JP2013038969A - Motor vehicle - Google Patents

Abstract

When an efficiency priority switch for instructing priority of energy efficiency of a vehicle with an accelerator off in a predetermined low vehicle speed range is turned on, power consumption by a motor and suppression of vehicle sliding down are reduced.
A motor is controlled so that a creep torque Tc is output when an accelerator is off in a predetermined low vehicle speed range (S110) and an eco switch (eco switch signal ECO) is off (S140). The motor MG2 is controlled so that the output of the creep torque Tc is limited when it is on (S170). When the eco switch is on, a larger braking force is applied to the vehicle than when the eco switch is off. The brake actuator is controlled (S180).
[Selection] Figure 2

Description

  The present invention relates to an automobile, and more specifically, a motor capable of outputting driving power, a battery capable of exchanging electric power with the motor, a braking force applying device capable of applying a braking force to the vehicle, and an energy efficiency of the vehicle. The present invention relates to an automobile provided with an efficiency priority switch for instructing priority.

  Conventionally, this type of automobile includes a motor that can output torque to the drive shaft, a battery that exchanges electric power with the motor, and a brake unit that applies braking torque to the wheel according to the amount of depression of the brake pedal. When the creep torque output condition is satisfied and the ECO switch is on, the ECO mode creep torque setting map and the brake pedal tend to make the target creep torque smaller than the normal creep torque setting map. A target creep torque is set using the amount of stepping on, and the motor is controlled so that torque based on the set target creep torque is output to the drive shaft (see, for example, Patent Document 1). In this automobile, such control makes it possible to select whether or not to give priority to energy efficiency when outputting creep torque to the drive shaft simply by operating the ECO switch.

JP 2008-154394 A

  In such an automobile, when the creep torque output condition is satisfied, if the creep torque is limited when the ECO switch is turned on compared to when the ECO switch is turned off, the vehicle on the slope depends on the degree of depression of the brake pedal. There is a possibility of slipping down easily.

  The automobile of the present invention is intended to suppress power consumption by the motor and to suppress vehicle slippage when the efficiency priority switch that instructs priority on the energy efficiency of the vehicle with the accelerator off in a predetermined low vehicle speed range is on. The main purpose.

  The automobile of the present invention has taken the following means in order to achieve the main object described above.

The automobile of the present invention
A motor capable of outputting driving power, a battery capable of exchanging electric power with the motor, a braking force applying device capable of applying a braking force to the vehicle, and an efficiency priority switch for instructing priority of energy efficiency of the vehicle, When the accelerator is off in a predetermined low vehicle speed range, creep control is performed to control the motor so that creep torque is output when the efficiency priority switch is off, and when the efficiency priority switch is on, the creep torque is controlled. Control means for executing creep restriction control for controlling the motor so that the output is restricted, and an automobile comprising:
When the accelerator is off in the predetermined low vehicle speed range and the efficiency priority switch is on, the control means controls the vehicle so that a larger braking force is applied to the vehicle than when the efficiency priority switch is off. A means for executing a large braking force control for controlling the power applying device.
This is the gist.

  In the automobile of the present invention, when the accelerator is off in a predetermined low vehicle speed range, creep control is executed to control the motor so that creep torque is output when the efficiency priority switch that gives priority to the energy efficiency of the vehicle is off. When the efficiency priority switch is on, the creep limit control is performed to control the motor so that the output of the creep torque is limited. When the accelerator is off in a predetermined low vehicle speed range, the efficiency priority switch is on. Then, large braking force control is executed to control the braking force applying device so that a larger braking force acts on the vehicle than when the efficiency priority switch is off. As a result, when the accelerator is off and the efficiency priority switch is on in a predetermined low vehicle speed range, it is possible to suppress power consumption by the motor (improve the energy efficiency of the vehicle) and to prevent the vehicle from sliding down (moving). Suppression can be achieved.

  In such an automobile of the present invention, the control means is means for controlling the motor so that torque is not output as the creep restriction control when the accelerator is off and the efficiency priority switch is on in the predetermined low vehicle speed range. Further, the control means is configured so that when the accelerator is turned off from the accelerator off during the execution of the creep control, the larger one of the accelerator corresponding torque according to the accelerator operation and the creep torque is output. It is also possible to control the motor so that the accelerator-corresponding torque is output when the accelerator is turned on from the accelerator-off state during the execution of the creep limit control. In this way, when the accelerator is turned off from the accelerator off during execution of the creep limit control, the torque is compared with that for controlling the motor so that the larger of the accelerator-corresponding torque and the creep torque is output. Since the increase from the value 0 (when the accelerator is off) can be made smooth, it is possible to suppress giving the driver a feeling of jumping out of the vehicle.

  In the automobile of the present invention, when the efficiency priority switch is turned off from on during the execution of the creep restriction control, the control means executes the creep restriction control regardless of the operation of the efficiency priority switch. It can also be a means of continuing. In this way, when the efficiency priority switch is turned off from on during creep restriction control execution (when the efficiency priority switch is turned off from on while the accelerator is off), the execution of creep restriction control is terminated. As compared with the one in which execution of creep control is started, it is possible to suppress the feeling of the vehicle jumping out by the operation of the efficiency priority switch to the driver.

  Furthermore, in the vehicle of the present invention, the control means may be means for ending execution of the large braking force control when the accelerator is turned off from the accelerator off during execution of the large braking force control. it can.

  Alternatively, in the automobile of the present invention, the control means applies the braking force as the large braking force control so that the predetermined braking force acts on the vehicle when the brake-corresponding braking force corresponding to the brake operation is equal to or less than the predetermined braking force. It is also possible to control the device and to control the braking force applying device so that the brake-corresponding sincerity power acts on the vehicle when the braking-corresponding braking force is greater than the predetermined braking force.

  In addition, in the automobile of the present invention, a planetary gear in which three rotating elements are connected to three axes of an engine, a generator, a drive shaft coupled to an axle, an output shaft of the engine, and a rotating shaft of the generator. The motor may be configured such that a rotation shaft is connected to the drive shaft.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. 5 is a flowchart illustrating an example of a control routine at an extremely low vehicle speed that is executed by an HVECU 70; An example of an eco switch signal ECO, an accelerator opening Acc, a brake pedal position BP, a required torque Tr *, a creep limit flag Fc, a traveling direction torque, and a time change of braking force when the brake is off in a predetermined low vehicle speed range It is explanatory drawing which shows. 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. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 320 of a modified example. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 420 according to a modification.

  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 drawing, the hybrid vehicle 20 of the embodiment includes an engine 22 that outputs power using gasoline or light oil as a fuel, an engine electronic control unit (hereinafter referred to as an engine ECU) 24 that controls the drive of the engine 22, an engine, and the like. A planetary gear 30 having a carrier connected to the crankshaft 26 and a ring gear connected to a drive shaft 36 connected to drive wheels 38a and 38b via a differential gear 37, and a rotor configured as a synchronous generator motor, for example. Motor MG1 connected to the sun gear of planetary gear 30, for example, a motor MG2 configured as a synchronous generator motor and having a rotor connected to drive shaft 36, inverters 41 and 42 for driving motors MG1 and MG2, By controlling the inverters 41 and 42 A motor electronic control unit (hereinafter referred to as a motor ECU) 40 for driving and controlling the motors MG1 and MG2 is configured as a lithium ion secondary battery, for example, and exchanges electric power with the motors MG1 and MG2 via inverters 41 and 42. A battery 50, a battery electronic control unit (hereinafter referred to as a battery ECU) 52 for managing the battery 50, a brake actuator 92 for controlling the brakes of the drive wheels 38a and 38b and the driven wheels 39a and 39b, and the entire vehicle And a hybrid electronic control unit (hereinafter referred to as HVECU) 70 to be controlled.

  Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . The engine ECU 24 receives signals from various sensors that detect the operating state of the engine 22, for example, a water temperature sensor that detects the crank position θcr from the crank position sensor that detects the rotational position of the crankshaft 26 and the coolant temperature of the engine 22. From the cam position sensor for detecting the cooling water temperature Tw from the cylinder, the in-cylinder pressure Pin from the pressure sensor installed in the combustion chamber, the rotational position of the intake valve for intake and exhaust to the combustion chamber and the camshaft for opening and closing the exhaust valve Position θca, throttle position TP from a throttle valve position sensor that detects the position of the throttle valve, intake air amount Qa from an air flow meter attached to the intake pipe, intake air temperature Ta from a temperature sensor also attached to the intake pipe, Installed in the exhaust system The air-fuel ratio AF from the air-fuel ratio sensor and the oxygen signal O2 from the oxygen sensor attached to the exhaust system are input via the input port, and the engine ECU 24 is for driving the engine 22. Various control signals, such as the drive signal to the fuel injection valve, the drive signal to the throttle motor that adjusts the throttle valve position, the control signal to the ignition coil integrated with the igniter, and the opening / closing timing of the intake valve can be changed A control signal to the variable valve timing mechanism is output via the output port. The engine ECU 24 is in communication with the HVECU 70, controls the operation of the engine 22 by a control signal from the HVECU 70, and outputs data related to the operation state of the engine 22 to the HVECU 70 as necessary. 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.

  Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . The motor ECU 40 receives signals necessary for driving and controlling the motors MG1 and MG2, for example, rotational positions θm1 and θm2 from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and not shown. A phase current applied to the motors MG1 and MG2 detected by the current sensor is input via the input port, and the motor ECU 40 outputs a switching control signal to switching elements (not shown) of the inverters 41 and 42. It is output through the port. The motor ECU 40 is in communication with the HVECU 70, controls the driving of the motors MG1 and MG2 by a control signal from the HVECU 70, and outputs data related to the operating state of the motors MG1 and MG2 to the HVECU 70 as necessary. The motor ECU 40 calculates the rotational angular velocities ωm1, ωm2 and the rotational speeds Nm1, Nm2 of the motors MG1, MG2 based on the rotational positions θm1, θm2 of the rotors of the motors MG1, MG2 from the rotational position detection sensors 43, 44. Or the driving wheel rotational angular velocity ωb as the rotational angular velocity of the driving wheels 38a, 38b converted to the rotational shaft of the motor MG2 based on the rotational angular velocity ωm2 of the motor MG2. Note that the driving wheel rotation angular velocity ωb is discrete using a zero-order hold at a control sample time with respect to a control system design model of a two-inertia system obtained by limiting to the characteristics between the motor MG2 and the driving wheels 38a and 38b. The calculation can be performed using a model that has been made, or the wheel speed sensor can be attached to the drive wheels 38a and 38b and the calculation can be performed based on the signal from the wheel speed sensor.

  Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . The battery ECU 52 receives signals necessary for managing the battery 50, for example, an inter-terminal voltage Vb from a voltage sensor (not shown) installed between the terminals of the battery 50 and a power line connected to the output terminal of the battery 50. The charging / discharging current Ib from the attached current sensor (not shown), the battery temperature Tb from the temperature sensor (not shown) attached to the battery 50, and the like are input. Send to. Further, in order to manage the battery 50, the battery ECU 52 is a power storage that is a ratio of the capacity of the electric power that can be discharged from the battery 50 at that time based on the integrated value of the charge / discharge current Ib detected by the current sensor. The ratio SOC is calculated, and 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 calculated storage ratio SOC and the battery temperature Tb. The input / output limits Win and Wout of the battery 50 are set to the basic values of the input / output limits Win and Wout based on the battery temperature Tb, and the output limiting correction coefficient and the input limiting limit are set based on the storage ratio SOC of the battery 50. It can be set by setting a correction coefficient and multiplying the basic value of the set input / output limits Win and Wout by the correction coefficient.

  The brake actuator 92 has a braking force corresponding to the share of the brake in the braking force applied to the vehicle by the pressure (brake pressure) of the brake master cylinder 90 and the vehicle speed V generated in response to the depression of the brake pedal 85. Regardless of adjusting the hydraulic pressure of the brake wheel cylinders 96a to 96d so as to act on the wheel 38b and the driven wheels 39a and 39b, or by depressing the brake pedal 85, the braking force acts on the driving wheels 38a and 38b and the driven wheels 39a and 39b. The hydraulic pressures of the brake wheel cylinders 96a to 96d can be adjusted. Hereinafter, the braking force applied to the drive wheels 38a and 38b and the driven wheels 39a and 39b by the operation of the brake actuator 92 may be referred to as a hydraulic brake. The brake actuator 92 is controlled by a brake electronic control unit (hereinafter referred to as a brake ECU) 94. The brake ECU 94 is in communication with the HVECU 70, and controls the drive of the brake actuator 92 by a control signal from the HVECU 70, and outputs data related to the state of the brake actuator 92 to the HVECU 70 as necessary.

  Although not shown, the HVECU 70 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. The HVECU 70 includes an ignition signal from the ignition switch 80, a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator opening degree from the accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. Acc, brake pedal position BP from the brake pedal position sensor 86 that detects the amount of depression of the brake pedal 85, vehicle speed V from the vehicle speed sensor 88, and eco switch 89 that gives priority to vehicle energy efficiency relative to drivability The eco switch signal ECO or the like is input via the input port. As described above, the HVECU 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, the battery ECU 52, and the brake ECU 94. . The shift position SP includes a parking position, a neutral position, a drive position for forward travel, a reverse position for reverse travel, and the like.

  In the hybrid vehicle 20 of the embodiment thus configured, the required torque Tr * to be output to the drive shaft 36 is calculated based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal by the driver. 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 Tr * is output to the drive shaft 36. As the operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that the power corresponding to the required power is output from the engine 22, and all the power output from the engine 22 is transmitted to the planetary gear 30 and the motor. The torque conversion operation mode in which the motor MG1 and the motor MG2 are driven and controlled so that the torque is converted by the MG1 and the motor MG2 and output to the drive shaft 36, and the sum of the required power and the power required for charging and discharging the battery 50 is met. Operation of the engine 22 is controlled so that power is output from the engine 22, and all or part of the power output from the engine 22 with charge / discharge of the battery 50 is torque generated by the planetary gear 30, the motor MG1, and the motor MG2. The required power is output to the drive shaft 36 with conversion. Charge-discharge drive mode for driving and controlling the motors MG1 and MG2, there is a motor operation mode in which operation control to output a power commensurate to stop the operation of the engine 22 to the required power from the motor MG2 to the drive shaft 36. The torque conversion operation mode and the charge / discharge operation mode are modes in which the engine 22, the motor MG1, and the motor MG2 are controlled so that the required power is output to the drive shaft 36 with the operation of the engine 22. Since there is no substantial difference in control, both are hereinafter referred to as the engine operation mode.

  In the engine operation mode, the HVECU 70 sets the required torque Tr * to be output to the drive shaft 36 based on the accelerator opening Acc from the accelerator pedal position sensor 84 and the vehicle speed V from the vehicle speed sensor 88, and the set required torque The travel power Pdrv * required for travel is calculated by multiplying Tr * by the rotational speed Nr of the drive shaft 36 (for example, the rotational speed obtained by multiplying the rotational speed Nm2 of the motor MG2 and the vehicle speed V by the conversion factor). The power to be output from the engine 22 by subtracting the charge / discharge required power Pb * (positive value when discharging from the battery 50) of the battery 50 obtained from the calculated traveling power Pdrv * based on the storage ratio SOC of the battery 50 Is set as the required power Pe *. Then, the target rotational speed Ne of the engine 22 is obtained using an operation line (for example, a fuel efficiency optimal operation line) as a relationship between the rotational speed Ne of the engine 22 and the torque Te that can efficiently output the required power Pe * from the engine 22. * And the target torque Te * are set, and the motor is controlled by the rotational speed feedback control so that the rotational speed Ne of the engine 22 becomes the target rotational speed Ne * within the range of the input / output limits Win and Wout of the battery 50. A torque command Tm1 * as a torque to be output from MG1 is set, and when the motor MG1 is driven by the torque command Tm1 *, the torque acting on the drive shaft 36 via the planetary gear 30 is subtracted from the required torque Tr * to reduce the motor MG2. Torque command Tm2 * is set, and the target rotational speed Ne * and target torque Te * are set. In its sent to the engine ECU 24, the torque command Tm1 *, the Tm2 * is sent to the motor ECU 40. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te *, controls the intake air amount, fuel injection control, and ignition of the engine 22 so that the engine 22 is operated by the target rotational speed Ne * and the target torque Te *. The motor ECU 40 that performs control or the like and receives the torque commands Tm1 * and Tm2 * performs switching control of the switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *.

  In the motor operation mode, the HVECU 70 sets a required torque Tr * to be output to the drive shaft 36 based on the accelerator opening Acc and the vehicle speed V, sets a value 0 to the torque command Tm1 * of the motor MG1, and sets the battery 50. The torque command Tm2 * of the motor MG2 is set and transmitted to the motor ECU 40 so that the required torque Tr * is output to the drive shaft 36 within the range of the input / output limits Win, Wout. Then, the motor ECU 40 that receives the torque commands Tm1 * and Tm2 * performs switching control of the switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *.

  Next, the operation of the hybrid vehicle 20 of the embodiment configured as described above, in particular, a predetermined low vehicle speed range (for example, a range of 5 km / h or less or 10 km / h) in the motor operation mode when the shift position SP is the drive position or the reverse position. Will be described. FIG. 2 is a flowchart showing an example of a very low vehicle speed control routine executed by the HVECU 70. This routine is repeatedly executed every predetermined time (for example, every several msec) when the shift position SP is the drive position or the reverse position and is in a predetermined low vehicle speed region in the motor operation mode. In the following description, for the vehicle speed V and torque (request torque Tr *, which will be described later, torque command Tm2 *, which will be described later), the value in the traveling direction corresponding to the shift position SP is positive, and braking force (which will be described later). As for the braking force command Fb *, etc., the value in the direction of decreasing the absolute value of the rotational speed of the drive shaft 36 is positive.

  When the extremely low vehicle speed control routine is executed, the HVECU 70 first shifts the shift position SP from the shift position sensor 82, the accelerator opening Acc from the accelerator pedal position sensor 84, and the brake pedal position from the brake pedal position sensor 86. Processing for inputting data necessary for control, such as BP, the vehicle speed V from the vehicle speed sensor 88, and the eco switch signal ECO from the eco switch 89, is executed (step S100).

  When the data is input in this way, it is determined whether the accelerator is on or off by checking the accelerator opening Acc (step S110). When the accelerator opening Acc is 0, that is, when the accelerator is off, the eco switch signal ECO is on. It is checked whether it is off (step S120). When the eco switch signal ECO is off, the value of the creep limit flag Fc is checked (step S130). Here, the value 0 is set as the initial value of the creep limit flag Fc, a value 1 is set when it is determined that the output of the creep torque Tc is limited, and a value when it is determined that the limit of the creep torque is subsequently released. 0 is a flag that is set.

  When the creep limit flag Fc is 0, the creep torque Tc is set to the torque command Tm2 * of the motor MG2 (step S140), and the braking force according to the brake pedal position BP (value 0 or less if the brake is off, The braking force command Fb * is set to the braking force command Fb * (step S150), the motor MG2 torque command Tm2 * is transmitted to the motor ECU 40, and the braking force command Fb * is transmitted to the brake ECU 94 ( Step S270), this routine is finished. Here, in the embodiment, the brake-corresponding braking force Fbp indicates the relationship between the brake pedal position BP and the brake-corresponding braking force Fbp, and the brake-corresponding braking force Fbp tends to increase from the value 0 as the brake pedal position BP increases from the value 0. Is stored in a ROM (not shown) as a brake-corresponding braking force setting map in advance, and when the brake pedal position BP is given, the corresponding brake-corresponding braking force Fbp is derived and set. Further, the motor ECU 40 that has received the torque command Tm2 * performs switching control of the switching element of the inverter 42 so that the motor MG2 is driven by the torque command Tm2 *. The brake ECU 94 that has received the braking force command Fb * drives and controls the brake actuator 92 so that the braking force of the braking force command Fb * acts on the drive wheels 38a and 38b and the driven wheels 39a and 39b. By such control, when the eco switch 89 is off and the accelerator is off, the creep torque Tc is output from the motor MG2 to the drive shaft 36, and the brake corresponding braking force Fbp (value 0 if brake is off) is driven by the brake actuator 92. It acts on the wheels 38a and 38b and the driven wheels 39a and 39b.

  When the eco switch signal ECO is ON in step S120, it is determined that the creep torque is limited. If the creep limit flag Fc is 0, the value is changed to 1 (steps S160 and S165), and the torque command Tm2 * of the motor MG2 is set. A value 0 is set (step S170), a braking force (Fbp + α) larger than the above-mentioned brake-corresponding braking force Fbp by a predetermined value α is set in the braking force command Fb * (step S180), and the torque command Tm2 * of the motor MG2 is set. Is transmitted to the motor ECU 40, and the braking force command Fb * is transmitted to the brake ECU 94 (step S270), and this routine is terminated. By such control, when the eco switch 89 is on and the accelerator is off, torque is not output from the motor MG2 to the drive shaft 36 (the output of the creep torque Tc from the motor MG2 to the drive shaft 36 is limited), and the brake-corresponding braking force. A braking force (Fbp + α) larger than Fbp is applied to the drive wheels 38a, 38b and the driven wheels 39a, 39b by the brake actuator 92. In this case, power consumption by the motor MG2 can be suppressed by not outputting torque (creep torque Tc) from the motor MG2. However, by not outputting the torque in the traveling direction from the motor MG2, the vehicle may slide down (move) on the slope. On the other hand, in the embodiment, the braking force (Fbp + α) larger than the braking-corresponding braking force Fbp is applied to the driving wheels 38a, 38b and the driven wheels 39a, 39b by the brake actuator 92, thereby causing the vehicle to slide down (move). Can be suppressed. The predetermined value α is determined as an addition amount required to suppress the vehicle from falling (moving). For example, a decrease in torque in the traveling direction caused by not outputting the creep torque Tc from the motor MG2 to the drive shaft 36. A value converted into braking force or a value in the vicinity thereof can be used.

  When the eco switch signal ECO is off in step S120 and the creep limit flag Fc is a value of 1 in step S130, a value of 0 is set in the torque command Tm2 * of the motor MG2 (step S170), and a predetermined value is determined from the brake corresponding braking force Fbp. A braking force (Fbp + α) that is larger by α is set in the braking force command Fb * (step S180), the torque command Tm2 * of the motor MG2 is transmitted to the motor ECU 40, and the braking force command Fb * is transmitted to the brake ECU 94. (Step S270), this routine is finished. Therefore, when the eco switch signal ECO is switched from on to off while the accelerator is off, torque is not output from the motor MG2 to the drive shaft 36 regardless of the switching. As a result, when the eco switch 89 is turned off while the accelerator is off, the vehicle is given a feeling of popping out by the operation of the eco switch 89 as compared with the case where the output of the creep torque Tc is started. Can be suppressed.

  When the accelerator opening Acc is larger than 0 in step S110, that is, when the accelerator is on, torque corresponding to the accelerator opening Acc (hereinafter referred to as accelerator-corresponding torque Tacc) is set as the required torque Tr * to be output to the drive shaft 36. (Step S190). Here, in the embodiment, the accelerator-corresponding torque Tacc is determined in advance so that the accelerator-corresponding torque Tacc increases from the value 0 as the accelerator opening Acc increases from the value 0. The accelerator corresponding torque setting map is stored in a ROM (not shown), and when the accelerator opening degree Acc is given, the corresponding accelerator corresponding torque Tacc is derived and set from the stored map.

  Subsequently, the value of the creep limit flag Fc is checked (step S200). When the creep limit flag Fc is 0, it is determined that the creep torque is not cut when the accelerator opening Acc is 0, and the required torque Tr The larger of * and creep torque Tc is set to the required torque Tr * (step S210), and the brake-corresponding braking force Fbp is set to the braking force command Fb * in the same manner as the processing of step S150 (step S220). The torque command Tm2 * for MG2 is transmitted to the motor ECU 40, the braking force command Fb * is transmitted to the brake ECU 94 (step S270), and this routine is terminated.

  When the creep limit flag Fc is 1 in step S200, the required torque Tr * is set to the torque command Tm2 * of the motor MG2 (step S230), and the required torque Tr * and the creep torque Tc are compared (step S240). When the required torque Tr * is equal to or less than the creep torque Tc, the processes after step S220 are executed. By such control, when the creep limit flag Fc is 1 and the accelerator is turned off, the larger of the required torque Tr * and the creep torque Tc is set to the required torque Tr *. The increase from the torque value 0 (when the accelerator is off) can be made smooth. As a result, it is possible to suppress giving the driver a feeling of jumping out of the vehicle.

  On the other hand, when the required torque Tr * is larger than the creep torque Tc in step S240, the value 0 is set in the creep limit flag Fc (step S250), and the brake corresponding braking force Fbp is set to the braking force command Fb * in the same manner as in step S150. (Step S260), the torque command Tm2 * of the motor MG2 is transmitted to the motor ECU 40, the braking force command Fb * is transmitted to the brake ECU 94 (step S270), and this routine is terminated. When the value 0 is set in the creep limit flag Fc in this way, when the routine is subsequently executed and the accelerator is on in step S110, the accelerator-corresponding torque Tacc is set as the required torque Tr * in step S190, and step S200. Thus, it is determined that the creep limit flag Fc is 0, and the processing after step S210 is executed.

  FIG. 3 shows the time change of the eco switch signal ECO, the accelerator opening Acc, the brake pedal position BP, the required torque Tr *, the creep limit flag Fc, the traveling direction torque, and the braking force when the brake is off in a predetermined low vehicle speed range. It is explanatory drawing which shows an example of the mode. First, when the eco switch 89 (eco switch signal ECO) is on, the accelerator is off and the brake is off, the torque in the traveling direction (creep torque Tc) is not output from the motor MG2 to the drive shaft 36, and the value 1 is set in the creep limit flag Fc. And a braking force (Fbp + α) that is larger than the braking-corresponding braking force Fbp (in this case, value 0) corresponding to the brake pedal position BP by a predetermined value α by the brake actuator 92 and the driving wheels 38a, 38b and the driven wheels 39a, 39b. To act on. Accordingly, it is possible to suppress power consumption by the motor MG2 (improve the energy efficiency of the vehicle) and to suppress the vehicle from sliding down (moving). When the eco switch 89 is turned off from on while the accelerator is off and the brake is off (time t1), torque (creep torque Tc) in the traveling direction is output from the motor MG2 to the drive shaft 36 regardless of the operation. Continue not to do. As a result, it is possible to suppress the driver from feeling the vehicle jumping out by operating the eco switch 89. Thereafter, when the accelerator is turned on (time t2), the braking force applied to the drive wheels 38a, 38b and the driven wheels 39a, 39b is changed from the braking force (Fbp + α) to the brake-corresponding braking force Fbp and the required torque Tr * (accelerator-corresponding). Torque Tacc) starts to be output from the motor MG2 to the drive shaft 36. As a result, the increase from the torque value 0 (when the accelerator is off) in the traveling direction is made smoother than that in which the larger of the required torque Tr * and the creep torque Tc is output from the motor MG2. Thus, it is possible to suppress giving the driver a feeling of jumping out of the vehicle. Then, when the accelerator pedal 83 is depressed and the required torque Tr * exceeds the creep torque Tc (time t3), the value 0 is set in the creep limit flag Fc. When the value 0 is set in the creep limit flag Fc in this way, when the accelerator is subsequently turned off, if the eco switch 89 is off, the creep limit flag Fc is held at the value 0, and the creep is applied from the motor MG2 to the drive shaft 36. The torque Tc is output and the brake-corresponding braking force Fbp is applied to the drive wheels 38a and 38b and the driven wheels 39a and 39b by the brake actuator 92. On the other hand, if the eco switch 89 is turned on when the accelerator is turned off, the value 1 is set in the creep limit flag Fc, the torque (creep torque Tc) is not output from the motor MG2 to the drive shaft 36, and the brake response control is performed. A braking force (Fbp + α) larger than the power Fbp is applied to the driving wheels 38a, 38b and the driven wheels 39a, 39b by the brake actuator 92.

  According to the hybrid vehicle 20 of the embodiment described above, the motor MG2 is controlled so that the creep torque Tc is output when the eco switch 89 (eco switch signal ECO) is off when the accelerator is off in a predetermined low vehicle speed range. When the eco switch 89 is on, the motor MG2 is controlled so that the output of the creep torque Tc is limited. When the eco switch 89 is on, the braking force is larger than when the eco switch 89 is off. Since the brake actuator 92 is controlled so as to act on the vehicle, the power consumption by the motor MG2 can be suppressed (the vehicle energy efficiency can be improved) when the accelerator switch is off and the eco switch 89 is on in a predetermined low vehicle speed range. In addition, the vehicle can be prevented from sliding down (moving).

  Further, according to the hybrid vehicle 20 of the embodiment, when the accelerator is on and the creep restriction flag Fc is 1, the motor MG2 is controlled so that the accelerator-corresponding torque Tacc corresponding to the accelerator opening Acc is output to the drive shaft 36. Therefore, compared to the case where the motor MG2 is controlled so that the larger one of the accelerator-corresponding torque Tacc and the creep torque Tc is output to the drive shaft 36, when the accelerator is turned off and the accelerator is turned on. The increase in torque output from the drive shaft 36 from the value 0 (when the accelerator is off) can be made smooth, and the vehicle can be prevented from giving a sense of popping out to the driver.

  In the hybrid vehicle 20 of the embodiment, when the accelerator is off and the eco switch 89 is on in a predetermined low vehicle speed range, no torque is output from the motor MG2 to the drive shaft 36, but creep torque is applied from the motor MG2 to the drive shaft 36. A torque Tc2 smaller than Tc may be output. In this case, when the accelerator is on and the creep limit flag Fc is 1, the larger torque of the accelerator-corresponding torque Tacc and the torque Tc2 may be output from the motor MG2 to the drive shaft 36.

  In the hybrid vehicle 20 of the embodiment, when the accelerator is on and the creep limit flag Fc is 1, the accelerator-corresponding torque Tacc corresponding to the accelerator opening Acc is output from the motor MG2 to the drive shaft 36. The larger torque of Tacc and creep torque Tc may be output from the motor MG2 to the drive shaft 36.

  In the hybrid vehicle 20 of the embodiment, when the eco switch signal ECO is turned off from on while the accelerator is off, the output of the creep torque Tc from the motor MG2 to the drive shaft 36 is continued. This restriction may be released (output of creep torque Tc is started).

  In the hybrid vehicle 20 of the embodiment, when the accelerator is off and the eco switch 89 is on in a predetermined low vehicle speed range, a braking force (Fbp + α) that is larger than the braking-corresponding braking force Fbp (value 0 if the brake is off). The brake actuator 92 is applied to the vehicle. However, when the brake-corresponding braking force Fbp is equal to or less than a predetermined braking force β (for example, the predetermined value α described above) required for suppressing the vehicle sliding (moving), the predetermined braking force is used. May be applied to the vehicle by the brake actuator 92, and when the brake corresponding braking force Fbp is greater than the predetermined braking force β, the brake corresponding braking force Fbp may be applied to the vehicle by the brake actuator 92. In this way, in a region where the braking-corresponding braking force Fbp is larger than the predetermined braking force β, an unnecessarily large hydraulic pressure is applied to the brake wheel cylinders 96a to 96d as compared with the case where the braking force (Fbp + α) is applied to the vehicle. Can be suppressed.

  In the hybrid vehicle 20 of the embodiment, when the accelerator is off and the eco switch 89 is on in a predetermined low vehicle speed range, a braking force (Fbp + α) that is larger than the braking-corresponding braking force Fbp (value 0 if the brake is off). The braking force that is applied to the vehicle by the brake actuator 92 and then applied to the vehicle when the accelerator is turned on is changed from the braking force (Fbp + α) to the brake-corresponding braking force Fbp. When * becomes larger than the creep torque Tc, the braking force applied to the vehicle may be changed from the braking force (Fbp + α) to the brake corresponding braking force Fbp.

  In the hybrid vehicle 20 of the embodiment, the power from the motor MG2 is output to the drive shaft 36. However, as illustrated in the hybrid vehicle 120 of the modified example of FIG. 4, the drive shaft 36 transmits the power from the motor MG2. It may be connected to an axle (an axle connected to the wheels 38c and 38d in FIG. 4) different from the connected axle (the axle to which the drive wheels 38a and 38b are connected).

  In the hybrid vehicle 20 of the embodiment, the power from the engine 22 is output to the drive shaft 36 connected to the drive wheels 38a and 38b via the planetary gear 30, but is exemplified in the hybrid vehicle 220 of the modification of FIG. As described above, the inner rotor 232 connected to the crankshaft of the engine 22 and the outer rotor 234 connected to the drive shaft 36 that outputs power to the drive wheels 38a and 38b have a part of the power from the engine 22. A counter-rotor motor 230 that transmits power to the drive shaft 36 and converts remaining power into electric power may be provided.

  In the hybrid vehicle 20 of the embodiment, the power from the engine 22 is output to the drive shaft 36 connected to the drive wheels 38a and 38b via the planetary gear 30, and the power from the motor MG2 is output to the drive shaft 36. However, as illustrated in the hybrid vehicle 320 of the modification of FIG. 6, a motor MG is attached to the drive shaft 36 connected to the drive wheels 38 a and 38 b via the transmission 330, and a clutch 329 is attached to the rotation shaft of the motor MG. The power from the engine 22 is output to the drive shaft 36 via the rotation shaft of the motor MG and the transmission 330, and the power from the motor MG is output to the drive shaft via the transmission 330. It is good also as what outputs to. Alternatively, as illustrated in the hybrid vehicle 420 of the modified example of FIG. 7, the power from the engine 22 is output to the drive shaft 36 connected to the drive wheels 38 a and 38 b via the transmission 430 and the power from the motor MG. May be output to an axle different from the axle to which the drive wheels 38a, 38b are connected (the axle connected to the wheels 38c, 38d in FIG. 7).

  In the embodiment, the present invention is applied to the hybrid vehicle 20 that travels using the power from the engine 22 and the power from the motor MG2, but the vehicle travels using only the power from the motor without the engine. It may be applied to an electric vehicle.

  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 motor MG2 corresponds to the “motor”, the battery 50 corresponds to the “battery”, the brake actuator 92 and the brake wheel cylinders 96a to 96d correspond to the “braking force applying device”, and the eco switch 89 is set to “ The HVECU 70 that executes the extremely low vehicle speed control routine, the motor ECU 40 that controls the motor MG2, and the brake ECU 94 that controls the brake actuator 92 correspond to “control means”.

  Here, the “motor” is not limited to the motor MG2 configured as a synchronous generator motor, and may be any one as long as it can output traveling power, such as an induction motor. The “battery” is not limited to the battery 50 configured as a lithium ion secondary battery, but can exchange power with a motor, such as a nickel hydride secondary battery, a nickel cadmium secondary battery, or a lead storage battery. It does not matter as long as there is any. The “braking force applying device” is not limited to the brake actuator 92 and the brake wheel cylinders 96a to 96d, and any device capable of applying a braking force to the vehicle may be used. The “efficiency priority switch” is not limited to the eco switch 89 and may be any switch as long as it gives an instruction to prioritize the energy efficiency of the vehicle. 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 is configured by a single electronic control unit. Also good. The “control means” controls the motor MG2 so that the creep torque Tc is output when the eco switch 89 (eco switch signal ECO) is off when the accelerator is off in a predetermined low vehicle speed range. The motor MG2 is controlled so that the output of the creep torque Tc is limited when 89 is on. When the eco switch 89 is on, a larger braking force acts on the vehicle than when the eco switch 89 is off. It is not limited to the one that controls the brake actuator 92, but when the accelerator is off in a predetermined low vehicle speed range, the creep control is executed to control the motor so that the creep torque is output when the efficiency priority switch is off. However, when the efficiency priority switch is on, the creep torque output is limited. The creep limit control is performed to control the motor, and when the accelerator is off in a predetermined low vehicle speed range, when the efficiency priority switch is on, a larger braking force is applied to the vehicle than when the efficiency priority switch is off. As long as the large braking force control for controlling the braking force applying device is executed, any device may be used.

  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. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. 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.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the automobile manufacturing industry.

  20, 120, 220, 320, 420 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 30 planetary gear, 36 drive shaft, 37 differential gear, 38a, 38b drive wheel, 38c, 38d Wheel, 39a, 39b Driven wheel, 40 Motor electronic control unit (motor ECU), 41, 42 Inverter, 43, 44 Rotation position detection sensor, 50 battery, 52 Battery electronic control unit (battery ECU), 70 Hybrid electronics Control unit (HVECU), 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake Pedal position sensor, 88 vehicle speed sensor, 90 brake master cylinder, 92 brake actuator, 94 brake electronic control unit (brake ECU), 96a to 96d brake wheel cylinder, 230 rotor motor, 232 inner rotor, 234 outer rotor, 329 Clutch, 330, 430 Transmission, MG, MG1, MG2 motor.

Claims (5)

A motor capable of outputting driving power, a battery capable of exchanging electric power with the motor, a braking force applying device capable of applying a braking force to the vehicle, and an efficiency priority switch for instructing priority of energy efficiency of the vehicle, When the accelerator is off in a predetermined low vehicle speed range, creep control is performed to control the motor so that creep torque is output when the efficiency priority switch is off, and when the efficiency priority switch is on, the creep torque is controlled. Control means for executing creep restriction control for controlling the motor so that the output is restricted, and an automobile comprising:
When the accelerator is off in the predetermined low vehicle speed range and the efficiency priority switch is on, the control means controls the vehicle so that a larger braking force is applied to the vehicle than when the efficiency priority switch is off. A means for executing a large braking force control for controlling the power applying device.
Automobile. The automobile according to claim 1,
The control means is means for controlling the motor so that torque is not output as the creep limit control when the accelerator is off and the efficiency priority switch is on in the predetermined low vehicle speed region,
Furthermore, the control means controls the motor to output a larger one of the accelerator-corresponding torque according to the accelerator operation and the creep torque when the accelerator is turned on from the accelerator-off state during execution of the creep control. And a means for controlling the motor so that the accelerator-corresponding torque is output when the accelerator is turned off from the accelerator off during the execution of the creep limit control.
Automobile. The automobile according to claim 1 or 2,
The control means is means for continuing execution of the creep restriction control regardless of operation of the efficiency priority switch when the efficiency priority switch is turned off from on during execution of the creep restriction control.
Automobile. The automobile according to any one of claims 1 to 3,
The control means is means for ending execution of the large braking force control when the accelerator is turned off from the accelerator off during execution of the large braking force control.
Automobile. The automobile according to any one of claims 1 to 4, wherein
An engine, a generator, a drive shaft coupled to an axle, and a planetary gear in which three rotating elements are connected to three axes of an output shaft of the engine and a rotating shaft of the generator;
The motor has a rotation shaft connected to the drive shaft.
Automobile.

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