Brake system control

• US 6,122,584 A
• Filed: 02/22/1999
• Issued: 09/19/2000
• Est. Priority Date: 11/10/1997
• Status: Expired due to Fees

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Chin, Yuen-Kwok, Lin, William Chin-Woei, Chen, Hsien Heng, Ghoneim, Youssef Ahmed, Sidlosky, David Michael
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): ARTHUR JEANGLAUDE, GERTRUDE
• Application Number:
  US09/253,369
• Time in Patent Office: 575 Days
• Field of Search: 701/41, 701/70, 701/71, 701/72, 701/74, 701/78, 701/83, 303/140, 303/146, 303/147, 303/148, 303/149, 303/150
• US Class Current: 701/70
• CPC Class Codes: B60T 2230/02 Side slip angle, attitude angle, floating angle, drift angle
• CPC Class Codes: B60T 8/1755 Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02

Abstract

A brake system control method, comprising the steps of: measuring a longitudinal speed and steering angle of the vehicle; specifying an un-damped natural frequency and a damping ratio for a linear reference model of said vehicle; determining a first gain parameter relating a desired value of steady state lateral velocity to the vehicle steering angle; computing a desired lateral velocity as a function of said first gain parameter, the measured longitudinal speed, the measured steering angle, and the specified un-damped natural frequency and damping ratio; determining a second gain parameter relating a desired value of steady state yaw rate to the vehicle steering angle; computing a desired yaw rate as a function of said second gain parameter, the measured longitudinal speed and steering angle, and the specified un-damped natural frequency and damping ratio; measuring a lateral acceleration and yaw rate of said vehicle, and forming a yaw rate command for said vehicle based at least part in a first deviation between said desired and measured yaw rates, and a second deviation between said measured lateral acceleration and a desired lateral acceleration based on said desired lateral velocity; and differentially braking wheels of said vehicle to impart a yaw moment corresponding to said yaw rate command.

Claims

1. A brake system control method, comprising the steps of:

measuring a longitudinal speed and a steering angle of a vehicle;

specifying an un-damped natural frequency and a damping ratio for a linear reference model of said vehicle;

determining a first gain parameter relating a desired value of steady state lateral velocity to the vehicle steering angle;

computing a desired lateral velocity as a function of said first gain parameter, the measured longitudinal speed, the measured steering angle, and the specified un-damped natural frequency and damping ratio;

determining a second gain parameter relating a desired value of steady state yaw rate to the vehicle steering angle;

computing a desired yaw rate as a function of said second gain parameter, the measured longitudinal speed and steering angle, and the specified un-damped natural frequency and damping ratio;

measuring a lateral acceleration and yaw rate of said vehicle, and forming a yaw rate command for said vehicle based at least in part on a first deviation between said desired and measured yaw rates, and a second deviation between said measured lateral acceleration and a desired lateral acceleration based on said desired lateral velocity; and

differentially braking wheels of said vehicle to impart a yaw moment corresponding to said yaw rate command.

2. A brake control method according to claim 1, wherein the step of specifying the un-damped natural frequency comprises calculating the un-damped natural frequency as a function of vehicle related coefficients of said linear reference model.

3. A brake control method of claim 1, wherein the step of specifying the damping ratio comprises calculating the damping ratio as a function of vehicle related coefficients of said linear reference model.

4. The brake control method of claim 1, wherein the step of specifying the un-damped natural frequency comprises storing specified values of the un-damped natural frequency in a look-up table as a function of vehicle speed, and retrieving the stored values from said look-up table during operation of said vehicle as a function of the measured speed.

5. A brake control method according to claim 1, wherein the step of specifying the damping ratio comprises storing specified values of the damping ratio in a look-up table as a function of vehicle speed, and retrieving the stored values from said look-up table during operation of said vehicle as a function of the measured vehicle speed.