Abstract
When designing vehicle suspensions, the dual objective is to minimize the vertical forces transmitted to the passengers (i.e., to minimize vertical car body acceleration) for passenger comfort, and to maximize the tire-to-road contact (i.e., to minimize wheelhop) for handling and safety. While traditional passive suspensions can negotiate this tradeoff effectively, active suspension systems have the potential to improve both ride quality and handling performance, with the important secondary benefits of better braking and cornering because of reduced weight transfer. This improvement, of course, is conditional upon the use of feedback to control the hydraulic actuators. In this paper we propose two methods for analysing this tradeoff. First, we use frequency domain analysis of passive quarter- car suspension system and second we design a backstepping controller for analyse a parallel active suspension in wich the hidraulic actuator force is viewed as the control input. Finally, some concluding remarks are given for further research.
Keywords: active suspension, control, transfer functions, backstepping.