JP2010202132A - Hybrid car and method for controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To output torque demanded for traveling, even if the temperature of an electric storage device is low, and to prevent a power generator from rotating excessively. <P>SOLUTION: Power P* for execution is set by using rate processing, based on a rate value Prt for the power which has a tendency of becoming smaller, the smaller the battery temperature θb is, with respect to request power Pe* which should be output from an engine (S160, S170), and the target rotational frequency Ne* and target torque Te* of the engine are set, on the basis of the power P* for execution (S180); and an engine 22 and motors MG1 and MG2 are controlled so that the engine can be operated with the target rotational frequency Ne* and the target torque Te*, and that the required torque Tr* can be output to a drive shaft to perform traveling (S190 to S250). Thus, it is possible to suppress the occurrence of the phenomenon of the temporary omission of driving torque which is generated, due to a sudden surge in the target number of revolutions Ne* of the engine. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  More particularly, the present invention relates to an internal combustion engine, a generator capable of inputting / outputting power, a drive shaft connected to an axle, an output shaft of the internal combustion engine, and a rotating shaft of the generator. A hybrid vehicle including a planetary gear mechanism in which three rotating elements are connected to three shafts, an electric motor capable of outputting power to a drive shaft, and a power storage unit capable of exchanging electric power with the electric motor, and such a hybrid vehicle Relates to the control method.

  Conventionally, this type of hybrid vehicle includes a planetary structure in which three rotating elements are connected to three axes of an engine, a drive shaft coupled to a first motor and an axle, an output shaft of the engine, and a rotation shaft of the first motor. In a hybrid vehicle including a gear mechanism, a second motor that outputs power to the drive shaft, and a battery that exchanges power with the first motor and the second motor, the engine of the multi-cylinder engine is stopped due to the low temperature of the battery. Is prohibited, the target power of the engine is set based on the required power required for the drive shaft from the accelerator pedal position and the vehicle speed and the remaining capacity of the battery. Control the two motors so that the required power is output to the drive shaft while supplying fuel to only some cylinders and outputting the target power from the engine It has been proposed to (for example, see Patent Document 1). Thereby, even when the battery is at a low temperature, the fuel consumption is suppressed from increasing along with the continuous operation of the engine.

JP 2004-44469 A

  In the hybrid vehicle described above, the required power required for the engine is obtained according to the torque required for running within the range of the maximum power that may charge and discharge the battery, and this required power is efficiently output from the engine. The operating point consisting of the rotational speed and torque that can be set is set as the target operating point of the engine, the torque command of the first motor is set so that the engine rotates at the rotational speed at the target operating point, and the torque required for traveling Is set to output to the drive shaft, and the engine, the first motor, and the second motor are driven so that the engine is operated at the target operation point and the first motor and the second motor are driven by the torque command. When the motor is controlled, but the accelerator pedal is depressed greatly when the battery temperature is low, the drive torque is reduced. Or phenomenon occurs that fall out in time, the possibility that the first motor overspeed occurs.

  The phenomenon that the drive torque is temporarily lost occurs as follows. When the accelerator pedal is depressed greatly, the target rotational speed as the target operating point of the engine rises rapidly. However, since the response of the engine itself is low, a torque command is set for the first motor to increase the rotational speed of the engine. The At this time, since the battery is low temperature, the power that can be output from the battery is limited and small, but the generated power is reduced or consumed in the first motor. The torque that can be output from the second motor becomes a small value, and not only the torque required for traveling cannot be output, but also the torque output to the drive shaft itself becomes small.

  The fear of the first motor over-rotating occurs as follows. When the accelerator pedal is depressed greatly from the accelerator off state, the driving direction of the gear mechanism, such as a differential gear, suddenly changes the direction of torque to suppress abnormal noise such as rattling noise from the gear mechanism. Increasing the torque on the shaft is performed more slowly than usual. At this time, in order to drive the engine at a relatively high rotation and high torque according to the amount of depression of the accelerator pedal, the first motor needs to be driven at a relatively high rotation and high torque, but the battery is at a low temperature. When the electric power that can charge the battery is limited, sufficient torque cannot be output from the first motor, and the rotational speed of the first motor increases rapidly due to the torque from the engine. There is a risk of over-rotation.

  The hybrid vehicle according to the present invention and the control method therefor include an internal combustion engine, a generator capable of inputting / outputting power, a drive shaft connected to the axle, an output shaft of the internal combustion engine, and a rotary shaft of the generator. In a hybrid vehicle comprising: a planetary gear mechanism to which two rotating elements are connected; an electric motor capable of outputting power to a drive shaft; and an electric storage device such as a generator and a battery capable of exchanging electric power with the electric motor. The main purpose is to be able to output the torque required for traveling even when the temperature of the generator is low and to prevent the generator from over-rotating.

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

The hybrid vehicle of the present invention
Planetary gear in which three rotating elements are connected to three axes of an internal combustion engine, a generator capable of inputting / outputting power, a drive shaft connected to an axle, an output shaft of the internal combustion engine, and a rotating shaft of the generator A hybrid vehicle comprising: a mechanism; an electric motor capable of outputting power to the drive shaft; and an electric storage means capable of exchanging electric power with the generator and the electric motor;
Battery temperature detecting means for detecting battery temperature which is the temperature of the power storage means;
An input / output limit setting means for setting an input / output limit as the maximum power that may be charged / discharged based on the state of the power storage means;
Requested torque setting means for setting a requested torque required for traveling based on an accelerator operation;
Based on the accelerator operation, the target power to be output from the internal combustion engine is set, and at least when the target power changes greatly, the lower the detected battery temperature, the lower the response, the slower the responsiveness to the set target power. Power setting means for performing and setting execution power;
A target operating point consisting of a target rotational speed and a target torque at which the internal combustion engine should be operated based on an operation line as a restriction imposed on the rotational speed and torque of the internal combustion engine and the set execution power. Target operation point setting means to be set;
The internal combustion engine and the power generator are operated so that the internal combustion engine is operated by the set target operation point within the set input / output limit range and the set required torque is output to the drive shaft. Control means for controlling the machine and the motor;
It is a summary to provide.

  In the hybrid vehicle according to the present invention, the target power to be output from the internal combustion engine is set based on the accelerator operation, and at least when the target power greatly changes, the lower the temperature of the power storage means, the lower the response to the target power with a lower response. The target power and the target torque for operating the internal combustion engine based on the operation line as a restriction imposed on the rotational speed and the torque of the internal combustion engine and the set execution power are set. Set the target operating point consisting of Then, the internal combustion engine is operated by the target operation point within the range of the input / output limit as the maximum power that may charge / discharge the power storage means, and the required torque required for traveling based on the accelerator operation is output to the drive shaft The internal combustion engine, the generator, and the electric motor are controlled so as to travel. That is, when the temperature of the power storage means is low, the degree of increase in the execution power is reduced. As a result, since the degree of increase in the target rotational speed of the internal combustion engine is also reduced, it is possible to suppress a decrease in the generated power of the generator and an increase in the power consumption of the generator. As a result, torque can be output from the electric motor using the generated power from the generator and the electric power from the storage means, and the torque output to the drive shaft can be prevented from temporarily decreasing. Further, in a hybrid vehicle in which the required torque to the drive shaft is increased more slowly than usual in a region where the sign of the torque output to the drive shaft changes, the execution power output from the internal combustion engine is low when the temperature of the power storage means is low. By reducing the degree of increase, the power generation torque output from the generator can be reduced, and the power generated by the power generator can be within the range of the sum of the power consumption of the motor and the input limit of the power storage means. It is possible to suppress the rapid increase in the number of rotations of the generator due to the torque.

  In such a hybrid vehicle of the present invention, the power setting means is means for setting the execution power using rate processing using a rate value that tends to decrease as the battery temperature decreases as the slow change processing. It can also be.

  In the hybrid vehicle of the present invention, the control means sets a generator torque command, which is a torque command of the generator, so that the internal combustion engine rotates at a target rotational speed at the set target operating point. The torque obtained by subtracting the torque acting on the drive shaft via the planetary gear mechanism when the generator is driven with the generator torque command from the set required torque is the motor torque that is the torque command of the motor. Set as a command, control the internal combustion engine so that the internal combustion engine is operated at the target operating point, control the generator so that the generator is driven by the generator torque command, and the motor Is a means for controlling the electric motor to be driven by the electric motor torque command. In this case, the control means may be means for setting the generator torque command by feedback control so that the internal combustion engine rotates at the target rotational speed. Of the torque output from the generator and the condition that the sum of the generator power as the power input / output from the machine and the motor power input / output from the motor is within the set input / output limit range The total torque of the sum of the torque that acts on the drive shaft out of the torque that acts on the drive shaft via the planetary gear mechanism and the torque that is output from the electric motor does not change the sign of the set required torque and Means for setting the generator torque command and the motor torque command within a range satisfying a condition that the magnitude of the total torque is equal to or less than the magnitude of the required torque; It can also be a.

The hybrid vehicle control method of the present invention includes:
Planetary gear in which three rotating elements are connected to three axes of an internal combustion engine, a generator capable of inputting / outputting power, a drive shaft connected to an axle, an output shaft of the internal combustion engine, and a rotating shaft of the generator A hybrid vehicle control method comprising: a mechanism; an electric motor capable of outputting power to the drive shaft; and an electric storage means capable of exchanging electric power with the generator and the electric motor,
Based on the accelerator operation, a target power to be output from the internal combustion engine is set, and at least when the target power changes greatly, the set target power is subjected to a gradual change process with lower responsiveness as the temperature of the power storage means decreases. The target engine speed and the target torque to be operated on the internal combustion engine based on the operation line as a restriction imposed on the engine speed and torque of the internal combustion engine and the set power for execution are set. The internal combustion engine is operated by the set target operation point within the range of the input / output limit as the maximum power that may charge / discharge the power storage means and is required for traveling. Controlling the internal combustion engine, the generator, and the electric motor so that the required torque is output to the drive shaft and travels.
It is characterized by that.

  In the hybrid vehicle control method of the present invention, the target power to be output from the internal combustion engine is set based on the accelerator operation, and at least when the target power changes greatly, the lower the temperature of the power storage means, the lower the response to the target power. The execution power is set by performing change processing, and the target rotational speed and the target for operating the internal combustion engine based on the operating line as a restriction imposed on the rotational speed and torque of the internal combustion engine and the set execution power Set a target operating point consisting of torque. Then, the internal combustion engine is operated by the target operation point within the range of the input / output limit as the maximum power that may charge / discharge the power storage means, and the required torque required for traveling based on the accelerator operation is output to the drive shaft The internal combustion engine, the generator, and the electric motor are controlled so as to travel. That is, when the temperature of the power storage means is low, the degree of increase in the execution power is reduced. As a result, since the degree of increase in the target rotational speed of the internal combustion engine is also reduced, it is possible to suppress a decrease in the generated power of the generator and an increase in the power consumption of the generator. As a result, torque can be output from the electric motor using the generated power from the generator and the electric power from the storage means, and the torque output to the drive shaft can be prevented from temporarily decreasing. Further, in a hybrid vehicle in which the required torque to the drive shaft is increased more slowly than usual in a region where the sign of the torque output to the drive shaft changes, the execution power output from the internal combustion engine is low when the temperature of the power storage means is low. By reducing the degree of increase, the power generation torque output from the generator can be reduced, and the power generated by the power generator can be within the range of the sum of the power consumption of the motor and the input limit of the power storage means. It is possible to suppress the rapid increase in the number of rotations of the generator due to the torque.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 according to an embodiment of the present invention. It is explanatory drawing which shows an example of the relationship between battery temperature (theta) b in the battery 50, and input / output restrictions Win and Wout. It is explanatory drawing which shows an example of the relationship between the remaining capacity (SOC) of the battery 50, and the correction coefficient of input / output restrictions Win and Wout. It is a flowchart which shows an example of the drive control routine at the time of acceleration performed by the electronic control unit for hybrids 70 of an Example. It is explanatory drawing which shows an example of the map for request | requirement torque setting. It is explanatory drawing which shows an example of the map for power rate value setting. It is explanatory drawing which shows a mode that an example of the operating line of the engine 22, the target rotational speed Ne *, and the target torque Te * are set. FIG. 3 is an explanatory diagram showing an example of a collinear diagram showing a dynamic relationship between the number of rotations and torque in a rotating element of a power distribution and integration mechanism 30 when traveling with power output from an engine 22; It is explanatory drawing explaining a mode that torque limitation Tm1min and Tm1max are set.

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

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. As shown in 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 vehicle.

  The engine 22 is, for example, 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) that inputs signals from various sensors that detect the operating state of the engine 22. ECU 24) receives operation control such as fuel injection control, ignition control, and intake air amount adjustment control. The engine ECU 24 is in communication with the hybrid electronic control unit 70, controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and, if necessary, transmits data related to the operating state of the engine 22 to the hybrid electronic control. Output to unit 70. The engine ECU 24 also calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22 based on a signal from a crank position sensor (not shown) attached to the crankshaft 26.

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

  The motor MG1 and the motor MG2 are both configured as well-known synchronous generator motors that can be driven as generators and can be driven as motors, and exchange power with the battery 50 via inverters 41 and 42. The power line 54 connecting the inverters 41 and 42 and the battery 50 is configured as a positive electrode bus and a negative electrode bus shared by the inverters 41 and 42, and the electric power generated by one of the motors MG1 and MG2 It can be consumed by a motor. Therefore, battery 50 is charged / discharged by electric power generated from one of motors MG1 and MG2 or insufficient electric power. If the balance of electric power is balanced by the motors MG1 and MG2, the battery 50 is not charged / discharged. The motors MG1 and MG2 are both driven and controlled by a motor electronic control unit (hereinafter referred to as a motor ECU) 40. The motor ECU 40 detects signals necessary for driving and controlling the motors MG1 and MG2, such as signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and current sensors (not shown). The phase current applied to the motors MG1 and MG2 to be applied is input, and a switching control signal to the inverters 41 and 42 is output from the motor ECU 40. The motor ECU 40 is in communication with the hybrid electronic control unit 70, controls the driving of the motors MG1 and MG2 by a control signal from the hybrid electronic control unit 70, and, if necessary, data on the operating state of the motors MG1 and MG2. Output to the hybrid electronic control unit 70. The motor ECU 40 also calculates the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 based on signals from the rotational position detection sensors 43 and 44.

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

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

  The hybrid vehicle 20 of the embodiment thus configured calculates the required torque to be output to the ring gear shaft 32a as the drive shaft based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal 83 by the driver. Then, the operation of the engine 22, the motor MG1, and the motor MG2 is controlled so that the required power corresponding to the required torque is output to the ring gear shaft 32a. As operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that 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 so as to be output to each other, and a motor operation mode in which the operation of the engine 22 is stopped and the power corresponding to the required power from the motor MG2 is output to the ring gear shaft 32a. and so on. The torque conversion operation mode and the charge / discharge operation mode are modes in which the engine 22 and the motors MG1, MG2 are controlled so that the required power is output to the ring gear shaft 32a with the operation of the engine 22. Since there is no difference in the control, both are hereinafter referred to as the engine operation mode.

  Next, the operation of the hybrid vehicle 20 of the embodiment thus configured, particularly the operation when the accelerator pedal 83 is greatly depressed will be described. FIG. 4 is a flowchart showing an example of an acceleration drive control routine executed by the hybrid electronic control unit 70 when the accelerator pedal 83 is largely depressed. 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, battery temperature θb, 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 battery temperature θb was detected by the temperature sensor 51 and input from the battery ECU 52 by communication. Further, the input / output limits Win and Wout of the battery 50 are set based on the battery temperature θb of the battery 50 and the remaining capacity (SOC) of the battery 50 and are input from the battery ECU 52 by communication.

  When the data is input in this way, it is necessary to output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b as the torque required for traveling of the vehicle based on the input accelerator opening Acc and the vehicle speed V. The required power required for the engine 22 as the sum of the torque Tdrv set and the set required torque Tdrv 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. Pe * 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 rotational speed Nr of the ring gear shaft 32a can be obtained by multiplying the vehicle speed V by a conversion factor k, or by dividing the rotational speed Nm2 of the motor MG2 by the gear ratio Gr of the reduction gear 35.

  Subsequently, it is determined whether or not the absolute value of the currently set required torque Tr * is greater than or equal to the threshold value Tref (step S120), and the absolute value of the currently set required torque Tr * is equal to or greater than the threshold value Tref. In some cases, the rate value Trt1 that is normally used is set to the torque rate value Trt (step S130), and the required torque Tdrv and the torque rate value Trt that has been set are added to the currently set required torque Tr *. The smaller one is set as the required torque Tr * (step S150), and when the absolute value of the currently set required torque Tr * is less than the threshold value Tref, a rate value Trt2 smaller than the normal rate value Trt1 is used for torque. The rate value Trt is set (step S140), and the torque set to the currently set required torque Tr * is set. Set the smaller as the required torque Tr * of and the required torque Tdrv plus click for rate value Trt (step S150). Here, the process of setting the smaller one of the required torque Tr * added to the torque rate value Trt and the required torque Tdrv as the required torque Tr * is requested by a gradual change process by the rate process. It can be said that the process sets the torque Tr *. The reason why the required torque Tdrv is not immediately set as the required torque Tr * is to prevent changes in the operating state of the engine 22 and changes in the driving state of the motors MG1 and MG2 from exceeding the capabilities of the engine 22 and the motors MG1 and MG2. . Further, when the currently set absolute value of the required torque Tr * is less than the threshold value Tref, a rate value Trt2 smaller than the normal rate value Trt1 is set as the torque rate value Trt to reduce the amount of change per time. The required torque Tr * is set to suppress the generation of noise such as rattling noise of a gear mechanism such as a differential gear when the torque acting on the ring gear shaft 32a serving as the drive shaft is near zero. Because. Therefore, the threshold value Tref is a threshold value for determining whether or not the torque acting on the ring gear shaft 32a as the drive shaft is close to the value 0, and can be set according to the performance of the engine 22 and the motors MG1 and MG2.

  When the required torque Tr * is thus set, the power rate value Prt is set based on the battery temperature θb (step S160), and the power rate value Prt is added to the currently set execution power P *. The smaller of the required power Pe * is set as a new execution power P * (step S170), and the target operation of the engine 22 is performed based on the operation line for efficiently operating the engine 22 and the set execution power P *. A target rotational speed Ne * and a target torque Te * are set as points (step S180). In the embodiment, the power rate value Prt is stored in the ROM 74 as a power rate value setting map by predetermining the relationship between the battery temperature θb and the power rate value Prt, and stored when the battery temperature θb is given. The corresponding power rate value Prt is derived and set from the map. FIG. 6 shows an example of the power rate value setting map. As shown in the figure, the power rate value Prt is set to the normal rate value Prt1 when the battery temperature θb is equal to or higher than the temperature θ1, and is smaller than the normal rate value Prt1 when the battery temperature θb is lower than the temperature θ2. When Prt2 is set and the battery temperature θb is equal to or higher than the temperature θ2 and lower than the temperature θ1, the value is set to be higher as the battery temperature θb is higher than the rate value prt2 and becomes the rate value Prt when the temperature is θ1. By setting in this way, when the battery temperature θb is low, the extent to which the execution power P * is increased can be reduced. FIG. 7 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 power P * (Ne * × Te *) for execution.

  Next, the target rotational speed Nm1 * of the motor MG1 is calculated by the following equation (1) using the target rotational speed Ne * of the engine 22, the rotational speed Nm2 of the motor MG2, and the gear ratio ρ of the power distribution and integration mechanism 30. Based on the calculated target rotational speed Nm1 * and the input rotational speed Nm1 of the motor MG1, a temporary motor torque Tm1tmp, which is a temporary value of the torque to be output from the motor MG1, is calculated by Expression (2) (step S190). Here, Expression (1) is a dynamic relational expression for the rotating element of the power distribution and integration mechanism 30. FIG. 8 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 when traveling with the power output from the engine 22. In the figure, the left S-axis indicates the rotation speed of the sun gear 31 that is the rotation speed Nm1 of the motor MG1, the C-axis indicates the rotation speed of the carrier 34 that is the rotation speed Ne of the engine 22, and the R-axis indicates the rotation speed of the motor MG2. The rotational speed Nr of the ring gear 32 obtained by dividing the number Nm2 by the gear ratio Gr of the reduction gear 35 is shown. Expression (1) can be easily derived by using this alignment chart. The two thick arrows on the R axis indicate that the torque Tm1 output from the motor MG1 acts on the ring gear shaft 32a and the torque Tm2 output from the motor MG2 acts on the ring gear shaft 32a via the reduction gear 35. Torque. Expression (2) is a relational expression in feedback control for rotating the motor MG1 at the target rotational speed Nm1 *. In Expression (2), “k1” in the second term on the right side is a gain of a proportional term. “K2” in the third term on the right side is the gain of the integral term.

Nm1 * = Ne * ・ (1 + ρ) / ρ-Nm2 / ρ (1)
Tm1tmp = ρ ・ Te * / (1 + ρ) + k1 (Nm1 * -Nm1) + k2∫ (Nm1 * -Nm1) dt (2)

  Subsequently, torque limits Tm1min and Tm1max are set as upper and lower limits of the torque that may be output from the motor MG1 that satisfies both the expressions (3) and (4) (step S200), and the set temporary torque Tm1tmp is expressed by the expression ( The torque command Tm1 * of the motor MG1 is set by limiting with the torque limits Tm1min and Tm1max according to 5) (step 210). Here, Expression (3) is a relationship in which the sum of torques output to the ring gear shaft 32a by the motor MG1 and the motor MG2 is within a range from the value 0 to the required torque Tr *, and Expression (4) is the relationship with the motor MG1. This is a relationship in which the sum of the electric power input and output by the motor MG2 is within the range of the input and output limits Win and Wout. An example of the torque limits Tm1min and Tm1max is shown in FIG. The torque limits Tm1min and Tm1max can be obtained as the maximum value and the minimum value of the torque command Tm1 * in the region indicated by the oblique lines in the figure.

0 ≦ −Tm1 / ρ + Tm2, Gr ≦ Tr * (3)
Win ≦ Tm1 / Nm1 + Tm2 / Nm2 ≦ Wout (4)
Tm1 * = max (min (Tm1tmp, Tm1max), Tm1min) (5)

  Then, the torque command Tm1 * set as the required torque Tr * is divided by the gear ratio ρ of the power distribution and integration mechanism 30 and further divided by the gear ratio Gr of the reduction gear 35 to obtain the torque to be output from the motor MG2. A temporary motor torque Tm2tmp, which is a temporary value, is calculated by the following equation (6) (step S220), and the current rotation speed Nm1 of the motor MG1 is set to the torque command Tm1 * set to the input / output limits Win and Wout of the battery 50. The torque limits Tm2min and Tm2max as upper and lower limits of the torque that may be output from the motor MG2 by dividing the deviation from the power consumption (generated power) of the motor MG1 obtained by multiplication by the rotational speed Nm2 of the motor MG2 7) and equation (8) (step S230) and the set temporary torque Tm2tmp is expressed by equation (9) Ri torque limit Tm2min, and limited by Tm2max to set a torque command Tm2 * of the motor MG2 (step S240). Here, Equation (6) can be easily derived from the alignment chart of FIG.

Tm2tmp = (Tr * + Tm1 * / ρ) / Gr (6)
Tm2min = (Win-Tm1 * ・ Nm1) / Nm2 (7)
Tm2max = (Wout-Tm1 * ・ Nm1) / Nm2 (8)
Tm2 * = max (min (Tm2tmp, Tm2max), Tm2min) (9)

  Thus, when the target engine speed Ne *, the target torque Te *, and the torque commands Tm1 *, Tm2 * of the motors MG1, MG2 are set, the target engine speed Ne * and the target torque Te * of the engine 22 are set in the engine ECU 24. Torque commands Tm1 * and Tm2 * for motors MG1 and MG2 are transmitted to motor ECU 40 (step S250), 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, let us consider a case where the driver depresses the accelerator pedal 83 greatly during steady running when the battery temperature θb of the battery 50 is low. When the accelerator pedal 83 is depressed greatly, a relatively large required torque Tdrv is set according to the accelerator opening Acc as the amount of depression of the accelerator pedal 83, and a large required power Pe * is set by the necessary torque Tdrv. However, since the battery temperature θb of the battery 50 is low, the execution power P * is set by the rate process using the small power rate value Prt, and the target rotational speed Ne * and the target torque Te * of the engine 22 are set. Torque command Tm1 * of motor MG1 is set so that engine 22 rotates at target rotation speed Ne *. The torque command Tm1 * at this time has a small deviation between the engine speed Ne and the target engine speed Ne * because the power rate value Prt is small, so the engine speed Ne is set to the target engine speed Ne *. The feed-forward terms (the second term and the third term on the right side of Equation (2)) for following are relatively small. The feedforward term (the first term on the right side of equation (2)) for the target torque Te * to be output from the engine 22 becomes dominant. For this reason, the torque command Tm1 * of the motor MG1 increases as the power generation torque in accordance with the degree of increase in the execution power P * due to the rate processing. On the other hand, the torque command Tm2 * of the motor MG2 can be driven by setting the torque command Tm2 * within the range of the sum of the electric power generated by the motor MG1 and the output limit Wout of the battery 50. The torque output from motor MG2 also increases according to the degree of increase in power P *. As a result, the phenomenon of temporary loss of drive torque caused by the rapid increase in the target rotational speed Ne * of the engine 22 does not occur.

  Next, let us consider a case where the driver greatly depresses the accelerator pedal 83 while traveling while outputting a slight braking torque by turning off the accelerator when the battery temperature θb of the battery 50 is low. When the accelerator pedal 83 is depressed greatly, a relatively large required torque Tdrv is set according to the accelerator opening Acc as the amount of depression of the accelerator pedal 83, and a large required power Pe * is set by the necessary torque Tdrv. When the absolute value of the required torque Tr * is less than the threshold value Tref near the value 0, the rate value Trt2 smaller than the normal rate value Trt1 is used as the torque rate value Trt in order to prevent the rattling noise of the differential gear 62 and the like. The required torque Tr * is set by the gradual change process. On the other hand, since the execution power P * output from the engine 22 is set by rate processing using a small power rate value Prt because the battery temperature θb of the battery 50 is low, the increase is performed more slowly than usual. It is. Accordingly, the target rotational speed Ne * and the target torque Te * of the engine 22 also increase more slowly than usual. The torque command Tm1 * of the motor MG1 increases as the power generation torque in accordance with the increase in the target rotational speed Ne * and the target torque Te * of the engine 22, but the degree of increase in the execution power P * and the increase in the required torque Tr *. As a result, a torque obtained by subtracting the torque acting on the ring gear shaft 32a as the drive shaft from the required torque Tr * from the required torque Tr * is output from the motor MG2. The input limit Win of the battery 50 will not be exceeded. As a result, there is a large difference between the increase in the execution power P * and the increase in the required torque Tr *, and the input of the battery 50 when the sum of the power generated by the motor MG1 and the power consumption by the motor MG2 is low. Over-rotation of the motor MG1 caused by exceeding the limit Win can be suppressed.

  According to the hybrid vehicle 20 of the embodiment described above, rate processing (slow change) by the power rate value Prt that tends to decrease as the battery temperature θb of the battery 50 decreases with respect to the required power Pe * to be output from the engine 22. The execution power P * is set using the processing), the target rotational speed Ne * and the target torque Te * of the engine 22 are set based on the execution power P *, and the engine 22 sets the target rotational speed Ne * and the target By controlling the engine 22 and the motors MG1 and MG2 so as to travel while being driven by the torque Te * and outputting the required torque Tr * to the ring gear shaft 32a as the drive shaft, the target rotational speed Ne * of the engine 22 rapidly increases. Thus, it is possible to suppress the occurrence of a temporary loss of driving torque caused by the operation. In addition, when the battery temperature θb of the battery 50 is low, even when the driver depresses the accelerator pedal 83 while driving while outputting a slight braking torque by turning off the accelerator, the required power Pe * By setting the execution power P * using the rate process (slow change process) based on the power rate value Prt that tends to decrease as the battery temperature θb of the battery 50 decreases, the extent and request for the increase in the execution power P * Since a large divergence in the degree of increase in the torque Tr * is suppressed, a large divergence occurs in the degree of increase in the execution power P * and the degree of increase in the required torque Tr *, and the generated power of the motor MG1 Suppressing over-rotation of the motor MG1 caused by the sum of the power consumption of the motor MG2 exceeding the input limit Win of the battery 50 at a low temperature Can do.

  In the hybrid vehicle 20 of the embodiment, rate processing (slow change processing) using a power rate value Prt that tends to decrease as the battery temperature θb of the battery 50 decreases with respect to the required power Pe * to be output from the engine 22 is used. The execution power P * is set. However, when the execution power P * is set, the slow change process is not limited to the rate process, and a slow change process other than the rate process, such as a smoothing process, is performed. May be used. When the annealing process is used, the degree of annealing may be increased as the battery temperature θb of the battery 50 decreases.

  In the embodiment, the hybrid vehicle 20 has been described. However, the present invention is not limited to the hybrid vehicle 20 and may be a hybrid vehicle control method.

  Here, the correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the engine 22 corresponds to an “internal combustion engine”, the motor MG1 corresponds to a “generator”, the power distribution and integration mechanism 30 corresponds to a “planetary gear mechanism”, and the motor MG2 corresponds to a “motor”. The battery 50 corresponds to “power storage means”, the temperature sensor 51 corresponds to “battery temperature detection means”, and the remaining capacity (SOC) of the battery 50 and the battery based on the integrated value of the charge / discharge current detected by the current sensor The battery ECU 52 that calculates the input / output limits Win and Wout, which are the maximum allowable power that may charge / discharge the battery 50 based on the battery temperature θb of 50, corresponds to the “input / output limit setting means”, and the accelerator opening degree Acc And the vehicle speed V, the required torque Tdrv is set. When the absolute value of the required torque Tr * set so far is equal to or greater than the threshold value Tref, the normal rate value Trt The required torque Tr * is set by the rate processing using, and when the absolute value of the required torque Tr * set so far is less than the threshold value Tref, the required torque is obtained by the rate processing using the rate value Trt2 smaller than the normal rate value Trt1. The hybrid electronic control unit 70 that executes the processing of steps S110 to S150 of the acceleration drive control routine of FIG. 4 for setting Tr * corresponds to “required torque setting means” and sets the required torque Tdrv based on the accelerator opening Acc. The required power Pe * required for the engine 22 is set based on this, and the execution power P * is set by rate processing using the power rate value Prt that tends to decrease as the battery temperature θb of the battery 50 decreases. Steps S110, S160, S170 of the acceleration drive control routine The hybrid electronic control unit 70 that executes processing corresponds to “power setting means”, and the target rotational speed as a target operating point of the engine 22 based on the operation line for efficiently operating the engine 22 and the execution power P *. The hybrid electronic control unit 70 that executes the process of step S180 of the acceleration drive control routine of FIG. 4 for setting Ne * and the target torque Te * corresponds to the “target operation point setting means”, and is the input / output of the battery 50. The motors MG1 and MG2 are operated so that the engine 22 is driven at the target rotational speed Ne * and the target torque Te * and outputs the required torque Tr * to the ring gear shaft 32a as the drive shaft within the limits Win and Wout. Torque commands Tm1 * and Tm2 * are set and the target rotational speed Ne * and target torque Te * are The hybrid electronic control unit 70 for executing the processing of steps S190 to S250 of the acceleration drive control routine of FIG. 4 transmitted to the motor ECU 40 for the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 to the gin ECU 24, and the target rotation The engine ECU 24 that controls the engine 22 based on the number Ne * and the target torque Te * and the motor ECU 40 that controls the motors MG1 and MG2 based on the torque commands Tm1 * and Tm2 * correspond to “control means”. .

  Here, the “internal combustion engine” is not limited to an internal combustion engine that outputs power using a hydrocarbon fuel such as gasoline or light oil, and may be any type of internal combustion engine such as a hydrogen engine. The “generator” is not limited to the motor MG1 configured as a synchronous generator motor, and may be any type of generator such as an induction motor that can input and output power. The “planetary gear mechanism” is not limited to the power distribution and integration mechanism 30 described above, but is connected to four or more shafts by using a double pinion type planetary gear mechanism or a combination of a plurality of planetary gear mechanisms. As long as the three rotating elements are connected to the three shafts of the drive shaft coupled to the axle, the output shaft of the internal combustion engine, and the rotating shaft of the generator, etc., any device may be used. The “motor” is not limited to the motor MG2 configured as a synchronous generator motor, and may be any type of motor as long as it can input and output power to the drive shaft, such as an induction motor. . The “storage means” is not limited to the battery 50 as a secondary battery, and may be anything as long as it can exchange electric power with a generator or an electric motor such as a capacitor. The “battery temperature detection means” is not limited to the temperature sensor 51, and any battery temperature detection means may be used as long as it detects the battery temperature that is the temperature of the power storage means. The “input / output limit setting means” is not limited to the one that calculates the input / output limits Win and Wout based on the remaining capacity (SOC) of the battery 50 and the battery temperature θb of the battery 50. In addition to SOC) and battery temperature θb, an input / output limit that is the maximum allowable power that may charge / discharge the power storage means is set based on the state of the power storage means, such as that calculated based on the internal resistance of the battery 50, etc. It does not matter as long as it does. As the “request torque setting means”, the required torque Tdrv is set based on the accelerator opening Acc and the vehicle speed V, and when the absolute value of the request torque Tr * set so far is equal to or greater than the threshold value Tref, the normal rate The requested torque Tr * is set by rate processing using the value Trt1, and when the absolute value of the requested torque Tr * set so far is less than the threshold value Tref, the rate processing using the rate value Trt2 smaller than the normal rate value Trt1 is performed. It is not limited to the one that sets the required torque Tr *, and the one that sets the required torque based only on the accelerator opening Acc or the one that the travel route is preset is set to the travel position on the travel route. What is required to set the required torque required for driving, such as those that set the required torque based on It may be as shall. As the “power setting means”, the required power Pe * required for the engine 22 is set based on the required torque Tdrv based on the accelerator opening Acc, and the power rate tends to decrease as the battery temperature θb of the battery 50 decreases. It is not limited to setting the execution power P * by rate processing using the value Prt, but sets the required power Pe * required for the engine 22 based on the required torque Tr * based on the required torque Tdrv. The target power to be output from the internal combustion engine is set based on the accelerator operation, and at least when the target power changes greatly, the target power is subjected to a gradual change process with a lower response as the battery temperature is lower. Anything can be used as long as it is set. “Target operation point setting means” sets a target rotational speed Ne * and a target torque Te * as target operation points of the engine 22 based on an operation line for efficiently operating the engine 22 and the execution power P *. The target rotational speed Ne * and the target torque Te * as the target operating point of the engine 22 are determined based on the operation line for outputting a large torque from the engine 22 and the execution power P *. A target operating point consisting of a target rotational speed and a target torque at which the internal combustion engine should be operated is set based on an operation line and execution power as constraints imposed on the rotational speed and torque of the internal combustion engine, such as setting. Any object can be used. The “control means” is not limited to the combination of the hybrid electronic control unit 70, the engine ECU 24, and the motor ECU 40, and may be configured by a single electronic control unit. Further, as the “control means”, the engine 22 is operated at the target rotational speed Ne * and the target torque Te * within the range of the input / output limits Win and Wout of the battery 50, and requested to the ring gear shaft 32a as the drive shaft. The engine 22 and the motors MG1, MG2 are not limited to controlling the motor 22 and the motors MG1 and MG2 so as to travel by outputting the torque Tr *. Anything can be used as long as it controls the internal combustion engine, the generator, and the motor so that the required torque is output to the drive shaft.

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

  The 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.

  The present invention can be used in the manufacturing industry of hybrid vehicles.

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

Claims (6)

Planetary gear in which three rotating elements are connected to three axes of an internal combustion engine, a generator capable of inputting / outputting power, a drive shaft connected to an axle, an output shaft of the internal combustion engine, and a rotating shaft of the generator A hybrid vehicle comprising: a mechanism; an electric motor capable of outputting power to the drive shaft; and an electric storage means capable of exchanging electric power with the generator and the electric motor;
Battery temperature detecting means for detecting battery temperature which is the temperature of the power storage means;
An input / output limit setting means for setting an input / output limit as the maximum power that may be charged / discharged based on the state of the power storage means;
Requested torque setting means for setting a requested torque required for traveling based on an accelerator operation;
Based on the accelerator operation, the target power to be output from the internal combustion engine is set, and at least when the target power changes greatly, the lower the detected battery temperature, the lower the response, the slower the responsiveness to the set target power. Power setting means for performing and setting execution power;
A target operating point consisting of a target rotational speed and a target torque at which the internal combustion engine should be operated based on an operation line as a restriction imposed on the rotational speed and torque of the internal combustion engine and the set execution power. Target operation point setting means to be set;
The internal combustion engine and the power generator are operated so that the internal combustion engine is operated by the set target operation point within the set input / output limit range and the set required torque is output to the drive shaft. Control means for controlling the machine and the motor;
A hybrid car with The hybrid vehicle according to claim 1,
The power setting means is means for setting the execution power using rate processing using a rate value that tends to decrease as the battery temperature decreases as the slow change processing.
Hybrid car. A hybrid vehicle according to claim 1 or 2,
The control means sets a generator torque command, which is a torque command of the generator, so that the internal combustion engine rotates at a target rotational speed at the set target operating point, and generates the generator from the set required torque. Is set as a motor torque command that is a torque command of the motor, and is obtained by subtracting the torque that acts on the drive shaft via the planetary gear mechanism when the motor is driven by the generator torque command. The internal combustion engine is controlled to operate at the target operating point, the generator is controlled so that the generator is driven by the generator torque command, and the electric motor is driven by the motor torque command. Means for controlling the electric motor,
Hybrid car. A hybrid vehicle according to claim 3,
The control means is means for setting the generator torque command by feedback control so that the internal combustion engine rotates at the target rotational speed.
Hybrid car. A hybrid vehicle according to claim 3 or 4,
The control means includes a condition that a sum of generator power as power input / output from the generator and motor power input / output from the motor is within the set input / output limit range and the generator Among the torques output from the motor, the sum of the torques acting on the drive shaft via the planetary gear mechanism and the torques acting on the drive shaft among the torques output from the motor is the set required torque. Means for setting the generator torque command and the motor torque command within a range that satisfies the condition that the sign does not change and the magnitude of the combined torque is equal to or less than the magnitude of the required torque,
Hybrid car. Planetary gear in which three rotating elements are connected to three axes of an internal combustion engine, a generator capable of inputting / outputting power, a drive shaft connected to an axle, an output shaft of the internal combustion engine, and a rotating shaft of the generator A hybrid vehicle control method comprising: a mechanism; an electric motor capable of outputting power to the drive shaft; and an electric storage means capable of exchanging electric power with the generator and the electric motor,
Based on the accelerator operation, a target power to be output from the internal combustion engine is set, and at least when the target power changes greatly, the set target power is subjected to a gradual change process with lower responsiveness as the temperature of the power storage means decreases. The target engine speed and the target torque to be operated on the internal combustion engine based on the operation line as a restriction imposed on the engine speed and torque of the internal combustion engine and the set power for execution are set. The internal combustion engine is operated by the set target operation point within the range of the input / output limit as the maximum power that may charge / discharge the power storage means and is required for traveling. Controlling the internal combustion engine, the generator, and the electric motor so that the required torque is output to the drive shaft and travels.
A control method for a hybrid vehicle.

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