JPH0595109U - Backward control of electric motors for electric vehicles - Google Patents

Abstract

(57) [Summary] [Purpose] To provide control at the time of backward movement of an electric motor for an electric vehicle, which prevents the vehicle from suddenly starting at the time of backward movement and being accelerated to an unnecessarily high speed. [Structure] The detection signals of the reverse movement detection means 11, the accelerator opening detection means 12, and the vehicle speed detection means 13 are input to a control unit 14. The control unit 14
The output current supplied to the electric motor 15 is controlled so that the vehicle speed when reversing becomes equal to or lower than a predetermined value even if the accelerator opening increases.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to backward control of an electric motor applied to an electric vehicle, and more particularly, to backward control of an electric motor for an electric vehicle that prevents sudden rearward movement during backward movement.

[0002]

[Prior Art]

 In order to respond to social demands such as energy saving and environmental problems, research and development of electric vehicles that use electric motors as a drive source to replace internal combustion engines are underway, and some have been put to practical use.

Therefore, a schematic configuration of the electric vehicle will be briefly described with reference to FIG. The electric vehicle 1 converts the electric energy stored in the storage battery 2 into a driving force by the electric motor 3 and transmits the driving force to the wheels 4 to run. The output current supplied to the electric motor 3 is adjusted by the control unit 5 in accordance with the accelerator opening degree (stepping amount) operated by the driver. The larger the current value, the larger the electric motor output and the vehicle speed. That is, the electric motor 3 corresponds to the engine of an internal combustion engine vehicle.

Further, the storage battery 2 corresponds to a fuel tank of an internal combustion engine vehicle, and receives the direct current obtained by converting the alternating current received from the general power source 6 by the charging device 7 to chemically store the electric energy. You can

The drive system for transmitting the driving force generated by the electric motor 3 to the wheels 4 is basically the same as that of an internal combustion engine vehicle, but the transmission can be omitted depending on the output characteristics of the electric motor. is there.

[0006]

[Problems to be solved by the device]

 By the way, a general automobile is designed for forward traveling, and backward traveling is limited to low speed traveling such as garage entry and direction change. Therefore, in an internal combustion engine vehicle equipped with a transmission, the reverse gear ratio having only one gear is set for low speed. However, in an electric vehicle, the transmission can be omitted due to the output characteristics of the electric motor, so that the two-stage shift between forward and reverse is the mainstream. Therefore, if the same electric motor control is performed both forward and backward, the disadvantage that the maximum speed that is the same as when moving forward can be reached will occur during backward movement. In particular, there is a risk that operational mistakes will be more likely to occur in a driving operation in which one of two types, forward or backward, is selected, and preventive measures and safety measures from all aspects are desired for such incorrect operation.

Therefore, the object of the present invention is to prevent the vehicle from suddenly moving backward and increasing the speed to a higher speed than necessary even if a reverse driving, which is generally unfamiliar, is mistakenly selected. , To provide backward control of an electric motor for an electric vehicle.

[0008]

[Means for Solving the Problems]

 The present invention solves the aforementioned problems. The first invention supplies a current corresponding to an accelerator opening signal detected by an accelerator opening detection means to a driving electric motor to control a vehicle speed. In an electric vehicle, there are a backward movement detecting means for detecting that the traveling direction of the vehicle is backward, a vehicle speed detecting means for detecting the traveling speed of the vehicle, the accelerator opening detecting means, the backward detecting means and the vehicle speed detecting means. An electric vehicle, comprising: a control unit for controlling the output current of the electric motor based on an input signal, wherein the control unit is configured to limit the vehicle speed when reversing to a predetermined value or less. This is control when the electric motor moves backward.

A second invention is an electric vehicle in which a current corresponding to an accelerator opening signal detected by an accelerator opening detection means is supplied to a driving electric motor to control a vehicle speed. And a control unit for controlling the output current of the electric motor based on the signals input from the accelerator opening detection means and the reverse movement detection means. This is a backward control of an electric motor for an electric vehicle, characterized in that the unit is configured to limit the current value at the time of backward movement to a predetermined value or less.

[0010]

[Action]

 According to the above-mentioned means, when it is detected that the traveling direction of the vehicle is backward, the first invention limits the vehicle speed to a predetermined value or less, and the second invention limits the current value supplied to the electric motor to a predetermined value. Since the value is limited to the value or less, in either case, the vehicle will not make a sudden start when moving backward, as in the case of moving forward, or will not run at the same high speed when moving backward when moving backward.

[0011]

【Example】

 An embodiment of backward control of an electric motor for an electric vehicle according to the present invention will be described with reference to the drawings.

FIGS. 1 to 3 show the first invention, in which the detection signals of the backward movement detecting means 11, the accelerator opening degree detecting means 12 and the vehicle speed detecting means 13 are inputted to the control unit 14, and the control unit 14 is operated. Is configured to control the current value supplied to the electric motor 15.

As the reverse detecting means 11, for example, a switch of a reverse lamp that is turned on when selecting reverse can be used, and when the switch is turned on, a signal indicating that the traveling direction of the vehicle is backward is sent to the control unit 14. input.

The accelerator opening detecting means 12 detects, for example, an accelerator opening operated by a driver, that is, a change in resistance value according to an amount of depression of an accelerator pedal (not shown). Then, the output current corresponding to the accelerator opening is controlled to be supplied to the electric motor 15. During normal forward movement, as indicated by the broken line in FIG. 3, the current value supplied to the electric motor 15 increases with the accelerator opening so that the vehicle speed increases as the accelerator opening increases.

The vehicle speed detecting means 13 detects the traveling speed of the own vehicle and inputs it to the control unit 14. It is widely used for various controls as a so-called vehicle speed sensor, or it is used as it is or other device. It can be used as

Next, as shown in the flow chart of FIG. 2, the control in the control unit 14 first checks the reverse signal input from the reverse detecting means 11 and also inputs from the accelerator opening detecting means 12. Read the accelerator opening signal. As a result, when it is determined that the traveling direction of the vehicle is backward, the motor output current command value at the time of backward movement is calculated based on the read accelerator opening signal. In this command value calculation, as indicated by the solid line in FIG. 3, until the vehicle speed detected by the vehicle speed detecting means 13 rises to a predetermined vehicle speed v, it is proportional to the increase in the accelerator opening as in the case of forward movement. The output current is controlled so that the vehicle speed increases. However, after the vehicle speed reaches a predetermined v, the output current is controlled so that the vehicle is not accelerated any more even if the accelerator opening becomes larger than a, and the vehicle speed during reverse is limited to v or less. Since the electric motor 15 does not have an idling operation like the internal combustion engine, the electric vehicle does not start until the current value increases to some extent.

On the other hand, when it is determined that the traveling direction of the vehicle is not backward (that is, forward), the motor output current command value during forward movement is calculated based on the read accelerator opening signal. In this case, the vehicle speed increases as the accelerator opening increases (see the broken line in FIG. 3), and the predetermined vehicle speed v set during reverse does not become the upper limit.

Due to the above-described reverse control, the vehicle speed during reverse is always limited to a low speed of v or less, and even if there is a erroneous operation, there is a sudden start to the rear and acceleration to a higher speed than necessary. There is no such thing.

4 to 5 show the second invention, in which the detection signals of the backward movement detecting means 21 and the accelerator opening detecting means 22 are inputted to the control unit 23, and the control unit 23 is driven by the electric motor. It is configured to control the current value supplied to 24.

In the second invention, unlike the vehicle speed limitation of the first invention described above, the output current at the time of reverse is limited by setting an upper limit. This control is performed inside the control unit 23, which will be described with reference to the flowchart of FIG.

In this control as well, the reverse signal input from the reverse detecting means 21 is first checked, and the accelerator opening signal input from the accelerator opening detecting means 22 is read. Then, the motor output current command value is calculated based on this accelerator opening signal.When the reverse signal is checked and it is determined that the vehicle is traveling in the reverse direction as a result of checking the reverse signal, even if the accelerator opening increases. The output current signal is limited so that the output current does not exceed a predetermined current value i. That is, as shown in FIG. 6, even if the accelerator opening degree is larger than b corresponding to the output current i, the output current value supplied to the electric motor 24 does not become larger than i.

On the other hand, when it is determined that the traveling direction of the vehicle is not backward (that is, forward), the output current is controlled to increase in proportion to the increase of the accelerator opening, as shown by the broken line in FIG. The current value i never becomes the upper limit.

By performing the reverse control as described above, the output current during the reverse is always limited to i or less. Therefore, even if there is a erroneous operation, there is a sudden start to the rear and acceleration to a higher speed than necessary. The output current as described above is not supplied to the electric motor 24.

In the first invention described above, the vehicle speed at the time of retreating is limited to a predetermined value or less, so that the upper limit of the vehicle speed is always kept constant (the output current varies when the vehicle retreats on a slope). On the other hand, in the second device, the upper limit of the output current is limited, so that the maximum vehicle speed is higher than on flat ground when moving backward on a downhill, and on the contrary, the maximum vehicle speed is lower on an uphill. Occurs.

[0025]

EFFECTS OF THE INVENTION According to the above-mentioned two inventions, the backward speed of an electric vehicle without a transmission is limited to a low speed, and even if an erroneous driving operation is carried out, the vehicle suddenly starts backward and is operated more than necessary. Since it will not be accelerated up to high speed, it will be a highly safe electric vehicle.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first device.

FIG. 2 is a flowchart showing a control example in the control unit of FIG.

FIG. 3 is a diagram showing a relationship between an accelerator opening and a vehicle speed in the motor output current command value calculation of FIG.

FIG. 4 is a block diagram showing a second device.

5 is a flowchart showing an example of control in the control unit of FIG.

6 is a diagram showing the relationship between the accelerator opening and the output current in the motor output command value calculation of FIG.

FIG. 7 is a block diagram showing a schematic configuration of an electric vehicle.

[Explanation of symbols]

 11, 21 Reverse detection means 12, 22 Accelerator opening detection means 13 Vehicle speed detection means 14, 23 Control unit 15, 24 Electric motor

Front page continued (72) Inventor Hiroyasu Suzuki 5-3-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (72) Inventor Kazuo Natori 2-4-1, Nishitsujikeoka, Chofu-shi, Tokyo TEPCO Inside Technical Research Institute (72) Inventor Noboru Fujiwara 2-4-1 Nishi Tsutsujigaoka, Chofu City, Tokyo Inside Tokyo Electric Power Co., Inc. Technical Research Institute

Claims (2)

[Scope of utility model registration request] 1. An electric vehicle in which a current corresponding to an accelerator opening signal detected by an accelerator opening detection means is supplied to a driving electric motor to control a vehicle speed, and it is detected that the traveling direction of the vehicle is backward. Reverse speed detecting means, vehicle speed detecting means for detecting the traveling speed of the vehicle, and the output current of the electric motor based on signals inputted from the accelerator opening detecting means, the reverse speed detecting means and the vehicle speed detecting means. A reverse control of an electric motor for an electric vehicle, comprising: a control unit, wherein the control unit is configured to limit a vehicle speed during reverse to a predetermined value or less. 2. An electric vehicle in which a current corresponding to an accelerator opening signal detected by an accelerator opening detecting means is supplied to a driving electric motor to control a vehicle speed, and it is detected that the traveling direction of the vehicle is backward. And a control unit for controlling the output current of the electric motor based on signals input from the accelerator opening detection means and the reverse movement detection means, and the control unit controls the current value during reverse movement. Is controlled to be equal to or less than a predetermined value.