Research On Vehicle Height Control System Of Air Suspension Based On Agent Theory

Air suspension is widely used due to its low vibration frequency,variable stiffness and adjustable vehicle height.As one of the characteristic functions of air suspension,vehicle height adjustment has attracted much attention from global scholars.Vehicles can alleviate the contradiction between ride comfort and control stability by adjusting vehicle height,and further improve the performance of vehicle.Therefore,combined with agent theory,advanced intelligent control concept is introduced into the vehicle height adjustment system to improve the effect of the vehicle height control system,which is of significance to improve the overall performance of air.Suspension.Based on the thorough investigation on the related literatures at home and abroad,in this paper,the air suspension is taken as the research object,and the vehicle height adjustment system is studied.Firstly,according to the working principle of air suspension charging and discharging system and thermodynamic theory,the key sub-modules of the system were modeled,the air suspension charging and discharging system model was established.On this basis,combining with vehicle dynamics,the height control system model of air suspension vehicle was established according to the structure of test sample vehicle.In addition,an air spring characteristic test platform was built to obtain spring parameters by bench test.In order to meet the needs of subsequent research,the vehicle information acquisition system was designed based on the Arduino electronic prototype platform,and the vehicle test is carried out to verify the accuracy of the vehicle dynamics model.Secondly,the vehicle height control system of air suspension was studied by using the established height control system model of air suspension vehicle.According to the design requirements of the vehicle height control system,the height control system of the whole vehicle was designed.Among them,in order to improve the adaptability of vehicle height control system in dynamic environment,a fuzzy-PID vehicle height controller was designed according to the theory of fuzzy control.Extended Kalman filter was used to process sensor signals to reduce the interference of road excitation.The simulation results prove that the designed height control system can effectively adjust the vehicle height,which lays a foundation for the follow-up study of the vehicle height intelligent control system.Finally,combined with agent theory,the overall structure of vehicle height intelligent control system based on hierarchical structure was designed.Among them,a target height control agent was constructed as the upper controller under the framework of BDI model.The perceptual behavior,reasoning behavior,learning behavior and decision-making behavior of the agent were emphatically designed.The simulation model of the vehicle height intelligent control system model was established under the environment of Matlab/Simulink simulation,and the corresponding simulation conditions were set up for simulation analysis.The simulation results under a single working condition verify the effectiveness of the learning behavior and the learning effect.The simulation results under a mixed working condition verify the control effect of the vehicle height intelligent control system of the air suspension.The results show that the vehicle handling stability can be improved without deteriorating ride comfort through the vehicle height intelligent control system.