Method for split-to-high mu detection and control for anti-lock brake systems
AssigneeKelsey-Hayes Company
InventorDarryl C. Weber
Life of this patent
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Abstract
A method is provided for modifying anti-lock brake control to a vehicle braking on a surface having a split-mu to higher-mu transition. The time duration of the apply stage of an anti-lock brake system cycle is measured for the two front wheels. The measured apply stage durations are compared to a selected threshold. The transition from the split-mu surface to the higher-mu surface is detected when the apply stage duration for the lower-mu wheel exceeds the selected threshold. An increased brake pressure rate is applied to both front wheels when the split-mu to high-mu transition is detected.
Claims15
A method of modifying an anti-lock brake system on a vehicle braking on a transition from a split-mu surface onto a higher-mu surface during an anti-lock brake system event, the vehicle comprising two wheels aligned on a latitudinal axis of the vehicle and an anti-lock brake system capable of independent cyclic control of brake pressure to each of the wheels with at least one pressure apply stage per anti-lock brake system cycle, the split-mu surface being characterized by one of the wheels on a lower-mu surface and the other wheel on a higher-mu surface, the method comprising the steps of:
- (a) measuring a time duration, defined in terms of the anti-lock brake system cycle for the lower-mu wheel;
- (b) comparing the time duration to a predetermined threshold;
- (c) detecting a split-mu to higher-mu transition if the time duration exceeds the predetermined threshold;
- (d) controlling the brake pressure to the lower-mu wheel utilizing a low-to-high pressure control algorithm;
- and
- (e) controlling the brake pressure to the higher-mu wheel utilizing a split-to-high pressure control algorithm.
Dependencies are inferred from the claim text.