Experiment Research on Fine Regulation of Wheel Cylinder Pressure Using PWM Technology

A test bench of ABS/ASR integrated hydraulic system is developed by using pulse-width modulation （PWM） technology. The effective duty ratio range of ABS outlet valve has been tested in PWM control. With 50 Hz carrier wave frequency, the tests are performed to determine the correspondence between duty ratio and the wheel cylinder pressure variation. The duty ratio range of ABS outlet valve in PWM control is determined and an experimental model of pressure reduction velocity （PRV） of wheel cylinder using PWM control is established. By comparison and test of the experimental model and realization of controlling the duty ratio of ABS outlet valves, the fine regulation of wheel cylinder PRV is realized in the working of ABS/ASR braking regulation, which is important and valuable to the improvement of the ABS/ASR controlling effect.