Control device for a hybrid electric vehicle

• US 7,823,668 B2
• Filed: 03/20/2007
• Issued: 11/02/2010
• Est. Priority Date: 03/20/2006
• Status: Expired due to Fees

• Current Assignee: Mitsubishi FUSO Truck & Bus Corporation (Daimler Truck Holding AG)
• Original Assignee: Mitsubishi FUSO Truck & Bus Corporation (Daimler Truck Holding AG)
• Inventors: Kiuchi, Tatsuo, Ogata, Makoto, Sakata, Kunio
• Primary Examiner(s): Vanaman; Frank B
• Assistant Examiner(s): Chibogu; Chiedu A
• Application Number:
  US11/723,476
• Publication Number:
  US 20070215395A1
• Time in Patent Office: 1,323 Days
• Field of Search: 180/65.265, 180/65.27, 180/65.275, 180/65.285, 903/930, 903/947, 701/48, 701/70
• US Class Current: 180/65.265
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60L 2250/10 by alarm
• CPC Class Codes: B60L 2250/26 by pedal actuation
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/40 Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: B60W 2510/18 Braking system
• CPC Class Codes: B60W 2710/08 Electric propulsion units
• CPC Class Codes: F02N 11/006 : using a plurality of electric motors
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y10S 903/947 : Characterized by control of braking, e.g. blending of regeneration, friction braking

Abstract

A hybrid electric vehicle is arranged such that a driving force of an electric motor can be transmitted to driving wheels and that a rotary shaft of the electric motor can be coupled with an output shaft of an engine. The vehicle comprises a starter motor provided separately from the electric motor, an electric power source provided separately from a battery that supplies power to the electric motor, to supply power to the starter motor, and a braking force maintaining device configured to be activated by power from the power source to maintain a braking force on the vehicle. When a request for starting the engine is made, if a specified abnormal condition which makes the starting of the engine by the electric motor impracticable is detected, an ECU causes the engine to be started by the starter motor when the braking force maintaining device is not active.

Claims

1. A control device for a hybrid electric vehicle arranged such that a driving force of an electric motor is transmitted to driving wheels and that a rotary shaft of the electric motor is coupled with an output shaft of an engine, comprising:

a starter motor provided separately from the electric motor to start the engine by transmitting a starter motor driving force to the output shaft of the engine;

a battery that supplies electric power to the electric motor;

an electric power source provided separately from the battery to supply electric power to the starter motor;

a braking force maintaining unit that is activated by the electric power from the electric power source to maintain a braking force on the vehicle;

an abnormality detection unit for detecting a specified abnormal condition which makes the starting of the engine by the electric motor impracticable; and

a control unit which, in a case where a request for starting the engine is made, if the abnormality detection unit does not detect the abnormal condition, causes the engine to be started by the electric motor, and if the abnormality detection unit detects the abnormal condition, causes the engine to be started by the starter motor when the braking force maintaining unit is not active,

wherein when a request for starting the engine is made, if the abnormality detection unit detects the abnormal condition and if the braking force maintaining unit is active, the control unit suspends the starting of the engine by the starter motor until the braking force maintaining unit is deactivated, and thereafter causes the engine to be started by the starter motor.

2. The control device for a hybrid electric vehicle according to claim 1, further comprising

a parking brake that is operated by a driver of the vehicle to produce a braking force on the vehicle, wherein

when a request for starting the engine is made, if the abnormality detection unit detects the abnormal condition and if the braking force maintaining unit is active, the control unit suspends the starting of the engine by the starter motor until the parking brake is operated to produce a braking force on the vehicle and thereby the braking force maintaining unit is deactivated.

3. The control device for a hybrid electric vehicle according to claim 1, further comprising

a brake pedal that is depressed by a driver of the vehicle to produce a braking force on the vehicle, wherein

when a request for starting the engine is made, if the abnormality detection unit detects the abnormal condition and if the braking force maintaining unit is active, the control unit suspends the starting of the engine by the starter motor until the brake pedal is depressed and thereby the braking force maintaining unit is deactivated.

4. The control device for a hybrid electric vehicle according to claim 1, further comprising

a warning unit for giving a warning, if the abnormality detection unit detects the abnormal condition and if the braking force maintaining unit is active when a request for starting the engine is made.