Vehicle motion control device

• US 20090157246A1
• Filed: 12/11/2008
• Published: 06/18/2009
• Est. Priority Date: 12/12/2007
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Sada, Takeshi, Sawada, Mamoru, Matsumoto, Toshiki, Mori, Katsuyuki
• Granted Patent: US 8,510,007 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 6/52 Driving a plurality of drive axles, e.g. four-wheel drive
• 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 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 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 2260/28 Four wheel or all wheel drive
• CPC Class Codes: B60L 2260/44 by parameter estimation
• 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: 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 20/11 using model predictive control [MPC] strategies, i.e. control methods based on models predicting performance utilising navigation and traffic information in the control strategy B60W20/12
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2540/10 : Accelerator pedal position
• CPC Class Codes: B60W 2540/18 : Steering angle
• CPC Class Codes: B60W 2710/0666 : Engine torque
• CPC Class Codes: B60W 2720/30 : Wheel torque
• CPC Class Codes: B60W 30/045 : Improving turning performance
• CPC Class Codes: B60W 30/20 : Reducing vibrations in the driveline
• CPC Class Codes: B60W 40/10 : related to vehicle motion
• 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

A vehicle motion control device adjusts vibrations occurring in components of a vehicle so as to control the motion of a vehicle having independent drive assemblies for front wheels and for rear wheels. The vehicle motion control device includes a base request torque calculation unit that calculates first and second base request torques in response to a request made by the driver of a vehicle. A correction torque calculation unit calculates first and second correction torques used to adjust vibrations in a low-frequency band and in a high-frequency band of the vibrations of the components of the vehicle. An internal combustion engine control unit and a motor generator control unit control an internal combustion engine and a motor generator so that the first and second base request torques are corrected with the first and second correction torques.

Claims

1. A vehicle motion control device mounted in a four-wheel-drive vehicle, the vehicle motion control device controlling motion operation of the four-wheel-drive vehicle having:

a first drive assembly including an internal combustion engine inducing a first torque in a first output shaft coupled to a first pair of wheels;

a second drive assembly including a motor inducing a second torque in a second output shaft coupled to a second pair of wheels, the second drive assembly independent of the first drive assembly; and

a vehicle state detection means for detecting states of components of the vehicle, the vehicle motion control device comprising;

a base request torque calculation unit coupled to the first drive assembly the second drive assembly and an input device, the base request torque calculation unit calculating a first base request torque for the first drive assembly and a second base request torque for the second drive assembly in response to a request received from the input device;

a correction torque calculation unit that estimates vibrational states of the components of the vehicle on the basis of the detected states of the components of the vehicle, and calculates a first correction torque associated with the first base request torque, the first correction torque used to adjust vibrations in a low-frequency band of vibration frequencies of the components of the vehicle, and a second correction torque associated with the second base request torque, the second correction torque used to adjust vibrations in a high-frequency band of the vibration frequencies of the components of the vehicle; and

first and second control units that control the internal combustion engine and motor respectively so that the first base request torque and the second base request torque are corrected with the first correction torque and the second correction torque respectively.

2. The vehicle motion control device according to claim 1, wherein the correction torque calculation unit calculates the first correction torque on the basis of a low-frequency band model modeling low-frequency band behaviors of the components of the vehicle, and calculates the second correction torque on the basis of a high-frequency band model modeling high-frequency band behaviors of the components of the vehicle.

3. The vehicle motion control device according to claim 2, wherein the low-frequency band model includes a first spring-mass model modeling vibrations associated with a vehicle body accommodating occupants.

4. The vehicle motion control device according to claim 3, wherein the correction torque calculation unit calculates the first correction torque for the adjusting the vibrations in the first spring-mass model on the basis of the conditions of the vibrations occurring in the first spring-mass model.

5. The vehicle motion control device according to claim 2, wherein the high-frequency band model includes a second spring-mass model modeling a chassis frame bearing a vehicle body, wheels joined to the chassis frame and elastic tires joined to the wheels.

6. The vehicle motion control device according to claim 5, wherein the correction torque calculation unit calculates the second correction torque for the adjusting the vibrations in the second spring-mass model on the basis of the conditions of the vibrations occurring in the second spring-mass model.

7. The vehicle motion control device according to claim 1, wherein the four-wheel-drive vehicle includes a power storage means connected to and feeding power to the motor, and a generator that uses the first torque of the first output shaft to generate electricity to charge the power storage means, the generator having a relatively higher frequency response than the internal combustion engine.

8. The vehicle motion control device according to claim 7, further comprising a generator request torque calculation unit that calculates a third base request torque including a required torque required by the generator for generating a first amount of the electricity necessary to retain a second amount of stored power at a predetermined reference level on the basis of the second amount of stored power and a power generation efficiency factor of the generator, wherein:

the first control unit controls the internal combustion engine so that the first base request torque will be corrected with the third base request torque.

9. The vehicle motion control device according to claim 8, wherein the generator request torque calculation unit calculates an excess torque which the internal combustion engine can induce in the first output shaft in addition to the first base request torque, the third base request torque being the smaller of the excess torque and the required torque.

10. The vehicle motion control device according to claim 9, wherein when the second amount of stored power falls below the reference value, the first control unit performs correction of the first base request torque using the third base request torque with a higher priority than performing correction of the first base request torque using the first correction torque.