Magneto-rheological Damping Based On Fuzzy Pid Control System Design And Implementation

The damping of traditional passive hydraulic absorber can not be adjusted, which leads to the smoothness of vehicle working in the poor conditions under different road excitations and driving situations. Magneto-Rheological (MR) damper is a new type of intelligent damper, which has many merits, such as large adjustable damping force, low power consumption and small size. So, it has become a research focus in the field of vehicle damping system at home and abroad.A mathematical model of the MR damper system is built firstly, and then based on the model, the system characteristics are analyzed. Secondly, the paper studies fuzzy PID control algorithm for the MR damping system. Lastly, the hardware and software of the MR damping control system are designed. Ultimately, the MR damping control system can adjust damping characteristics in real-time, which can ensure the riding comfort of vehicles. The main research topics are as follows:(1) The mathematical model of the MR damping system is established. Firstly, according to the MR damper working principle and mode, the damping force model of the MR damper is set up under the mixed working mode. Then, based on the damping force model, using the Newton's second law, this paper builds the mathematical model of the MR fluid damping system.(2) The characteristic of the MR damping system is analyzed. First of all, this paper analyzes the passive MR damping system in frequency domain, based on the mathematical model of MR damping system. Then, for a certain road input, by setting various damping ratio, the dynamic characteristic of the semi-active MR damping system is analyzed. The optimum damping ratio are obtained, which effectively ensures ride comfort of the vehicle.(3) Fuzzy PID controller is designed. Due to nonlinearity, time variability and multi freedom vibration of the MR damper system, a fuzzy PID control algorithm is adopted to control the acceleration of the vehicle body, based on the mathematical model and characteristic analysis results. Through comparing with the passive control and PID control algorithm, the simulation results show that the MR fluid damping system has a better performance under the fuzzy PID control.(4) MR damping control system is designed. For the fuzzy PID control algorithm and system control accuracy requirements, this paper takes TMS320F2812 as the main controller. Then it designs the hardware circuits and software algorithms. Ultimately, the MR fluid control system is realized.(5) Experimental program is proposed and tested. Based on the experimental platform, the experimental program is developed, and the controller of the MR damper is tested. The experimental results show that the MR fluid damper control system can adjust the damping force in real time, which effectively ensure the smoothness of vehicles.