Based On Multi-Objective Optimization Of Dynamic Programming Fuzzy Control In Vehicles Semi-active Suspension System

As one of the most advanced suspension systems, the semi-active suspension system can be in the best optimal damping state when adjusting the damping and the stiffness, which being achieved the perfect combination, timely according to the real-time condition. In recent years, the semi-active suspension system as the focussed research program of the suspension systems has become the one of the most popular technology for the automotive research.For the vehicle semi-active suspension systems, we use the method of fuzzy control which is more popular in controlling and simulating in recent years. At home and abroad, fuzzy control is used in the semi-active suspension control based on the experience of experts to determine the parameters of fuzzy controllers, which have great limitations. In this paper, we will use the method of Multi-Objective Optimization of Dynamic Programming to search for the fuzzy controller rules and the membership functions of the Fuzzy partition for the optimal control, and then give the simulation for fuzzy control.The adoption of this paper is the commonly used 1/4 vehicles model. Through the equation given by the literature, the fourth vehicle with two degree of freedom suspension model is established, and further the state equations are derived. For the control problem of Multi-Objective Optimization, firstly, we divide it into multiple stages reasonably. According to each stage of the requirements of control, through the transfer equation of state we use a reasonable decision-making and strategy to reach the local optimal policy, then we can reach the approximation overall optimal policy via the Algorithm of the Multi-Objective Optimization of Dynamic Programming. So we can choose and give each of control rules, then through the fuzzy relationship, according to the fuzzy reasoning to get the inquiry form of control. With Matlab software, the simulation for controlling the model of semi-active suspension control system of vehicle which using a dual-input and single-output fuzzy controller of is given. Through the results of simulation, it shows that the method for improving the performance of semi-active suspension system is feasible.This thesis not only provides an basis for the semi-active suspension system in the actual applications of the vehicle manufacture, but also provides the theoretical basis for further studying on the performance of vehicle dynamics and the computer control.