Study On The CVT Control Strategy Based On Fuzzy PID

Continuously variable transmission（CVT）is a new type of transmission devicethat can change transmission ratio in succession. It can satisfy the requirements ofpower performances, fuel economy of the vehicle and driving comfort commendably.Control performance is the important factors influencing the CVT product features.Combining the reality of enterprise product research, the transmission characteristicsof CVT, the control strategy and control method were studied for a certain type CVT.(1) Speed ratio change rule was analysisd and the speed ratio control strategyand target speed ratio function was determined under driving conditions such asaccelerate, driving stability and slow down. CVT speed ratio control was researchedusing the fuzzy PID control method(2) Vehicle simulation model was established and simulated based on the AVLCRUISE software platform to evaluate automobile power performance and fueleconomy as evaluation target. The correctness of the model was verified bycomparing the measured data.(3) Using MATLAB/SIMULINK module was to establish the fuzzy PID speedratio control model. According to the EUDC, ECE15and NEDC three standardoperating modle, the vehicle tracking characteristics of the speed ratio was showed.The rationality of the control model and control strategy is confirmed.Research results show that: The throttle opening rate and driving resistance isthe main factors which influences the performance of CVT speed ratio control.FuzzyPID control is a good way to meet the requirements of speed ratio change underdifferent driving conditions, and it has good robustness. Fuzzy PID speed ratiocontrol model has good traceability, and control model and control strategy isreasonable.