Robust Control For Vehicle Active Suspension

The suspension is one of important automotive assembly, which has prodigious influence on performance of ride quality and handing stability. So it is crucial to design excellent suspension system for automotive quality. As a result of advances in electronics and control technology , control of vehicle dynamics has become a subject of widening interest during the last two decades. The article is based on the moving equation of the suspension, using nonlinear controller and robust controller to gain the super quality.First basing on the moving equation of suspension, I design the nonlinear controller using Backstepping way, so improve the inherent tradeoff between ride quality and suspension travel. The novelty is in the use of a nonlinear filter whose effective bandwidth depends on the magnitude of the suspension travel. Thus our nonlinear design allows the closed-loop system to behave differently in different operating regions, thereby elimination the dilemma of whether to use a soft or stiff suspension setting.Second A very important method in modern robust control theory is based on Lyapunov function. With the nonlinear systems being study advancing and the appearing of new ways to nonlinear systems base on non-sourcing, the idea is developing quickly. The article introduce the nonlinear robust control theory and design method, and get good controller. A important part of robust control is the robust control with adaptive function, and it could be applied on active suspension. The article use three ways to design controller with adaptive robust control theory, it include state feedback adaptive robust controller, output feedback adaptive robust controller and modular adaptive robust controller. In the last, give the simulations about the controllers.Last the article compare the nonlinear controller with the adaptive robust controller and simulate them and build a model to test the controller. The output display that the nonlinear controller responding is faster and the robust controller could adaptive to uncertainty more than other controller.