The Speed Ratio Control Strategy Research Of Metal-belt Type CVT Based On Hysteresis Characteristic

With the continuous development of economic construction and people’s livingstandard，cars have gradually become people’s transport in the modern society，moreand more used by the ordinary people. At the same time，various performance ofautomobile is also put forward higher request，Especially in the area of economicperformance and dynamic performance.In order to better improve economic performance and dynamic performance ofcar, we can consider to use metal belt type stepless transmission (CVT) as an idealtransmission of the car. CVT with excellent performance, simple structure, realizingauto stepless speed changing, etc. Through reasonable control of stepless transmissionratio. Can make the car to achieve dynamic optimal matching according to driver’sintentions between the car driving resistance and the engine power output. Making theEconomy performance and power performance of the car to the limit state.First of all，Based on consulting a large number of literature at home and abroad，the paper discussed the advantages and disadvantages of stepless transmission,development trend and research status at home and abroad, analyzed The structure ofmetal belt type stepless transmission and working mechanism. Then, In the MATLABenvironment, the engine bench test data are analyzed, Got the Feature model of theoutput torque of the motor model, power output, specific fuel consumption. Then,Setting up a simulation model of CVT vehicle transmission system, based on thesimulation model, Put forward to solve transmission system response lag in CVT ratiocontrol strategy, the results show that the economic performance is improved. The last,control strategy is improved the bench test of speed ratio following experimental. Theresults show that this ratio based on hysteresis control strategy is correct and feasible.