JP2002369316A - Acceleration controller of motor vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an acceleration controller of a motor vehicle in which sufficient acceleration performance can be attained while sustaining motor performance without causing any deterioration by utilizing the safety marginal region of motor output effectively through setting of a control program without increasing the size or cost of the motor, an inverter or a battery. SOLUTION: In the acceleration controller of a motor vehicle comprising a motor, a vehicle controller and a battery where the motor is set with a maximum current at the time of traveling, the vehicle controller has a means for identifying the acceleration condition and performs boost control for passing a current higher than the maximum current for a specified time when the acceleration condition is identified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an acceleration control device for an electric vehicle.

[0002]

2. Description of the Related Art In general, in an electric vehicle, a current proportional to the throttle opening is supplied to a motor to drive the motor to drive. At this time, a maximum current value at the time of use is set as the current to be supplied to the motor, and the motor is controlled by supplying a current value equal to or less than the maximum current value. The maximum current value is set in consideration of a motor margin, a motor driving inverter or a battery, and a safety margin. Therefore, the maximum current value is a value that is smaller than the drive limit current value of the motor in consideration of a safety margin.
During normal use, the current value to be supplied to the motor is controlled by setting a control program of a control circuit such as a vehicle controller so as to be equal to or less than the maximum current.

[0003]

However, during acceleration, a large current is required to increase the output of the motor. Even during such acceleration, drive control must be performed at a value equal to or less than the maximum current value. Therefore, in order to secure stable acceleration performance, it is necessary to increase the maximum current value. However, to increase the maximum current value,
Motors, inverters, and batteries must be changed to match the maximum current value, and are structurally bulky and expensive. Also, if the motor output is set near the maximum current value within the range where the minimum required feeling of acceleration can be obtained in order to increase the motor output during normal driving, the current value during acceleration is insufficient and sufficient acceleration is achieved. Performance may not be obtained and the vehicle may fluctuate and become unstable.

The present invention has been made in consideration of the above-mentioned prior art, and effectively utilizes a safety margin area of a motor output by setting a control program without increasing the size of a motor, an inverter, a battery, or the like, or increasing the cost. Another object of the present invention is to provide an acceleration control device for an electric vehicle that can obtain sufficient acceleration performance without deteriorating while maintaining the performance of a motor and the like.

[0005]

To achieve the above object, according to the present invention, there is provided a motor, a vehicle controller, and a battery, wherein the motor accelerates an electric vehicle in which a maximum current value during running is set. In the control device, the vehicle controller includes an acceleration state identification unit, and performs a boost control for supplying a current larger than the maximum current value for a predetermined time when the acceleration state is identified. A control device is provided.

According to this configuration, a current exceeding the maximum current value is supplied for a predetermined short time during acceleration so as not to deteriorate the motor performance, so that the output in the safety margin area of the motor is effectively used. In order to secure the output required during acceleration, it is possible to obtain sufficient acceleration performance at a small size and at low cost without using a high-output motor to secure the output required only during acceleration. And a stable running state can always be maintained.

In a preferred configuration example, the acceleration state identification means includes a vehicle speed detection means, and performs the boost control at the time of acceleration at a predetermined speed or less.

According to this configuration, the vehicle speed is detected by the encoder of the motor or the vehicle speed sensor provided on the axle or the like. A current that is equal to or greater than the maximum current value is supplied to the motor for a predetermined short time necessary for acceleration without deteriorating the motor. Thereby, the output is increased and the acceleration operation is performed smoothly.

In another preferred embodiment, the acceleration state discriminating means includes a throttle opening detecting means, and performs the boost control when a change amount of the throttle opening is equal to or more than a predetermined value.

According to this configuration, the acceleration state according to the driver's intention is detected by the change in the throttle opening, and based on this, a current equal to or greater than the maximum current value is supplied, and sufficient acceleration performance can be obtained.

In another preferred embodiment, the acceleration state discriminating means includes a motor speed detecting means, and performs the boost control at the time of acceleration when the motor speed is equal to or lower than a predetermined motor speed.

According to this configuration, acceleration performance particularly at low speed is improved.

In another preferred embodiment, the acceleration state discriminating means includes a torque detecting means, and performs the boost control at the time of acceleration when the torque is equal to or more than a predetermined torque.

According to this configuration, the motor can be controlled according to the torque during acceleration.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an external view of a small electric scooter to which the present invention is applied.

The electric scooter 1 is provided with a main frame 2 constituting a vehicle body, and a front fork 4 is provided through a head pipe 3 at a front portion thereof, and a front wheel 5 is mounted on the front fork 4. A swing arm 6 is swingably attached via a swing pivot 7 from the main frame 2 at the center of the vehicle body toward the rear. The swing arm 6 is integrated with a wheel motor unit 9 mounted on an axle 13 of the rear wheel 8 to form a drive unit 12. A wheel motor (not shown) and a transmission (not shown) serving as a power source for driving the vehicle are incorporated in the wheel motor unit 9. Wheel motor unit 9
Is connected to the lower end of the shock absorber 11 via the suspension pivot 10. The upper end of the shock absorber 11 is attached to the main frame 2 at the rear end of the vehicle body. Thereby, the rear wheel (drive wheel) 8 incorporating the wheel motor is swingably supported with respect to the main frame 2.

A shift operation switch 15 is provided at the base of the handle 14 for steering the front wheel 5 via the front fork 4. The shift operation switch 15 includes a shift changeover switch 28 (FIG. 2) for selecting one of a manual shift and a manual shift, and a shift-up switch 29 (FIG. 2) for shifting to a higher gear when the manual shift is selected. ) And a downshift switch 30 (FIG. 2) for shifting to a lower gear.

A vehicle speed sensor 16 is mounted on the axle of the front wheel 5. The battery 17 is located below the seat 19 in the center of the vehicle body.
Is stored. A vehicle controller 18 including a control circuit having a program for controlling a motor and a transmission is provided below the seat 19 at the rear of the vehicle body.

FIG. 2 is a configuration diagram of the electric vehicle according to the present invention. A vehicle speed sensor 16 is provided on the axle of the front wheel 5, a vehicle speed is displayed on a speedometer 20, and a vehicle speed signal is input to a vehicle controller 18. The vehicle controller 18 further includes a main switch 22 for turning on and off the motor 21 and various switches 2 such as a flasher and a horn.
3. The throttle 24 and the torque sensor 25 are connected. The switches 23 include a brake switch that is turned on when a brake is operated, a vehicle speed setting switch for setting a constant speed in the case of constant speed traveling control, and the like. The motor 21 is a wheel-in motor mounted in the hub of the rear wheel 8. The motor 21 is connected to a power module 26 including an inverter circuit for controlling output. The power module 26 includes the vehicle controller 1
8 may be incorporated.

The current signal of the motor 21 is input to the vehicle controller 18 via the power module 26. The motor 21 drives the vehicle via a transmission 27. The transmission 27 is automatically controlled by the vehicle controller 18 or manually controlled by the shift operation switch 15 (see FIG. 1). The shift operation switch 15 includes a shift switch 28, an upshift switch 29, and a downshift switch 30. The motor 21 is provided with an encoder 31 and the magnetic pole position signal is transmitted to the vehicle controller 18.
And the number of rotations of the motor is detected. Further, a motor temperature detection signal is input to the vehicle controller 18.

The vehicle is provided with a battery 32, which is discharged by an ON signal of the main switch 22 via a battery management controller 33 to drive the motor 21. The battery 32 can be charged by a vehicle-mounted or external charger 34. The battery 32 is provided with a cooling fan 35, which is controlled on / off by the vehicle controller 18.

FIG. 3 is a block diagram of the two-stage transmission.
(A) is a sectional view of the second speed gear, and (B) is an overall configuration diagram. The dog gear 37 is inserted into the second speed gear 38 by the actuator 36, and the speed is changed from the first speed to the second speed to drive at a high speed. The shift from the second gear to the first gear is performed by the actuator 3
By removing the dog gear 37 from the second speed gear 38 by 6, the rear wheel 8 is driven at a low speed via only the first speed gear 39.

FIG. 4 is a graph of a shift map. The horizontal axis shows the motor speed, and the vertical axis shows the throttle opening. Graph a
Indicates a shift from the second speed to the first speed, and a graph b indicates a shift from the first speed to the second speed. That is, the shift operation from the first speed to the second speed is automatically performed based on the map of graph b, and
The shift operation from the first speed to the first speed is automatically performed based on the map of the graph a.

FIG. 5 is a flowchart of a boost control operation of the electric vehicle acceleration control device according to the present invention.

Step S1: Using the throttle sensor,
Detect throttle opening. Step S2: A current command value for energizing the motor is calculated so that an output corresponding to the throttle opening is obtained.

Step S3: The vehicle speed is detected from a vehicle speed sensor or a motor encoder, and it is determined whether the vehicle speed is lower than a predetermined value. The boost control (step S7) is performed when the vehicle speed is lower than the predetermined value and the other conditions (steps S4 to S7) are satisfied. This is because during high-speed operation, the current supplied to the motor increases and approaches the maximum current, so that a large acceleration output cannot be obtained even if the current region of the margin is used.

Step S4: A change in the throttle opening is detected to determine whether or not the vehicle is accelerating. If the change in the throttle opening is equal to or more than a predetermined amount, that is, if the throttle is opened at a high speed, it is determined that the vehicle is accelerating, and if other conditions are satisfied, the boost control is performed.

Step S5: The motor rotation speed is detected, and when the rotation speed is less than a predetermined value, such as when starting or running at low speed, boost control is performed if other conditions are satisfied.

Step S6: The torque of the motor is detected by the torque sensor, and it is determined whether the torque is equal to or more than a predetermined value. If the other conditions are satisfied when the torque is equal to or more than the predetermined value, boost control is performed so that a sufficient acceleration output is obtained.

Step S7: It is determined whether a short boost time (for example, 1 to 2 seconds) necessary for acceleration has elapsed. If the boost time has not elapsed, the boost control is continued until the boost time elapses.

Step S8: A boost current corresponding to the acceleration state is added to the current command value to the motor corresponding to the throttle opening. At this time, the current value supplied to the motor may be a current value exceeding the maximum current value. In this way, the program of the vehicle controller or the like is set so that a current exceeding the maximum current value is supplied. Thereby, the output of the motor is improved and sufficient acceleration performance is obtained.

Step S9: The motor is driven and controlled with a current equal to or less than the normal maximum current value. In the above flow, the vehicle speed is determined (step S3), the throttle opening change is determined (step S4), and the motor speed is determined (step S3).
It is not necessary to perform all of 5) and the torque determination (step S6), and any one or any two or three may be performed in combination.

FIG. 6 is a graph of the rear wheel driving force characteristics. The horizontal axis indicates the vehicle speed, and the vertical axis indicates the rear wheel driving force. Graph a shows the characteristics at the first speed, graph b shows the characteristics at the second speed, and graph c shows the characteristics when the acceleration control of the present invention is performed. According to the acceleration control of the present invention, the driving force in the low speed region at the first speed is improved.

FIG. 7 is a graph of arrival time against distance. Graph a is a graph when acceleration control is not performed, and graph b is a graph when acceleration control is performed. The arrival time is shortened by performing the acceleration control.

[0035]

As described above, according to the present invention, a current exceeding the maximum current value is supplied for a predetermined short time during acceleration to prevent the motor performance from deteriorating. Output can be secured by effectively utilizing the output of the motor, and the output can be reduced without using a high-power motor to secure the output required only for acceleration.
Sufficient acceleration performance can be obtained at low cost, and wobble during acceleration can be eliminated, and a stable running state can always be maintained.

[Brief description of the drawings]

FIG. 1 is an external view of an electric scooter according to the present invention.

FIG. 2 is a configuration diagram of a vehicle control device including an acceleration control device according to the present invention.

FIG. 3 is a configuration diagram of a transmission mechanism according to the present invention.

FIG. 4 is a diagram showing an example of a shift map.

FIG. 5 is a flowchart showing the operation of the acceleration control device according to the present invention.

FIG. 6 is a graph of rear wheel driving force characteristics.

FIG. 7 is a graph showing arrival time against distance.

[Explanation of symbols]

1: Electric scooter, 2: Main frame, 3: Head pipe, 4: Front fork, 5: Front wheel, 6: Swing arm, 7: Swing pivot, 8: Rear wheel, 9: Wheel motor unit, 10: Suspension pivot, 1
1: Shock absorber, 12: Drive unit, 13:
Axle, 14: steering wheel, 15: shift operation switch, 1
6: vehicle speed sensor, 17: battery, 18: vehicle controller, 19: seat, 20: speedometer, 21: motor, 22: main switch, 23: switches, 2
4: throttle, 25: torque sensor, 26: power module, 27: transmission, 28: transmission changeover switch,
29: shift up switch, 30: shift down switch, 31: encoder, 32: battery, 33: battery management controller, 34: charger, 35: cooling fan, 36: actuator, 37: dog gear, 38:
2nd gear, 39: 1 gear.

Claims (5)

[Claims] 1. An acceleration control device for an electric vehicle, comprising: a motor, a vehicle controller, and a battery, wherein the motor has a maximum current value during traveling set, wherein the vehicle controller has an acceleration state identification means. An acceleration control device for an electric vehicle, comprising: performing boost control for supplying a current larger than the maximum current value for a predetermined time when an acceleration state is identified. 2. An acceleration control device for an electric vehicle according to claim 1, wherein said acceleration state discriminating means includes a vehicle speed detecting means, and performs said boost control at the time of acceleration at or below a predetermined speed. 3. The boosting control device according to claim 1, wherein the acceleration state discriminating means includes a throttle opening degree detecting means, and performs the boost control when a change amount of the throttle opening degree is equal to or more than a predetermined value. Electric vehicle acceleration control device. 4. The apparatus according to claim 1, wherein said acceleration state discriminating means includes a motor speed detecting means, and performs said boost control at the time of acceleration at a predetermined motor speed or less.
4. The acceleration control device for an electric vehicle according to 2 or 3. 5. The electric motor according to claim 1, wherein said acceleration state discriminating means includes a torque detecting means, and performs said boost control at the time of acceleration at a predetermined torque or more. Vehicle acceleration control device.