Research On Control Strategy Of Rocker-pin Jointed CVT Speed Ratio Based On Genetic Algorithm

Continuously Variable Transmission (CVT) is simple in structure and can realize contionuous change of speed ratio within a certain range.so that the engine always keeps working in the optimum area,and improves the economy,power and smoothness of the whole vehicle effectively.Aiming at nonlinear and time delay problem of complex systems which are difficult to be solved by tradition methods.In this paper,genetic algorithm is introduced into the control system of CVT to explore better control effect.The main work content are as follows:Then the structure and working principle of rocker-pin jointed CVT were analyzed,the dynamic relationship between the parameters was determine in the process of automobile operation.The chenge rule of CVT speed ratio is analyzed,and control strategy of CVT speed ratio in three common working conditions was determined.Secondly,the engine test data were analyzed and processed in Matlab to obtain the engine's output torque mdoel and fule consumption rate model,then further processing to obtain the engine's optimal economic and power performance curve.Then CVT drive system was analyzed with its hydraulic system is simplified appropriately,the mathematical model of drive system and simulation model were established,It manly includes rnginr simulation sub-model,target speed ratio sub-model and speed ratio fyzzy controller simulation sub-model.Then the controller was verified on the co-simulation platform of Simulink and Cruise.Compared with the traditional speed ratio control method,genetic algorithm was used to optimize the paramreters of the fuzzy controller,and the simulation was carried out under the working conditions.The research and analysis of the CVT speed ratio control stategy in this paper provide a theoretical basis for the later development of the control strategy,and there was a certain automobiles...