JP2018093640A - Vehicular control apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular control apparatus for suppressing discomfort forced to a driver as a result of the deceleration of the vehicle decreasing at the time of turning off the accelerator while the vehicle is decelerating.SOLUTION: A control apparatus includes a controller for executing brake force control exerting brake force to a vehicle by controlling a traveling motor in the state of turning off an accelerator while the vehicle is decelerating. The controller performs: changing the brake force in accordance with deceleration of the vehicle; and causing brake force to track so as to increase the brake force in a direction where the deceleration decreases, and causing the brake force to not track so as to decrease the brake force in a direction where the deceleration increases.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a vehicle control device that includes a traveling motor and applies a braking force to the vehicle by the traveling motor.

  Conventionally, there has been proposed a hybrid vehicle equipped with an engine that outputs torque by combustion of fuel and an electric motor that outputs torque by supplying electric power and can transmit the torque of the engine and the electric motor to driving wheels (for example, , See Patent Document 1). This hybrid vehicle can control the motor so that the braking force acts on the vehicle when the accelerator is off when the accelerator pedal is not depressed. When the accelerator is off and the eco mode is set to run with priority on fuel efficiency compared to the normal mode, the braking force is reduced compared to the normal mode.

JP 2013-35370 A

  In the vehicle described above, when the accelerator is off and the eco mode is set, the braking force is relatively small, so the vehicle deceleration may be small. When the vehicle deceleration decreases, for example, when the road surface changes such as a downhill road or a flat road where the downhill slope becomes gentler, the vehicle deceleration may decrease and give the driver a sense of discomfort. .

  An object of the present invention is to suppress a driver from feeling uncomfortable due to a decrease in vehicle deceleration when the accelerator is off.

  In order to achieve the above object, according to the present invention, in a vehicle control device including a traveling motor and a battery that exchanges electric power with the motor, a braking force is applied to the vehicle by the motor when the accelerator is off. A controller, wherein the controller changes the braking force according to the deceleration of the vehicle, causes the braking force to follow in a direction in which the deceleration decreases, and increases the braking force. The braking force is not allowed to follow so that the braking force decreases in the direction in which the speed increases.

  According to the present invention, when the accelerator is off, the braking force is caused to follow in such a direction that the vehicle braking force increases in the direction in which the vehicle deceleration decreases, and the vehicle braking force in the direction in which the vehicle deceleration increases. The braking force of the vehicle is not allowed to follow so as to decrease. For this reason, for example, when the traveling road surface changes such as a downhill road or a flat road where the downward slope becomes gentle from the downhill road, the vehicle is reduced when the braking force is caused to follow so that the braking force applied to the vehicle is reduced. It is possible to suppress the speed from decreasing and causing the driver to feel uncomfortable.

It is explanatory drawing which shows an example of the vehicle in embodiment of this invention. It is explanatory drawing which shows an example of the correspondence of the longitudinal acceleration of a vehicle, and each braking mode. It is explanatory drawing which shows an example of the relationship between the braking force and vehicle speed in each braking mode. It is a flowchart which shows an example of the operation | movement procedure of braking force control. It is a flowchart which shows an example of the procedure of the pre-processing in braking force control. It is a flowchart which shows an example of the procedure of the other pre-processing in braking force control. It is a time chart which shows an example of transition of braking mode. It is a time chart which shows the other example of transition of a braking mode.

  FIG. 1 shows an example of a vehicle according to an embodiment of the present invention. As shown in FIG. 1, a vehicle 10 includes an engine 11, an engine ECU (Electronic Control Unit) 12, a planetary gear 13, a first motor (MG1) 14, a second motor (MG2) 15, a motor ECU 16, a first inverter 17, 2 A hybrid vehicle including an inverter 18, a battery 19, a battery ECU 20, and an HVECU (Hybrid Vehicle Electronic Control Unit) 21. The engine 11 is an example of an internal combustion engine that outputs driving force using gasoline, light oil, or the like as fuel, and its operation is controlled by an engine ECU 12.

  The engine ECU 12 includes a microcomputer (not shown) having a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), an input / output port, and the like, and temporarily stores the RAM. The functions of the engine 11 are used to control the operation of the engine 11 and the like by executing various programs stored in advance in the ROM. Specifically, a plurality of signals obtained from various sensors necessary for controlling the operation of the engine 11 are input to the engine ECU 12 via an input port. For example, a crank position sensor 23 that detects the rotational position of the crankshaft 22 is attached to the engine 11. A signal of the crank angle θcr obtained from the crank position sensor 23 is input to the engine ECU 12. The engine ECU 12 calculates or determines various control signals for controlling the operation of the engine 11 based on various programs using a plurality of signals input from the input port as parameters, and outputs the various control signals calculated or determined. Output through port. The engine ECU 12 calculates the crank angle rotation speed, that is, the engine rotation speed Ne based on the signal obtained from the crank position sensor 23. The engine ECU 12 is connected to the HVECU 21 via a communication port.

  The planetary gear 13 is an example of a power split mechanism that performs a differential action by an input element to which the driving force output from the engine 11 is input, a reaction force element connected to the first motor 14 and an output element. A rotor of the first motor 14 is connected to the input element, for example, the sun gear S. A reaction shaft, such as a ring gear R, is connected to a drive shaft 28 that is fast-coupled to drive wheels 25 and 26 via a differential gear 27. The output shaft, for example, the carrier C, is connected to the crankshaft 22 via the damper mechanism 29. Note that the power split mechanism may be a combination of a plurality of planetary gear mechanisms.

  The first motor 14 is configured, for example, as a synchronous generator motor, and the rotor is connected to the sun gear S as described above. The second motor 15 is configured as a synchronous generator motor, for example, and the rotor is connected to the drive shaft 28. The first inverter 17 is connected to the first motor 14 and connected to the battery 19 via the power line 30. The second inverter 18 is connected to the second motor 15 and connected to the battery 19 via the power line 30. The first motor 14 is driven by switching control of a plurality of switching elements (not shown) included in the first inverter 17 under the control of the motor ECU 16. The second motor 15 is driven by switching control of a plurality of switching elements (not shown) included in the second inverter 18 under the control of the motor ECU 16.

  The motor ECU 16 includes the same or similar microcomputer as the engine ECU 12. The motor ECU 16 includes signals from various sensors necessary to control the driving of the first motor 14 and the second motor 15, for example, a first rotational position detection sensor 31 that detects the rotational position of the rotor of the first motor 14. And the rotational position θm2 from the second rotational position detection sensor 32 that detects the rotational position of the rotor of the second motor 15 are input via the input port. The motor ECU 16 outputs a switching control signal to the plurality of switching elements included in the first inverter 17 and a switching control signal to the plurality of switching elements included in the second inverter 18 via the output port. The motor ECU 16 calculates the rotation speed Nm1 of the first motor 14 based on the rotation position of the rotor of the first motor 14 obtained from the first rotation position detection sensor 31, and obtains it from the second rotation position detection sensor 32. The rotational speed Nm2 of the second motor 15 is calculated based on the rotational position of the rotor of the second motor 15 to be operated.

  The battery 19 is configured as, for example, a lithium ion secondary battery or a nickel hydride secondary battery, and is connected to the first inverter 17 and the second inverter 18 via the power line 30. The battery 19 manages information such as the remaining capacity SOC of the battery 19 and the amount of power consumption under the control of the battery ECU 20.

  The battery ECU 20 includes a microcomputer that is the same as or similar to the engine ECU 12. Signals from various sensors necessary for managing the battery 19 are input to the battery ECU 20 via the input port. Examples of information input to the battery ECU 20 include a battery voltage obtained from a voltage sensor 34 attached between terminals of the battery 19, a battery current obtained from a current sensor 35 attached to an output terminal of the battery 19, and the battery 19. The battery temperature obtained from the temperature sensor 36 attached to is included. The battery ECU 20 is connected to the HVECU 21 via a communication port. The battery ECU 20 calculates the remaining capacity SOC indicating the ratio of the remaining capacity to the full charge capacity based on the integrated value of the battery current obtained from the current sensor.

  The HVECU 21 includes a microcomputer that is the same as or similar to the engine ECU 12. The HVECU 21 is input with signals obtained from various sensors via an input port. The signal input to the HVECU 21 includes, for example, an ignition signal obtained from the ignition switch 38 and a shift position signal obtained from the shift position sensor 40 that detects the operation position of the shift lever 39. Here, the shift position 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, as a signal input to the HVECU 21, for example, a signal corresponding to the accelerator opening degree ACC obtained from the accelerator sensor 42 that detects the depression amount of the accelerator pedal 41, and a brake sensor 44 that detects the depression amount of the brake pedal 43 are obtained. And a signal corresponding to the vehicle speed V obtained from the vehicle speed sensor 45 that detects the vehicle speed V. Further, it includes a signal of the longitudinal acceleration α obtained from the acceleration sensor 47 that detects the longitudinal acceleration G of the vehicle 10 generated when the vehicle 10 is accelerated or decelerated.

  The HVECU 21 sets the required driving force of the drive shaft 28 based on the accelerator opening Acc and the vehicle speed V, and operates the engine 11 so that the driving force corresponding to the required driving force is output to the drive shaft 28. An operation mode for controlling the driving of the motor 14 and the driving of the second motor 15 is set. The operation mode includes a first operation mode, a second operation mode, and a third operation mode.

  In the first operation mode, the operation of the engine 11 is controlled so that the driving force corresponding to the required driving force is output from the engine 11, and all of the driving force output from the engine 11 is transmitted to the planetary gear 13 and the first motor. In this mode, torque is converted by the motor 14 and the second motor 15 and the driving of the first motor 14 and the second motor 15 is controlled so that the converted driving force is transmitted to the drive shaft 28. That is, this is an operation mode in which the driving force output from the engine 11 and the driving force output from the first motor 14 and the second motor 15 are combined and transmitted to the drive shaft 28. In this case, for example, the remaining capacity SOC is equal to or greater than a predetermined value, and thus the battery 19 is in an operating state where charging is not necessary.

  In the second operation mode, the operation of the engine 11 is controlled so that the power corresponding to the sum of the required driving force and the power necessary for charging / discharging the battery 19 is output from the engine 11, and the driving output from the engine 11 is performed. The first motor is such that all or part of the force is torque-converted by the planetary gear 13, the first motor 14, and the second motor 15 with charging / discharging of the battery 19, and the required driving force is output to the drive shaft 28. 14 and the mode of controlling the driving of the second motor 15. That is, the driving force output from the engine 11 is divided and input to the driving shaft 28 and the first motor 14, and the driving force output from the second motor 15 is combined with the driving shaft to drive wheels 25, 26 is an operation mode to be transmitted to H.26. In this operation mode, the first motor 14 acts as a generator, and the second motor 15 is driven for traveling using the electric power generated by the first motor 14. In this case, for example, the remaining capacity SOC is equal to or less than a predetermined value and the battery 19 is in an operating state in which charging is required.

  The third operation mode is an operation mode in which the operation of the engine 11 is stopped and the driving force output from the second motor 15 is transmitted to the drive wheels 25 and 26 so that the required driving force is output to the drive shaft 28. It has become.

  The HVECU 21 sets the vehicle 10 when the vehicle 10 is traveling in any one of the first operation mode to the third operation mode, the accelerator is off, and the vehicle 10 is decelerated. Brake force control for applying a braking force is executed. The braking force control includes control for applying the braking force by regenerative control of the second motor 15 and control for applying the braking force by motoring the engine 11 with the first motor 14. In the braking force control, any one of the first braking mode, the second braking mode, and the third braking mode is set based on the longitudinal acceleration G of the vehicle 10, and the temporal acceleration of the longitudinal acceleration G of the vehicle 10 is set. The braking mode is changed according to various changes. Note that the first braking mode to the third braking mode are determined such that the braking force applied to the vehicle 10 differs according to the vehicle speed V. The HVECU 21 is an example of a controller in the embodiment of the present invention.

  FIG. 2 shows an example of the correspondence between the longitudinal acceleration G of the vehicle 10 and each braking mode. The horizontal direction in the explanatory diagram of FIG. 2 represents the longitudinal acceleration of the vehicle 10. When the longitudinal acceleration G of the vehicle 10 increases to the positive side (right direction in the figure), the deceleration of the vehicle 10 decreases and the vehicle 10 increases. When the longitudinal acceleration G increases on the negative side (left direction in the figure), the deceleration of the vehicle 10 increases and the vehicle 10 decelerates. When the longitudinal acceleration G of the vehicle 10 is greater than or equal to a predetermined threshold G_α, the first braking mode is set. When the longitudinal acceleration G of the vehicle 10 is greater than or equal to a predetermined threshold G_β and less than the threshold G_α, the second braking mode is set. When the longitudinal acceleration G of the vehicle 10 is less than the threshold value G_β, the third braking mode is set. If the positive side of the longitudinal acceleration G is a large value, the threshold has a relationship of “G_α> G_β”.

  In the first braking mode, the braking force applied to the vehicle 10 is set to the smallest value among the three braking modes. In the third braking mode, the braking force applied to the vehicle 10 is set to the largest value. In the second braking mode, the braking force applied to the vehicle 10 is set to an intermediate magnitude among the three modes.

  In the braking force control, the third braking mode, the second braking mode, and the first braking mode are changed in order. In other words, the change of the braking mode in the direction in which the braking force increases is permitted. Then, the change of the braking mode in the opposite direction, that is, the direction in which the braking force decreases is not permitted. That is, the braking force control prohibits the change of the braking force from the first braking mode to the second braking mode, from the second braking mode to the third braking mode, and from the first braking mode to the third braking mode, respectively.

  Thus, when the accelerator is off, the braking force applied to the vehicle 10 is changed according to the deceleration of the vehicle 10, and the direction in which the deceleration increases, that is, the direction toward the negative side of the longitudinal acceleration G (the vehicle 10 decelerates). The braking force is made to follow in such a way that the braking force increases in the direction in which the braking force increases. Further, the braking force is not allowed to follow so that the braking force decreases in the direction in which the deceleration decreases, that is, the direction toward the positive side of the longitudinal acceleration G (the direction in which the vehicle 10 accelerates). As a result, for example, when the traveling road changes from a steep downhill road to a gentle downhill road, or when the road changes to a flat road, the braking force is changed in the direction in which the braking force decreases, and the driver feels uncomfortable. Can be suppressed.

  FIG. 3 shows an example of the relationship between the braking force and the vehicle speed in each braking mode when the accelerator is off. As shown in FIG. 3, in the first braking mode, the braking force is set to a larger value than when the second braking mode is set in a specific range of the vehicle speed V. In the third braking mode, the braking force is set to a smaller value than when the second braking mode is set in a specific range of the vehicle speed V. In the second braking mode, the braking force is set to a value smaller than that when the first braking mode is set in a specific range and larger than when the third braking mode is set. The first braking mode and the second braking mode are set so that the braking force to be changed has a specific width according to the vehicle speed V in a specific range. The specific width is such that the braking force is large when the vehicle speed V is medium and the braking force is small when the vehicle speed is low and high, so that there is no overlap in each braking mode. It has been decided. In the third braking mode, the braking force that is applied to the vehicle 10 in a specific range of the vehicle speed V is determined to be substantially “0”. Note that the third braking mode may be set so that the braking force to be changed has a specific width according to the vehicle speed V in the same or similar manner to the first braking mode and the second braking mode.

  FIG. 4 shows an example of the operation procedure of the braking force control. This procedure is a main routine for braking force control, and is repeatedly executed every predetermined time (for example, several msec) by the HVECU 21 when the accelerator is off during traveling. As shown in FIG. 4, in step S1, it is determined whether a condition for permitting the start of the braking force control is satisfied. The conditions for permitting the start of braking force control are determined according to the amount of depression of the brake pedal, the amount of depression of the accelerator pedal, the vehicle speed, the longitudinal acceleration, and the like, and when established, the Ptrq1 determination flag is set to “ON”. . When the condition for permitting the start of the braking force control is satisfied (in the case of Yes), the process proceeds to step S2. Otherwise, the process proceeds to step S3, and the Ptrq2 determination flag is set to “OFF”.

  In step S2, it is determined whether or not the Ptrq2 determination flag is “OFF”. If the Ptrq2 determination flag is “OFF” (in the case of Yes), the process proceeds to step S4. When that is not right (in the case of No side), it transfers to step S5 and the 2nd braking mode is selected. It is then returned. As will be described in detail later, the Ptrq2 determination flag is a flag that is set to “ON” when the period in which the longitudinal acceleration G is equal to or greater than the threshold value G_β continues for a predetermined period.

  In step S4, it is determined whether the longitudinal acceleration G is less than a predetermined threshold G_β. When the longitudinal acceleration G is less than the threshold value G_β (in the case of Yes), the process proceeds to step S6. Otherwise (in the case of No), the process proceeds to step S7. In step S6, the counter value of the Ptrq2 determination counter is cleared.

  In step S7, the Ptrq2 determination counter is counted up, and then the process proceeds to step S9. In step S9, it is determined whether or not the count value of the Ptrq2 determination counter has exceeded a predetermined determination value Ctrq. If the count value of the Ptrq2 determination counter exceeds the determination value Ctrq (Yes side), the process proceeds to step S10. Otherwise (in the case of No), the process proceeds to step S8 and the third braking mode is set.

  In step S10, the Ptrq2 determination flag is set to “ON”, and the process proceeds to step S11. In step S11, the second braking mode is set, and then the process returns.

  In step S3, the Ptrq2 determination flag is set to “OFF”, and the process proceeds to step S12. In step S12, the count value of the Ptrq2 determination counter is cleared, and then the process proceeds to step S13. In step S13, the first braking mode is set, and then the process returns.

  FIG. 5 shows an example of a pre-processing procedure in the braking force control described with reference to FIG. The procedure shown in FIG. 5 is a first subroutine prepared in advance in the main routine executed by the HVECU 21 so that signals input from the brake sensor 44, the accelerator sensor 42, the vehicle speed sensor 45, the acceleration sensor 47, and the like are sequentially confirmed. It is executed repeatedly.

  As shown in FIG. 5, based on the signal obtained from the brake sensor 44 in step S14, it is determined whether or not it is detected that the pedal 43 is not depressed (brake OFF). When the brake OFF is detected (in the case of Yes side), the process proceeds to step S15, and when not (in the case of No side), the process proceeds to step S16. In step S16, the BK flag is set to “OFF”, and then the process proceeds to step S17. In step S15, the BK flag is set to “ON”, and then the process proceeds to step S17. The BK flag ON represents a state where the brake pedal 43 is not depressed.

  In step S18, it is determined whether or not it is detected that the accelerator pedal 41 is not depressed (accelerator OFF) based on a signal obtained from the accelerator sensor 42. If accelerator-off is detected (Yes side), the process proceeds to step S18. If not (No side), the process proceeds to step S19. In step S18, the ACC flag is set to “ON”, and then the process proceeds to step S20. In step S19, the ACC flag is set to “OFF”, and then the process proceeds to step S20. The ACC flag ON represents a state where the accelerator pedal 41 is not depressed.

  In step S20, it is determined whether or not the vehicle speed V exceeds a predetermined threshold value K1. If the vehicle speed V exceeds the threshold value K1 (in the case of Yes), the process proceeds to step S21, and if not (in the case of No), the process proceeds to step S22. In step S21, the SPD flag is set to “ON”, and then the process proceeds to step S22. The SPD flag ON represents a state in which the vehicle speed V exceeds the threshold value K1.

  In step S22, it is determined whether or not the vehicle speed V is less than a predetermined threshold value K2. If the vehicle speed V is less than the threshold value K2 (in the case of Yes), the process proceeds to step S23, and if not (in the case of No), the process proceeds to step S24. In step S23, the SPD flag is set to “OFF”, and then the process proceeds to step S24. The SPD flag OFF represents a state where the vehicle speed V is less than the threshold value K2.

  In the procedure from step S24 to step S27, the G flag is set to “ON” when the period in which the longitudinal acceleration G is less than the predetermined threshold value α continues for the first predetermined period (for example, the predetermined threshold value C1trq). To do. That is, it is determined in step S24 whether the longitudinal acceleration G is less than the threshold value α. If the longitudinal acceleration G is less than the threshold value α (in the case of Yes), the process proceeds to step S25, and if not (in the case of No), the process proceeds to step S26.

  In step S25, in order to time the period in which the longitudinal acceleration G is less than the threshold value α, the G permission counter starts counting (G permission counter_up), and then the process proceeds to step S27. In step S27, it is determined whether or not the time of the G permission counter exceeds a predetermined threshold value C1trq. If the time of the G permission counter exceeds the threshold value C1trq (in the case of Yes), the process proceeds to step S28, and if not, the process proceeds to step S29. In step S28, the G flag is set to “ON”, and then the process proceeds to step S29. In step S26, the time count of the G permission counter is cleared, and then the process proceeds to step S29.

  The procedure from step S29 to step S33 is to set the G flag to “OFF” when the period in which the longitudinal acceleration G exceeds the predetermined threshold α continues for the second predetermined period (for example, the predetermined threshold C2trq). . That is, it is determined in step S29 whether the longitudinal acceleration G has exceeded the threshold value α. If the longitudinal acceleration G exceeds the threshold value α (in the case of Yes), the process proceeds to step S30. If not (in the case of No), the process proceeds to step S31.

  In step S30, in order to measure the period in which the longitudinal acceleration G exceeds the threshold value α, the G non-permission counter starts counting (G non-permission counter_up), and then the process proceeds to step S32. In step S32, it is determined whether or not the time of the G non-permission counter exceeds a predetermined threshold C2trq. When the time count of the G non-permission counter exceeds the threshold C2trq (in the case of Yes), the process proceeds to step S33, and otherwise returns. In step S33, the G flag is set to “OFF”, and then the process returns. In step S31, the time count of the G non-permission counter is cleared, and then the process returns.

  FIG. 6 shows an example of another pre-processing procedure in the braking force control described with reference to FIG. The procedure shown in FIG. 6 is based on the BK flag, SPD flag, G flag, and ACC flag described in FIG. 5 and is prepared in advance for setting the Ptrq1 determination flag used in the main routine described in FIG. 2 subroutines, which are repeatedly executed every predetermined time. As shown in FIG. 6, in step S34, it is determined whether or not a condition that the BK flag is “ON”, the SPD flag is “ON”, and the G flag is “ON” is satisfied. If all are ON (Yes side), the process proceeds to Step S35, and if not (No side), the process proceeds to Step S38.

  In step S35, it is determined whether or not the ACC flag is “OFF”. If the ACC flag is “ON” (in the case of Yes), the process proceeds to step S36, and if not, the process proceeds to step S38. In step S36, it is determined whether or not the previous ACCold flag is “OFF” and the current ACC flag is “ON”, that is, whether or not the ACC flag has changed from “OFF” to “ON”. If the ACC flag changes from “OFF” to “ON” (in the case of Yes), the process proceeds to step S37, and otherwise, the process proceeds to step S39. In step S37, the Ptrq1 determination flag for permitting the change of the braking torque is set to “ON”, and then the process proceeds to step 39. In step S39, the current ACC flag setting is replaced with the previous ACCold setting, and then the process returns. In step S38, the Ptrq1 determination flag is set to “OFF”, and then the process proceeds to step S39.

  FIG. 7 shows an example of the transition of the braking mode. As shown in FIG. 7, before the time t1, the accelerator pedal 41 is in a depressed state (reference numeral 7A) and the deceleration of the vehicle 10 is increased (reference numeral 7B). During this time, for example, the first braking mode is selected (symbol 7C), but the braking force control is not started because the accelerator pedal 41 is depressed, so the braking force according to the first braking mode is not started. Does not act on the vehicle 10. At time t1, the state changes from the accelerator-on state to the accelerator-off state (symbol 7D), and the brake pedal 43 is not depressed (symbol 7E). The deceleration of the vehicle 10 is increased due to a change in the traveling road surface at this time (reference numeral 7F), and a condition for starting the braking force control is established. Based on the vehicle speed V and the longitudinal acceleration G at this time, Three braking modes are selected (reference numeral 7G). The deceleration of the vehicle 10 is reduced by selecting the third braking mode and the change in the traveling road surface at this time (reference numeral 7H).

  At time t2, when the third braking mode is selected, the inclination in the direction in which the acceleration increases gradually changes (reference numeral 7H '). Based on the vehicle speed V and the longitudinal acceleration G at this time, the second braking mode is selected (reference numeral 7I). Thereafter, at time t3, the acceleration of the vehicle 10 is increased by selecting the second braking mode (reference numeral 7J), and the first braking mode is selected based on the vehicle speed v and the longitudinal acceleration G at this time ( 7K). Then, after time 3, even if the deceleration of the vehicle 10 changes in a direction to decrease (symbol 7L) on the condition that the accelerator-off state is continued, the brake mode is not changed to reduce the braking force. Thus, the change of the braking force is prohibited (reference numeral 7M).

  FIG. 8 shows an example of a braking mode in which the vehicle transits on a road surface different from that in FIG. In the example shown in FIG. 8, it is shown that the operation is continued until the state changes to the accelerator-on state or the brake-on state in the period in which the change of the braking mode for reducing the braking force is prohibited. As shown in FIG. 8, before time t4, the accelerator is on (reference 8A) and the acceleration of the vehicle 10 is increased (reference 8B). During this time, the first braking mode is selected (reference 8C), but since the accelerator is on, the braking force control is not started. At time t4, the state changes from the accelerator-on state to the accelerator-off state (reference 8D), and the brake is off (reference 8E). The deceleration of the vehicle 10 is increased by the change of the traveling road surface at this time (reference numeral 8F). Then, the condition for starting the braking force control is established, and the third braking mode is selected based on the vehicle speed v and the longitudinal acceleration G at this time (reference numeral 8G). The deceleration of the vehicle 10 is reduced by the selection of the third braking mode and the change of the traveling road surface at this time (reference numeral 8H).

  At time t5, the inclination toward the direction in which the deceleration of the vehicle 10 decreases (symbol 8H '). Thereby, the second braking mode is selected (reference numeral 8I). Thereafter, at time t6, the state changes to an accelerator-on state (reference numeral 8K). As a result, the condition for executing the braking force control is not satisfied, and the braking force control is terminated. Accordingly, the process for prohibiting the change to the braking force mode for reducing the braking force is released. At time t6, the first braking mode is selected (reference numeral 8L), but since the braking force control is finished, the braking force in the first braking mode does not act on the vehicle 10. Thereafter, when the accelerator is turned off at time t7 (symbol 8M), the deceleration of the vehicle 10 is increased (symbol 8N), and the third braking mode is based on the vehicle speed v and the longitudinal acceleration G at this time. Is selected (reference 8P). Thereafter, at time t8, the brake pedal is depressed and the brake is turned on (reference numeral 8Q). Even when the accelerator is off, the brake force control is terminated by changing to the brake on state, and the process of prohibiting the change to the braking force mode for reducing the braking force is released. At this time, the first braking mode is selected (reference numeral 8R), but since the braking force control is finished, the braking force in the first braking mode does not act on the vehicle 10.

  As described above, the present invention has been described based on the embodiment. However, the present invention is not limited to the above-described embodiment, and various modifications are made without departing from the spirit of the present invention. . For example, the condition for executing the braking force control may include a condition that an eco mode that gives higher priority to fuel efficiency than the normal mode is selected as the travel mode. In this case, an eco switch that instructs the eco mode may be provided. Moreover, in each said embodiment, although the deceleration of the vehicle 10 is detected using the acceleration sensor 47, you may detect the deceleration of the vehicle 10 based on the change of the vehicle speed V, for example.

  In each of the above embodiments, the engine 11 is connected to the engine 11 as an example of the internal combustion engine, the first motor 14 capable of inputting / outputting driving force, the output shaft of the engine 11, the rotating shaft of the first motor 14, and the driving shaft 28. Although described as the vehicle 10 including the planetary gear (planetary gear mechanism) and the second motor 15 capable of inputting / outputting power to / from the drive shaft 28, the present invention is not limited thereto, and for example, includes a motor for traveling. Any vehicle may be used as long as the vehicle can apply a braking force to the vehicle by a traveling motor.

  In each of the above embodiments, not only the longitudinal acceleration G of the vehicle 10, but also based on any one or more of the lateral acceleration of the vehicle 10, the vertical acceleration of the vehicle 10, the yaw rate, the road surface gradient, and the friction coefficient of the road surface, for example. The braking force of the vehicle 10 may be changed. Further, in the above embodiment, the braking mode is set to three modes from the first braking mode to the third braking mode. However, in the present invention, the mode is not limited to three modes, for example, two or four or more modes. It may be set.

  In each of the above embodiments, three braking modes are prepared in advance. However, the present invention is not limited to this, and instead of preparing three braking modes in advance, for example, a braking force is generated according to the deceleration of the vehicle 10. The braking force may be obtained by calculation so as to change continuously.

  DESCRIPTION OF SYMBOLS 10 ... Vehicle, 11 ... Engine, 12 ... Engine ECU, 13 ... Planetary gear, 14 ... First motor, 15 ... Second motor, 16 ... Motor ECU, 19 ... Battery, 20 ... Battery ECU, 21 ... HVECU, 41 ... Accelerator Pedal, 43 ... Brake pedal, 47 ... Acceleration sensor.

Claims (1)

In a control device for a vehicle comprising a motor for traveling and a battery that exchanges electric power with the motor,
A controller that applies a braking force to the vehicle by the motor when the accelerator is off; the controller changes the braking force according to the deceleration of the vehicle, and the braking force is reduced in the direction in which the deceleration decreases. The vehicle control device according to claim 1, wherein the braking force is caused to follow so as to increase, and the braking force is not allowed to follow so that the braking force decreases in a direction in which the deceleration increases.

Images