Hybrid vehicle control system and control method

• US 20030094816A1
• Filed: 11/04/2002
• Published: 05/22/2003
• Est. Priority Date: 03/06/2001
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Kazama, Isamu
• Granted Patent: US 6,891,279 B2
• Time in Patent Office: Days
• US Class Current: 290/40.00C
• CPC Class Codes: B60K 6/32 characterised by the fuel cells
• 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 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/30 using propulsion power stored mechanically, e.g. in fly-wheels
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/40 for controlling a combination of batteries and fuel cells
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/24 including control of energy storage means
• 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 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2710/081 : Speed
• CPC Class Codes: B60W 2710/083 : Torque
• CPC Class Codes: B60W 2710/242 : for electrical energy
• CPC Class Codes: Y02T 10/40 : Engine management systems
• 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: Y02T 90/40 : Application of hydrogen technology to transportation, e.g. using fuel cells
• CPC Class Codes: Y10S 903/908 : Fuel cell

Abstract

A control system for a vehicle, having drive sections (104, 107, 109), a power supply section (101, 103, 107, 109) including an electric power storage unit to supply power to the drive section, includes a demanded power calculating section (1) calculating a demanded drive power required for driving the vehicle, an allowable drive electric power output calculating section (2) calculating allowable drive electric power output of the electric power storage unit necessary for compensating a delayed response of the power supply section with respect to a variation in the demanded power, an available electric power output calculating section (3) calculating available electric power output of the electric power storage unit on the basis of a stage of charge of the electric power storage unit, and a target power calculating unit (4, 7, 9) calculating target power to be produced by the power supply section on the basis of the demanded drive power, allowable drive electric power output and available electric power output.

Claims

1. A control system for a vehicle having an electric power generator, an electric power storage unit, a drive motor driven by electric power supplied from at least one of the electric power generator and the electric power storage unit, and drive wheels driven by drive power supplied from the drive motor, the control system comprising:

a demanded drive power calculating section calculating a demanded drive power required for driving the vehicle;

an allowable drive electric power output calculating section calculating allowable drive electric power output of the electric power storage unit required for compensating a delayed response of the electric power generator with respect to a variation in the demanded drive power;

an available electric power output calculating section calculating available electric power output of the electric power storage unit to be outputted on the basis of a state of charge of the electric power storage unit, the available electric power output being electric power outputable from the electric power storage unit; and

a target electric power output calculating section calculating to be produced from the electric power generator on the basis of the demanded drive power, the allowable drive electric power output of the electric power storage unit and the available electric power output of the electric power storage unit,

wherein the control system controls the electric power storage unit on the basis of the allowable drive electric power output and the available electric power output, and the electric power generator on the basis of the target electric power output so as to control the vehicle correspondingly to the demanded drive power.

2. A control system according to claim 1, wherein the target electric power output calculating section determines the target electric power by subtracting a value, obtained by subtracting the allowable drive electric power output of the electric power storage unit from the available electric power output of the electric power storage unit, from demanded drive electric power of the drive motor corresponding to the demanded drive power when the state of charge of the electric power storage unit is equal to or greater than a given value and the available electric power output of the electric power storage unit is equal to or greater than the allowable drive electric power output of the electric power storage unit.

3. A control system according to claim 1, wherein the target electric power output calculating section determines the target electric power output to be demanded drive electric power of the drive motor corresponding to the demanded drive power when the available electric power output of the electric power storage unit is less than the allowable drive electric power output of the electric power storage unit.

4. A control system according to claim 1, further comprising an accessory-unit electric power consumption calculating section determining accessory-unit electric power consumption of accessory units of the vehicle;

wherein the target electric power output calculating section determines the target electric power output by subtracting a value, obtained by subtracting the allowable drive electric power output of the electric power storage unit from the available electric power output of the electric power storage unit, from a value obtained by adding the accessory-unit electric power consumption to demanded drive electric power of the drive motor corresponding to the demanded drive power when the state of charge of the electric power storage unit is equal to or greater than a given value and the available electric power output of the electric power storage unit is equal to or greater than the allowable drive electric power output of the electric power storage unit.

5. A control system according to claim 1, further comprising an accessory-unit electric power consumption calculating section determining accessory-unit electric power consumption of accessory units of the vehicle;

wherein the target electric power output calculating section determines the target electric power output to be a value obtained by adding the accessory-unit electric power consumption to a demanded drive electric power of the drive motor corresponding to the demanded drive power when the available electric power output of the electric power storage unit is less than the allowable drive electric power output of the electric power storage unit.

6. A control system according to claim 1, wherein the allowable drive electric power output calculating section calculates the allowable drive electric power output of the electric power storage unit on the basis of at least one of a vehicle speed and the demanded drive power.

7. A control system according to claim 6, wherein the allowable drive electric power output calculating section selects a small one of first allowable drive electric power output of the electric power storage unit determined on the basis of the vehicle speed and a second allowable drive electric power output of the electric power storage unit determined on the basis of the demanded drive power.

8. A control system according to claim 1, wherein the electric power generator is stopped in operation when demanded drive electric power of the drive motor corresponding to the demanded drive power is less than a value obtained by subtracting the allowable drive electric power output of the electric power storage unit, which is attained during a stop condition of the electric power generator, from the available electric power output of the electric power storage unit.

9. A control system according to claim 1, wherein the electric power generator is driven by use of a fuel cell or the engine.

10. A control system for a vehicle having an electric power generator, an electric power storage unit, a drive motor driven by electric power supplied from at least one of the electric power generator and the electric power storage unit, and drive wheels driven by drive power supplied from at least one of the engine and the drive motor the drive motor, the control system comprising:

a demanded drive power calculating section calculating a demanded drive power required for driving the vehicle;

an allowable drive electric power output calculating section calculating allowable drive electric power output of the electric power storage unit required for compensating a delayed response of the electric power generator with respect to a variation in the demanded drive power;

an available electric power output calculating section calculating available electric power output of the electric power storage unit to be outputted on the basis of a state of charge of the electric power storage unit, the available electric power output being electric power outputable from the electric power storage unit;

a target engine power calculating section calculating a target engine power of the engine on the basis of the demanded drive power, the allowable drive electric power output of the electric power storage unit and the available electric power output of the electric power storage unit;

a real engine power calculating section calculating a real power of the engine;

a demanded motor drive electric power calculating section calculating demanded motor drive electric power to be supplied to the drive motor on the basis of the demanded power and the real engine power; and

a drive motor control section controlling the drive motor in accordance with the demanded motor drive electric power,

wherein the control system controls the electric power storage unit on the basis of the allowable drive electric power output and the available electric power output, the engine on the basis of the target engine power, and the drive motor on the basis of the demanded motor drive electric power so as to control the vehicle correspondingly to the demanded drive power.

11. A control system according to claim 10, wherein the target engine power calculating section determines the target engine power by subtracting a value, obtained by subtracting the allowable drive electric power output of the electric power storage unit from the available electric power output of the electric power storage unit, from the demanded drive power when the state of charge of the electric power storage unit is equal to or greater than a given value and the available electric power output of the electric power storage unit is equal to or greater than the allowable drive electric power output of the electric power storage unit.

12. A control system according to claim 10, wherein the target engine power calculating section determines the target engine power to be the demanded drive power when the available electric power output of the electric power storage unit is less than the allowable drive electric power output of the electric power storage unit.

13. A control system according to claim 10, wherein the demanded motor drive electric power calculating section determines the demanded motor drive electric power to be a value obtained by subtracting the real engine power from the demanded drive power.

14. A control system according to claim 10, further comprising an accessory-unit electric power consumption calculating section determining accessory-unit electric power consumption of accessory units of the vehicle;

wherein the target engine power calculating section determines the target engine power by subtracting a value, obtained by subtracting the allowable drive electric power output of the electric power storage unit from the available electric power output of the electric power storage unit, from a value obtained by adding the accessory-unit electric power consumption to the demanded drive power when the state of charge of the electric power storage unit is equal to or greater than a given value and the available electric power output of the electric power storage unit is equal to or greater than the allowable drive electric power output of the electric power storage unit.

15. A control system according to claim 10, further comprising an accessory-unit electric power consumption calculating section determining accessory-unit electric power consumption of accessory units of the vehicle;

wherein the target engine power calculating section determines the target engine power to be a value obtained by adding the accessory-unit electric power to the demanded drive power when the available electric power output of the electric power storage unit is less than the allowable drive electric power output of the electric power storage unit.

16. A control system according to claim 10, wherein the allowable drive electric power output calculating section calculates the allowable drive electric power output of the electric power storage unit on the basis of at least one of a vehicle speed and the demanded drive power.

17. A control system according to claim 16, wherein the allowable drive electric power output calculating section selects a small one of a first allowable drive electric power output of the electric power storage unit determined on the basis of the vehicle speed and a second allowable drive electric power output of the electric power storage unit determined on the basis of the demanded drive power.

18. A control system according to claim 10, wherein the engine is stopped in operation when the demanded drive power is less than a value obtained by subtracting the demanded drive electric power, which is attained during a stop condition of the engine, from the available electric power output of the electric power storage unit.

19. A control system for a vehicle having a driving means, and a power supplying means including an electric power storage unit and supplying power output to the driving means, the control system comprising:

demanded power calculating means for calculating a demanded drive power required for driving the vehicle;

allowable electric power output calculating means for calculating allowable electric power output of the electric power storage unit necessary for compensating a delayed response of the power supplying means with respect to a variation in the demanded drive power;

available electric power output calculating means for calculating available electric power output of the electric power storage unit on the basis of a state of charge of the electric power storage unit; and

target power output calculating means for calculating target power output to be produced by the power supplying means on the basis of the demanded drive power, the allowable electric power output and the available electric power output,

wherein the control system controls the vehicle correspondingly to the demanded drive power on the basis of the allowable drive electric power output, the available electric power output and the target power output.

20. A method of controlling a vehicle having a drive section, and a power supply section including an electric power storage unit and supplying power output to the drive section, the method comprising:

calculating a demanded drive power required for driving the vehicle;

calculating allowable electric power output of the electric power storage unit necessary for compensating a delayed response of the power supply section with respect to a variation in the demanded drive power;

calculating available electric power output of the electric power storage unit on the basis of a state of charge of the electric power storage unit; and

calculating target power output to be produced by the power supply section on the basis of the demanded drive power, the allowable electric power output and the available electric power output,

wherein the vehicle is controlled correspondingly to the demanded drive power on the basis of the allowable drive electric power output, the available electric power output and the target power output.