Slip control system for motor vehicle

• US 5,262,952 A
• Filed: 02/21/1991
• Issued: 11/16/1993
• Est. Priority Date: 02/22/1990
• Status: Expired due to Fees

• Current Assignee: Mazda Motor Corporation No 3-1 Shinchi Fuchu-Cho Aki-Gun Hiroshima-Ken Japan
• Original Assignee: Mazda Motor Corporation
• Inventors: Kawamura, Makoto, Kageyama, Fumio, Sone, Akira, Tsuyama, Toshiaki, Nobumoto, Kazutoshi
• Primary Examiner(s): Black, Thomas G.
• Application Number:
  US07/658,859
• Time in Patent Office: 999 Days
• Field of Search: 364/426.01, 364/426.02, 364/426.03, 364/424.1, 180/197, 74/866
• US Class Current: 701/87
• CPC Class Codes: B60K 28/165 acting on elements of the vehicle drive train other than the propulsion unit and brakes, e.g. transmission, clutch, differential acting on brakes B60T8/17
• 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 8/48 connecting the brake actuator to an alternative or additional source of fluid pressure , e.g. traction control systems
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/10 including control of change-speed gearings
• CPC Class Codes: B60W 10/11 Stepped gearings
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 2552/40 Coefficient of friction
• CPC Class Codes: B60W 30/18172 Preventing, or responsive to skidding of wheels
• CPC Class Codes: B60W 30/1819 Propulsion control with control means using analogue circuits, relays or mechanical links
• CPC Class Codes: F16H 2059/087 Winter mode, e.g. to start on snow or slippery surfaces
• CPC Class Codes: F16H 2059/506 Wheel slip
• CPC Class Codes: F16H 2061/0227 Shift map selection, i.e. methods for controlling selection between different shift maps, e.g. to initiate switch to a map for up-hill driving
• CPC Class Codes: F16H 61/0213 characterised by the method for generating shift signals

Abstract

A slip control system for a motor vehicle controls slips in driving wheels and includes a sensor for detecting a slip ratio of each driving wheel and a traction control system for decreasing a slip of each driving wheel by controlling a driving force transmitted to each driving wheel so that the slip ratio of each driving wheel is at least equal to a predetermined desired slip ratio when the slip ratio of the driving wheel becomes equal to the desired slip ratio. An automatic transmission control system controls an automatic transmission by using a first shift property for a normal operation, and a second shift property for a traction control operation which is adapted to determine a relative higher speed stage. A device is provided for switching the first shift property to the second shift property when the traction control operation is started by the traction control system.

Claims

1. A slip control system for a motor vehicle controlling slips in driving wheels comprising:

means for detecting a slip ratio of each driving wheel;

traction control means for decreasing a slip of each driving wheel by controlling a driving force transmitted to each driving wheel so that the slip ratio of each driving wheel is at least equal to a predetermined desired slip ratio when the slip ratio of the driving wheel becomes equal to the desired slip ratio;

means for controlling an automatic transmission by using a first shift property for a normal operation and a second shift property for a traction control operation which is adapted to determine a relative higher speed stage;

means for switching the first shift property to the second shift property when the traction control operation is started by the traction control means; and

means for prohibiting the automatic transmission from shifting up in a predetermined time after said traction control means starts to control the driving force.

2. A slip control system for a motor vehicle in accordance with claim 1 in which said means for prohibiting includes means for delaying the shifting up of the automatic transmission during the predetermined time when said means for controlling said automatic transmission determines the shifting up to be based on the second shift property.

3. A slip control system for a motor vehicle in accordance with claim 1 in which said first shift property includes a first shift map and said second shift property includes a second shift map.

4. A slip control system for a motor vehicle in accordance with claim 3 in which said second shift map includes no shift line from a first stage to a second stage.

5. A slip control system for a motor vehicle in accordance with claim 1 in which said prohibiting means includes means for delaying the switching from the first shift property to the second shift property in the predetermined time.