JP2001218303A - Method and device for controlling running of electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for controlling the running of an electric vehicle, that enables a driver to feel smooth deceleration with a simple control, even when a brake pedal is pressed and that can improve the collecting efficiency of regenerative energy, by combining creeping control and the changeover control of regenerative torque by the 'on-off' of the brake pedal. SOLUTION: In a first state, in which the brake pedal is 'off', a first regenerative torque T1 is caused to begin decreasing from a first set vehicle speed V1, in such a way as to become zero at a second set vehicle speed V2 that is lower than the first one V1, and a creeping torque is generated in the low- speed range in which the speed is lower than the one V2. In a second state, in which the brake pedal is 'ON', a second regenerative torque T2 that is larger than the first one T1 is caused to begin declining from a third vehicle speed V3, that is lower than the first one V1, and the generation of the creeping torque is limited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for controlling the running of an electric vehicle (including a hybrid vehicle of a motor and an internal combustion engine) that drives wheels by using a motor as a drive source, and more particularly to creep control and braking. Pedal on
The present invention relates to a traveling control method and apparatus for an electric vehicle that performs regenerative torque control by turning off.

[0002]

2. Description of the Related Art As a conventional electric vehicle, for example, Japanese Unexamined Patent Publication No. Hei 6-70406 detects whether a brake pedal is depressed (on / off) and determines whether an accelerator pedal is depressed (on / off). When the accelerator pedal is turned off during traveling, a predetermined level of regenerative torque is generated to perform regenerative braking, and when the brake pedal is turned on, the regenerative torque further added to the above-mentioned predetermined level Are generated to perform regenerative braking.

[0003] Japanese Patent Application Laid-Open No. 6-78416 discloses that
The shift position is set to a travel range in order to bring the electric vehicle closer to the running feeling of an AT car using an internal combustion engine, and to facilitate the handling of the vehicle at the time of garage entry or side approach, A system is disclosed in which when the accelerator pedal and the brake pedal are off and the vehicle speed is lower than a set speed, a constant pseudo creep torque is generated to cause the vehicle to creep.

[0004]

By the way, the switching control of the regenerative torque by turning on and off the brake pedal and the creep control for generating the creep torque when the vehicle speed is lower than the set speed are combined to provide a brake pedal. When the brake pedal is turned on, the vehicle is shifted to the creep region at the set speed in the same manner as when the brake pedal is turned off. As shown in FIG. 5, the relationship between the vehicle speed and the motor-generated torque is higher than when the brake pedal is on. Since the regenerative torque is also large, the decrease start speed Von of the regenerative torque T2 when the brake pedal is on is set to be faster than the decrease start speed Voff of the regenerative torque T1 when the brake pedal is off.

However, since the regenerative braking force decreases at a high vehicle speed, a feeling that the braking effect is delayed, that is, a so-called brake loss feeling occurs, so that a smooth deceleration feeling cannot be obtained and regenerative energy is recovered. Efficiency will also decrease.

A method for avoiding such a phenomenon is as follows.
For example, as shown in FIG. 6, the decrease start speed Von of the regenerative torque T2 when the brake pedal is on is equal to the decrease start speed Voff of the regenerative torque T1 when the brake pedal is off, and the brake pedal is off at zero speed. It is conceivable to control so as to generate the same creep torque as in the case of (1).

With this configuration, even when the brake pedal is on, the regenerative braking force starts to decrease from the same vehicle speed as when the brake pedal is off, so that it is possible to prevent the occurrence of a feeling that the brake is missing, and to regenerate the brake. Since the speed at which the power becomes zero is lower than when the brake pedal is off, the regenerative energy can be increased by an area E1 shown by hatching in FIG.

However, in this case, since the same creep torque is generated when the brake pedal is turned on as when the brake pedal is turned off, the strong regenerative braking force is sharply reduced, and the deceleration is also smooth. The feeling is not obtained, and the control becomes complicated. Also, the amount of increase in regenerative energy is small, and the recovery efficiency is not sufficient.

Accordingly, a first object of the present invention, which has been made in view of such a point, is to combine creep control and regenerative torque switching control by turning on / off a brake pedal, and to provide simple control even when the brake pedal is turned on. It is an object of the present invention to provide a travel control method for an electric vehicle, which can provide a smooth feeling of deceleration at the same time and can improve the recovery efficiency of regenerative energy.

A second object of the present invention is to provide a travel control device for an electric vehicle which can easily implement the above-described travel control method.

[0011]

According to a first aspect of the present invention, there is provided an electric vehicle running control method for driving a wheel through a transmission using a motor as a driving source. In a traveling control method for an electric vehicle for controlling traveling of an automobile, when the shift position is in a traveling range and in a first state in which an accelerator pedal and a brake pedal are not depressed, a speed exceeding a first set vehicle speed. In the range, a first regenerative torque is generated from the motor, and in a low-speed range below the first set vehicle speed, the generated regenerative torque is reduced so as to become zero at the second set vehicle speed. Generates the creep torque in the low speed range of the above, the shift position is in the running range, the accelerator pedal is not depressed, and the brake pedal is depressed When in the second state is the
In a speed region exceeding a third set vehicle speed lower than the first set vehicle speed, a second regenerative torque larger than the first regenerative torque is generated from the motor, and a low speed region equal to or lower than the third set vehicle speed is generated. Is characterized by reducing the generated regenerative torque and limiting the generation of creep torque.

According to the first aspect of the present invention, in the second state, the first state in the first state when the brake pedal is off.
The regenerative torque starts decreasing from the third set vehicle speed that is lower than the set vehicle speed, and the generation of creep torque is limited, so that a smooth feeling of deceleration can be obtained with simple control, and the regenerative energy recovery efficiency Can be increased.

According to a second aspect of the present invention, in the driving control method for an electric vehicle according to the first aspect, the third set vehicle speed is set between the first set vehicle speed and the second set vehicle speed. It is characterized by having done.

According to the second aspect of the present invention, in the second state, between the first set vehicle speed which is the reduction start speed of the regenerative torque in the first state and the second set vehicle speed at which the regenerative torque becomes zero. Since the regenerative torque starts to decrease from the third set vehicle speed, a smoother feeling of deceleration can be obtained.

According to a third aspect of the present invention, in the driving control method for an electric vehicle according to the first aspect, the third set vehicle speed is set to be lower than the second set vehicle speed.

According to the third aspect of the present invention, in the second state, the regenerative torque starts decreasing from the third set vehicle speed lower than the second set vehicle speed at which the regenerative torque becomes zero in the first state. Therefore, it is possible to further improve the recovery efficiency of the regenerative energy.

According to a fourth aspect of the present invention, in the traveling control method for an electric vehicle according to the third aspect, in the first state,
It is preferable that the generated torque of the motor is set to zero between the second set vehicle speed and a fourth set vehicle speed lower than the third set vehicle speed, and the creep torque is generated from the fourth set vehicle speed or less. Features.

According to the present invention, in the first state, the second set vehicle speed at which the regenerative torque becomes zero is set near the first set vehicle speed, so that the regenerative energy in the second state is set. It is possible to further improve the collection efficiency.

According to a fifth aspect of the present invention, in the traveling control method for an electric vehicle according to any one of the first to fourth aspects, the creep torque is limited to zero in the second state.

According to the fifth aspect of the present invention, no creep torque is generated in the second state, so that the control can be simplified and the recovery efficiency of the regenerative energy can be increased as compared with the case where the creep torque is generated. It is possible to further reduce unnecessary energy consumption and to stably maintain the stopped state of the vehicle.

According to a sixth aspect of the present invention, there is provided a travel control device for an electric vehicle which drives wheels by using a motor as a drive source, wherein a motor drive means for driving the motor and a shift position are provided. Shift position detecting means for detecting, brake operation detecting means for detecting whether a brake pedal is depressed, accelerator operation detecting means for detecting whether an accelerator pedal is depressed, vehicle speed detecting means for detecting a vehicle speed, and the shift position Based on the outputs of the detecting means, the brake operation detecting means, the accelerator operation detecting means, and the vehicle speed detecting means, when the shift position is in the traveling range and the accelerator pedal and the brake pedal are in the first state where they are not depressed. In the speed range exceeding the first set vehicle speed, the first regenerative torque And reducing the regenerative torque to be generated in a low-speed region equal to or lower than the first set vehicle speed so as to become zero at a second set vehicle speed, and generating a creep torque in a low-speed region equal to or lower than the second set vehicle speed. When the shift position is in the travel range and the accelerator pedal is not depressed and the brake pedal is depressed in a second state, a third set vehicle speed lower than the first set vehicle speed In the speed range exceeding the first regenerative torque, the motor generates a second regenerative torque larger than the first regenerative torque. In the low speed range below the third set vehicle speed, the generated regenerative torque is reduced, and the generation of the creep torque is reduced. Control means for controlling the motor driving means so as to limit the motor driving means.

According to the present invention, the shift position detecting means, the brake operation detecting means, the accelerator operation detecting means, and the vehicle speed detecting means are usually mounted on an electric vehicle, and the electronic control is also provided with the control means. The change can be easily dealt with by changing the logic of the unit, so that it is possible to easily implement the unit without adding a part.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method and an apparatus for controlling the running of an electric vehicle according to the present invention will be described below in detail with reference to FIGS.

(First Embodiment) FIGS. 1 and 2 show a first embodiment of the present invention. FIG. 1 is a block diagram of a travel control device of an electric vehicle, and FIG. 2 is a diagram showing vehicle speed and motor generated torque. FIG.

In FIG. 1, a motor 1 as a drive source of an electric vehicle is composed of, for example, a three-phase AC induction motor, and is driven under the control of a controller 4 by an inverter 3 constituting a motor drive means using a battery 2 as a power source. It is supposed to be. In the present embodiment, shift position detecting means 5 for detecting a shift position, brake operation detecting means 6 for detecting the presence or absence of operation of a brake pedal, accelerator operation detecting means 7 for detecting the presence or absence of operation of an accelerator pedal, and vehicle speed detection A vehicle speed detecting means 8 is provided, and the controller 4 controls the inverter 3 based on the output of the vehicle speed detecting means 8 so that the motor 1 generates a torque as shown in FIG.

Here, the shift position detecting means 5
With a known configuration, a parking position “P”, a neutral position “N”, a reverse position “R”, a drive position “D”, and the like are detected.

The brake operation detecting means 6 detects by a brake switch, or based on an output of a hydraulic pressure sensor for detecting a hydraulic pressure of a brake path or a stroke sensor for detecting an amount of depression of a brake pedal, so that the brake pedal is depressed. The controller 4 supplies a brake-on signal to the controller 4 when it is depressed and a brake-off signal when it is not depressed.

The accelerator operation detecting means 7 detects, for example, whether or not the accelerator pedal is depressed by a switch, and outputs an accelerator-on signal when the accelerator pedal is depressed and an accelerator-off signal when the accelerator pedal is not depressed. The data is supplied to the controller 4.

The vehicle speed detecting means 8 is configured to calculate the vehicle speed by detecting, for example, the rotation speed of the wheels or the motor 1 by an encoder or the like.

That is, in the present embodiment, as shown in FIG. 2, the shift position detecting means 5 detects that the vehicle is in the traveling range, a brake operation detecting means 6 supplies a brake-off signal, and an accelerator operation detecting means. In the first state in which the accelerator-off signal is supplied from the means 7, the first regenerative torque T1 is generated from the motor 1 in the speed region exceeding the first set vehicle speed V1, and the first set vehicle speed V1 In the low speed range from the second set vehicle speed V2 to the second set vehicle speed V2, the regenerative torque to be generated is reduced in proportion to the deceleration of the vehicle speed so as to become zero at the second set vehicle speed V2. Control is performed such that creep torque is generated in a low speed region where the vehicle speed is zero from the set vehicle speed V2.

On the other hand, the shift position detecting means 5
When the vehicle is in the traveling range, the accelerator operation detecting means 7 supplies an accelerator-off signal and the brake operation detecting means 6 supplies a brake-on signal. In a speed range exceeding the third set vehicle speed V3 between the set vehicle speed V1 and the second set vehicle speed V2, the second regenerative torque T2 larger than the first regenerative torque T1 is generated from the motor 1 and the third regenerative torque T2 is generated. In the low-speed region from the set vehicle speed V3 to the vehicle speed of zero, the regenerative torque to be generated is reduced in proportion to the vehicle speed deceleration so that the generated regenerative torque becomes zero at the vehicle speed of zero, so that the creep torque is not generated.

The first and second regenerative torques T1,
T2 and the first to third set vehicle speeds V1 to V3 are stored in a memory in the controller 4 in advance.

As described above, in the present embodiment, the third set vehicle speed V3, which is the speed at which the second regenerative torque T2 starts decreasing in the second state, is changed to the first regenerative torque T1 in the first state. Since the speed is lower than the first set vehicle speed V1, which is the decrease start speed, and higher than the second set vehicle speed V2, at which the regenerative torque becomes zero, it is possible to obtain a sense of smooth deceleration without causing a sense of brake loss. Can be. Also,
In the second state, the regenerative torque is reduced to zero at the vehicle speed of zero, so that the creep torque is not generated. Therefore, compared to the case of FIG. 5, the regenerative energy corresponding to the area E2 shown by hatching in FIG. Can be increased, the recovery efficiency of the regenerative energy can be increased by simple control, and the stationary state of the vehicle can be stably maintained without wasteful energy consumption.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention.
FIG. 5 is a diagram illustrating a relationship between a vehicle speed and a motor generated torque for describing the embodiment.

In the second embodiment, in the configuration shown in FIG. 1, the third set vehicle speed V3, which is the speed at which the second regenerative torque T2 starts decreasing in the second state, is regenerated in the first state. This is set at a speed lower than the second set vehicle speed V2 at which the torque becomes zero, and the other controls are the same as in the first embodiment.

Therefore, according to the second embodiment, the amount of increase in the regenerative energy is the area E3 shown by hatching in FIG. 3, so that the recovery efficiency of the regenerative energy is higher than in the first embodiment. Can be enhanced.

(Third Embodiment) FIG. 4 shows a third embodiment of the present invention.
FIG. 5 is a diagram illustrating a relationship between a vehicle speed and a motor generated torque for describing the embodiment.

In the third embodiment, in the configuration shown in FIG. 1, after the regenerative torque is set to zero at the second set vehicle speed V2 in the first state, the state where the regenerative torque is zero is changed to the third state. A fourth set vehicle speed V4 lower than the set vehicle speed V3 is maintained, and a creep torque is generated in a low speed region from the fourth set vehicle speed V4. Other controls are the same as in the second embodiment. It is. Note that the fourth set vehicle speed V
4 is stored in advance in a memory in the controller 4 in the same manner as the first and second regenerative torques T1 and T2 and the first to third set vehicle speeds V1 to V3.

Therefore, according to the third embodiment, the amount of increase in the regenerative energy is the area E4 shown by hatching in FIG. 4, so that the second state in which the regenerative torque becomes zero in the first state. By setting the set vehicle speed V2 near the first set vehicle speed V1, the recovery efficiency of the regenerative energy in the second state can be further increased.

The present invention is not limited to the above embodiment, but can be variously modified without departing from the spirit of the invention. For example, in each of the above embodiments, in the second state, the regenerative torque is set to zero at the vehicle speed of zero, and the creep torque is not generated.However, the regenerative torque is set to zero at a predetermined low speed near the vehicle speed of zero. It is also possible to control so as to generate a creep torque that is more limited than in the first state, between a predetermined low speed and zero vehicle speed. Further, the present invention is not limited to a motor using a three-phase AC induction motor as the motor 1, but can be effectively applied to an electric vehicle using a known motor such as a brushless DC motor.

[0041]

According to the electric vehicle running control method of the present invention described above, the creep control and the regenerative torque switching control by turning on / off the brake pedal are combined, and the second state when the brake pedal is on is provided. The regenerative torque starts decreasing from a third set vehicle speed that is lower than the first set vehicle speed that is a decrease start speed of the regenerative torque in the first state when the brake pedal is off, and the generation of creep torque is limited. Therefore, with a simple control, a smooth deceleration feeling can be obtained, and the recovery efficiency of the regenerative energy can be improved.

Further, according to the traveling control device for an electric vehicle of the present invention, the shift position detecting means, the brake operation detecting means, the accelerator operation detecting means and the vehicle speed detecting means can be those normally mounted on the electric vehicle. Also, the control means can be easily dealt with by changing the logic of the electronic control unit which is usually mounted, so that it can be easily implemented without adding components.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a traveling control device for an electric vehicle according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a relationship between a vehicle speed and a motor generated torque according to the first embodiment.

FIG. 3 is a diagram illustrating a relationship between a vehicle speed and a motor generated torque according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a relationship between a vehicle speed and a motor-generated torque according to a third embodiment.

FIG. 5 is a diagram for explaining a conventional technique.

FIG. 6 is also a diagram for explaining a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motor 2 Battery 3 Inverter 4 Controller 5 Shift position detecting means 6 Brake operation detecting means 7 Accelerator operation detecting means 8 Vehicle speed detecting means

Claims (6)

[Claims] 1. A traveling control method for an electric vehicle in which wheels are driven by using a motor as a driving source, wherein the shift position is in a traveling range and an accelerator pedal and a brake pedal are not depressed. In the first state, the first regenerative torque is generated from the motor in a speed range exceeding the first set vehicle speed, and the generated regenerative torque is generated in the low speed range below the first set vehicle speed in the second range.
At the set vehicle speed of
When the shift position is in the traveling range, the accelerator pedal is not depressed and the brake pedal is depressed in the second state, In a speed range exceeding a third set vehicle speed lower than the first set vehicle speed, a second regenerative torque larger than the first regenerative torque from the motor is output from the motor.
A regenerative torque is generated, and in a low-speed region equal to or lower than a third set vehicle speed, the generated regenerative torque is reduced, and the generation of creep torque is limited. 2. The method according to claim 1, wherein the third set vehicle speed is set between the first set vehicle speed and the second set vehicle speed. 3. The method according to claim 1, wherein the third set vehicle speed is set to be lower than the second set vehicle speed. 4. In the first state, the torque generated by the motor is set to zero between the second set vehicle speed and a fourth set vehicle speed lower than the third set vehicle speed, and 4. The running control method for an electric vehicle according to claim 3, wherein a creep torque is generated from a set vehicle speed or less. 5. The running control method for an electric vehicle according to claim 1, wherein the creep torque is limited to zero in the second state. 6. A travel control device for an electric vehicle that drives wheels by using a motor as a drive source, comprising: a motor drive unit that drives the motor; a shift position detection unit that detects a shift position; and whether a brake pedal is depressed. Brake operation detecting means for detecting, accelerator operation detecting means for detecting whether or not an accelerator pedal is depressed, vehicle speed detecting means for detecting vehicle speed, shift position detecting means, brake operation detecting means, accelerator operation detecting means, and vehicle speed detecting When the shift position is in the travel range and in the first state in which the accelerator pedal and the brake pedal are not depressed based on the output of the means, the motor is switched from the motor in the speed range exceeding the first set vehicle speed. 1 generates a regenerative torque, and in a low-speed region below the first set vehicle speed. Reduces the regenerative torque to be generated so that it becomes zero at the second set vehicle speed, and generates a creep torque in a low-speed region equal to or lower than the second set vehicle speed. When the vehicle is not in the second state in which the brake pedal is depressed and the brake pedal is depressed, the first regeneration from the motor is performed in a speed range exceeding a third set vehicle speed lower than the first set vehicle speed. Second greater than torque
And control means for controlling the motor drive means so as to reduce the regenerative torque to be generated in a low speed region below the third set vehicle speed and to limit the generation of creep torque. Control device for an electric vehicle.