초록 ▼

A brake control system is described that maximizes the braking efficiency of an under-damped actuator, such as a motor-driven linear screw. When an incipient lock condition is detected, the system determines the optimal brake pressure, relieves brake pressure and measures the duration of the pressur

A brake control system is described that maximizes the braking efficiency of an under-damped actuator, such as a motor-driven linear screw. When an incipient lock condition is detected, the system determines the optimal brake pressure, relieves brake pressure and measures the duration of the pressure release. When the wheel is approaching recovery, but has not yet substantially recovered, the system holds brake pressure constant at a value calculated to represent the amount of pressure remaining at the wheel brake. This calculated hold value is based upon the measured optimal pressure and the measured release duration, and allows the wheel to continue to reaccelerate towards recovery while preventing unnecessary pressure relief. Once the wheel recovers, the system reapplies brake pressure to a substantial fraction of the optimal pressure without over-exciting the actuator and over-shooting the desired pressure.

대표청구항 ▼

A wheel lock control system for limiting a pressure applied to a brake of a vehicle wheel traveling over a road surface, the system comprising: means for detecting an incipient wheel lock condition; means for storing a value of brake pressure at which the incipient wheel lock condition occurred; mea

A wheel lock control system for limiting a pressure applied to a brake of a vehicle wheel traveling over a road surface, the system comprising: means for detecting an incipient wheel lock condition; means for storing a value of brake pressure at which the incipient wheel lock condition occurred; means for relieving wheel brake pressure to alleviate the incipient wheel lock condition; means for measuring an elapsed time while wheel brake pressure is being relieved; means for detecting a first condition in which the wheel is approaching recovery from the lock condition; means responsive to a detected first condition for calculating a value of wheel brake pressure corresponding to an amount of pressure remaining at the wheel brake after having relieved wheel brake pressure for the measured elapsed time by (a) multiplying the stored value of brake pressure by the elapsed time to approximate an amount of pressure having been relieved from the wheel brake during the measured elapsed time, (b) multiplying the stored pressure value by a calibrated amount to arrive at a value representative of all pressure having been relieved from the wheel brake, and (c) subtracting (1) the approximated amount of pressure relieved from (2) the value representative of all pressure having been relieved to arrive at a calculated value of pressure remaining at the wheel brake; means for controlling the wheel brake pressure constant at the calculated value of pressure remaining at the wheel brake while the wheel is approaching recovery; means for detecting a second condition in which the wheel has recovered from the incipient lock condition; means for increasing wheel brake pressure in response to the detected recovery to a value which is a substantial fraction of the stored pressure value; and means for increasing wheel brake pressure gradually from the significant fraction of the stored pressure value until an incipient wheel lock condition is again detected.