John B Dombrowski

48366161, Jun 6, 1989

Jul 7, 1988

7/216918

Daniel W. Roper - Rochester MI
Dennis A. Kramer - Troy MI
Mark E. Malinowski - Farmington Hills MI
John Dombrowski - Redford MI

Rockwell International Corporation - Pittsburgh PA

B60T 888

303 92

A antilock brake system utilizes a microprocessor controller to monitor the rate of speed decay of a braked wheel of a vehicle and to cause release of braking force under incipient wheel lock-up conditions. The microprocessor receives a single digital wheel speed input signal and processes the latter in accordance with a program whereby a reference signal is generated and is periodically compared with the wheel speed signal to determine if a lock-up condition is in progress. The microprocessor compares the speed signal with the reference signal at frequent sampling intervals and when the wheel speed decreases at a rate exceeding a desired value, the reference signal is varied by the microprocessor to decrease at a predetermined first rate of decrement until the wheel speed signal and the reference signal correspond to each other, indicating that the wheel speed is dropping at a rate in excess of a desired rate of speed decay. The microprocessor adjusts the rate of decrement of the reference signal at a second maximum rate and generates a brake release signal to relieve the brake force applied to the wheel. When the wheel speed signal again crosses over the reference signal, the brake force is restored and the reference signal again tracks the wheel speed signal at a value less than the wheel speed signal.