Electric vehicle

• US 20050087373A1
• Filed: 09/24/2004
• Published: 04/28/2005
• Est. Priority Date: 10/28/2003
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Shimizu, Norikazu, Kawakami, Toshiaki, Wakitani, Tsutomu
• Granted Patent: US 7,267,188 B2
• Time in Patent Office: Days
• US Class Current: 180/6.500
• CPC Class Codes: B62D 11/003 Electric or electronic control systems
• CPC Class Codes: B62D 11/04 by means of separate power sources
• CPC Class Codes: B62D 51/001 characterised by the vehicle control device mechanical features of control devices in general G05G; arrangements of vehicle control devices in general B60K20/00, B60K23/00, B60K26/00
• CPC Class Codes: B62D 55/06 with tracks without ground wheels
• CPC Class Codes: E01H 5/04 Apparatus propelled by animal or engine power; Apparatus propelled by hand with driven dislodging or conveying levelling elements, conveying pneumatically for the dislodged materialE01H5/10, E01H5/12 take precedence

Abstract

An electric vehicle includes left and right electric motors for separately driving left and right traveling apparatuses, respectively, and a control unit for controlling the left and right electric motors, separately. When operation of the electric vehicle is switched from a turning mode to a straight-traveling mode if one of the electric motors disposed on the same side as a turning direction of the electric vehicle has a speed not exceeding a predetermined minimum reference speed, the control unit abruptly increases a level of an accelerating control signal for a temporary time from the switching of operation to abruptly accelerate the one electric motor, such that the speed of the one electric motor can be made close to that of the opposite electric motor in a shorter time.

Claims

1. An electric vehicle comprising:

a vehicle body;

left and right crawler belts disposed leftward and rightward of the vehicle body, respectively;

left and right electric motors for driving the left and right crawler belts, respectively;

a control unit for controlling the left and right electric motors, separately;

the control unit having;

a turning-side electric motor decelerating control function of, when the electric vehicle turns either leftward or rightward, performing deceleration control to decelerate one of the left and right electric motors disposed on the same side as a turning direction of the electric vehicle; and

a turning-side electric motor accelerating control function of outputting an accelerating control signal for performing acceleration control to accelerate said one electric motor when operation of the electric vehicle is switched from a turning mode to a straight-traveling mode,

wherein when said one electric motor has a speed not exceeding a predetermined minimum reference speed at the time of the switching of the operation of the electric vehicle from the turning mode to the straight-traveling mode, the turning-side electric motor accelerating control function performs the acceleration control such that a level of the accelerating control signal is increased abruptly for a temporary time from the switching of the operation of the electric vehicle from the turning mode to the straight-traveling mode.

2. An electric vehicle according to claim 1, wherein the level of the accelerating control signal is abruptly increased for the temporary time such that the speed of said one electric motor is increased substantially by 35%.

3. An electric vehicle according to claim 1, wherein the turning-side electric motor accelerating control function performs the acceleration control by using an acceleration correction map represented by an acceleration correction coefficient versus time characteristic curve including a pulse-like raised portion having a starting point coincided with the time of the switching of the operation of the electric vehicle from the turning mode to the straight-traveling mode, a peak point and an end point, the acceleration correction coefficient increasing from the starting point to the peak point and decreasing from the peak point to the end point, the acceleration correction coefficient at the end point being larger than at the starting point.

4. An electric vehicle according to claim 3, wherein the acceleration correction coefficient at the peak point is set such that the speed of said one electric motor is increased substantially by 35%.

5. An electric vehicle according to claim 3, wherein the pulse-like raised portion is triangular.

6. An electric vehicle comprising:

a vehicle body;

left and right traveling apparatuses disposed leftward and rightward of the vehicle body, respectively;

left and right electric motors for driving the left and right traveling apparatuses, respectively;

a control unit for controlling the left and right electric motors, separately;

the control unit having;

a turning-side electric motor decelerating control function of, when the electric vehicle turns either leftward or rightward, performing deceleration control to decelerate one of the left and right electric motors disposed on the same side as a turning direction of the electric vehicle; and

a turning-side electric motor accelerating control function of outputting an accelerating control signal for performing acceleration control to accelerate said one electric motor when operation of the electric vehicle is switched from a turning mode to a straight-traveling mode,

wherein when said one electric motor has a speed not exceeding a predetermined minimum reference speed at the time of the switching of the operation of the electric vehicle from the turning mode to the straight-traveling mode, the turning-side electric motor accelerating control function performs the acceleration control such that a level of the accelerating control signal is increased abruptly for a temporary time from the switching of the operation of the electric vehicle from the turning mode to the straight-traveling mode.

7. An electric vehicle according to claim 6, wherein each of the traveling apparatuses comprises a crawler belt.

8. An electric vehicle according to claim 6, wherein the level of the accelerating control signal is abruptly increased for the temporary time such that the speed of said one electric motor is increased substantially by 35%.

9. An electric vehicle according to claim 6, wherein the turning-side electric motor accelerating control function performs the acceleration control by using an acceleration correction map represented by an acceleration correction coefficient versus time characteristic curve including a pulse-like raised portion having a starting point coincided with the time of the switching of the operation of the electric vehicle from the turning mode to the straight-traveling mode, a peak point and an end point, the acceleration correction coefficient increasing from the starting point to the peak point and decreasing from the peak point to the end point, the acceleration correction coefficient at the end point being larger than at the starting point.

10. An electric vehicle according to claim 9, wherein the acceleration correction coefficient at the peak point is set such that the speed of said one electric motor is increased substantially by 35%.

11. An electric vehicle according to claim 9, the pulse-like raised portion is triangular.