CONTROL APPARATUS FOR ELECTRIC VEHICLE

• US 20100049414A1
• Filed: 07/21/2009
• Published: 02/25/2010
• Est. Priority Date: 08/22/2008
• Status: Abandoned Application

• Current Assignee: Fuji Heavy Industries Limited (Subaru Corp.)
• Original Assignee: Fuji Heavy Industries Limited (Subaru Corp.)
• Inventors: Ohtomo, Yosuke, Seta, Itaru
• Application Number:
  US12/506,407
• Publication Number:
  US 20100049414A1
• Time in Patent Office: Days
• US Class Current: 701/70
• CPC Class Codes: B60L 15/2063 for creeping
• CPC Class Codes: B60L 3/08 Means for preventing excessive speed of the vehicle
• CPC Class Codes: B60L 7/18 Controlling the braking effect B60L7/12, B60L7/14, B60L7/16 take precedence
• CPC Class Codes: B60T 1/10 by utilising wheel movement for accumulating energy, e.g. driving air compressors
• CPC Class Codes: B60T 13/586 the retarders being of the electric type
• CPC Class Codes: B60T 17/221 Procedure or apparatus for checking or keeping in a correct functioning condition of brake systems hydraulic pressure systems in general F15B19/00, F15B21/04; testing structures or apparatus G01M
• CPC Class Codes: B60T 7/042 by electrical means, e.g. using travel or force sensors
• CPC Class Codes: B60T 8/3205 acceleration B60T8/34, B60T8/52, B60T8/54, B60T8/56, B60T8/58, B60T8/72, B60T8/86, B60T8/88 take precedence
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2530/10 Weight
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 30/18063 Creeping
• CPC Class Codes: B60W 50/038 Limiting the input power, torque or speed
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

The present invention provides a control apparatus for an electric vehicle which improves safety in an electric vehicle capable of traveling using creep torque. The electric vehicle includes a motor/generator for driving vehicle wheels. In a low vehicle speed region during startup or the like, creep torque is output from the motor/generator even when an accelerator pedal has not been operated, and therefore the electric vehicle can be started gently. The electric vehicle is also provided with a friction brake system for applying vehicle braking through frictional force. When an EV control unit for setting a target creep torque of the motor/generator determines that an abnormality has occurred in the friction brake system (step S20), the target creep torque is set lower than normal (step S30). Therefore, when an abnormality that may cause a reduction in a braking force occurs in the friction brake system, a propulsive force of the electric vehicle can be reduced, and as a result, the safety of the electric vehicle can be improved.

Claims

1. A control apparatus for an electric vehicle having an electric motor for driving vehicle wheels, comprising:

torque setting means for setting a target creep torque of said electric motor on the basis of a vehicle condition;

motor control means for drive-controlling said electric motor on the basis of said target creep torque;

brake abnormality detecting means for detecting an abnormality in a brake system for applying vehicle braking; and

torque reducing means for lowering said target creep torque when said abnormality occurs in said brake system.

2. The control apparatus for an electric vehicle according to claim 1, further comprising weight estimating means for estimating a vehicle weight,

wherein said torque reducing means lowers said target creep torque by a steadily larger amount as said estimated vehicle weight increases.

3. The control apparatus for an electric vehicle according to claim 1, further comprising information means for informing a passenger of said abnormality in said brake system.