Research On Optimization And Control Of Hydro-pneumatic Suspension Matching Mechanical Elastic Wheels

Hydro-pneumatic suspension is a widely used non-linear suspension system,which plays an important role in improving vehicle ride comfort and stability.Mechanical elastic wheels have a negative impact on vehicle ride comfort and stability because of its large radial stiffness.In order to improve the driving performance of the vehicle with mechanical elastic wheels,the matching research of hydro-pneumatic suspension and mechanical elastic wheels was carried out.The research contents include:(1)Collected the relevant data of hydro-pneumatic suspension,described the development of structure,modeling method,optimization method and control strategy of hydro-pneumatic suspension.(2)The characteristics of various types of hydro-pneumatic suspension were considered.An external single-chamber hydro-pneumatic suspension was selected and its structure,working principle and mathematical formula were analyzed.The mathematical model of hydro-pneumatic suspension was established by SIMULINK,and its non-linear characteristics were discussed.(3)By fitting the stiffness of mechanical elastic wheels,a mechanical elastic wheel model was established in SIMULINK.The parameters of hydro-pneumatic suspension were preliminarily designed according to the characteristics of wheels,and the vibration characteristics of suspension system were explored.The ride comfort and stability of the vehicle with mechanical elastic wheels and hydro-pneumatic suspension were studied by using the joint simulation of SIMULINK and CarSim,and compared with the common inflation wheels.(4)By studying the influence of various parameters of hydro-pneumatic suspension on its stiffness and damping characteristics,a Four-Degree-of-Freedom half-car vibration model and road roughness input model were established to determine the evaluation index of vehicle ride comfort and stability,and the optimization of hydro-pneumatic suspension was transformed into a mathematical problem.The principle and advantages of quantum genetic algorithm were studied and applied to the parameter optimization of hydro-pneumatic suspension.The results of quantum genetic algorithm are compared with those of traditional genetic algorithm.(5)Based on reinforcement learning theory,the semi-active control method of hydro-pneumatic suspension was studied.The application scenarios of different reinforcement learning methods were analyzed,and DQN and DDPG were used to adjust the parameters of suspension damper valve hierarchically and continuously,respectively.Using the mixed programming of MATLAB and python,a two-degree-of-freedom vibration model was established in MATLAB,and the real-time informationwas transmitted for python to learn,and the control strategy obtained by reinforcement learning was input into MATLAB to verify the control effect.Through the optimization and control of the hydro-pneumatic suspension,the performance of the vehicle with mechanical elastic wheels has been improved.