The Application Of Al Control On Semi-active Suspension

Suspension is one of the most important parts of automobile. Whether the kind of its construction and the parameters of performances are reasonable or not has a direct influence on the ride stability and the comfort of automobile. Traditional passive suspension has difficulty to meet people's demands, because its damp coefficient or spring firmness can not be adjustable. However, the semi-active suspension has adjustable damp coefficient. Compared with active suspension, the semi-active suspension does not demand superfluity equipment to offer energy, so semi-active suspension is much cheaper and much simple than active suspension. At same time, the control effect is nearly as same as the active suspension. The development of semi-active suspension attracts more and more people's attentions in automobile engineering industry.There are many AI (artificial intelligence) methods on suspension system, such as traditional PID, Optimal Control, Adaptive Control, Neutral Networks Control, Fuzzy Control and so on. All of these control methods whether it is classic or modern control theory; it has both disadvantages and advantages. A new control theory is brought forward in this paper. This is an algorithm based on grey theory and PID method. As a typical grey system, using grey theory on automobile suspension system research is feasible. This control strategy can enhance the semi-active suspension system control performance because it combines the advantages of both grey control theory and PID algorithm's advantages. In this dissertation, according to Newton's second law an automotive vibration model of 1/4 body is created at first, it has 2 degree-of-freedoms. Then two input model are built as the different signal. It is good for researching. At the result, simulation model is built by Matlab software.This new control strategy genetic algorithm is verified through the computer simulation. According to qualitative analysis and quantitative analysis on the simulation result, we know grey PID control algorithm is feasible and effective than traditional PID control method. By comparing with the Grey PID algorithm and traditional PID algorithm, the first can reduce the vertical acceleration, velocity and displacement vibration of automobile suspension. From the simulation result, we also can see this new control method has fairly good robustness. At the same time, Grey PID control method brought in this dissertation is proved that it can enhance the integrated performances of the suspension and meet people's demands.