Control of an anti-lock braking system using fuzzy logic

The control device of a vehicle's anti-lock braking system (ABS) most commonly implements two-position control. In modern automation systems, many other control laws are used, which in certain cases are much better than the two-position control. This article discusses the development of a fuzzy PID controller for the control of an ABS. The fuzzy PID controller is tuned using the optimization method, which employs a genetic algorithm to determine the optimal solution. A comparison is made between the transient processes in the ABS control device with a two-position controller, a PID controller and a fuzzy PID controller, and the robustness of the system is evaluated. The 14 s braking time for the two-position controller decreases to 13 s when operating with a PID controller and to 11 s when operating with a fuzzy controller, which represents a 25% reduction in braking time, and therefore a shorter braking distance. The developed fuzzy controller also provides a better system robustness and will reduce pressure fluctuations in the pipes.