JP2018007443A - Vehicle - Google Patents

Abstract

To improve energy efficiency. When the accelerator is off and the brake is off, the motor is controlled such that the first braking force acts on the vehicle by regenerative driving of the motor. Further, when the accelerator is off and the brake is on, the braking force that is the sum of the first braking force and the second braking force corresponding to the amount of brake operation with the upper limit braking force is obtained by the regenerative drive of the motor. The motor is controlled so as to act on the vehicle, and when the second braking force is greater than the upper limit braking force, the braking force applying device is controlled so that the difference braking force acts on the vehicle. When the accelerator is off and the brake is off, the braking force reduction control is performed to reduce the first braking force when the braking force reduction condition is satisfied compared to when the reduction condition is not satisfied. When the brake is turned on during execution of the control, the first braking force is made larger than before the brake is turned on. [Selection] Figure 4

Description

  The present invention relates to an automobile, and more particularly, to an automobile including a motor and a battery.

  2. Description of the Related Art Conventionally, as this type of automobile, there has been proposed an automobile that includes a traveling motor and controls the motor so that braking force acts on the vehicle when the accelerator is off (see, for example, Patent Document 1). In this automobile, when the accelerator is off, the braking force applied to the vehicle is made smaller in the eco mode than in the normal mode.

JP 2013-35370 A

  In such an automobile, when the accelerator is off and the brake is off, the first braking force is applied to the vehicle by regenerative driving of the motor. When the accelerator is off and the brake is on, a braking force that is the sum of the first braking force and the braking force obtained by limiting the second braking force according to the amount of brake operation with the upper limit braking force is applied to the vehicle by regenerative driving of the motor. In addition, when the second braking force is greater than the upper limit braking force, the difference braking force is applied to the vehicle by a hydraulic brake. In such an automobile, when the accelerator is off in the eco mode, if the braking force is relatively small regardless of whether the brake is off or the brake is on, when the driver tries to brake on to apply a certain amount of braking force to the vehicle. In addition, the brake operation amount becomes relatively large, and the second braking force tends to be larger than the upper limit braking force (the braking force that is the sum of the first braking force and the second braking force cannot be easily provided by the regenerative driving of the motor. ). For this reason, a hydraulic brake is easy to operate | move and energy efficiency may become comparatively low.

  The main object of the automobile of the present invention is to improve energy efficiency.

  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 for traveling,
A battery that exchanges power with the motor;
A braking force applying device that applies a braking force to the vehicle by hydraulic pressure;
A control device for controlling the motor and the braking force applying device;
A car equipped with
The controller is
When the accelerator is off and the brake is off, the motor is controlled so that the first braking force acts on the vehicle by the regenerative drive of the motor,
When the accelerator is off and the brake is on, the sum of the first braking force and the post-limit braking force obtained by limiting the second braking force according to the brake operation amount with the upper limit braking force is The motor is controlled so as to act on the vehicle by regenerative driving, and when the second braking force is larger than the upper limit braking force, the difference braking force acts on the vehicle by the braking force applying device. Controlling the braking force applying device;
Further, the control device is configured to reduce the first braking force when the braking force reduction condition is satisfied when the accelerator is off and the brake is off as compared to when the reduction condition is not satisfied. When the brake is turned on during execution of the braking force reduction control, the first braking force is increased as compared to before the brake is turned on.
This is the gist.

  In the automobile of the present invention, when the accelerator is off and the brake is off, the motor is controlled such that the first braking force acts on the vehicle by the regenerative drive of the motor. Further, when the accelerator is off and the brake is on, the braking force that is the sum of the first braking force and the second braking force corresponding to the amount of brake operation with the upper limit braking force is obtained by the regenerative drive of the motor. The motor is controlled so as to act on the vehicle, and when the second braking force is greater than the upper limit braking force, the braking force applying device is controlled so that the difference braking force acts on the vehicle. In this type of control, when the accelerator is off and the brake is off, the braking force reduction control is performed to reduce the first braking force when the braking force reduction condition is satisfied, compared to when the reduction condition is not satisfied. When the brake is turned on during the execution of the braking force reduction control, the first braking force is made larger than before the brake is turned on. As a result, the amount of brake operation and the second braking force when the driver tries to brake on and apply a certain amount of braking force to the vehicle can be made relatively small. Therefore, the second braking force can be prevented from becoming larger than the upper limit braking force, and the sum of the first braking force and the second braking force can be easily provided by the regenerative driving of the motor. As a result, energy efficiency can be improved.

  In such a hybrid vehicle of the present invention, the control device may stop the braking force reduction control when the brake is turned on during execution of the braking force reduction control. In this case, the first braking force is set to a value when the braking force reduction control is not performed, and the second braking force can be suppressed from becoming larger than the upper limit braking force.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. It is a flowchart which shows an example of the control routine at the time of accelerator off performed by HVECU70 of an Example. It is explanatory drawing which shows an example of the map for accelerator off torque setting. It is explanatory drawing which shows an example of the map for brake torque setting. It is a flowchart which shows an example of a braking force reduction flag setting routine. It is explanatory drawing which shows an example when a brake is turned on from the state which is performing braking force reduction control by accelerator-off and brake-off. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. It is a block diagram which shows the outline of a structure of the electric vehicle 220 of 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 illustrated, the hybrid vehicle 20 of the embodiment includes an engine 22, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50, a hydraulic brake device 90, and a hybrid electronic control unit (hereinafter referred to as a hybrid electronic control unit). , “HVECU”) 70.

  The engine 22 is configured as an internal combustion engine that outputs power using gasoline or light oil as a fuel. The operation of the engine 22 is controlled by an engine electronic control unit (hereinafter referred to as “engine ECU”) 24.

  Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and includes, in addition to the CPU, a ROM that stores a processing program, a RAM that temporarily stores data, an input / output port, and a communication port. . The engine ECU 24 receives signals from various sensors necessary to control the operation of the engine 22, for example, a crank angle θcr from a crank position sensor that detects the rotational position of the crankshaft 26 of the engine 22 from an input port. ing. Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 via an output port. The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 calculates the rotational speed Ne of the engine 22 based on the crank angle θcr from the crank position sensor 23.

  The planetary gear 30 is configured as a single pinion type planetary gear mechanism. The sun gear of planetary gear 30 is connected to the rotor of motor MG1. The ring gear of the planetary gear 30 is connected to a drive shaft 36 that is coupled to the drive wheels 39a and 39b via a differential gear 38. A crankshaft 26 of the engine 22 is connected to the carrier of the planetary gear 30 via a damper 28.

  The motor MG1 is configured as, for example, a synchronous generator motor, and the rotor is connected to the sun gear of the planetary gear 30 as described above. The motor MG2 is configured as, for example, a synchronous generator motor, and a rotor is connected to the drive shaft 36. Inverters 41 and 42 are connected to motors MG <b> 1 and MG <b> 2 and to battery 50 via power line 54. The motors MG1 and MG2 are driven to rotate by switching control of a plurality of switching elements (not shown) of the inverters 41 and 42 by a motor electronic control unit (hereinafter referred to as “motor ECU”) 40.

  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 from various sensors necessary for driving and controlling the motors MG1 and MG2, for example, rotational positions θm1 from rotational position detection sensors 43 and 44 that detect rotational positions of the rotors of the motors MG1 and MG2. , Θm2, etc. are input via the input port. From the motor ECU 40, switching control signals to a plurality of switching elements (not shown) of the inverters 41 and 42 are output via an output port. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 calculates 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.

  The battery 50 is configured as, for example, a lithium ion secondary battery or a nickel hydride secondary battery, and is connected to the inverters 41 and 42 via the power line 54. The battery 50 is managed by a battery electronic control unit (hereinafter referred to as “battery ECU”) 52.

  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. . Signals from various sensors necessary for managing the battery 50 are input to the battery ECU 52 via the input port. Examples of signals input to the battery ECU 52 include a battery voltage Vb from a voltage sensor 51 a installed between terminals of the battery 50, a battery current Ib from a current sensor 51 b attached to an output terminal of the battery 50, and a battery 50. The battery temperature Tb from the temperature sensor 51c attached to can be mentioned. The battery ECU 52 is connected to the HVECU 70 via a communication port. The battery ECU 52 calculates the storage ratio SOC based on the integrated value of the battery current Ib from the current sensor 51b. The storage ratio SOC is a ratio of the capacity of power that can be discharged from the battery 50 to the total capacity of the battery 50.

  The hydraulic brake device 90 includes brake wheel cylinders 96a, 96b, 96c, and 96d attached to the drive wheels 39a and 39b and the driven wheels 39c and 39d, and a brake actuator 94. The brake actuator 94 is configured as an actuator for adjusting the hydraulic pressure of the brake wheel cylinders 96a, 96b, 96c, 96d to apply a braking force to the drive wheels 39a, 39b and the driven wheels 39c, 39d. The brake actuator 94 is driven and controlled by a brake electronic control unit (hereinafter referred to as “brake ECU”) 98.

  Although not shown, the brake ECU 98 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. . Signals from various sensors necessary to drive and control the brake actuator 94 are input to the brake ECU 98 via an input port. From the brake ECU 98, a drive control signal and the like to the brake actuator 94 are output via an output port. The brake ECU 98 is connected to the HVECU 70 via a communication port.

  Although not shown, the HVECU 70 is configured as a microprocessor centered on a CPU, and includes a ROM that stores a processing program, a RAM that temporarily stores data, an input / output port, and a communication port in addition to the CPU. Signals from various sensors are input to the HVECU 70 via input ports. Examples of the signal input to the HVECU 70 include an ignition signal from the ignition switch 80 and a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81. Here, the shift position SP includes a parking position (P position), a reverse position (R position), a neutral position (N position), a forward position (D position), and the like. Further, the accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83, the brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, and the vehicle speed sensor 88 The vehicle speed V can also be mentioned. Furthermore, an eco-switch signal from the eco-switch 89 that instructs an eco-mode that gives higher priority to fuel efficiency than the normal mode can be cited as the travel mode Md. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, the battery ECU 52, and the hydraulic brake device 90 via the communication port.

In the hybrid vehicle 20 of the embodiment thus configured, the required driving force of the drive shaft 36 is set based on the accelerator opening Acc and the vehicle speed V, and the required power corresponding to the required driving force is output to the drive shaft 36. In addition, the engine 22 and the motors MG1, MG2 are controlled to operate. As operation modes of the engine 22 and the motors MG1, MG2, there are the following modes (1) to (3).
(1) Torque conversion operation mode: The engine 22 is operated and controlled so that power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is transmitted to the planetary gear 30 and the motors MG1 and MG2. (2) Charging / discharging operation mode: sum of required power and electric power necessary for charging / discharging of the battery 50. In this mode, the motor MG1 and MG2 are driven and controlled so that the required power is output to the drive shaft 36. The engine 22 is operated and controlled so that the power suitable for the engine 22 is output from the engine 22, and all or a part of the power output from the engine 22 is charged with the battery 50 by the planetary gear 30 and the motors MG1 and MG2. The motors MG1 and MG2 are driven so that the torque is converted by the motor and the required power is output to the drive shaft 36. Gosuru mode (3) motor drive mode: stop the operation of the engine 22, required power to drive control of the motor MG2 to be outputted to the drive shaft 36 mode

  Next, the operation of the hybrid vehicle 20 of the embodiment thus configured, particularly the operation when the accelerator is off during traveling will be described. FIG. 2 is a flowchart illustrating an example of an accelerator-off time control routine executed by the HVECU 70 of the embodiment. This routine is repeatedly executed every predetermined time (for example, several milliseconds) when the accelerator is off during traveling. When the accelerator is off during traveling, in parallel with this routine, a plurality of inverters 41 are controlled so that the engine 22 is stopped and torque is not output from the motor MG1 by cooperative control of the HVECU 70, the engine ECU 24, and the motor ECU 40. Switching control of the switching element is performed.

  When the accelerator-off time control routine is executed, the HVECU 70 first inputs data such as the vehicle speed V, the brake pedal position BP, and the braking force reduction flag Fbr (step S100). Here, the vehicle speed V is input by the vehicle speed sensor 88. As the brake pedal position BP, the one detected by the brake pedal position sensor 86 is input. The braking force reduction flag Fbr is a flag indicating whether or not an accelerator off torque Td1 described later is a relatively large value (a relatively small value as a braking force), and is determined by a braking force reduction flag setting routine described later. It was assumed that what was set was entered.

  When the data is input in this way, based on the input vehicle speed V and the braking force reduction flag Fbr, the accelerator-off torque Td1 required for the vehicle as the accelerator-off (required for the drive shaft 36) is set (step S110). Here, in the embodiment, the accelerator off torque Td1 is stored in a ROM (not shown) as an accelerator off torque setting map by predetermining the relationship among the vehicle speed V, the braking force reduction flag Fbr, and the accelerator off torque Td1. When V and the braking force reduction flag Fbr are given, the corresponding accelerator off torque Td1 is derived from this map and set. An example of the accelerator off torque setting map is shown in FIG. If accelerator off torque Td1, brake torque Td2, brake torque Td2ad after limitation, requested torque Td *, torque command Tm2 * of motor MG2, and brake torque command Thb * are negative, it means that braking torque is requested. To do. As shown in the figure, the accelerator-off torque Td1 is set to be larger when the braking force reduction flag Fbr is 1 than when the braking force reduction flag Fbr is 0 (smaller as braking force).

  Subsequently, it is determined whether the brake is on or off based on the brake pedal position BP (step S120), and when it is determined that the brake is off, the vehicle is requested for the accelerator off torque Td1 (requested to the drive shaft 36). Is set as the required torque Td * (step S130), and the set required torque Td * is set as the torque command Tm2 * of the motor MG2 and transmitted to the motor ECU 40 (step S140). The torque command Thb * is set to a value of 0 and transmitted to the brake ECU 98 (step S150), and this routine is terminated. When motor ECU 40 receives torque command Tm2 * of motor MG2, motor ECU 40 performs switching control of a plurality of switching elements of inverter 42 such that motor MG2 is driven by torque command Tm2 *. When torque command Tm2 * of motor MG2 is negative (when it is braking torque), negative torque, that is, braking torque is output to drive shaft 36 by regenerative driving of motor MG2. When the brake ECU 98 receives a brake torque command Thb * having a value of 0, the brake ECU 98 does not apply the braking torque from the hydraulic brake device 90 to the drive wheels 39a and 39b and the driven wheels 39c and 39d. With this control, when the braking force reduction flag Fbr is a value 1, the accelerator off torque Td1, the required torque Td *, and the torque command Tm2 * of the motor MG2 are set larger than when the braking force reduction flag Fbr is a value 0 ( The motor MG2 is controlled with a small braking force. Therefore, hereinafter, the control when the braking force reduction flag Fbr is 1 is referred to as “braking force reduction control”.

  When it is determined in step S120 that the brake is on, the brake torque Td2 required for the vehicle (required for the drive shaft 36) is set according to the amount of brake operation based on the vehicle speed V and the brake pedal position BP. (Step S160). Here, in the embodiment, the brake torque Td2 is stored in a ROM (not shown) as a brake torque setting map by predetermining the relationship among the vehicle speed V, the brake pedal position BP, and the brake torque Td2, and the vehicle speed V and the brake pedal. Given the position BP, the corresponding brake torque Td2 is derived from this map and set. An example of the brake torque setting map is shown in FIG. As shown in the figure, the brake torque Td2 decreases as the brake pedal position BP increases (the braking force increases).

  When the brake torque Td2 is thus set, the brake torque Td2 is limited (lower limit guard) by the torque limit Td2lim, and the post-limit brake torque Td2ad is set (step S170). The torque limit Td2lim will be described later. Subsequently, the sum of the accelerator off torque Td1 and the brake torque after limitation Td2ad is set as the required torque Td * (step S180), and the set required torque Td * is set as the torque command Tm2 * of the motor MG2 to the motor ECU 40. Transmit (step S190).

  Then, the brake torque Td2 is compared with the torque limit Td2lim (step S200). This process determines whether the brake torque Td2 is within the range of the torque limit Td2lim, that is, whether the sum of the accelerator off torque Td1 and the brake torque Td2 (Td1 + Td2) can be covered by the regenerative drive of the motor MG2. It is processing. When the brake torque Td2 is equal to or greater than the torque limit Td2lim, it is determined that the torque (Td1 + Td2) can be covered by the regenerative drive of the motor MG2, and a value of 0 is set in the brake torque command Thb * of the hydraulic brake device 90 to the brake ECU 98. (Step S150), and this routine is finished.

  When the brake torque Td2 is smaller than the torque limit Td2lim in step S200, it is determined that the torque (Td1 + Td2) cannot be covered by the regenerative drive of the motor MG2, and a value obtained by subtracting the torque limit Td2lim from the brake torque Td2 is determined. The brake torque command Thb * is transmitted to the brake ECU 98 (step S210), and this routine is terminated. When the brake ECU 98 receives a negative value of the brake torque command Thb *, the brake actuator 98 so that the brake torque of the brake wheel cylinders 96a to 96d is equivalent to the brake torque command Thb * when converted to the drive shaft 36. 94 is driven and controlled. As described above, when the brake torque Td2 is smaller than the torque limit Td2lim, that is, when the torque (Td1 + Td2) cannot be covered by the regenerative drive of the motor MG2, the torque (the regenerative drive of the motor MG2 and the braking torque by the hydraulic brake device 90) (Td1 + Td2) is covered. The torque limit Td2lim described above is determined so that the response delay due to the hydraulic brake is within an allowable range when the braking torque by the hydraulic brake device 90 is applied to the brake operation by the driver.

  Next, processing for setting the braking force reduction flag Fbr used in the accelerator-off control routine of FIG. 2 will be described. FIG. 5 is a flowchart showing an example of a braking force reduction flag setting routine. This routine is repeatedly executed every predetermined time (for example, several milliseconds) regardless of whether the accelerator is on or off. The braking force reduction flag Fbr and an accelerator off history flag Fao described later are set to an initial value 0 when the ignition is on.

  When the braking force reduction flag setting routine is executed, the HVECU 70 first inputs the shift position SP, the accelerator opening Acc, the brake pedal position BP, and the travel mode Md (step S300). Here, the shift position SP is input as detected by the shift position sensor 82. As the accelerator opening Acc, the value detected by the accelerator pedal position sensor 84 is input. As the brake pedal position BP, the one detected by the brake pedal position sensor 86 is input. As the travel mode Md, one set based on the eco switch signal from the eco switch 89 (normal mode or eco mode) is input.

  When the data is thus input, it is determined whether the travel mode Md is the normal mode or the eco mode (step S310), and it is determined whether the shift position SP is the D position (step S320). In the embodiment, the processes in steps S310 and S320 and steps S350 and S390 described later are processes for determining whether or not a condition for reducing the braking force when the accelerator is off is satisfied.

  When it is determined in steps S310 and S320 that the traveling mode Md is the normal mode (not the eco mode) or the shift position SP is determined not to be the D position, a condition for reducing the braking force when the accelerator is off is established. If not, the value 0 is set in the braking force reduction flag Fbr (step S340), and this routine is terminated.

  If it is determined in steps S310 and S320 that the travel mode Md is the eco mode and the shift position SP is the D position, it is determined whether the brake is on or off based on the brake pedal position BP (step S350). When it is determined that the brake is on, it is determined that the condition for reducing the braking force when the accelerator is off is not satisfied, the accelerator off history flag Fao is set to 0 (step S330), and the braking force is reduced. A value 0 is set in the flag Fbr (step S340), and this routine ends. Here, the accelerator-off history flag Fao is a flag indicating whether or not there is a history of accelerator-off with brake-off.

  If it is determined in step S350 that the brake is off, it is determined whether the accelerator is on or off based on the accelerator opening Acc (step S360). When it is determined that the accelerator is off, a value 1 is set to the accelerator off history flag Fao (step S370). On the other hand, when it is determined that the accelerator is on, the process of step S370 is not performed.

  Subsequently, the value of the braking force reduction flag (previous Fbr) set at the previous execution of this routine is checked (step S380). When the previous braking force reduction flag (previous Fbr) is 0, the accelerator-off history flag Fao Is 1 and it is determined whether the current accelerator opening Acc is larger than a threshold value Aref (for example, 8%, 10%, 12%, etc.) (step S390).

  If it is determined in step S390 that the accelerator-off history flag Fao is 0 or the accelerator opening Acc is less than or equal to the threshold value Aref, it is determined that the condition for reducing the braking force when the accelerator is off is not satisfied. Then, the braking force reduction flag Fbr is set to 0 (step S400), and this routine is terminated.

  If it is determined in step S390 that the accelerator-off history flag Fao is 1 and the current accelerator opening Acc is larger than the threshold value Aref, it is determined that the condition for reducing the braking force when the accelerator is off is satisfied, and the braking force is reduced. A value of 1 is set in the flag Fbr (step S410), and this routine ends.

  When the value 1 is set to the braking force reduction flag Fbr in this way, at the next execution of this routine, in steps S310, S320, and S350, when the traveling mode Md is the eco mode, the shift position SP is the D position, and the brake is off, In step S380, it is determined that the previous braking force reduction flag (previous Fbr) has a value of 1, and it is determined that the braking force reduction condition when the accelerator is off continues, and the braking force reduction flag Fbr has a value of 1. Is set (step S410), and this routine is terminated.

  When the braking force reduction flag Fbr is a value 1, it is determined in step S310 that the travel mode Md has become the normal mode, in step S320 it is determined that the shift position SP is no longer the D position, or in step S350 If it is determined that the braking force is turned on, it is determined that the condition for reducing the braking force when the accelerator is off is not satisfied, and the braking force reduction flag Fbr is switched to 0 in step S340.

  Thus, since the value 0 is set in the braking force reduction flag Fbr when the brake is on, the accelerator off torque Td1 is made smaller than when the value 1 is set in the braking force reduction flag Fbr (as the braking torque). That is, braking force reduction control is not performed. When the brake is turned on from the state in which the braking force reduction control is performed with the accelerator off and the brake off, the execution of the braking force reduction control is stopped (the accelerator off torque Td1 is reduced (the braking torque is increased)). Thus, the following effects can be obtained.

  FIG. 6 is an explanatory diagram showing an example of a state when the brake is turned on from the state where the braking force reduction control is performed with the accelerator off and the brake off (the braking force reduction flag Fbr is 1). The left side of FIG. 6 stops execution of the braking force reduction control when the brake is turned on (the braking force reduction flag Fbr is set to a value of 0) to relatively reduce the accelerator off torque Td1 (to increase the braking torque). The mode of an Example is shown. Further, the right side of FIG. 6 continues execution of the braking force reduction control even when the brake is turned on (holding the braking force reduction flag Fbr at a value of 1), and relatively increases the accelerator off torque Td1 (as the braking torque). Indicates a relatively small state.

  In the case of the comparative example, as shown on the right side of FIG. 6, even if the brake is turned on, the execution of the braking force reduction control is continued and the accelerator off torque Td1 is made relatively large (the braking torque is made relatively small). Therefore, when applying a certain amount of braking force to the vehicle, the brake pedal position BP tends to be relatively large and the brake torque Td2 tends to be relatively small (the braking torque tends to be large). For this reason, the brake torque Td2 tends to exceed the torque limit Td2lim, and the torque (Td1 + Td2) cannot be covered by the regenerative drive of the motor MG2, so that the braking force by the hydraulic brake device 90 is likely to act on the vehicle.

  On the other hand, in the case of the embodiment, as shown on the left side of FIG. 6, when the brake is turned on, the execution of the braking force reduction control is stopped and the accelerator off torque Td1 is made relatively small (as the braking torque). Therefore, when applying the same braking torque to the vehicle as in the comparative example, the brake pedal position BP becomes smaller and the braking torque Td2 becomes larger than in the comparative example. (The braking torque becomes smaller). For this reason, it is possible to suppress the brake torque Td2 from exceeding the torque limit Td2lim, and it is possible to easily cover the torque (Td1 + Td2) by the regenerative drive of the motor MG2. As a result, energy efficiency can be improved.

  In the hybrid vehicle 20 of the embodiment described above, when the accelerator is off and the brake is off, the accelerator off torque Td1 is set as the torque command Tm2 * of the motor MG2 to control the motor MG2. In addition, when the accelerator is off and the brake is on, the sum of the brake-off torque Td2ad obtained by limiting the accelerator-off torque Td1 and the brake torque Td2 with the torque limit Td2lim is set as the torque command Tm2 * of the motor MG2. When MG2 is controlled and the brake torque Td2 is smaller than the torque limit Td2lim (the brake torque is large), the difference torque between the brake torque Td2 and the torque limit Td2lim is set as the brake torque command Thb * of the hydraulic brake device 90. Thus, the hydraulic control device 90 is controlled. In such control, when the accelerator is off and the brake is off, the accelerator off torque Td1, that is, the torque command Tm2 * of the motor MG2, is set when the braking force reduction condition is satisfied, compared to when the reduction condition is not satisfied. When the braking force reduction control is executed to increase (decrease the braking torque) and the brake is turned on while the braking force reduction control is being executed, the braking force reduction control is stopped, so that the braking force is reduced. Thus, the accelerator off torque Td1 is decreased (the braking torque is increased). As a result, it is possible to suppress the brake pedal position BP from increasing when the brake is on, and to prevent the brake torque Td2 from exceeding the torque limit Td2lim, and to regenerate the torque (Td1 + Td2) by the regenerative drive of the motor MG2. It can make it easier to cover. As a result, energy efficiency can be improved.

  In the hybrid vehicle 20 of the embodiment, when the brake is turned on from the state in which the braking force reduction control is executed when the accelerator is off and the brake is off, the execution of the braking force reduction control is stopped, compared to before the brake is turned on. Thus, the accelerator off torque Td1 is reduced (the value when the braking force reduction flag Fbr is 0). However, when the brake is turned on from the state in which the braking force reduction control is executed when the accelerator is off and the brake is off, the execution of the braking force reduction control is continued and the accelerator off torque Td1 is made smaller than before the brake is turned on. (The braking force reduction flag Fbr in FIG. 3 is larger than the value when the value is 0 and smaller than when the braking force reduction flag Fbr is the value 1).

  In the hybrid vehicle 20 of the embodiment, the engine ECU 24, the motor ECU 40, and the HVECU 70 are provided. However, the engine ECU 24, the motor ECU 40, and the HVECU 70 may be configured as a single electronic control unit.

  In the hybrid vehicle 20 of the embodiment, the engine 22 and the motor MG1 are connected to the drive shaft 36 connected to the drive wheels 39a and 39b via the planetary gear 30, and the motor MG2 is connected to the drive shaft 36. However, as shown in the modified hybrid vehicle 120 of FIG. 7, the motor MG is connected to the drive shaft 36 connected to the drive wheels 39a and 39b via the transmission 130 and the clutch 129 is attached to the rotation shaft of the motor MG. It is good also as a structure which connects the engine 22 via. Moreover, as shown in the electric vehicle 220 of the modification of FIG. 8, it is good also as a structure of the electric vehicle which connects the motor MG for driving | running | working to the drive shaft 36 connected with the drive wheels 39a and 39b. In other words, any configuration may be used as long as it includes a traveling motor.

  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 hydraulic brake device 90 corresponds to the “braking force applying device”, and the accelerator off-time control routine of FIG. The HVECU 70 and the motor ECU 40 that execute the braking force reduction flag setting routine are equivalent to the “control device”.

  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 Hybrid vehicle, 22 engine, 23 crank position sensor, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 planetary gear, 36 drive shaft, 38 differential gear, 39a, 39b drive wheel, 39c 39d, driven wheel, 40 motor electronic control unit (motor ECU), 41, 42 inverter, 43, 44 rotational position sensor, 50 battery, 51a voltage sensor, 51b current sensor, 51c temperature sensor, 52 battery electronic control unit ( Battery ECU), 54 Electric power line, 70 Hybrid electronic 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, 89 eco switch, 90 hydraulic brake device, 94 brake actuator, 96a to 96d brake wheel cylinder, 98 electronic control unit for brake (brake ECU) 129, clutch, 130 transmission, 220 electric vehicle, MG, MG1, MG2 motor.

Claims (1)

A motor for traveling,
A battery that exchanges power with the motor;
A braking force applying device that applies a braking force to the vehicle by hydraulic pressure;
A control device for controlling the motor and the braking force applying device;
A car equipped with
The controller is
When the accelerator is off and the brake is off, the motor is controlled so that the first braking force acts on the vehicle by the regenerative drive of the motor,
When the accelerator is off and the brake is on, the sum of the first braking force and the post-limit braking force obtained by limiting the second braking force according to the brake operation amount with the upper limit braking force is The motor is controlled so as to act on the vehicle by regenerative driving, and when the second braking force is larger than the upper limit braking force, the difference braking force acts on the vehicle by the braking force applying device. Controlling the braking force applying device;
Further, the control device is configured to reduce the first braking force when the braking force reduction condition is satisfied when the accelerator is off and the brake is off as compared to when the reduction condition is not satisfied. When the brake is turned on during execution of the braking force reduction control, the first braking force is increased as compared to before the brake is turned on.
Automobile.

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