Control system for hybrid vehicle

• US 6,124,690 A
• Filed: 02/01/1999
• Issued: 09/26/2000
• Est. Priority Date: 02/03/1998
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Yano, Toru, Tamagawa, Yutaka, Tatara, Yusuke
• Primary Examiner(s): Ro, Bentsu
• Application Number:
  US09/240,586
• Time in Patent Office: 603 Days
• Field of Search: 318/139, 318/375, 318/376, 180/65.1-65.4, 180/65.6, 180/65.7, 180/65.8, 320/2, 320/5, 320/61, 701/22
• US Class Current: 318/376
• CPC Class Codes: B60K 6/28 characterised by the electric energy storing means, e.g. batteries or capacitors
• CPC Class Codes: B60K 6/485 Motor-assist type
• CPC Class Codes: B60K 6/54 Transmission for changing ratio
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 15/2054 by controlling transmissions or clutches
• CPC Class Codes: B60L 50/15 with additional electric power supply with capacitors charged by engine-driven generators B60L50/40; with batteries charged by engine-driven generators B60L50/61
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 7/10 Dynamic electric regenerative braking B60L7/22 takes precedence
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• 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 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60Y 2400/114 Super-capacities
• 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 903/903 having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/907 Electricity storage, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/917 : with transmission for changing gear ratio
• CPC Class Codes: Y10S 903/947 : Characterized by control of braking, e.g. blending of regeneration, friction braking

Abstract

A control system controls a hybrid vehicle having an engine for rotating a drive axle, an electric motor for assisting the engine in rotating the drive axle with electric energy and converting kinetic energy of the drive axle into electric energy, and an electric energy storage unit or a capacitor for supplying electric energy to the electric motor and storing electric energy outputted by the electric motor. When the remaining capacity CAPAremc of the capacitor is smaller than a first predetermined remaining capacity REMC1 or the remaining capacity CAPAremc of the capacitor is smaller than a second predetermined remaining capacity REMC2 (>REMC1) and an assistive-mode integrated discharged value DISCHG of the capacitor 14, which is calculated while the electric motor has operated in a latest mode to assist in running the hybrid vehicle, is greater than a predetermined discharged quantity disch1, the control system calculates a regenerated quantity increasing corrective coefficient Kregup (>1) depending on the vehicle speed. The control system multiplies a basic decelerating regenerative quantity DECreg by the corrective coefficient Kregup to determine a demand output power MOTORpower for the electric motor for thereby increasing the amount of electric energy regenerated by the electric motor when the hybrid vehicle decelerates.

Claims

1. A control system for controlling a hybrid vehicle having an engine for rotating a drive axle, an electric motor for assisting the engine in rotating the drive axle with electric energy and converting kinetic energy of the drive axle into electric energy, and electric energy storage means for supplying electric energy to the electric motor and storing electric energy outputted by the electric motor, comprising:

remaining capacity detecting means for detecting a remaining capacity of the electric energy storage means; and

decelerating regenerative control means for establishing an amount of electric energy to be regenerated by said electric motor when the hybrid vehicle decelerates depending on at least a vehicle speed of the hybrid vehicle, and causing said electric motor to regenerate the established amount of electric energy;

said decelerating regenerative control means comprises means for correcting said amount of electric energy to be regenerated by said electric motor depending on the remaining capacity of the electric energy storage means as detected by said remaining capacity detecting means and means for establishing said amount of electric energy to be regenerated by said electric motor such that said amount of electric energy to be regenerated by said electric motor, prior to being corrected depending on the remaining capacity of the electric energy storage means as detected by said remaining capacity detecting means, increases as said vehicle speed is higher.

2. A control system for controlling a hybrid vehicle having an engine for rotating a drive axle, an electric motor for assisting the engine in rotating the drive axle with electric energy and converting kinetic energy of the drive axle into electric energy, and electric energy storage means for supplying electric energy to the electric motor and storing electric energy outputted by the electric motor, comprising:

remaining capacity detecting means for detecting a remaining capacity of the electric energy storage means; and

decelerating regenerative control means for establishing an amount of electric energy to be regenerated by said electric motor when the hybrid vehicle decelerates depending on at least a vehicle speed of the hybrid vehicle, and causing said electric motor to regenerate the established amount of electric energy;

said decelerating regenerative control means comprises means for correcting said amount of electric energy to be regenerated by said electric motor depending on the remaining capacity of the electric energy storage means as detected by said remaining capacity detecting means and means for establishing said amount of electric energy to be regenerated by said electric motor, prior to being corrected depending on the remaining capacity of the electric energy storage means as detected by said remaining capacity detecting means, depending on said vehicle speed and a rotational speed of said engine or said electric motor.

3. The control system according to claim 2 wherein said decelerating regenerative control means further comprises:

means for establishing said amount of electric energy to be regenerated by said electric motor such that said amount of electric energy to be regenerated by said electric motor, prior to being corrected depending on the remaining capacity of the electric energy storage means as detected by said remaining capacity detecting means, increases as said vehicle speed is higher, and increases as the rotational speed of said engine or said electric motor is higher.

4. The control system according to claim 2 wherein said electric energy storage means comprises an electric double-layer capacitor.

5. A control system for controlling a hybrid vehicle having an engine for rotating a drive axle, an electric motor for assisting the engine in rotating the drive axle with electric energy and converting kinetic energy of the drive axle into electric energy, and electric energy storage means for supplying electric energy to the electric motor and storing electric energy outputted by the electric motor, comprising:

remaining capacity detecting means for detecting a remaining capacity of the electric energy storage means; and

decelerating regenerative control means for establishing an amount of electric energy to be regenerated by said electric motor when the hybrid vehicle decelerates depending on at least a vehicle speed of the hybrid vehicle, and causing said electric motor to regenerate the established amount of electric energy;

said decelerating regenerative control means comprises means for correcting said amount of electric energy to be regenerated by said electric motor depending on the remaining capacity of the electric energy storage means as detected by said remaining capacity detecting means and means for increasing said amount of electric energy to be regenerated by said electric motor if the remaining capacity of the electric energy storage means as detected by said remaining capacity detecting means is smaller than a first predetermined remaining capacity.

6. The control system according to claim 5, wherein a first predetermined remaining capacity is established on the basis of driving efficiency characteristics of the electric motor with respect to remaining capacity of the electric energy storage means when the electric motor operates to assist in running the hybrid vehicle.

7. The control system according to claim 6, further comprising:

discharged quantity integrating means for integrating a discharged quantity of said electric energy storage means each time and while the electric motor operates to assist in running the hybrid vehicle;

said decelerating regenerative control means comprising means for increasing said amount of electric energy to be regenerated by said electric motor if the remaining capacity of the electric energy storage means as detected by said remaining capacity detecting means is smaller than a second predetermined remaining capacity which is greater than said first predetermined remaining capacity and if an integrated value of the discharged quantity of said electric energy storage means, which is integrated by said discharged quantity integrating means while the electric motor has operated in a latest mode to assist in running the hybrid vehicle before the hybrid vehicle decelerates, is greater than a predetermined value.

8. The control system according to claim 7, further comprising:

voltage lowering means for converting an output voltage of said electric energy storage means into a lower voltage;

said electric energy storage means being connected through said voltage lowering means to electric components on the hybrid vehicle for supplying electric energy to said electric components, said second predetermined remaining capacity being established on the basis of operating efficiency characteristics of said voltage lowering means.

9. The control system according to claim 5 or 7, wherein said decelerating regenerative control means further comprises:

means for establishing a quantity by which to increase said amount of electric energy to be regenerated by said electric motor, depending on said vehicle speed.

10. The control system according to claim 9, wherein said decelerating regenerative control means further comprises:

means for establishing said quantity such that said quantity increases as said vehicle speed is higher.

11. A control system for controlling a hybrid vehicle having an engine for rotating a drive axle, an electric motor for assisting the engine in rotating the drive axle with electric energy and converting kinetic energy of the drive axle into electric energy, and electric energy storage means for supplying electric energy to the electric motor and storing electric energy outputted by the electric motor, comprising:

remaining capacity detecting means for detecting a remaining capacity of the electric energy storage means; and

decelerating regenerative control means for establishing an amount of electric energy to be regenerated by said electric motor when the hybrid vehicle decelerates depending on at least a vehicle speed of the hybrid vehicle, and causing said electric motor to regenerate the established amount of electric energy;

said decelerating regenerative control means comprises means for correcting said amount of electric energy to be regenerated by said electric motor depending on the remaining capacity of the electric energy storage means as detected by said remaining capacity detecting means, means for determining a demand drive power for the hybrid vehicle depending on an accelerator pedal operation of the hybrid vehicle, means for determining a running resistance of the hybrid vehicle depending on said vehicle speed, and means for deciding whether the hybrid vehicle is decelerating or not based on the determined demand drive power and the determined running resistance.

12. A control system for controlling a hybrid vehicle having an engine for rotating a drive axle, an electric motor for assisting the engine in rotating the drive axle with electric energy and converting kinetic energy of the drive axle into electric energy, and electric energy storage means for supplying electric energy to the electric motor and storing electric energy outputted by the electric motor, comprising:

remaining capacity detecting means for detecting a remaining capacity of the electric energy storage means; and

decelerating regenerative control means for establishing an amount of electric energy to be regenerated by said electric motor when the hybrid vehicle decelerates depending on at least a vehicle speed of the hybrid vehicle, and causing said electric motor to regenerate the established amount of electric energy;

said decelerating regenerative control means comprises means for correcting said amount of electric energy to be regenerated by said electric motor depending on the remaining capacity of the electric energy storage means as detected by said remaining capacity detecting means and means for increasing an output power of the engine when said decelerating regenerative control means increases said amount of electric energy to be regenerated by said electric motor.