Wheel slip control system

• US 5,328,255 A
• Filed: 04/02/1992
• Issued: 07/12/1994
• Est. Priority Date: 10/09/1989
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Isella, Thomas
• Primary Examiner(s): Butler, Douglas C.
• Assistant Examiner(s): Muratori, Alfred
• Application Number:
  US07/846,998
• Time in Patent Office: 831 Days
• Field of Search: 303/113.1, 303/113.2, 303/113.4, 303/113.5, 303/103, 303/106, 303/111, 180/197, 364/426.01-426.03
• US Class Current: 303/140
• CPC Class Codes: B60T 2201/09 Engine drag compensation
• CPC Class Codes: B60T 2201/16 Curve braking control, e.g. turn control within ABS control algorithm
• CPC Class Codes: B60T 8/175 Brake regulation specially adapted to prevent excessive wheel spin during vehicle acceleration, e.g. for traction control safety devices for propulsion unit control responsive to, or preventing, skidding of wheels B60K28/16
• 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
• CPC Class Codes: B60T 8/17616 Microprocessor-based systems

Abstract

A wheel slip control system (ABS and/or drive slip control and/or engine drag moment control system) is formed so that when vehicle motion along curvilinear path is detected the control system is switched to different permitted wheel slip values on different sides of the vehicle, in such a way that a yawing moment is created which acts counter to the yawing moment produced by the vehicle'"'"'s tendency to oversteer or understeer.

Claims

1. An antilocking brake control system for a vehicle having wheels, consisting of:

sensing means (1 to

     4) for determining a vehicle wheel speed of each of said vehicle wheels and for producing vehicle wheel speed signals for each of said wheels according to said vehicle wheel speeds;

means (12) for producing a vehicle speed signal (V_Ref) characteristic of a vehicle speed connected to said sensing means for said wheels to receive vehicle wheel speed signals and to determine said vehicle speed from said vehicle wheel speeds;

means (13,

     14) for determining wheel slip values for said wheels from said vehicle wheel speed signals and said vehicle speed signal, said means for determining wheel slip values being connected to said sensing means (1 to

     4) for said wheels and said means for producing a vehicle speed signal (12) to receive said vehicle speed signal therefrom;

comparison means (15,

     16) for comparing said wheel slip value at each of said wheels with a wheel slip value limit, said comparison means being connected with said means (13,

     14) for determining wheel slip values to receive said wheel slip values therefrom;

means for varying a braking force at each of said wheels and hence a wheel slip value at each of said wheels within said wheel slip value limit;

curvilinear vehicle motion detection means (20) for detecting a curvilinear vehicle motion and for producing a curvilinear vehicle motion signal; and

a brake control system (17) connected to said curvilinear vehicle motion detection means to receive said curvilinear vehicle motion signal and to means (19) for generating a recognition signal when said vehicle speed is greater than one of said vehicle wheel speeds, and containing means for setting said wheel slip value limit of said comparison means according to said curvilinear vehicle motion signal, and said recognition signal so that, when curvilinear motion of said vehicle and said recognition signal are detected, the wheel slip value limits for wheels on different sides of the vehicle are set to different values in such a way that a yawing moment is created so as to counteract a tendency to oversteer or understeer.

2. A drive slip control system for a vehicle including two driven wheels and two nondriven wheels, consisting of:

sensing means (1 to

     4) for determining a vehicle wheel speed of each of said vehicle wheels and for producing vehicle wheel speed signals for each of said wheels according to said vehicle wheel speeds;

means (12) for producing a vehicle speed signal characteristic of a vehicle speed connected to said sensing means (3,

     4) for said nondriven wheels to receive said vehicle wheel speed signals for said nondriven wheels therefrom and to determine said vehicle speed from said vehicle wheel speeds for said nondriven wheels;

means (13,

     14) for determining wheel slip values for said driven wheels from said vehicle wheel speed signals of said driven wheels and said vehicle speed signal, said means (13,

     14) for determining wheel slip values being connected to said means for producing said vehicle speed signal to receive said vehicle speed signal therefrom;

comparison means (15,

     16) for comparing said wheel slip value at each of said driven wheels with a wheel slip value limit at each of said driven wheels, said comparison means (15,

     16) being connected with said means (13,

     14) for determining wheel slip values to receive said wheel slip values therefrom;

means (6,

     7) for varying a braking force at each of said driven wheels and hence a wheel slip value at each of said wheels within said wheel slip value limit;

curvilinear vehicle motion detection means (20) for detecting a curvilinear vehicle motion and for producing a curvilinear vehicle motion signal; and

a drive slip control system (17) connected to said curvilinear vehicle motion detection means and to means (19) for generating a recognition signal when said vehicle speed is greater than one of said wheel speeds to receive said curvilinear vehicle motion signal and said recognition signal, and containing means for setting a wheel slip value limit of said comparison means at each of said driven wheels according to said curvilinear vehicle motion signal, and said recognition signal so that, when curvilinear motion of said vehicle and said recognition signal are detected, the wheel slip value limits for said driven wheels on different sides of the vehicle are set to different values in such a way that a yawing moment is created which counteracts a tendency to oversteer or understeer.

3. A drive slip control system according to claim 2, including engine moment control means for reducing a wheel slip created by an engine moment by decreasing said engine moment, said engine moment control means including an actuator connected with said drive slip control system.