Process for improved determination of the ratio among the radii of the wheels of a vehicle
AssigneeWABCO GmbH & Co. OHG
InventorsThomas Dieckmann, Arne Michaelsen
Life of this patent
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Abstract
A process for determining the wheel radius ratios of a vehicle equipped with an anti-lock braking system uses the rotational speeds of the vehicle wheels to determine a vehicle drive slip value. This drive slip value and the driving force of the vehicle drive wheels are combined in a Kalman filter to compute the wheel radius ratio data. When traveling around curves, however, the drive slip value calculation can become inaccurate, thereby corrupting the computed wheel radius ratio data. To correct for this curve travel effect, the inventive process includes the yawing rate of the vehicle in its computations. As a result, the corrected wheel radius ratios can be more reliably used for detecting tire pressure problems.
Claims13
A process for determining a wheel radius ration for a vehicle, including compensation for curve travel, comprising the following steps:
- a) measuring a rotations-speed of each wheel of said vehicle,
- b) calculating an angular velocity for each wheel of said vehicle, based on said rotational speed measurements,
- c) measuring a vehicle movement signal,
- d) calculating a yawing rate for said vehicle, based on said vehicle movement signal measurement,
- e) calculating a drive slip for each side of said vehicle, based on corresponding said angular velocities and said yawing rate, wherein said drive slip calculation uses said yawing rate to compensate for curve travel effects, and
- f) determining said wheel radius ratios, based on said calculated drive slip signal and said vehicle movement signal received from said vehicle.
Dependencies are inferred from the claim text.