Method of improving ABS control behaviour on cornering

• US 6,289,272 B1
• Filed: 09/17/1999
• Issued: 09/11/2001
• Est. Priority Date: 07/18/1996
• Status: Expired due to Term

• Current Assignee: Continental Teves AG & Co. OHG (Continental AG)
• Original Assignee: Continental Teves AG & Co. OHG (Continental AG)
• Inventors: Schmidt, Holger, Batistic, Ivica
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): To, Tuan C
• Application Number:
  US09/214,976
• Time in Patent Office: 725 Days
• Field of Search: 701/72, 701/76, 303/100, 303/95, 303/103
• US Class Current: 701/72
• CPC Class Codes: B60T 2201/16 Curve braking control, e.g. turn control within ABS control algorithm
• 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

In a method of improving the control behavior of an ABS control system in corners, a special control mode or rather a corner control mode is put into operation instead of the standard control mode when a cornering situation is identified, said special control mode or corner control mode causing a reduction of the braking pressure on the front wheel and/or on the rear wheel on the inside of the curve. When, in the partial braking range, a threshold value (th) of a wheel speed difference is exceeded, which difference is the difference between the side sums formed from the speeds of the two wheels of one vehicle side there will be a braking pressure reduction on the front wheel and/or on the rear wheel on the inside of the curve until there is again a drop below the threshold value (th,th_H) and, additionally, below a hysteresis band (H). (FIG. 2)

Claims

1. A method of improving the control behavior of an ABS control system for a four-wheel, two-axle vehicle, comprising the steps of:

measuring individual wheel speeds;

deriving a reference speed of the vehicle;

obtaining criteria for identifying a cornering situation and the direction of the curve from the rotational behavior of the vehicle wheels,

applying a special control mode causing a reduction of the braking pressure on at least one of the curve-inner wheels in a partial-braking range, with a threshold value of the wheel speed difference being exceeded, which difference is the difference between the wheel speed sums per side formed from the speeds of the two wheels of each side of the vehicle; and

maintaining the special control mode until there is a drop below the threshold value and below hysteresis band (H)

wherein the hysteresis band lies in the order of magnitude of approximately 2-6 k.p.h., in particular of 3-4 k.p.h.

2. A method as claimed in claim 1, wherein the threshold value of the wheel speed difference is varied in dependence on the vehicle, speed.

3. A method of improving the control behavior of an ABS control system for a four-wheel, two-axle vehicle comprising the steps of:

measuring individual wheel speeds;

deriving a reference speed of the vehicle;

obtaining criteria for identifying a cornering situation and the direction of the curve from the rotational behavior of the vehicle wheels;

applying a special control mode when a cornering situation is identified, said special control mode causing a reduction of the braking pressure on at least one of the curve-inner wheels in a partial-braking range, with a threshold value of the wheel speed difference being exceeded which difference is the difference between the wheel speed sums per side formed from the speeds of the two wheels of each side of the vehicle; and

maintaining the special control mode until there is a drop below the threshold value and below a hysteresis band (H),

wherein the threshold value is varied in dependence on the vehicle reference steed, by decreasing approximately linearly with the vehicle speed in a lower range, increasing approximately linearly with the vehicle speed in a medium speed range and being approximately constant in an upper speed range.

4. A method as claimed in claim 3, wherein the lower speed range reaches as far as a vehicle speed value between approximately 40-60 k.p.h., the medium speed range reaches as far as a value between approximately 110 and 150 k.p.h., for instance, as far as approximately 130 k.p.h., which then is followed by the upper speed range.

5. A method as claimed in claim 3, wherein the hysteresis band lies in the order of magnitude of approximately 2-6 k.p.h., in particular of 3-4 k.p.h.