WO2015080021A1

WO2015080021A1 - Control device for electric vehicle

Info

Publication number: WO2015080021A1
Application number: PCT/JP2014/080750
Authority: WO
Inventors: 李国棟
Original assignee: Ntn株式会社; 李国棟
Priority date: 2013-11-28
Filing date: 2014-11-20
Publication date: 2015-06-04
Also published as: JP2015104295A

Abstract

Provided is a control device for an electric vehicle, said device capable of reducing shock during a switch between powering control and regenerative control, and shortening a braking distance. A motor controller (29) of the control device for an electric vehicle includes a powering control means (33a), a regenerative control means (33b), and a powering/regenerative control switching controller (33c) that switches between using the powering control means (33a) and the regenerative control means (33b) using a command flag from an ECU (21). A speed detection means (37) is further provided, and a means (34) for changing the increase ratio of powering/regenerative command torque is provided to the motor controller (29), and differentiates the increase ratio per time period of the powering or regenerative command torque in response to the speed detected by the speed detection means (37), the depression amount of an accelerator pedal (16a), and the depression amount of a brake pedal (17a) during a switch between powering control and regenerative control that is based on the command flag from the ECU (21).

Description

Electric vehicle control device

Related applications

This application claims the priority of Japanese Patent Application No. 2013-245786 filed on Nov. 28, 2013, which is incorporated herein by reference in its entirety.

For example, in an electric vehicle including an in-wheel motor drive device that drives one of two front wheels and two rear wheels, or four wheels of a vehicle, the shock at the time of switching between power running and regeneration is reduced. The present invention relates to a control device for an electric vehicle capable of realizing a more comfortable riding comfort.

Conventionally, there has been proposed a control device for a permanent magnet motor for an electric vehicle which performs vector control by dividing the drive of the permanent magnet motor into torque current and excitation current (Patent Document 1). This control device gradually changes the magnitude of the component orthogonal to the excitation current of the torque current in vector control when switching between power running and regenerative braking. By gradually changing the magnitude of the component of the torque current that is orthogonal to the excitation current, the motor-generated torque gradually changes, and the shock at the time of switching between power running and regenerative braking can be reduced.

JP 2003-174702 A

In the prior art, since the magnitude of the component orthogonal to the excitation current of the torque current is gradually changed, if the switching time is extended, the braking distance may be increased.

An object of the present invention is to provide a control device for an electric vehicle capable of reducing a shock at the time of switching between power running control and regenerative control and shortening a braking distance.

Hereinafter, in order to facilitate understanding, the present invention will be described with reference to the reference numerals of the embodiments for convenience.

The control apparatus for an electric vehicle of the present invention includes an ECU 21 that is an electric control unit that controls the entire vehicle, a power circuit unit 28 that includes an inverter 31 that converts DC power into AC power used to drive the motor 6 for traveling, and An inverter device 22 having a motor control unit 29 for controlling the power circuit unit 28 in accordance with a torque command from the ECU 21;
The motor control unit 29 uses power running control means 33a for power running control of the motor 6, regenerative control means 33b for regenerative control of the motor 6, and which of the power running control means 33a and the regeneration control means 33b is used. A control device for an electric vehicle having a power running / regenerative control switching control unit 33c that switches according to a command flag from the ECU 21,
Vehicle speed detecting means 37 for detecting the vehicle speed;
When the motor control unit 29 switches between power running control based on a command flag from the ECU 21 and regenerative control, the vehicle speed detected by the vehicle speed detecting means 37 and the depression amount of the accelerator pedal 16a or the brake pedal 17a Power running / regenerative command torque increase rate changing means 34 is provided for varying the power running per time or the increase rate of the regenerative command torque in accordance with the amount of stepping.

According to this configuration, the power running control means 33a increases the power running command torque as the amount of depression of the accelerator pedal 16a increases. The regeneration control means 33b increases the regeneration command torque as the depression amount of the brake pedal 17a increases. The power running / regeneration command torque increase rate changing means 34 changes the vehicle speed and the accelerator pedal when switching between the power running control and the regenerative control based on the command flag from the ECU 21 with respect to the increase rate when increasing the power running or the regenerative command torque. The rate of increase in power running or regenerative command torque per hour is varied according to the amount of depression of 16a and the amount of depression of brake pedal 17a. For example, in the first stage, the power running or regenerative command torque is increased at an increase rate A, and in the second stage, it is increased at an increase rate B (increase rate B> increase rate A). Thus, by changing the power running per time or the increase rate of the regeneration command torque, the shock at the time of switching between the power running control and the regeneration control can be reduced. If the increase rate B in the second stage is larger than the increase rate A in the first stage, the braking time can be shortened, and therefore the braking distance can be shortened.

The power running / regenerative command torque increase rate changing means 34 changes the regeneration command torque according to the vehicle speed detected by the vehicle speed detecting means 37 and the depression amount of the brake pedal 17a when switching from power running control to regenerative control. It is good also as what gives in several steps within a fixed time. In this case, the power running / regenerative command torque increase rate changing means 34 changes the regenerative command torque as the amount of depression of the brake pedal 17a increases or the vehicle speed increases, for example, when switching from power running control to regenerative control. Increase the rate of increase. Thereby, shortening of braking time can be aimed at.

The power running / regenerative command torque increase rate changing means 34 changes the power running command torque according to the vehicle speed detected by the vehicle speed detecting means 37 and the depression amount of the accelerator pedal 16a when switching from regenerative control to power running control. It is good also as what gives in several steps within a fixed time. In this case, the power running / regenerative command torque increase rate changing means 34 changes the power running command torque as the amount of depression of the accelerator pedal 16a increases or the vehicle speed decreases, for example, when switching from regenerative control to power running control. Increase the rate of increase. As a result, the vehicle can be accelerated without delay.

The motor 6 drives one or both of the front wheel 3 and the rear wheel 2 of the vehicle, and constitutes an in-wheel motor drive device 8 including the motor 6, the wheel bearing 4, and the speed reducer 7. Also good. In this case, since the in-wheel motor drive device is arranged under the spring, it is sensitive to a shock at the time of switching between the power running and the regenerative control, but at the time of switching between the power running control and the regenerative control, Shock caused by backlash between gears can be reduced.

The vehicle speed detection means may be a rotation angle sensor that detects a rotation angle of a wheel. In this case, the vehicle speed can be calculated by differentiating the detected rotation angle of the wheel, and the number of parts can be reduced and the cost can be reduced.

Any combination of at least two configurations disclosed in the claims and / or the specification and / or the drawings is included in the present invention. In particular, any combination of two or more of each claim in the claims is included in the invention.

The present invention will be understood more clearly from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are for illustration and description only and should not be used to define the scope of the present invention. The scope of the invention is defined by the appended claims. In the accompanying drawings, the same reference numerals in a plurality of drawings indicate the same or corresponding parts.

1 is a block diagram of a conceptual configuration showing an electric vehicle according to an embodiment of the present invention in a plan view. It is a block diagram of conceptual composition, such as an inverter device of the electric vehicle. It is a figure which shows the increase rate of the regeneration command torque per time at the time of switching to regeneration control. It is a figure which shows the relationship between the depression amount of a brake pedal, and the regeneration command torque increase rate. It is a figure which shows the increase rate of the power running command torque per time at the time of switching to power running control. It is a figure which shows the relationship between the depression amount of an accelerator pedal, and a power running command torque increase rate. It is a conceptual block diagram of the IPM motor of the same electric vehicle. It is a figure explaining a well-known vector control method. It is a block diagram of the torque and rotation speed control system of the motor control unit of the electric vehicle. It is a flowchart which shows the control method at the time of switching from power running control to regeneration control. It is a flowchart which shows the control method at the time of switching from regenerative control to power running control.

An electric vehicle control apparatus according to an embodiment of the present invention will be described with reference to FIGS. The following description also includes a description of a control method for the electric vehicle. FIG. 1 is a block diagram of a conceptual configuration showing the electric vehicle according to this embodiment in a plan view. This electric vehicle is a four-wheeled vehicle in which the wheels 2 that are the left and right rear wheels of the vehicle body 1 are driving wheels, and the wheels 3 that are the left and right front wheels are steering wheels of driven wheels. Each of the

wheels

2 and 3 serving as the driving wheel and the driven wheel has a tire and is rotatably supported by the vehicle body 1 via wheel bearings 4 and 5, respectively.

The wheel bearings 4 and 5 are abbreviated as “H / B” in FIG. The left and

right wheels

2, 2 serving as driving wheels are driven by

independent traveling motors

6, 6, respectively. The rotation of the motor 6 is transmitted to the wheel 2 via the speed reducer 7 and the wheel bearing 4. The motor 6, the speed reducer 7, and the wheel bearing 4 constitute an in-wheel motor driving device 8 that is one assembly part, and the in-wheel motor driving device 8 is partially or entirely inside the wheel 2. Placed in. The motor 6 is a synchronous or induction type AC motor. The speed reducer 7 is a cycloid speed reducer, for example. Each

wheel

2, 3 is provided with an

electric brake

9, 10. Further, the

wheels

3 and 3 which are the steering wheels as the left and right front wheels can be steered via the steering mechanism 11 and are steered by the steering means 12.

FIG. 2 is a block diagram of a conceptual configuration of an inverter device and the like of the electric vehicle, and is a diagram mainly used for explaining power running and regenerative control of the present embodiment. The electric vehicle includes an ECU 21 that is an electric control unit that controls the entire vehicle, and an inverter device 22 that controls the motor 6 for traveling in accordance with a command from the ECU 21. The ECU 21 includes a computer, a program executed by the computer, various electronic circuits, and the like. The ECU 21 includes a torque rotation speed control command unit 21a and a power running / regeneration control command unit 21b.

The torque rotation speed control command unit 21a determines the left and right wheels from the acceleration command (drive) output from the accelerator operation means 16, the deceleration command (regeneration) output from the brake operation means 17, and the turning command from the steering means 12. Each acceleration / deceleration command given to the traveling

motors

6, 6 is generated as a torque command value and is output to the inverter device 22 of each motor 6. In addition to the above, the torque rotation speed control command section 21a outputs an acceleration / deceleration command to be output from a rotation sensor (not shown) provided on the wheel bearings 4 and 5 of the

wheels

2 and 3, respectively. You may have the function corrected using the information of number, and the information of each vehicle-mounted sensor. The power running / regeneration control command unit 21b gives a command flag for switching between power running / regeneration to a motor power running / regeneration control unit 33 of the motor control unit 29 described later.

The accelerator operation means 16 has an accelerator pedal 16a and a sensor 16b that detects the amount of depression of the accelerator pedal 16a and outputs the acceleration command. The brake operating means 17 includes a brake pedal 17a and a sensor 17b that detects the depression amount of the brake pedal 17a and outputs the deceleration command.

Each inverter device 22 has a power circuit unit 28 provided for each motor 6 and a motor control unit 29 for controlling the power circuit unit 28. Although not shown, the inverter device 22 is provided for each motor, and there are two inverter devices in this embodiment. The power circuit unit 28 includes an inverter 31 that converts the DC power of the battery 19 into three-phase AC power used for powering and regeneration of the motor 6, and a PWM driver 32 that controls the inverter 31.

The motor 6 is a three-phase synchronous motor or the like. The motor 6 is provided with a rotation angle sensor 36 that detects a rotation angle as an electrical angle of a rotor of the motor 6. The inverter 31 is composed of a plurality of semiconductor switching elements, and the PWM driver 32 performs pulse width modulation on the input current command and gives an on / off command to each of the semiconductor switching elements.

The motor control unit 29 is constituted by a computer, a program executed on the computer, and various electronic circuits. As a basic control unit, the motor control unit (drive) / regeneration control unit 33 and a power running / regeneration command torque increase. Rate changing means 34. The motor power running / regeneration control unit 33 converts the motor power running / regeneration control unit 33 into a current command in accordance with an acceleration (power running) / deceleration (regeneration) command based on a torque command or a rotational speed command given from the ECU 21 which is the higher-level control means. This is means for giving a current command to the PWM driver 32.

Switching between acceleration (power running) and deceleration (regeneration) is performed by a command flag from the power running / regeneration control command unit 21b of the ECU 21. The motor power running / regeneration control unit 33 includes a power running control unit 33a, a regeneration control unit 33b, and a power running / regeneration control switching control unit 33c. The power running control means 33a increases the power running command torque as the depression amount of the accelerator pedal 16a increases. The regeneration control means 33b increases the regeneration command torque as the depression amount of the brake pedal 17a increases. The power running / regenerative control switching control unit 33c selects and switches which one of the power running control means 33a and the regeneration control means 33b is used by the command flag from the power running / regeneration control command section 21b.

The motor power running / regenerative control unit 33 generates a command current value for the motor 6 by using a torque map preset in, for example, the ROM 35 inside the inverter, based on the torque command given from the ECU 21 and the command flag. At this time, the current actually flowing to the motor 6 is detected, and the motor 6 is controlled by PI control in order to make this current coincide with the command current.

The power running / regenerative command torque increase rate changing means 34 depends on the vehicle speed detected by the vehicle speed detecting means 37, the depression amount of the accelerator pedal 16a, and the depression amount of the brake pedal 17a when switching between the power running control and the regeneration control. Thus, the power running per hour or the increase rate of the regenerative command torque is varied.

In addition, communication among ECU21, the inverter apparatus 22, the brake controller 23, and the steering means 12 is performed by controller area network (CAN) communication.

FIG. 3 is a diagram showing an increase rate of the regenerative command torque per time when switching from power running control to regenerative control. The vertical axis represents the regenerative command torque value, and the horizontal axis represents time. Hereinafter, description will be made with reference to FIG. 2 as appropriate. For example, the power running / regenerative command torque increase rate changing means 34 keeps the regenerative command torque constant according to the vehicle speed detected by the vehicle speed detecting means 37 and the depression amount of the brake pedal 17a when switching from power running control to regenerative control. It is divided into several stages within the time (two stages in this figure).

(Step 1) The regeneration command torque is increased at an increase rate A, for example, between t _{0 and} t ₁ .
(Step 2) in t ₁ after increases the regeneration instruction torque for example, increase rate B. However, increase rate B> increase rate A.
t ₀ : time immediately after switching from power running control to regenerative control t ₁ : time after elapse of, for example, several milliseconds from time t ₀

Powering and regeneration instruction torque increase rate changing means 34, in step 1, to the regeneration instruction torque from the time t ₀ after switching straight into regenerative control until the time t _1, is increased slowly than Step 2 at an increased rate A Thus, when switching to the regenerative control, a shock caused by a backlash between the gears of the speed reducer 7 can be reduced. After time t ₁ , the regeneration command torque is increased more steeply than step 1 at an increase rate B, so that the braking time can be prevented from becoming longer and the braking time can be shortened.

FIG. 4 is a diagram showing the relationship between the depression amount (horizontal axis) of the brake pedal 17a and the regeneration command torque increase rate (vertical axis) when switching from power running control to regenerative control. In FIG. 4, the vehicle speed 2 is higher than the vehicle speed 1. The power running / regenerative command torque increase rate changing means 34 increases the regeneration command torque increase rate as the amount of depression of the brake pedal 17a increases and the vehicle speed increases, for example, when switching from power running control to regenerative control. To do. Thereby, shortening of braking time can be aimed at.

FIG. 5 is a diagram showing an increase rate of the power running command torque per time when switching from the regeneration control to the power running control. The vertical axis is the power running command torque value, and the horizontal axis is the time. For example, the power running / regenerative command torque increase rate changing means 34 keeps the power running command torque constant according to the vehicle speed detected by the vehicle speed detecting means 37 and the depression amount of the accelerator pedal 16a when switching from regenerative control to power running control. It is divided into several stages within the time (two stages in this figure).
(Step 1) The powering command torque is increased at an increase rate A, for example, between t _{0 and} t ₁ .
(Step 2) in t ₁ after increases the power running command torque for example, increase rate B. However, increase rate B> increase rate A.
t ₀ : time immediately after switching from regenerative control to power running control t ₁ : time after several milliseconds elapse from time t ₀

In step 1, the power running / regenerative command torque increase rate changing means 34 increases the power running command torque from time t ₀ to time t ₁ immediately after switching to power running control at a rate of increase A more slowly than in step 2. Thus, when switching to the power running control, the shock caused by the backlash between the gears of the speed reducer 7 can be reduced. Time t ₁ after, by sharply increasing than Step 1 at an increased rate B powering command torque, resulting accelerated without delay vehicle, thereby shortening the acceleration time.

FIG. 6 is a diagram showing the relationship between the amount of depression of the accelerator pedal 16a (horizontal axis) and the power running command torque increase rate (vertical axis) when switching from regenerative control to power running control. In FIG. 6, the vehicle speed 1 is lower than the vehicle speed 2. The power running / regeneration command torque increase rate changing means 34 increases the power running command torque increase rate as the amount of depression of the accelerator pedal 16a increases and the vehicle speed decreases when switching from regeneration control to power running control. As a result, the vehicle can be accelerated without delay.

FIG. 7A is a conceptual configuration diagram of an IPM motor of the electric vehicle. As shown in FIG. 7A, when the motor for driving the wheel is an IPM motor, that is, an embedded magnet type synchronous motor, the magnetic resistance in the q-axis direction orthogonal to the d-axis direction, which is the magnet axis, is smaller. The q-axis inductance Lq is larger than the d-axis inductance Ld. Due to this saliency, reluctance torque Tr can be used in addition to magnet torque Tm, and high torque and high efficiency can be achieved.
Magnet torque Tm: Torque generated by attracting and repelling the magnetic field generated by the permanent magnet of the rotor and the rotor magnetic field generated by the winding.
Reluctance torque Tr: A torque generated when a salient pole portion of a rotor is attracted to a rotating magnetic field by a winding.

The total torque generated by the motor is as follows.
T = p × {Ke × Iq + (Ld−Lq) × Id × Iq} = Tm + Tr
p: number of pole pairs Ld: d-axis inductance of motor Lq: q-axis inductance of motor Ke: effective value of motor induced voltage constant

As shown in FIG. 7B, a vector control method is known in which a primary current Ia flowing through an IPM motor is separated into a torque generation current q-axis current Iq and a magnetic flux generation current d-axis current Id and can be controlled independently. .
Id = −Ia × sin β
Iq = Ia × cosβ
β: Current advance angle

Here, the motor voltage equation is expressed as follows.

Vd: d-axis voltage Vq: q-axis voltage ω: motor angular speed Ke: induced voltage constant Id: d-axis current Iq: q-axis current Ld: d-axis inductance Lq: q-axis inductance R: armature resistance p: differential operator

The three-phase motor currents Iu, Iv, Iw flowing in the respective phases of the three-phase coil of the permanent magnet motor are converted into actual currents Id, Iq flowing in the d-axis and the q-axis using the detection value Θ of the rotation angle sensor 36. The motor angular speed ω is calculated from the detected value Θ of the rotation angle sensor 36 by the speed calculator 46 shown in FIG.

FIG. 8 is a block diagram focusing on the torque / rotation speed control system in the power running control means 33a or the regeneration control means 33b (FIG. 2) of the motor control unit 29 (FIG. 2) of this electric vehicle. The power running control means 33a or the regeneration control means 33b is a means for controlling the motor drive current, and includes the torque command section 40 of FIG. 8, and in addition, a current PI control section 41, a three-phase / two-phase conversion section 42, A two-phase / three-phase converter 44 and a speed calculator 46 are included. The torque command unit 40 includes a detection value obtained by detecting the drive current applied to the motor 6 by the current detection unit 43, and a torque command value by an acceleration / deceleration command generated by the torque rotation speed control command unit 21a of the ECU 21. From the torque map, a corresponding command current is generated. The direction of the command current is switched by a command flag given from the power running / regenerative control command unit 21b of the ECU 21. A torque command value is output from the ECU 21 with a sign indicating the direction of the command current.

The motor power running / regeneration control unit 33 (FIG. 2) of the inverter device 22 obtains the rotation angle of the rotor of the motor 6 from the rotation angle sensor 36 and performs vector control. Here, the motors 6 provided on the left and right rear wheels of the vehicle body have different torque generation directions both during power running and during regeneration. That is, when the motor 6 is viewed from the direction of the output shaft, for example, when the left rear wheel driving motor 6 generates torque in the CW direction, the right rear wheel driving motor 6 is in the CCW direction. Torque is generated (left and right sides are determined by the direction seen from the rear of the vehicle). The torques generated by the left and right motors 6 are in opposite directions as described above, and are transmitted to the tires via the speed reducer 7 and the wheel bearings 4. Further, the direction of torque generation during regeneration in the motor 6 for the left and right tires is different from the direction of torque generation during power running.

From the maximum torque control table included in the torque map, a corresponding torque command value is calculated according to the accelerator signal (acceleration command) and the rotation speed of the motor 6. The torque command unit 40 generates a primary current (Ia) and a current advance angle (β) of the motor 6 based on the calculated torque command value. Based on the values of the primary current (Ia) and the current advance angle (β), the torque command unit 40 has two commands: a command value O_Id for the d-axis current (field component) and a command value O_Iq for the q-axis current. Generate current.

The current PI control unit 41 is calculated by the three-phase / two-phase conversion unit 42 from the values of the d-axis command current O_Id and q-axis command current O_Iq output from the torque command unit 40 and the motor current and the rotor angle. From the phase currents Id and Iq, control amounts Vdc and Vqc based on voltage values by PI control are calculated. In the three-phase / two-phase converter 42, v obtained from the detected value of the u-phase current (Iu) and the w-phase current (Iw) of the motor 6 detected by the current sensor 43 by the following formula Iv = − (Iu + Iw) A phase current (Iv) is calculated and converted from a three-phase current of Iu, Iv, and Iw to a two-phase current of Id and Iq.

The rotor angle Θ of the motor 6 used for this conversion is acquired from the rotation angle sensor 36. The two-phase / three-phase converter 44 converts the input two-phase control amounts Vdc, Vqc and the rotor angle into three-phase PWM duties Vu, Vv, Vw. The power conversion unit 45 performs PWM control of the inverter 31 according to the PWM duties Vu, Vv, and Vw, and drives the motor 6. The two-phase / three-phase conversion unit 44 and the power conversion unit 45 exist in the power circuit unit 28 of FIG.

FIG. 9 is a flowchart showing a control method when switching from power running control to regenerative control. After starting this process, the power running / regenerative control command unit 21b determines whether or not the amount of depression of the accelerator pedal 16a is zero (step S1). When the depression amount of the accelerator pedal 16a is not zero (step S1: NO), the process returns to step S1. When the amount of depression of the accelerator pedal 16a is zero (step S1: YES), when a certain time has elapsed (step S2: YES), the power running / regenerative control command unit 21b sets the command flag to “1” (step S4). The command flag “1” is given to the motor power running / regeneration control unit 33.

If the depressing amount of the accelerator pedal 16a is zero and a certain time has not elapsed (step S2: NO), when the depressing amount of the brake pedal 17a is larger than zero (step S3: YES), the process proceeds to step S4 and power running / regeneration is performed. The control command unit 21b sets the command flag to “1”. Here, when the depression amount of the brake pedal 17a is zero (step S3: NO), the process returns to step S2. After step S4, the power running / regenerative control switching control unit 33c switches from power running control to regenerative control by the command flag “1” (step S5). After that, as described above, the power running / regenerative command torque increase rate changing means 34 depends on the vehicle speed detected by the vehicle speed detecting means 37 and the depression amount of the brake pedal 17a when switching from power running control to regenerative control. The regeneration command torque is given in several stages within a certain time.

FIG. 10 is a flowchart showing a control method when switching from regenerative control to power running control. After the start of this process, the power running / regenerative command torque increase rate changing means 34 determines whether or not the vehicle speed detected by the vehicle speed detecting means 37 is smaller than the vehicle speed threshold 1 (for example, 10 km / h) (step a1). The vehicle speed threshold 1 is determined by a test, simulation, or the like, and is stored in the ROM 35 so as to be rewritable. When the vehicle speed is smaller than the vehicle speed threshold 1 (step a1: YES), the power running / regenerative control command unit 21b determines whether or not the depression amount of the brake pedal 17a is zero (step a2). When the depression amount of the brake pedal 17a is not zero (step a2: NO), the process returns to step a1.

When the amount of depression of the brake pedal 17a is zero (step a2: YES), step a3 is repeated until a predetermined time elapses (step a3: NO), and after a predetermined time elapses (step a3: YES), the power running / regenerative control command unit 21b sets the command flag to “0” (step a5) when the depression amount of the accelerator pedal 16a is larger than zero (step a4: YES). The power running / regeneration control command unit 21 b gives the command flag “0” to the motor power running / regeneration control unit 33. When the depression amount of the accelerator pedal 16a is zero (step a4: NO), the process returns to step a1.

In step a1, even when the vehicle speed is not smaller than the vehicle speed threshold 1 (step a1: NO), the process proceeds to step a5, and the power running / regenerative control command unit 21b sets the command flag to “0”. Thereafter, the power running / regenerative control switching control unit 33c switches from the regenerative control to the power running control by the command flag “0” (step a6). Thereafter, as described above, the power running / regenerative command torque increase rate changing means 34 changes the power running command according to the vehicle speed detected by the vehicle speed detecting means 37 and the depression amount of the accelerator pedal 16a when switching to power running control. Torque is given in several stages within a certain time.

According to the electric vehicle control apparatus described above, the power running control means 33a increases the power running command torque as the amount of depression of the accelerator pedal 16a increases. The regeneration control means 33b increases the regeneration command torque as the depression amount of the brake pedal 17a increases. The power running / regenerative command torque increase rate changing means 34 changes the vehicle speed and the regeneration rate when switching between the power running control and the regenerative control based on the command flag from the ECU 21. Depending on the amount of depression of the accelerator pedal 16a or the amount of depression of the brake pedal 17a, the rate of increase in power running or regeneration command torque per hour is varied. For example, in the first stage, the power running or regenerative command torque is increased at an increase rate A, and in the second stage, it is increased at an increase rate B (increase rate B> increase rate A). In this way, by varying the rate of increase of power running or regenerative command torque per hour, it is possible to reduce shocks caused by backlash between gears of the speed reducer 7 when switching between power running control and regenerative control. Can do. Further, if the increase rate B in the second stage is larger than the increase rate A in the first stage, for example, the braking time can be shortened during braking, and thus the braking distance can be shortened.

The vehicle speed detecting means 37 may calculate the vehicle speed by differentiating the rotation angle detected by, for example, the rotation angle sensor 36 that detects the rotation angle of the wheel. The power running or regenerative command torque value or the rate of increase (FIGS. 3 to 6) may be increased along a quadratic curve, for example. In the above embodiment, the left and right rear wheels are drive wheels, but the present invention is not limited to this example. For example, the left and right front wheels may be drive wheels, the drive wheels may be driven by individual motors, and the left and right rear wheels may be driven wheels. The present invention can be applied not only to the in-wheel motor type but also to an electric vehicle driven by a motor outside the wheel such as an on-board type.

As described above, the preferred embodiments have been described with reference to the drawings. However, those skilled in the art will readily assume various changes and modifications within the obvious scope by looking at the present specification. Accordingly, such changes and modifications are to be construed as within the scope of the invention as defined by the appended claims.

DESCRIPTION OF SYMBOLS 2 ... Wheel 4 ... Wheel bearing 6 ... Motor 7 ... Reduction gear 8 ... In-wheel motor drive device 16a ... Accelerator pedal 17a ... Brake pedal 21 ... ECU
DESCRIPTION OF SYMBOLS 22 ... Inverter apparatus 28 ... Power circuit part 29 ... Motor control part 31 ... Inverter 33a ... Power running control means 33b ... Regeneration control means 33c ... Power running / regenerative control switching control part 34 ... Power running / regenerative command torque increase rate change means 36 ... Rotation Angle sensor 37: vehicle speed detection means

Claims

ECU that is an electric control unit that controls the entire vehicle, a power circuit unit that includes an inverter that converts DC power into AC power used to drive a driving motor, and controls the power circuit unit in accordance with a torque command from the ECU An inverter device having a motor control unit,
The motor control unit is a power running control unit that performs power running control of the motor, a regeneration control unit that performs regenerative control of the motor, and which of the power running control unit and the regeneration control unit is used according to a command flag from the ECU A control device for an electric vehicle having a power running / regenerative control switching control unit for switching,
Vehicle speed detection means for detecting the vehicle speed;
When the motor control unit switches between power running control based on a command flag from the ECU and regenerative control, the vehicle speed detected by the vehicle speed detecting means, and the accelerator pedal depression amount or the brake pedal depression amount A control device for an electric vehicle provided with power running / regenerative command torque increase rate changing means for varying the power running per time or the increase rate of the regenerative command torque in response.
2. The electric vehicle control device according to claim 1, wherein the power running / regenerative command torque increase rate changing means changes the vehicle speed detected by the vehicle speed detecting means when the power running control is switched to the regenerative control, and the depression of the brake pedal. A control device for an electric vehicle that gives a regenerative command torque in several stages within a certain time according to the amount.
3. The electric vehicle control device according to claim 1, wherein the power running / regenerative command torque increase rate changing means is a vehicle speed detected by the vehicle speed detecting means when switching from regeneration control to power running control, and A control device for an electric vehicle that gives a power running command torque in several stages within a predetermined time according to the amount of depression of an accelerator pedal.
4. The electric vehicle control device according to claim 1, wherein the motor drives one or both of a front wheel and a rear wheel of the vehicle, and the motor, a wheel bearing, An electric vehicle control device constituting an in-wheel motor drive device including a reduction gear.
5. The electric vehicle control device according to claim 1, wherein the vehicle speed detecting means is a rotation angle sensor that detects a rotation angle of a wheel.