Research On Speed Ratio Control Of Metal Belt Continuously Variable Transmission Based On Fuzzy Immune Pid

As the current ideal transmission of vehicle, Continuously Variable Transmission (CVT) can achieve the best match of engine- transmission - road environment. CVT control system is the key to realize the best match. CVT speed ratio control is one of the key technologies of CVT control system impacting on the car power, fuel economy and driving performance directly. Thesis takes a metal belt type continuously variable transmission of passenger car as the research object and studies fuzzy immune PID intelligent control method of CVT speed ratio control and intelligent control strategy under drive mode based the subjective will of driver.Firstly, according to the dynamic equations of CVT, the transmission system model is set up. Then, the regulation characteristics of engine speed are considered and the optimal power schedule and optimal economic performance route are determined. On this basis, the goal ratio of CVT under power and economy mode is calculated, and the CVT ratio control strategy and Real-time adjustment strategy are studied to achieve optimal engine power, economy and improve the car's driving performance.Secondly, in order to verify if the fuzzy immune PID CVT speed ratio control method is feasible or not , fuzzy immune PID of the CVT speed ratio control method based on analysis of PID control, fuzzy control, and biological immune feedback control and design the fuzzy immune PID Ratio Controller are discussed; Then, PID control and fuzzy immune PID control under automotive common conditions are compared to study the effect of fuzzy immune PID speed ratio control, and the results show that the fuzzy immune PID ratio control is superior than PID control in accuracy and response speed significantly.Lastly, in order to improve driving performance of car with CVT, the intelligent control strategies of CVT under CVT drive model are discussed. On the basis of describing the driving characteristics of drivers, CVT drive mode shift schedule is drafted. And power factor is proposed to express subjective drivers'wishes when the throttle is steady. Then, fuzzy control method is used to design an intelligent controller, and the simulation effect is analyzed. The simulation results show that the intelligent control reasonably reflects the drivers'wishes and realize the human - vehicle coordination.