybrid vehicle 20 of the embodiment, the engine 22, the motor MG 1 and the drive shaft are connected to the power distribution and integration mechanism 30, the motor MG 2 is connected to the drive shaft, and the battery 50 exchanges power with the motors MG 1 and MG 2. Although the configuration is adopted, any configuration may be used as long as it can output the power from the engine to the drive shaft and can output the power from the motor to the drive shaft.

  In addition, it is not limited to those applied to such hybrid vehicles, but is incorporated into non-moving equipment such as forms of power output devices mounted on moving bodies such as vehicles other than automobiles, ships, and aircraft, and construction equipment. A power output device may be used. 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.

It is a block diagram which shows the outline of a structure of the hybrid vehicle 20 carrying the power output device which is one Example of this invention. 2 is a configuration diagram showing an outline of the configuration of an engine 22. FIG. 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 the battery temperature Tb in the battery 50, and the input / output restrictions Win and Wout. It is explanatory drawing which shows an example of the relationship between the remaining capacity (SOC) of the battery 50, and the correction coefficient of input / output restrictions Win and Wout. It is explanatory drawing which shows an example of the map for request | requirement torque setting. It is explanatory drawing which shows an example of the relationship between atmospheric pressure Pa and correction coefficient (alpha) p. It is explanatory drawing which shows an example of the relationship between intake temperature Ta and correction coefficient (alpha) t. It is explanatory drawing which shows an example of the relationship between the output limitation Wout of the battery 50, and the correction value (beta). It is explanatory drawing which shows a mode that an example of the operating line of the engine 22, and target rotational speed Ne * and target torque Te * are set. 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), 24a CPU, 24b ROM, 24c RAM, 26 crankshaft, 28 damper, 30 power distribution integration mechanism, 31 sun gear, 32 ring gear, 32a ring gear shaft, 33 pinion gear, 34 carrier, 35 reduction gear, 40 motor electronic control unit (motor ECU), 41, 42 inverter, 43, 44 rotational position detection sensor, 50 battery, 51 temperature sensor, 52 battery electronic control Unit (battery ECU), 54 power line, 60 gear mechanism, 62 differential gear, 63a, 63b driving wheel, 64a, 64b wheel, 70 hybrid electronic control unit, 72 CPU, 74 ROM, 76 RAM, 0 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, 89 atmospheric pressure sensor, 122 air cleaner, 124 throttle valve, 126 Fuel injection valve, 128 intake valve, 130 spark plug, 132 piston, 134 purification device, 136, throttle motor, 138 ignition coil, 140 crank position sensor, 142 water temperature sensor, 143 pressure sensor, 144 cam position sensor, 146 throttle valve position Sensor, 148 Air flow meter, 149 Temperature sensor, 150 Variable valve timing mechanism. 230 Counter rotor motor, 232 Inner rotor 234 Outer rotor, MG1, MG2 motor.

Claims (9)

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;
An air density related physical quantity detecting means for detecting an air density related physical quantity related to the density of air sucked into the internal combustion engine;
Target driving force setting means for setting a target driving force to be output to the driving shaft based on the required driving force required for the driving shaft and the detected air density-related physical quantity;
Control means for controlling the internal combustion engine and the electric motor so that the set target driving force is output to the driving shaft;
A power output device comprising:   The target driving force setting means sets a limiting driving force based on an upper limit driving force that is an upper limit of a driving force that can be requested for the driving shaft and the detected air density-related physical quantity, and the set limiting driving force. The power output apparatus according to claim 1, wherein the power output device is a means for setting a drive force that limits the required drive force as the target drive force.   The power output apparatus according to claim 1 or 2, wherein the air density related physical quantity detection means includes an atmospheric pressure detection means for detecting atmospheric pressure.   The power output apparatus according to any one of claims 1 to 3, wherein the air density related physical quantity detection means includes temperature detection means for detecting intake air temperature which is a temperature of air taken into the internal combustion engine.   5. The target driving force setting unit is a unit that sets the target driving force based on the required driving force, the detected air density related physical quantity, and an output limit of the power storage unit. Power output device. The power output device according to any one of claims 1 to 5,
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 means for controlling the internal combustion engine, the electric motor, and the power power input / output means so that the set target drive force is output to the drive shaft.   The power power input / output means is connected to three shafts of the output shaft of the internal combustion engine, the drive shaft, and the rotating shaft, and the remaining shaft based on the power input / output to / from any two of the three shafts The power output apparatus according to claim 6, further comprising: a three-axis power input / output unit that inputs / outputs power to / from the power generator, and a generator that can input / output power to / from the rotating shaft.   A vehicle on which the power output device according to claim 1 is mounted and an axle is 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;
A target driving force to be output to the driving shaft is set based on a required driving force required for the driving shaft and an air density related physical quantity related to the density of air sucked into the internal combustion engine, and the set target A method for controlling a power output apparatus, wherein the internal combustion engine and the electric motor are controlled such that a driving force is output to the driving shaft.

Images