Traction control system with wheel speed correction to compensate for different tire diameters
AssigneesRobert Bosch GmbH, Bayerische Motoren Werke Aktiengesellschaft, Mercedes-Benz AG
InventorsJohannes Schmitt, Dirk Saewe, Armin Mueller, Alfred Straub
Life of this patent
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Abstract
In order to avoid faults as a result of different diameters of tires, under prescribed conditions a correction of one wheel speed with respect to the other on each side of the vehicle is performed. The conditions are based on a comparison of the throttle valve angle to the zero torque angle, and a comparison of the speed of the driven wheel to the speed of the non-driven wheel.
Claims5
Traction control method for a vehicle having driven wheels, non-driven wheels, and an engine generating torque determined by a throttle valve, said method comprising
- determining a throttle valve angle DKI,
- determining a zero torque angle NMK,
- determining the speed VANX of a driven wheel on one side of the vehicle,
- determining the speed VNAX of a non-driven wheel on said one side of the vehicle,
- comparing DKI to NMK,
- comparing VANX to VNAX,
- determining that a first pair of conditions is satisfied when DKI.gtoreq.NMK and VANX<VNAX,
- determining that a second pair of conditions is satisfied when DKI<NMK and VANX.gtoreq.VNAX,
- correcting wheel speeds on said one side of said vehicle to compensate for different tire diameters when one of said first and second pair of conditions is satisfied,
- determining drive slip based on said corrected wheel speeds, and
- varying wheel speeds until said drive slip falls below a threshold value.
Dependencies are inferred from the claim text.