US 5,634,698 AGranted

System for controlling brake pressure based on fuzzy logic using steering angle and yaw speed

AssigneeRobert Bosch GmbH

InventorsChi-Thuan Cao, Rolf Becker, Ulrich Belzner, Thorsten-Wilhelm Moeller, Bernd Lieberoth-Leden

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Abstract

An ABS which evaluates slip values prescribes pressure values for the wheel brakes. In order to improve the driving stability, these pressure values are varied by a brake controller using the deviation of the yawing speed from a set value and the front-axle steering angle as input variables. The brake controller determines its output values (variation values) with the aid of the fuzzy logic. Additionally, rear-axle steering is integrated into the system, the system partially also using fuzzy logic. Subsequently, an adaptation which is based on fuzzy logic and uses the brake controller and the rear-axle steering controller in a weighted fashion is proposed.

Claims14

Dependent claims

Vehicle dynamics control system for a vehicle having wheels, said system comprising

means for determining desired slip values .lambda..sub.is for said wheels,
means for determining actual slip values .lambda..sub.i at said wheels,
an antilock controller which determines first desired pressure values P.sub.is by comparing said actual slip values .lambda..sub.i to said desired slip values .lambda..sub.is,
means for determining the front axle steering angle .delta.,
means for determining the yaw speed w,
a fuzzy logic brake controller which determines correction values .DELTA.P.sub.is in dependence on the front steering angle .delta. and the yaw speed w,
adding means for determining second desired pressure values P*.sub.is according to P*.sub.is =P.sub.is +.DELTA.P.sub.is,
a pressure controller for generating brake pressure control signals in dependence on said second desired pressure values P*.sub.is, and
brake control valves responsive to said brake pressure control signals.

6 more elements

Vehicle dynamics control system for a vehicle having wheels, said system comprising

means for determining first desired slip values .lambda..sub.is for said wheels,
means for determining actual slip values .lambda..sub.i at said wheels,
means for determining the front axle steering angle .delta.,
means for determining the yaw speed w,
a fuzzy logic brake controller which determines correction values .DELTA..lambda..sub.is in dependence on the front steering angle .delta. and the yaw speed w,
adding means for determining second desired slip values .lambda.*.sub.is according to .lambda.*.sub.is =.lambda..sub.is +.DELTA..lambda..sub.is,
an anti-lock controller which determines desired pressure values P.sub.is by comparing said actual slip values .lambda..sub.i with said second desired slip values .lambda.*.sub.is,
a pressure controller for generating brake pressure control signals in dependence on said desired pressure values P.sub.is, and
brake control valves responsive to said brake pressure control signals.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/391,809Filed 21 Feb 1995
Priority: DE 44 05 379.719 Feb 1994
Granted: 3 Jun 1997
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

B60T 8/174
Using electrical or electronic regulation means to control braking: characterised by using special control logic, e.g. fuzzy logic , neural computing
B60T 8/1755
Using electrical or electronic regulation means to control braking: brake regulation specially adapted to control the stability of the vehicle,…
B62D 7/159
Characterised by means varying the ratio between the steering angles of the steered wheels: characterised by computing methods or stabilisation…
B60T 2260/022
Active Steering, Steer-by-Wire: rear-wheel steering; Four-wheel steering