Traction control apparatus and method for vehicles

• US 6,269,297 B1
• Filed: 05/26/2000
• Issued: 07/31/2001
• Est. Priority Date: 06/08/1999
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Saito, Yasuhiro, Yokokawa, Mitsuyoshi, Takagi, Masashi, Hosomi, Kazushi
• Primary Examiner(s): CAMBY, RICHARD M
• Application Number:
  US09/580,269
• Time in Patent Office: 431 Days
• Field of Search: 701/82, 701/83, 701/84, 701/87, 701/88, 701/90, 303/91, 180/197
• US Class Current: 701/82
• CPC Class Codes: B60K 1/00 Arrangement or mounting of electrical propulsion units B60K7/00 takes precedence; arrangement or mounting of plural diverse prime-movers for mutual or common propulsion B60K6/00; electric transmission arrangements B60K17/12; electric equipment or propulsion of electrically-propelled vehicles per se B60L; current-collectors for power supply lines of electrically-propelled vehicles B60L5/00
• CPC Class Codes: B60K 28/16 responsive to, or preventing, skidding of wheels brake control systems for vehicle drive stability B60T8/1755; arrangements responsive to a speed condition for adjusting wheel braking force B60T8/32; control of vehicle driving stability otherwise than by controlling the propulsion unit only B60W30/02; preventing wheel slippage by reducing power in rail vehicles B61C15/00
• 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: B60W 2510/0628 Inlet air flow rate
• CPC Class Codes: B60W 2710/0616 Position of fuel or air injector
• CPC Class Codes: B60W 2710/0622 Air-fuel ratio

Abstract

A traction control apparatus for vehicles according to the present invention has a slip state detector for detecting a slip state of a wheel, a parameter determining device for determining a control parameter for generating braking force according to the slip state detected, a control permitting device for permitting traction control, a parameter changer for changing the control parameter so as to decrease the braking force when the control parameter is one to generate the braking force at the wheel over permissible braking force at the start of control, and a traction control for executing the traction control, based on the control parameter. Thus the apparatus can restrain uncomfortableness during the traction control and can prevent large input from entering the power train.

Claims

1. A traction control apparatus for vehicles comprising:

slip state detecting means for detecting a slip state of a wheel mounted on a vehicle;

parameter determining means for determining a control parameter for generating braking force according to the slip state detected by said slip state detecting means;

control permitting means for permitting traction control;

parameter changing means for changing said control parameter so as to decrease the braking force generated at said wheel when said determined control parameter at the time of permission of the traction control given by said control permitting means is one to generate the braking force at said wheel over permissible braking force at a start of the control; and

traction control means for executing the traction control by controlling the braking force at said wheel, based on said changed control parameter.

2. The traction control apparatus for vehicles according to claim 1, wherein said traction control means comprises braking force adjusting means for effecting braking at said wheel by increasing hydraulic pressure in a wheel cylinder to urge a frictional material against said wheel or against a rotary member coupled thereto, and

wherein said control parameter is a pressure increase rate of said hydraulic pressure and said parameter changing means changes said pressure increase rate determined by said parameter determining means, to a lower rate.

3. The traction control apparatus for vehicles according to claim 1, wherein said traction control means comprises braking force adjusting means for effecting braking at said wheel by increasing hydraulic pressure in a wheel cylinder to urge a frictional material against said wheel or against a rotary member coupled thereto, and

wherein said control parameter is a target pressure of said hydraulic pressure and said parameter changing means changes said target pressure determined by said parameter determining means, to a lower pressure value.

4. A traction control apparatus for vehicles comprising:

slip state detecting means for detecting a slip state of a wheel mounted on a vehicle;

parameter determining means for determining a control parameter for decreasing driving force transmitted to said wheel in accordance with the slip state detected by said slip state detecting means;

control permitting means for permitting traction control;

parameter changing means for changing said control parameter so as to decrease a decrease amount of the driving force when said determined control parameter at the time of permission of the traction control given by said control permitting means is one to cause a decrease of the driving force over a permissible decrease amount at a start of the control; and

traction control means for executing the traction control by decreasing the driving force transmitted to said wheel, based on said changed control parameter.

5. The traction control apparatus for vehicles according to claim 4, wherein said traction control means comprises driving force adjusting means for adjusting driving force generated by an engine and transmitted to said wheel, and

wherein said control parameter is intake air volume of said engine and said parameter changing means changes said intake air volume determined by said parameter determining means, to larger volume so as to decrease said driving force.

6. The traction control apparatus for vehicles according to claim 4, wherein said traction control means comprises driving force adjusting means for adjusting driving force generated by an engine and transmitted to said wheel, and

wherein said control parameter is a fuel injection amount of said engine and said parameter changing means changes said fuel injection amount determined by said parameter determining means, to a smaller amount so as to decrease said driving force.

7. The traction control apparatus for vehicles according to claim 4, wherein said traction control means comprises driving force adjusting means for adjusting driving force generated by an engine and transmitted to said wheel, and

wherein said control parameter is ignition timing of said engine and said parameter changing means changes said ignition timing determined by said parameter determining means, so as to decrease said driving force.

8. The traction control apparatus for vehicles according to claim 4, wherein said traction control means comprises driving force adjusting means for adjusting driving force generated by an electric motor and transmitted to said wheel, and

wherein said control parameter is output torque of said electric motor and said parameter changing means changes said output torque determined by said parameter determining means, so as to decrease said driving force.

9. A traction control method for vehicles comprising the steps of:

detecting a slip state of a wheel mounted on a vehicle;

determining a control parameter for generating braking force according to the detected slip state;

permitting traction control;

changing said control parameter so as to decrease the braking force generated at said wheel when said determined control parameter at the time of permission of the traction control is one to generate the braking force at said wheel over permissible braking force at a start of the control; and

executing the traction control by controlling the braking force at said wheel, based on said changed control parameter.

10. The traction control method for vehicles according to claim 9, wherein the step of executing the traction control includes effecting braking at said wheel by increasing hydraulic pressure in a wheel cylinder to urge a frictional material against said wheel or against a rotary member coupled thereto,

wherein the step of determining said control parameter includes determining a pressure increase rate of said hydraulic pressure as said control parameter, and

wherein the step of changing said control parameter includes changing said determined pressure increase rate to a lower rate.

11. The traction control method for vehicles according to claim 9, wherein the step of executing the traction control includes effecting braking at said wheel by increasing hydraulic pressure in a wheel cylinder to urge a frictional material against said wheel or against a rotary member coupled thereto,

wherein the step of determining said control parameter includes determining a target pressure of said hydraulic pressure as said control parameter, and

wherein the step of changing said control parameter includes changing said determined target pressure to a lower pressure value.

12. A traction control method for vehicles comprising the steps of:

detecting a slip state of a wheel mounted on a vehicle;

determining a control parameter for decreasing driving force transmitted to said wheel in accordance with the detected slip state;

permitting traction control;

changing said control parameter so as to decrease a decrease amount of the driving force when said determined control parameter at the time of permission of the traction control is one to cause a decrease of the driving force over a permissible decrease amount at a start of the control; and

executing the traction control by decreasing the driving force transmitted to said wheel, based on said changed control parameter.

13. The traction control method for vehicles according to claim 12, wherein the step of executing the traction control includes adjusting driving force generated by an engine and transmitted to said wheel,

wherein the step of determining said control parameter includes determining intake air volume of said engine as said control parameter, and

wherein the step of changing said control parameter includes changing said determined intake air volume to larger volume so as to decrease said driving force.

14. The traction control method for vehicles according to claim 12, wherein the step of executing the traction control includes adjusting driving force generated by an engine and transmitted to said wheel,

wherein the step of determining said control parameter includes determining a fuel injection amount of said engine as said control parameter, and

wherein the step of changing said control parameter includes changing said determined fuel injection amount to a smaller amount so as to decrease said driving force.

15. The traction control method for vehicles according to claim 12, wherein the step of executing the traction control includes adjusting driving force generated by an engine and transmitted to said wheel,

wherein the step of determining said control parameter includes determining ignition timing of said engine as said control parameter, and

wherein the step of changing said control parameter includes changing said determined ignition timing so as to decrease said driving force.

16. The traction control method for vehicles according to claim 12, wherein the step of executing the traction control includes adjusting driving force generated by an electric motor and transmitted to said wheel,

wherein the step of determining said control parameter includes determining output torque of said electric motor as said control parameter, and

wherein the step of changing said control parameter includes changing said determined output torque so as to decrease said driving force.