A Study Of Harmony On Semi-active Suspension System And Vehicle Performance

The ride comfort and handling are two of the main performance indexes of vehicle, Vehicle suspension system plays an important part in improving vehicle ride comfort and handling. The traditional passive suspension has become incapacity in improving the two performance of vehicle, With the demanding of improving vehicle performance further, the traditional passive suspension can't meet the demand of the vehicle step by step, and so the non-passive suspension using electronic control method to improve the quality of suspension system has been studied. Although the active suspension system removes the restrictions of the passive suspension system, its cost in hardware is high. Therefore there are few actual active suspension system to be found on the vehicles. The semi-active suspension as compromise between the conventional passive suspension system and active suspension system, can perform the function of active suspension system, but the requirements of the power is very few. So a variety of semi-active suspension systems have been into practice. The thesis studied preliminarily on the semi-active suspension.First, On the basis of NJ130 damper, the blue print of the variable-damper was conceived. A method was put forward which change damp by turning up throttle scoop, and produced the variable-damper for test. After the test, the dynamic characteristic of the variable-damper was analyzed and the blue print was validated which provided the reliable gist for constituting more applicable model of semi-active suspension. The problem in testing was analyzed detailedly which established the basis for designed the good variable-damper.Secondly, Refering to the dynamic characteristic of the variable-damper, the thesis established the 1/4 vehicle non-linear model of the semi-active suspension. Compared to traditional linear model, analyzed the virtue and flaw of the model, demonstrated the model more reasonable, provided the gist for designing the neural network system and the learning method, established the basis for designing the semi-active suspension to harmonize the vehicle performance.Finally, A feedback control system of neural network was designed and a special learning method was produced to train the neural network which was applied in the non-linear model of semi-active suspension. The result of test showed ride comfort and handling was improved preferably after the control, and the semi-active suspension system harmonized the vehicle performance with the controller.