Research On Vertical Dynamics Of Motorcycle Suspension System Based On Approximate Model

With the diversification of motorcycle consumption,large-displacement motorcycles are favored by people for their outstanding power.Therefore,it is necessary to improve the ride comfort and ride comfort of large-displacement motorcycles by studying the suspension system of large-displacement motorcycles while ensuring the high-speed driving power of large-displacement motorcycles.Taking a domestic 550 sports large-displacement motorcycle as the research object,a complete motorcycle dynamics model is established in the dynamics simulation software Bike Sim for simulation analysis to characterize the ride comfort and riding comfort of large-displacement motorcycles.The index body pitching vibration acceleration and the front and rear wheel vertical vibration acceleration peaks are the target response.Sensitivity analysis and approximate modeling of the relevant parameters of the suspension system are carried out to achieve efficient and convenient multi-objective optimization and improve the performance of large-displacement motorcycles.Ride comfort and ride comfort,and use real-vehicle experiments to verify the optimization results.The specific research content is as follows:(1)After a comprehensive comparison and analysis,the global dynamic equation of motorcycle is derived by Lagrange method,and a complete motorcycle model is established in Bike Sim for simulation analysis.The simulation results are compared with the pitch vibration and vertical direction of the motorcycle during high-speed driving.The problem of vibration coincides.(2)Aiming at the pitching vibration problem of large-displacement motorcycles at high speeds,in order to reduce the pitching vibrations of large-displacement motorcycles at high speeds and improve the riding comfort and riding comfort of motorcycles,a multidisciplinary optimization scheme based on dynamic simulation,sensitivity analysis of experimental design and approximate model of radial basis function neural network was proposed.The results show that after optimization,the simulation analysis shows that the pitching vibration velocity of the vehicle body is reduced to 63.15deg/s,and the pitching vibration acceleration is reduced to 52.05deg/s~2.The pitching vibration problem of the motorcycle is preliminarily solved.(3)Considering the problems of pitching vibration and vertical vibration comprehensively,the acceleration of pitching vibration and vertical vibration which characterize the ride comfort of motorcycle are obtained through the simulation analysis of motorcycle on C-class road.The peak values of the above two indexes are taken as the target response,and the sensitivity analysis and approximate modeling of suspension system parameters are carried out by using the optimal Latin hypercube sampling method The results are analyzed by using radial basis function neural network approximation model and NSGA-Ⅱmethod for multi-objective optimization.The results show that the peak value of the pitch vibration acceleration of the optimized motorcycle is reduced by 19.20%,and the vertical vibration acceleration of the front and rear wheels is reduced The peak value of decreased by 16.22%and 53.85%respectively,which improved the ride comfort and ride comfort of motorcycle.(4)The optimized target response was verified by actual vehicle experiments.The results showed that the optimized peak value of pitching vibration acceleration was actually reduced by 17.21%after actual vehicle verification;the front wheel vertical vibration acceleration optimized The peak value is actually reduced by 8.11%after actual vehicle verification;the optimized peak value of the rear wheel vertical vibration acceleration is actually reduced by 24.18%after actual vehicle verification;it proves the feasibility of the scheme.It provides a certain reference for the dynamic research of domestic large displacement motorcycle suspension system,and has certain engineering value.