Vehicle-drive control system and method and program therefor

• US 20040255904A1
• Filed: 06/01/2004
• Published: 12/23/2004
• Est. Priority Date: 06/06/2003
• Status: Active Grant

• Current Assignee: Aisin AW Company Limited (Aisin Corp.)
• Original Assignee: Aisin AW Company Limited (Aisin Corp.)
• Inventors: Hisada, Hideki, Hasegawa, Kazuma, Izawa, Kazuyuki, Inagaki, Tomochika, Nomura, Masaki, Yamaguchi, Kozo, Okoshi, Toshio
• Granted Patent: US 7,228,209 B2
• Time in Patent Office: Days
• US Class Current: 123/352
• CPC Class Codes: B60K 6/445 Differential gearing distribution 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 15/2009 for braking
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/12 Speed
• 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 2240/425 Temperature
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 2260/26 Transition between different drive modes
• CPC Class Codes: B60L 2270/145 Structure borne vibrations
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 58/12 : responding to state of charge [SoC]
• CPC Class Codes: B60L 7/14 : for vehicles propelled by ac motors
• 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 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 2510/0685 : Engine crank angle
• CPC Class Codes: B60W 30/18018 : Start-stop drive, e.g. in a traffic jam
• CPC Class Codes: F02D 2041/0095 : Synchronisation of the cylinders during engine shutdown
• CPC Class Codes: F02D 2200/0404 : Throttle position
• CPC Class Codes: F02D 2200/501 : Vehicle speed
• CPC Class Codes: F02D 2250/26 : by applying a torque limit
• CPC Class Codes: F02D 41/009 : using means for generating position or synchronisation signals
• CPC Class Codes: F02D 41/042 : for stopping the engine
• CPC Class Codes: F02D 41/062 : for starting F02D41/061 takes precedence
• CPC Class Codes: F02N 11/04 : the motors being associated with current generators
• CPC Class Codes: F02N 11/0814 : comprising means for controlling automatic idle-start-stop
• CPC Class Codes: F02N 15/003 : Starters comprising a brake mechanism
• CPC Class Codes: F02N 19/005 : Aiding engine start by starting from a predetermined position, e.g. pre-positioning or reverse rotation
• CPC Class Codes: F02N 2019/008 : the engine being stopped in a particular position
• 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

Abstract

The invention includes a target-engine-speed acquisition element that acquires a target engine speed necessary to reduce engine speed, thereby stopping the engine at a target stop position; a crank-angle acquisition element that acquires a crank angle indicative of the position of a crankshaft; and a target-engine-speed correction element that corrects the target engine speed according to the acquired crank angle. Because the target engine speed is corrected according to the crank angle, the engine can be stopped at the target stop position even if the friction in the engine, the electric motor, etc. varies, the temperature or viscosity of the lubricating and cooling oils varies, or the vehicle is accelerated or decelerated during the reduction of the engine speed.

Claims

1. A vehicle-drive control system, comprising:

target-engine-speed acquisition means for acquiring a target engine speed necessary to reduce engine speed, thereby stopping an engine at a target stop position;

crank-angle acquisition means for acquiring a crank angle indicative of the position of a crankshaft; and

target-engine-speed correction means for correcting a target engine speed according to the acquired crank angle.

2. The vehicle-drive control system according to claim 1, further comprising crank-angle-deviation calculation means for calculating a deviation of the crank angle from a reduction-start reference position serving as the reference to start the reduction of the engine speed according to the acquired crank angle, wherein the target-engine-speed correction means corrects the target engine speed according to the deviation of the crank angle.

3. The vehicle-drive control system according to claim 1, further comprising a target deviation map in which a target deviation is set which is indicative of a deviation used as a target of the crank angle from the reduction-start reference position, wherein the target-engine-speed correction means corrects the target engine speed according to a deviation between the target deviation and the calculated crank-angle deviation.

4. The vehicle-drive control system according to claim 3, further comprising target-engine-speed correction-value calculation means for calculating a correction value of the target engine speed from the deviation, wherein the target-engine-speed correction means corrects the target engine speed according to the correction value.

5. The vehicle-drive control system according to claim 1, further comprising:

stroke calculation means for calculating a stroke to the target stop position from the acquired crank angle; and

rate-of-change calculation means for calculating a rate of change in target engine speed from the stroke, wherein the target-engine-speed correction means corrects the target engine speed according to the rate of change.

6. The vehicle-drive control system according to claim 5, wherein the stroke calculation means calculates a total stroke from a reduction start position to the target stop position based on a reduction start position at a start of the reduction of the engine speed and the target stop position, and calculates the stroke to the target stop position based on the total stroke and the acquired crank angle, wherein the rate-of-change calculation means calculates the rate of change in target engine speed from the stroke and the target engine speed.

7. The vehicle-drive control system according to claim 6, further comprising crank-angle-deviation calculation means for calculating a deviation of the crank angle from the reduction start position according to the acquired crank angle, wherein the stroke calculation means calculates the stroke to the target stop position from the total stroke and the calculated crank-angle deviation.

8. The vehicle-drive control system according to claim 1, wherein the target-engine-speed correction means corrects the target engine speed every correction switch timing.

9. The vehicle-drive control system according to claim 2, wherein the deviation of the crank angle is an integrated value of the crank angles from the start of a reduction of the engine speed.

10. The vehicle-drive control system according to claim 1, wherein the target-engine-speed correction means reduces the engine speed by controlling an electric motor mechanically joined to the engine.

11. The vehicle-drive control system according to claim 10, further comprising:

target-electric-motor-speed calculation means for calculating a target electric-motor speed from a corrected target engine speed; and

electric-motor-speed control means for calculating a target electric-motor torque from the target electric-motor speed to control a torque of an electric motor.

12. The vehicle-drive control system according to claim 11, wherein the engine and the electric motor are joined to different elements of a differential rotator having at least three elements, wherein other elements of the differential rotator are joined to the driving wheels of the vehicle, and wherein the target-electric-motor-speed calculation means calculates the target electric-motor speed from the target engine speed and the rotational speed of the other elements of the differential rotator.

13. The vehicle-drive control system according to claim 10, wherein the target-engine-speed correction means brings a target electric-motor torque to zero when the engine speed becomes lower than a specified value.

14. The vehicle-drive control system according to claim 13, wherein the specified value is set lower than a resonance speed of a damper gear disposed between the engine and an electric motor.

15. The vehicle-drive control system according to claim 1, wherein the crank-angle acquisition means acquires the crank angle indicative of the position of a crankshaft, detected by a crank-angle detecting section.

16. The vehicle-drive control system according to claim 1, wherein the crank-angle acquisition means acquires the crank angle indicative of the position of a crankshaft, according to a rotor position of an electric motor mechanically connected to the engine.

17. The vehicle-drive control system according to claim 16, wherein the crank-angle acquisition means comprises synchronizing means for synchronizing the crank angle calculated from the rotor position with an actual crank angle.

18. The vehicle-drive control system according to claim 17, wherein the synchronizing means synchronizes the crank angle with the actual crank angle when torsion generated in a damper gear disposed between the engine and an electric motor is low and when specified synchronizing conditions for causing no torsion fluctuation are met.

19. The vehicle-drive control system according to claim 17, wherein the synchronizing means synchronizes the crank angle with the actual crank angle in accordance with the difference between a crank angle detected by the crank-angle detecting section at specified timing and a crank angle calculated from the rotor position at the timing.

20. A method for controlling the drive of a vehicle, comprising:

reducing an engine speed;

acquiring a target engine speed which is necessary to stop an engine at a target stop position;

acquiring a crank angle indicative of the position of a crankshaft; and

correcting the target engine speed according to the acquired crank angle.

21. A program for a method for controlling the drive of a vehicle, wherein a computer functions as target-engine-speed acquisition means for acquiring a target engine speed necessary to reduce engine speed, thereby stopping the engine at a target stop position;

as a crank-angle acquisition means for acquiring a crank angle indicative of the position of a crankshaft; and

as a target-engine-speed correction means for correcting the target engine speed according to the acquired crank angle.