Research On Fuzzy-Sliding Mode Control Method Of Active Suspension

The suspension system and its control method are always being concerned in the field ofresearch and development. Whether the suspension system and its control method are developedor not, has an important indicator to check the safety of the vehicles, stability of the car and thecomfort of the drivers. An advanced active suspension control method can come across theterrible environment more easily by adjust its posture better, which means a lot to the safety andriding comfort of the cars. Therefore, to research and promote the active suspension system is abreakthrough in the field of auto industry and also an important issue of the auto industry of ourcountry and the world’s.Firstly, a simple overview of the active suspension system and its control method at home andabroad has been introduced, and also the common control methods of active suspension systemand their advantages and shortcomings. Then the paper presents Sliding Mode Control (SMC)strategy in suspension systems as well as the purpose of this paper and significance. The mainpart of the paper established the incentive model of vehicle’s four pavements based on roadroughness and simulated the excitation signal in time-domain in the uniform traffic condition bysimulation software. Followed, the full car active suspension model is established. Based on theSMC theory, the pole placement design method is applied to design the SMC switching surfaceand control rate of7-DOF active suspension system of the vehicle model. The vertical vibration,pitch, roll of the body of the car, the four wheels’ vertical displacements and their accelerationsare the state variables here. In order to start SMC, algorithm is selected to adjust each activeforce of the actuator, and a better analysis is done for the vehicle. To suppress the jitter problemeffectively of SMC, Fuzzy Control (FC) algorithm is used to blur the switch function value andits differential of the sliding surface and output. During the simulation section, passivesuspension model, SMC model and FSMC model of active suspension were established. In theMATLAB/Simulink simulation software, vehicle vertical vibration, pitch, roll, and the fourtires’ displacements and their acceleration signal simulation results were presented under thethree different control strategies. The simulation data shows that the control method suppressedthe vibration of the body, improved vehicle ride comfort aspects indicators by30%to40%thanthe traditional passive suspension, verifying the robustness and stability of the control method.The full text of the research and simulation analysis shows that the proposed FSMC method is feasible to improve the vehicle performance and control robustness of active suspension, thisstrategy can significantly improve the performance of vehicle suspension with importanttheoretical and practical significance.