Method and a system for controlling traction in motor vehicles with mechanical gearboxes

• US 5,107,430 A
• Filed: 12/26/1990
• Issued: 04/21/1992
• Est. Priority Date: 12/28/1989
• Status: Expired due to Fees

• Current Assignee: Fiat Auto S.p.A.
• Original Assignee: Fiat Auto S.p.A.
• Inventors: Magnino, Carlo
• Primary Examiner(s): Lall, Parshotam S.
• Assistant Examiner(s): ZANELLI, MICHAEL J
• Application Number:
  US07/633,854
• Time in Patent Office: 482 Days
• Field of Search: 364/426.01, 364/426.02, 364/426.03, 364/426.04, 364/431.07, 364/424.1, 180/197, 303/94-97, 303/99, 303/109, 303/111
• US Class Current: 701/83
• 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 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/1005 Transmission ratio engaged
• CPC Class Codes: B60W 2710/021 Clutch engagement state
• CPC Class Codes: B60W 2720/28 Wheel speed
• CPC Class Codes: B60W 30/18172 Preventing, or responsive to skidding of wheels

Abstract

A method for preventing the driving wheels of a motor vehicle with a mechanical gearbox from slipping consists of detecting the rate of rotation of the vehicle'"'"'s engine, the speed of the vehicle, the angular velocities of the driving wheels and the gear ratio engaged, and obtaining corresponding signals indicative of the parameters detected. By means of these signals, the rate of rotation of the driving wheels is controlled and reduced automatically to below the slippage threshold by the adjustment of the engagement of the friction clutch, the adjustment of the rate revolution of the engine and the application of a suitable braking torque to one or both of the driving wheels. The control procedure depends on the speed of the vehicle and may also take account of its sideways acceleration.

Claims

1. A method for preventing the slippage of the driving wheels of a motor vehicle with a mechanical gearbox and a friction clutch consisting of detecting the rate of rotation of the vehicle'"'"'s engine, the vehicle'"'"'s speed, the angular velocity of the driving wheels (5) and the gear ratio engaged and obtaining corresponding signals indicative of the parameters detected whereby the speed of rotation of the driving wheels (5) is controlled automatically and reduced to below the slippage threshold by the following procedures:

between zero speed and a first predetermined vehicle speed (V₁);

adjusting the engagement of the friction clutch, adjusting the rate of revolution of the engine, applying a suitable braking torque to one or both of the driving wheels;

between the first predetermined speed (V₁) and a second, higher predetermined vehicle speed (V₂);

adjusting the rate of revolution of the engine and applying a braking torque to one or both of the driving wheels;

between the second predetermined speed (V₂) and a third, higher predetermined vehicle speed (V₃);

adjusting the rate of revolution of the engine;

between the third predetermined speed (V₃) and a fourth, higher predetermined vehicle speed (V₄);

adjusting the rate of revolution of the engine with reduced sensitivity;

the control being prevented at speeds above the fourth predetermined vehicle speed (V₄).

2. A method according to claim 1 further providing for the detection of the sideways acceleration of the vehicle and the provision of corresponding signals indicative of the sideways acceleration detected whereby the adjustment of the rate of revolution of the engine is prevented when a predetermined threshold of the sideways acceleration is reached, above a predetermined vehicle speed (V_L).

3. A system for preventing the slippage of the driving wheels (5) of a motor vehicle with a mechanical gearbox and a friction clutch, comprising:

means (2, 3, 4,

     10) for detecting the rate of rotation of the vehicle'"'"'s engine, the vehicle'"'"'s speed, the angular velocity of the driving wheels and the gear ratio engaged, the detector means being adapted to generate electrical signals indicative of the parameters detected,

actuator means (7, 8,

     9) for adjusting the rate of revolution of the engine, for adjusting the engagement of the friction clutch, and for applying a braking torque to one or both of the driving wheels, and

an electronic control unit (1) supplied with the electrical signals generated by the detector means (2, 3, 4,

     10) and arranged to compare these signals with corresponding reference parameters and consequently to pilot the actuator means (7, 8,

     9) so as to automatically control and reduce the speed of rotation of the driving wheels (5) to below the slipping threshold by the following procedures;

between zero speed and a first predetermined vehicle speed (V₁);

adjusting the engagement of the friction clutch, adjusting the rate of revolution of the engine, applying a suitable braking torque to one or both of the driving wheels;

between the first predetermined speed (V₁) and a second, higher predetermined vehicle speed (V₂);

adjusting the rate of revolution of the engine and applying a braking torque to one or both of the driving wheels (5);

between the second predetermined speed (V₂) and a third, higher predetermined vehicle speed (V₃);

adjusting the rate of revolution of the engine;

between the third predetermined speed (V₃) and a fourth, higher predetermined vehicle speed (V₄);

adjusting the rate of revolution of the engine with reduced sensitivity;

the electronic unit (1) also being arranged to prevent the control being effected at speeds above the fourth predetermined vehicle speed (V₄).

4. A system according to claim 3, further including a sensor (6) for sensing the sideways acceleration of the vehicle and for supplying the control unit (1) with electrical signals indicative of the sideways acceleration detected, and in that the control unit (1) is also arranged to prevent the adjustment of the rate of revolution of the engine when a predetermined threshold of the sideways acceleration is reached, above a predetermined vehicle speed (V_L).