A Novel Fuzzy Logic Control on the FVVT Lift of Internal Combustion Engine

In the research of intelligent control on the internal combustion engine, especially in the control of fully variable valve timing (FVVT) system, the efficiency of valve tracking control can be improved by accurate control of the valve lift. This paper bases on the valve lift PID controller and integrates the application of fuzzy logic which has an advantage can be shown on the fully variable valve timing. The mathematical model is established by analyzing the working principle of the fully variable valve timing. The PID parameter adjustment and response programs are developed respectively by studying the relationship between fuzzy logic and the controlled actuator. Based on the Delphi method, the fuzzy logic controller (FLC) is designed by selecting the fuzzy membership function and the fuzzy logic rules which will effect status of system. The Simulink model is built, compared with the incremental PID controller, the result is that the fuzzy logic PID controller performance and robustness are better than the incremental PID controller not only the case of steady speed but also the case of changing speed, which can provide an valuable reference for enhancing the efficiency of fully variable valve timing tracking control on the internal combustion engine.