Research of Continuous Variable Camshaft Timing system based on fuzzy-PID control method

Aiming at the control requirements of high speed, accuracy and stability for Continuous Variable Camshaft Timing (CVCT) system, an approach is proposed to adjust PID parameters online and realize by hardware. It combines fuzzy controller with PID controller to realize the self-adjustment of the PID control parameters in which the phase error e and the phase error rate ec are as inputs and the PID controller parameters are as outputs based on fuzzy control rules. The FPGA is employed to implement the algorithm and guarantee that it is fast and reliable. Finally, the experiments are executed on CVCT Test Desk and the results show that the control method can satisfy the condition that the adjustment time of system is less than 400 ms and the overshoot is less than 3°when the phase error is in the range of [−15, 15] degree.