Kelsey-hayes Company

Dan Negrin

Darryl C Weber

A method and system are disclosed for controlling an anti-lock brake system based on vehicle deceleration. The system includes a wheel speed sensor and control unit for performing the method steps of sensing a wheel speed and determining a wheel deceleration and a vehicle deceleration therefrom. The control unit also performs the method steps of determining an initial deceleration threshold representing a pre-lockup condition, determining a final deceleration threshold based on the vehicle deceleration, comparing the wheel deceleration to the final deceleration threshold, and activating the vehicle anti-lock brake system if the wheel deceleration exceeds the final deceleration threshold.

Method and system for controlling an anti-lock brake system

A method and system for correcting an overestimated vehicle reference speed is presented. In one embodiment, speed, slip, and acceleration quantities are computed for at least one wheel of a vehicle. The speed, slip, and acceleration quantities are compared to selected speed, slip, and acceleration thresholds, respectively. A count is incremented if the quantities are consistent with at least one vehicle reference speed being overestimated. The existence of at least one overestimated vehicle reference speed is detected when the count attains a selected threshold. The vehicle reference speeds are modified when the overestimated vehicle reference speed is detected.

Method and system for detecting and correcting vehicle speed reference

A method and system for modifying anti-lock brake control to a vehicle braking on a surface having a low-mu to split-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 threshold. The braking coefficients of the two front wheels are qualified based on these comparisons. Each wheel is qualified as normal-duration if the apply stage duration is less than the threshold, and long-duration if the apply stage duration is greater than the threshold. Normal low-mu pressure control is continued if both front wheels are qualified as normal-duration. Split-mu pressure control is activated when exactly one of the front wheels is qualified as long-duration. The split-mu pressure control restricts the rate of brake pressure applied to the long-duration wheel. Low-mu to high-mu pressure control is utilized when both wheels are qualified as long-duration.

Growing community of inventors

Westmount, Canada

Dan Negrin