Method and system for sampling input time data for wheel speed sensor in an automotive anti-skid brake control system

摘要

An anti-skid control system records the input timing of the first of every group of sensor pulses of a given size, the given size being so selected that the intervals between recorded inputs are greater than a predetermined value. The anti-skid control system performs this sampling operation as an interrupt routine intermittently interrupting a main job which periodically derives a control signal for increasing, decreasing or holding constant the fluid pressure applied to the wheel cylinder. The occurrences of interruptions are counted and the interrupt count is decremented upon completion of each cycle of the main job. Under normal conditions, the sampling routine is performed in response to every sensor signal pulses. When the counter value becomes larger than a predetermined value, the sampling routine starts to sample only the first pulse of each group of a predetermined number of sensor signals.