Analyse Of MR Damper's Magnetic Circuit And Study On The Control Policy Of MR Semi-active Suspension

Adjustable damper is the main part that has great effect on the vibration control of simi-active suspension, correlative research are getting increasingly recognition. Depend on the magnetic field, MR damper can adjust the damp and bring best damp force which can make the semi-active suspension control come ture and has strong reliability. Compared with passive suspension, the vehicle semi-active suspension improves both riding comfort and vehicle maneuverability. The semi-active suspension with MR damper has arosed great attention in recent years.Research status and development course about MR Fluid and MR dampers are introduced in this paper.The development trend of vehicle semi-active suspension are summarized. According to key questions of the MR damper, magnetic circuit design of MR damper has been discussed. Semi-active suspension vebrition model has been established with Fuzzy-PID control theory. The control theory of vehicle semi-active suspension with MR damper has been researched.Working principle of MR fluid and MR damper has been discussed, magnetic circuit design principle has been analysised. Foundational design theory of MR damper's magnetic circuit was given in the paper. MR damper's electromagnetism field was simulated with Finite Element Analysis way and field distributing were researched. The influce deal to the MR damper's magnetic circuit of structure size and characteristic of excitation materal in the field were studied.The fluence dealed by magnetic circuit structure parameter has been reseached with different magnetic circuit classes.Experiment has been done to test the damp characteristics of MR Damper. Result shows the controllable character and delay character of the MR Damper. Relationship between coulomb damper force and current were analysed . Curves about coulomb damper force and current were drafted based on the test data which give theory sustain to the control system of semi-active suspension and control model of MR damper.Fuzzy-PID switch control strategy was established basd on fuzzy control and PID control. Based on 2 DOF 1/4 car model,the control simulation of MR simi active suspension has been down, results show that spring mass acceleration and suspension dynamic load reduced while Fuzzy-PID switch control was used to compare with Fuzzy control strategy, the riding comfort got improved. The control effect of Fuzzy-PID switch control is furthermore well.Hardware and software of control system has been developed. Fuzzy-PID control progam of magnetorheological semi-active suspension has been written and Fuzzy-PID controller has been empoldered based on SCM.Experiment has been done with controller. Results show that suspension with controller can minish spring mass acceleration compared with suspension without control, especially at low frenquence. Experiment data validated that the trait of Fuzzy-PID switch control was correct and feasible, the control system can good restrain the vibration of vehicle.