WO2013084682A1

WO2013084682A1 - Control device for motor vehicle and method for controlling same

Info

Publication number: WO2013084682A1
Application number: PCT/JP2012/079602
Authority: WO
Inventors: 東谷幸祐; 浅川雅信
Original assignee: 本田技研工業株式会社
Priority date: 2011-12-09
Filing date: 2012-11-15
Publication date: 2013-06-13
Also published as: JPWO2013084682A1

Abstract

Provided are a control device for a motor vehicle (10) and a method for controlling the same whereby during switchback deceleration can be generated by regenerative braking regardless of the state of charge in an electricity storage device (22). Even when the electricity storage device (22) is in the state of being fully charged (including a state of being nearly full) in which regenerative braking is generally prohibited (step S2: YES), if the vehicle (10) is brought into a switchback state where the vehicle moves backwards (rotational direction of motor reversed) and a shift position is in a forward position (D) (step S5: NO), the control for braking force is switched from general control based on friction braking that uses a friction brake (18) to exceptional control (steps S8, S9) based on regenerative braking that uses a motor (12).

Description

Control device and control method for electric vehicle

The present invention relates to a control device and a control method for an electric vehicle that applies a braking force to the vehicle by regenerative braking and friction braking.

2. Description of the Related Art Conventionally, in an electric vehicle that uses an electric motor (hereinafter also referred to as a motor) as driving power, when a shift operation (hereinafter referred to as a shift operation) is performed during traveling and the traveling direction is switched, for example, a shift position (shift When the range is shifted backward by the accelerator pedal operation at the R position (reverse range) to the D position (drive range) and the accelerator pedal operation is continued to move forward, the motor is turned into a generator. There is known a travel technique of so-called switchback operation, in which the electric vehicle is smoothly stopped from the reverse state by applying the regenerative braking, and the reverse direction from the stop to the forward state in this case is established. [0003]} of Japanese Patent No. -74817 (hereinafter referred to as JP2007-74817A).

The operation outline as a comparative example at the time of this switchback is shown in the time chart of FIG. 6A. In the state where the shift position is retreating at the R position (the motor rotation speed is the reverse rotation side and the motor torque is the power running side), when it is desired to switch the traveling direction to the forward direction, the shift operation is performed from the R position to the D position at time ta. . When the motor torque is switched from the power running side to the regenerative side at time tb, the motor is decelerated in the regenerative braking state, stops at time tc, the motor rotation speed is changed from the reverse rotation side to the normal rotation side, and the traveling direction of the electric vehicle moves backward. Reverse from direction to forward direction.

By the way, in the electric vehicle according to the comparative example, as shown in the time chart of FIG. 6B, the traveling direction in the state where the shift position is retracted at the R position (the motor rotation speed is the reverse rotation side and the motor torque is the power running side). Is switched from the R position to the D position at the time ta, and when the motor torque is about to switch from the power running side to the regeneration side at the time tb, the battery is fully charged. In other words, regenerative braking is not applied, in other words, regenerative braking is restricted (referred to as regenerative restriction), and as a result, cooperative control between regenerative braking and friction braking may be required.

However, the cooperative control of regenerative braking and friction braking at the time of this switchback is extremely complicated control over various conditions.

The present invention has been made in consideration of such problems, and an object thereof is to provide a control device and a control method for an electric vehicle in which regenerative braking is applied at the time of switchback regardless of the state of charge of the power storage device. And

An electric vehicle control device according to the present invention is an electric vehicle control device that travels using the power of an electric motor driven by electric power from a power storage device and applies a braking force by friction braking and / or regenerative braking by the electric motor. , Control of the braking force for the host vehicle based on the determination result of the full charge state determination unit and the full charge state determination unit for determining whether or not the state of charge of the power storage device is a full charge state while traveling on a slope A braking force control unit configured to perform braking when the charging state of the power storage device is not fully charged during traveling on the slope. And when the power storage device is fully charged while traveling on the slope, the regenerative braking is prohibited and the braking control is applied to the host vehicle by the friction braking, and the regenerative braking The braking force is applied by any one of the exception control that releases the prohibition and permits the regenerative braking and applies the braking force to the host vehicle by the regenerative braking, and reduces the forward direction of the host vehicle. Due to the vehicle operation of the driver who reverses from the hill direction to the uphill direction, when the moving direction of the host vehicle is in the reverse direction and the shift position is in the switchback state, the control of the braking force is performed. The principle control is switched to the exception control.

The electric vehicle control method according to the present invention controls an electric vehicle that travels using the power of an electric motor driven by electric power from a power storage device and applies a braking force by friction braking and / or regenerative braking by the electric motor. In the method, a full charge state determination step for determining whether or not the state of charge of the power storage device is a full charge state while traveling on a slope, and a braking force for the host vehicle is controlled based on the determination result of the full charge state A braking force control step that applies a braking force to the host vehicle by regenerative braking when the charging state of the power storage device is not fully charged during traveling on the slope. The principle of prohibiting the regenerative braking and applying a braking force to the host vehicle by the friction braking when the state of charge of the power storage device is fully charged while traveling on the slope The braking force is applied by one of the control and the exception control in which the prohibition of the regenerative braking is canceled and the regenerative braking is permitted and the braking force is applied to the host vehicle by the regenerative braking. If the driver's vehicle operation that reverses the forward direction of the vehicle from the downhill direction to the uphill direction causes the vehicle to move backward and the shift position is switched to the forward position, the control is performed. The power control is switched from the principle control to the exception control.

According to each of the above-described inventions, even when the state of charge of the power storage device is a fully charged state that prohibits regenerative braking in principle (including a state close to the fully charged state), When the movement direction is in the reverse direction and the shift position is in the switchback state, the braking force application (control) is switched from the principle control by friction braking to the exception control by regenerative braking. Sometimes, just by depressing the accelerator pedal, regenerative braking is applied, the deceleration is smoothly performed, the host vehicle is stopped, and the vehicle can be further advanced. Therefore, regenerative braking can be applied during switchback regardless of the state of charge of the power storage device.

In this case, even when the fully charged state exceeds the electrochemical full charged state of the power storage device in which the power storage device deteriorates (when overcharging occurs), regenerative braking is applied with priority on the drivability. Preferably, the full-charge state determination unit sets the full-charge state to a first full-charge state (remaining capacity smaller than the electrochemical full-charge state of the power storage device). The braking force control unit applies a braking force to the host vehicle by the regenerative braking when the charging state of the power storage device is not the first full charging state during traveling on the slope. When the charge state of the power storage device is the first fully charged state during traveling on the slope, the principle control for prohibiting the regenerative braking and applying a braking force to the host vehicle by the friction braking; and Regenerative braking The storage device is overcharged and deteriorated by controlling the braking force by any one of the exception control that releases the prohibition, permits the regenerative braking, and applies the braking force to the host vehicle by the regenerative braking. Therefore, regenerative braking can be permitted at the time of switchback, so that the life of the power storage device can be extended and the merchantability can be further improved.

More specifically, when the regenerative braking is prohibited during the principle control, the braking force control unit limits the regenerative side torque value of the electric motor to a zero value, and the host vehicle remains forward. , When the driver's vehicle operation reverses the moving direction of the own vehicle from the downhill direction to the uphill direction, when the moving direction of the own vehicle is in the reverse direction and the shift position is in the switchback state. By restricting the regeneration side torque value of the electric motor to a predetermined value, overcharging of the power storage device can be more reliably prevented.

According to the present invention, when the shift position is switched to the forward position in a state where the shift position is set to the reverse position and the electric vehicle is moved backward by the operation of the accelerator, the regenerative braking is performed even in the fully charged state. Since the vehicle decelerates and stops and moves forward while the vehicle is applied, regenerative braking can be applied during switchback regardless of the state of charge of the power storage device. The full charge state is preferably set in advance to a value smaller than the electrochemical full charge state of the power storage device in anticipation of regeneration at the time of switchback.

1 is a block diagram of an embodiment of a control device that implements an electric vehicle control method according to the present invention. FIG. It is a time chart explaining the operation | movement including cancellation | release of the regeneration restriction | limiting at the time of climbing up by switchback from the time of a full-downhill charge. It is a characteristic view which shows the relationship between a charge condition and the amount of regeneration. It is a control flowchart explaining the setting of the regeneration side motor torque. It is a characteristic view which shows the relationship between a charge condition and the amount of regeneration explaining a modification. FIG. 6A is a time chart for explaining the operation when reversing the traveling direction while decelerating by regenerative braking at the time of switchback, and FIG. 6B requires complicated cooperative control of regenerative braking and friction braking at the time of switchback. It is a time chart explaining the operation | movement which becomes.

Hereinafter, a control device and a control method for an electric vehicle according to the present invention will be described with reference to the drawings for an electric vehicle using an embodiment of the control device that performs the control method.

FIG. 1 is a schematic block diagram of an electric vehicle (also referred to as own vehicle) 10 according to this embodiment. The electric vehicle 10 includes an electric motor 12 that generates power, and the rotating shaft of the electric motor 12 is connected to the wheel 16 via a transmission 14 and the like. A friction brake 18 for applying a friction braking force is engaged with the wheel 16.

The motor 12 is connected to an inverter 20 (power converter) via a three-phase connection, and the inverter 20 is connected to a power storage device 22, and a motor that controls the motor 12 by controlling the drive of the inverter 20. An ECU (Electronic Control Unit) 24 is connected.

The power storage device 22 is an energy storage, and a lithium ion secondary battery, a nickel hydride secondary battery, a capacitor, or the like can be used. In this embodiment, a lithium ion secondary battery is used.

The power storage device 22 has a built-in charge / discharge circuit 60 for controlling or limiting the charge / discharge current. While controlling the charging / discharging current of the charging / discharging circuit 60, the SOC detection unit 72 that detects the SOC (state of charge) that is the state of charge of the power storage device 22 and the regeneration limit that limits the charging current (regeneration amount) A battery ECU 26 including a unit 74 is connected to the power storage device 22. The state of charge SOC of the power storage device 22 detected by the battery ECU 26 is supplied to the motor ECU 24.

The motor ECU 24 includes an accelerator opening degree θ in which the operation amount of the accelerator pedal 28 is detected by the operation amount sensor 30, a brake operation amount B in which the operation amount of the brake pedal 32 is detected by the operation amount sensor 34, and a shift lever 36. The shift position SP of the parking position P (P position), reverse position R (R position), or forward position D (D position) detected by the shift position sensor 38 (SP is P, R, or D), the vehicle speed Vs detected by the vehicle speed sensor 40, the motor rotational speed Nm detected by a rotational speed sensor such as a resolver constituting the electric motor 12, and the motor rotational direction (forward direction, stop, reverse direction) Md, etc. And are respectively supplied.

The navigation ECU 42 is also connected to the motor ECU 24, and the position, altitude, etc. of the host vehicle 10 on the map are supplied from the navigation ECU 42.

A brake ECU 50 is further connected to the motor ECU 24. A brake operation amount B is supplied from the operation amount sensor 34 of the brake pedal 32 to the brake ECU 50, and a braking force by friction braking is applied to the wheel 16 via the fluid pressure modulator 52 and the friction brake 18.

On the other hand, the motor ECU 24 applies a braking force for braking the wheel 16 by the regenerative braking of the motor 12 by causing the power storage device 22 to collect the regenerative power of the motor 12 through the inverter 20. The motor ECU 24, the brake ECU 50, and the battery ECU 26 perform coordinated control of the braking force due to regenerative braking and the braking force due to friction braking.

Each of the motor ECU 24, the battery ECU 26, the navigation ECU 42, and the brake ECU 50 is a computer including a microcomputer, and includes a CPU (central processing unit), a ROM (including EEPROM), and a RAM (random access). Memory), other input / output devices such as A / D converters and D / A converters, timers as timers, etc., and the CPU reads out and executes programs recorded in the ROM And function as various function realization units (function realization means) such as a control unit, a calculation unit, and a processing unit.

The battery ECU 26, the motor ECU 24, and the brake ECU 50 are communicably connected, for example, using data mutually through a communication line (not shown) related to a communication network such as CAN (Controller Area Network). Note that the communication network may be a wireless network.

In this embodiment, as described above, the battery ECU 26 functions as the SOC detection unit 72 that detects the state of charge SOC (remaining capacity) of the power storage device 22 and is charged from the electric motor 12 to the power storage device 22 through the inverter 20. It functions as a regeneration limiting unit 74 that limits a regenerative current (also referred to as a regeneration amount). The navigation ECU 42 functions as an altitude detection unit or the like.

The motor ECU 24 functions as a traveling path detection unit that detects whether the road is a slope (downhill or climbing road) or a flat road based on altitude information from the navigation ECU 42 and the power storage device 22 during traveling on the slope. Functions as a full charge state determination unit 62 that determines whether or not the state of charge SOC is a full charge state, and further controls the braking force on the host vehicle 10 based on the determination result of the full charge state determination unit 62 and the like. It functions as the braking force control part 64 etc. to perform. The fully charged state determination unit 62 may be provided in the battery ECU 26, and the regeneration limiting unit 74 of the battery ECU 26 may be provided in the motor ECU 24.

Here, the braking force control unit 64 of the motor ECU 24 basically applies to the host vehicle 10 by the regenerative braking of the electric motor 12 when the state of charge SOC of the power storage device 22 is not fully charged during traveling on the slope. On the other hand, when the charging state SOC of the power storage device 22 is fully charged while traveling on the slope, the regenerative braking of the electric motor 12 is prohibited and the friction braking by the friction brake 18 is performed automatically. One of the principle control for applying the braking force to the vehicle 10 and the exception control for releasing the prohibition of the regenerative braking and permitting the regenerative braking and applying the braking force to the host vehicle 10 by the regenerative braking. The braking force is applied by the control.

The braking force control unit 64 causes the host vehicle 10 to operate due to the driver's operation of the shift lever 36 (shift operation from the reverse position R to the forward position D) that reverses the forward direction of the own vehicle 10 from the downhill direction to the uphill direction. When the switch direction of 10 is the reverse direction and the shift position SP is the forward position D, the brake force control function is switched from the principle control to the exception control.

Basically, the operation of the motor ECU 24 as the control device of the electric vehicle 10 according to this embodiment configured as described above will be described below with reference to the time chart of FIG.

The time chart of FIG. 2 shows, as an example, a downhill (downhill road) from a parking lot such as a home located on a hill at a forward position D of a shift position SP (downhill), and a shop located under the hill. After the vehicle is parked (stopped) in the forward state (forward) and the shift position SP is set to the parking position P, after the product is purchased at the store, the accelerator pedal is moved from the parking lot of the store or the like to the reverse position R. A switch for entering in the reverse state (forward) by the operation of 28, switching to the forward position D while stepping on the accelerator pedal 28 in the reverse state (backward), and changing the host vehicle 10 from the reverse state to the forward state through the stop state. It shows the change state of each item related to regenerative braking when going up (climbing) the slope (uphill) at the forward position D through the back state and returning to the home or the like on the slope.

In the time chart of FIG. 2, the shift position SP detected by the motor ECU 24 and the traveling direction of the host vehicle 10 (which can be detected by the motor rotation direction Md of normal rotation or reverse rotation), altitude, and the motor ECU 24 through the battery ECU 26. Detected state of charge SOC and motor rotation speed Nm (motor rotation direction Md), and motor torque MT calculated by the motor ECU 24 {regeneration side motor torque limit value (also referred to as a regeneration limit value) indicated by a thick dashed line. including. } Items are listed.

In the time chart of FIG. 2, the full charge state depicted in the item of the charge state SOC may be the electrochemical full charge state of the power storage device 22, but when charged more than the electrochemical full charge state Since the deterioration of the power storage device 22 is accelerated, the first full charge state (also referred to as a deemed full charge state), which is a remaining capacity smaller than the electrochemical full charge state, is set. The traveling direction (forward direction, backward direction, or stop) of the host vehicle 10 can be detected by the motor rotation direction Md or the like. If the motor rotation direction Md is the forward rotation direction, the traveling direction corresponds to the forward direction. If the motor rotation direction Md is the reverse direction, the traveling direction corresponds to the backward direction. When the motor rotation speed Nm is 0 or the motor rotation direction Md indicates stop, the traveling direction is set to the stop state.

In the time chart of FIG. 2, the value of the power storage device regeneration limit drawn in the item of state of charge SOC is the electrochemical full charge state (electrochemical full charge state> first full charge state = deemed full charge state). Corresponds to the value of.

From time t0 to time t5, a downhill traveling state in the forward direction at the shift position D is shown.

In this downhill traveling state, the fully charged state determination unit 62 determines that the state of charge is not in the fully charged state (here, the first fully charged state) from time t0 to time t3. Is controlled in the regenerative state, and the power storage device 22 is charged, so the state of charge SOC gradually increases.

At time t3, when the state of charge SOC becomes a fully charged state (here, the first fully charged state (deemed fully charged state)), the braking force control unit 64 stops the inverter 20 and passes through the regeneration limiting unit 74. By prohibiting charging by the charge / discharge circuit 60, charging of the power storage device 22 by regeneration from the electric motor 12 is stopped. Thereby, regenerative braking is prohibited between time t3 and time t5.

The host vehicle 10 is stopped (stopped) at time t5 by operating the brake pedal 32 from time t4. At time t6, the shift position 36 is operated from the forward position D to the parking position P by operating the shift lever 36.

FIG. 3 shows a regenerative amount (also referred to as a regenerative amount or a regenerative limit value), that is, a charging current characteristic 100 with respect to the value of the state of charge SOC of the power storage device 22. As the state of charge SOC approaches the fully charged state, the regenerative amount is limited to be smaller. When the state of charge SOC increases and reaches the value of the state of charge SOC of the preset regeneration control switching threshold, the regeneration amount characteristic when the accelerator pedal 28 is released (accelerator pedal off) (the regeneration amount characteristic when the accelerator pedal is released) 100ap As shown in FIG. 2, the charge state SOC is limited to the value of the first fully charged state by limiting earlier than the switchback regeneration amount characteristic 100sb, while the switch state regeneration amount characteristic 100sb The limit is relaxed to the value of the storage device regeneration limit (of the state of charge SOC).

In the motor torque item in the time chart of FIG. 2, the regenerative limit value indicated by a one-dot chain line is a characteristic corresponding to the regenerative amount characteristics 100, 100ap, and 100sb of FIG. From time t0 to time t1, all of the regenerative current from the electric motor 12 is regenerated (charged) to the power storage device 22, but from the time t1, the regeneration side motor torque is regenerated along the regeneration amount characteristics 100 and 100ap. When the state of charge SOC is limited to the limit value and the state of charge SOC becomes the value of the first fully charged state at time t3, the braking force control unit 64 regenerates the power storage device 22 through the charge / discharge circuit 60 via the regeneration limit unit 74. The flow of current (charging current) is blocked from time t3 to time t5 (may be time t6).

At time t7, the shift position SP is switched from the parking position P to the reverse position R in order to return from the parking lot of the store below the hill to the house above the hill, and the accelerator pedal 28 is stepped forward at the time t8. The parked vehicle 10 is once moved backward, and the shift position SP is switched from the reverse position R to the forward position D at the time t9 in the reverse state.

During this time point t9 or between time point t9 and time point t10, the braking force control unit 64 of the motor ECU 24 determines that the host vehicle 10 is in the switchback state, and the characteristics 100 of the regeneration amount shown in FIG. Switching from the regeneration amount characteristic 100ap when the pedal is released to the regeneration amount characteristic 100sb at the time of switchback. That is, the limit of the state of charge SOC is switched from the fully charged state shown in FIG. 2 to the value of the power storage device regeneration limit (see also FIG. 3).

Then, the motor rotation speed Nm starts to increase from time t9 (the rotation speed in the reverse rotation direction decreases). Therefore, the motor torque moves from the power running side to the regeneration side, and moves from the power running side to the regeneration side at time t10. At this time, since the motor rotation speed Nm gradually approaches (decreases) the zero value from the time point t10 to the time point t11, regeneration occurs in the electric motor 12, and the regenerative portion is used as the charge state SOC for the power storage device regeneration limit. Is regenerated (charged) in the power storage device 22 that has been switched to (changed). Thereby, at the time of switchback, the regeneration side motor torque can be generated from the time point t10 to the time point t11 when the vehicle speed Vs becomes zero. Since the braking force due to this regenerative braking is applied to the wheels 16 via the transmission 14, the host vehicle 10 smoothly decelerates and stops. That is, as shown in FIG. 6A, at the time of switchback, the traveling direction is always reversed after the vehicle is decelerated by the regenerative operation regardless of the value of the state of charge SOC.

After time t11, since the motor rotation speed Nm is in the forward direction and the motor torque is on the power running side, no braking force is applied due to regenerative braking, and the hill climbs smoothly through continuous operation of the accelerator pedal 28. Can be done.

FIG. 4 shows a control flowchart of the regeneration side motor torque controlled cooperatively by the motor ECU 24 and the battery ECU 26.

In step S1 after time t0, based on the current motor rotation speed Nm and the regenerative power limit value (regeneration amount in FIG. 3), a corresponding map (not shown) is searched to determine the regeneration side motor torque limit value.

In step S2, it is determined whether or not the state of charge SOC is in a fully charged state, in this case, the first fully charged state. If not in the fully charged state (step S2: NO), regeneration is performed in step S3. Braking is permitted, and in step S4, the regeneration side motor torque limit value calculated in step S1 is set as the regeneration side motor torque limit final value (for example, the period from time t0 to time t3 in FIG. 2 corresponds). ).

On the other hand, if it is determined in step S2 that the state of charge SOC is in the fully charged state (first fully charged state) (step S2: YES), the shift position SP corresponds to the motor rotation direction Md in step S5. It is determined whether or not. When the shift position SP is the forward position D and the motor rotation direction Md is normal rotation, and when the shift position SP is the reverse position R and the motor rotation direction Md is reverse rotation, both are determined to be compatible ( Step S5: YES), in other cases, that is, when the shift position SP is the forward position D and the motor rotation direction Md is reverse, and when the shift position SP is the reverse position R and the motor rotation direction Md is normal rotation In this case, it is determined that they do not correspond to each other (step S5: NO).

In this case, it is determined that the shift position SP (SP ← D) corresponds to the motor rotation direction Md (forward rotation) between the time point t0 and the time point t5, and the battery is fully charged between the time point t3 and the time point t5. In this state (step S2: YES), regenerative braking is prohibited in step S6, and the regenerative motor torque limit final value is set to 0 [Nm] in step S7 (period from time t3 to time t5). Corresponding to).

In step S5, as shown in the period from time t9 to time t11, it is determined that the shift position SP (SP ← D: forward position) does not correspond to the motor rotation direction Md (reverse rotation). If (step S5: NO), it is determined at the time of switchback.

At the time of this switchback, regenerative braking is permitted in step S8, and the maximum value that the state of charge SOC can take is determined from the value of the fully charged state (first fully charged state) shown in FIGS. In step S9, the regeneration side motor torque limit final value is set to the switchable executable motor torque limit value (in the time chart of FIG. 2, the broken line in the motor torque item). Corresponding to the “regenerative amount necessary for switchback”).

As described above, when the switchback control for switching the traveling direction of the host vehicle 10 from backward to forward is performed by switching the shift position SP from the reverse position R to the forward position D and operating the accelerator pedal 28 from time t8. The regeneration (charging) is permitted even when the power storage device 22 is nearly fully charged. In addition, the first full charge threshold for prohibiting regeneration is set to be small in advance in anticipation of regeneration due to switchback.

For this reason, even when the remaining capacity of the power storage device 22, that is, the state of charge SOC is nearly fully charged so that regenerative braking is prohibited, the braking force generated by regenerative braking can be achieved by simply depressing the accelerator pedal 28 at the time of switchback. Is applied to the wheel 16 and the vehicle 10 can be stopped and moved forward. In other words, the switchback can be performed smoothly without depending on the state of charge of the power storage device 22.

[Effects of Embodiment]
As described above, according to the above-described embodiment, the vehicle travels using the power of the electric motor 12 driven by the electric power from the power storage device 22, and the braking force is generated by the friction braking by the friction brake 18 and / or the regenerative braking by the electric motor 12. In the control method of the electric vehicle 10 to be applied, a fully charged state determination step for determining whether or not the charged state of the power storage device 22 is a fully charged state (including the vicinity of the fully charged state) during traveling on a slope road (step S2). ) And a braking force control step (steps S2 to S9) for controlling the braking force on the host vehicle 10 based on the determination result of the fully charged state. In the braking force control step, the vehicle is traveling on the slope. If the state of charge of the power storage device 22 is not fully charged (step S2: NO), a braking force is applied to the host vehicle 10 by the regenerative braking ( Steps S3 and S4) When the power storage device 22 is fully charged while traveling on the slope (step S2: YES), the regenerative braking is prohibited (step S6). Control to apply braking force to the vehicle (step S7), and prohibition of the regenerative braking is released to permit the regenerative braking (step S8). Exception control to apply braking force to the host vehicle 10 by the regenerative braking The driver's vehicle operation, in this case a shift operation (time point t9), is applied by the control of any one of (Step S9) and reverses the forward direction of the host vehicle 10 from the downhill direction to the uphill direction. As a cause, when the moving direction of the host vehicle 10 is in the reverse direction and the shift position SP is in the switchback state of the forward position D, the braking force is controlled in principle (step S6). Since switching from S7) to exception control (steps S8 and S9) is performed, at the time of switchback, regenerative braking is applied simply by depressing the accelerator pedal 28, the deceleration is smoothly performed, the host vehicle 10 is stopped, and the vehicle is further advanced. be able to.

In this case, the full-charge state determination unit 62 sets the full-charge state to a first full-charge state (deemed full-charge state) that is smaller than the electrochemical full-charge state of the power storage device 22, and a braking force control unit 64, when the state of charge of the power storage device 22 is not the first fully charged state during traveling on the slope, the braking force is applied to the host vehicle 10 by the regenerative braking, and the power storage device 22 is applied during traveling on the slope. When the charging state of the vehicle is the first fully charged state, the regenerative braking is prohibited and the principle control for applying the braking force to the host vehicle 10 by the friction braking and the regenerative braking prohibition are canceled and the regenerative braking is disabled. Since the braking force is controlled by any one of the exceptional control that permits braking and applies braking force to the host vehicle 10 by the regenerative braking, the power storage device 22 is deteriorated by overcharge. Without It is possible to allow the regenerative braking at the time of switchback, Hakare an extended service life of the power storage device, it is possible to improve marketability.

To explain the effect more simply, even if the state of charge SOC of the power storage device 22 is in a fully charged state in which regenerative braking is prohibited in principle (including a case in which the state is close to the fully charged state) ( (Step S2: YES) When the moving direction of the host vehicle 10 is in the reverse direction (the motor rotation direction Md is the reverse direction) and the shift position SP is in the switchback state of the forward position D (Step S5: NO), Since the power control is switched from the principle control by friction braking using the friction brake 18 to the exception control (steps S8 and S9) by regenerative braking of the electric motor 12, deceleration by regenerative braking cannot be performed at the time of switchback. It is possible to prevent the need for complicated cooperative control with friction braking.

As shown in FIG. 5, the full charge state exceeds the electrochemical full charge state of power storage device 22 in which power storage device 22 deteriorates (corresponding to the value of the power storage device regeneration limit in FIG. 5). Even in the case of overcharging, the power storage device regeneration limit at the time of switchback is set to the excessive power storage device regeneration as shown by the characteristic 100 sb ′ so that regenerative braking is applied by preventing complex cooperative control with friction braking. Setting the limit value is also included in the present invention.

It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted as described below based on the description in this specification.

For example, even on a flat road, when the shift position SP is in the forward parking state of the parking position P, the charging facility (including homes, public facilities, commercial facilities, etc.) is charged to the fully charged state, and after the fully charged state Then, the shift position SP is set to the reverse position R and the accelerator pedal 28 is operated to move backward, the shift position SP is set to the forward position D during the reverse movement, and the operation of the accelerator pedal 28 is continued, and the host vehicle 10 is moved backward. The regenerative braking can be obtained at the time of switchback in the case of making a transition to a forward state through a stop.

Further, a switchback state in which the moving direction of the host vehicle 10 is the backward direction and the shift position SP is the forward position D is caused by the driver's vehicle operation that reverses the forward direction of the own vehicle 10 from the downhill direction to the uphill direction. In such a case, the switching of the braking force control from the principle control by friction braking using the friction brake 18 to the exception control by regenerative braking of the electric motor 12 includes a case where the shift operation is not caused.

For example, if the host vehicle 10 is stopped when the shift position SP reaches the uphill road after traveling down a long downhill road at the forward position D, and the vehicle 10 moves down again, the movement of the own vehicle 10 Since the direction is the reverse direction and the shift position SP is the forward position D (also referred to as a switchback state in this case), simply by depressing the accelerator pedal 28, the control is switched to exception control and regenerative braking is applied. From the stop to a forward state (starting on a slope and traveling on the uphill road). In this traveling state, the shift operation is not performed.

Further, for example, while the shift position SP is the forward position D and the vehicle is traveling downhill on a downhill road, the host vehicle 10 is turned 180 ° and the front part of the vehicle body is turned upward, and the brake pedal 32 is stepped on to temporarily stop. Even when the brake pedal 32 is switched to the accelerator pedal 28 from this temporary stop state and the vehicle starts on a hill, the moving direction of the host vehicle 10 is the backward direction and the shift position SP is the forward position D (this state is also a switchback). Therefore, it is similarly switched to exception control, and regenerative braking is applied, and the host vehicle 10 can be moved from a stopped state to a forward state (starting on a slope). Even in this traveling state, the shift operation is not performed.

In addition, while the shift position SP is the forward position D and the vehicle is traveling downhill on the downhill road, the vehicle 10 is turned 180 ° and the front of the vehicle body is turned upward, the shift position SP is set to the parking position P and an ignition switch ( The main switch) is turned off, the vehicle is parked, the ignition switch is turned on again, the shift position SP is shifted from the parking position P to the forward position D, and the accelerator pedal 28 is depressed to generate a slope. Since the moving direction of the vehicle 10 is the reverse direction and the shift position SP is the forward position D (this state is also referred to as a switchback state), the control is similarly switched to the exception control.

In the above embodiment, the electric vehicle 10 starting and running with the electric motor 12 is described as an example. However, the electric vehicle according to the present invention includes at least a hybrid vehicle including an internal combustion engine that starts with the electric motor 12, and a plug. Needless to say, in-hybrid vehicles and fuel cell vehicles are included.

Claims

Control device for electric vehicle (10) that travels using the power of electric motor (12) driven by electric power from power storage device (22) and applies braking force by friction braking and / or regenerative braking by electric motor (12) In
A full charge state determination unit (62) for determining whether or not the state of charge of the power storage device (22) is a full charge state while traveling on a slope;
A braking force control unit (64) for controlling the braking force on the host vehicle (10) based on the determination result of the full charge state determination unit (62);
The braking force control unit (64)
When the state of charge of the power storage device (22) is not fully charged during traveling on the slope, a braking force is applied to the host vehicle (10) by the regenerative braking,
When the state of charge of the power storage device (22) is fully charged while traveling on the slope,
The principle control for prohibiting the regenerative braking and applying the braking force to the host vehicle (10) by the friction braking, and the prohibition of the regenerative braking to permit the regenerative braking and the regenerative braking to the host vehicle ( 10) to provide the braking force by any one of the exception control to apply the braking force to,
Switchback state in which the moving direction of the host vehicle (10) is the backward direction and the shift position is the forward position due to the driver's vehicle operation that reverses the forward direction of the host vehicle (10) from the downhill direction to the uphill direction. When it becomes, control of the said braking force is switched from the said principle control to the said exceptional control. The control apparatus of the electric vehicle (10) characterized by the above-mentioned.
In the control device of the electric vehicle (10) according to claim 1,
The full charge state determination unit (62)
The full charge state is a first full charge state that is a remaining capacity smaller than the electrochemical full charge state of the power storage device (22),
The braking force control unit (64)
When the state of charge of the power storage device (22) is not the first fully charged state during traveling on the slope, a braking force is applied to the host vehicle (10) by the regenerative braking,
When the state of charge of the power storage device (22) is the first fully charged state during traveling on the slope,
The principle control for prohibiting the regenerative braking and applying the braking force to the host vehicle (10) by the friction braking, and the prohibition of the regenerative braking to permit the regenerative braking and the regenerative braking to the host vehicle ( The control device for the electric vehicle (10), wherein the braking force is controlled by any one of the exceptional control for applying the braking force to 10).
In the control device of the electric vehicle (10) according to claim 2,
The braking force control unit (64)
When the regenerative braking is prohibited during the principle control, the regenerative side torque value of the electric motor (12) is limited to a zero value, and the forward direction of the host vehicle (10) is changed from the downhill direction to the uphill direction. When the moving direction of the host vehicle (10) is in the backward direction and the shift position is in the switchback state due to the vehicle operation of the driver to be reversed, the regeneration side torque value of the electric motor (12) Is limited to a predetermined value. A control device for an electric vehicle (10).
A method for controlling an electric vehicle (10) that travels using the power of an electric motor (12) driven by electric power from a power storage device (22) and applies braking force by friction braking and / or regenerative braking by the electric motor (12) In
A full charge state determination step (S2) for determining whether or not the charge state of the power storage device (22) is a full charge state while traveling on a slope;
A braking force control step (steps S2-S9) for controlling the braking force for the host vehicle (10) based on the determination result of the fully charged state,
In the braking force control step (step S2-step S9),
When the power storage device (22) is not fully charged while traveling on the slope, a braking force is applied to the host vehicle (10) by the regenerative braking (steps S3 and S4).
When the state of charge of the power storage device (22) is fully charged while traveling on the slope,
The principle control (step S7) for prohibiting the regenerative braking and applying the braking force to the host vehicle (10) by the friction braking (step S7), and releasing the prohibition of the regenerative braking to permit the regenerative braking and by the regenerative braking. The braking force is applied by any one of the exception control (step S9) for applying a braking force to the host vehicle (10),
Switchback state in which the moving direction of the host vehicle (10) is the reverse direction and the shift position is the forward position due to the driver's vehicle operation that reverses the forward direction of the host vehicle (10) from the downhill direction to the uphill direction. If it becomes, the control method of the electric vehicle (10), wherein the control of the braking force is switched from the principle control to the exception control.