The springs of the car suspenion support the weight of the
vehicle, maintain ride height, and absorb road shock. Springs are the
flexible links that allow the frame and the body to ride relatively
undisturbed while the tires and car suspension follow the bumps in the
road. The absorber absorbs the enery.
One of the main challenges in the design of car suspension systems is then to determine the optimum parameters to satisfy the generally conflicting ride, handling and working space requirements. However with conventional passive car suspensions where the suspension parameters are fixed once they are designed, the versatility is not always enough. In passenger vehicles handling is sacrificed for more comfort and in sport cars with stiff suspensions ride is compromised.
Active or dynamic car suspensions on the other hand are adaptive systems with modulating properties that can provide a much superior performance in the trade-off between ride and handling. Based on the sensor readings and a designed control algorithm, the actuator(s) in an active suspension can supply energy into the system or modulate the rate of energy dissipation from the system and therefore offer more room for improving the performance of the car suspensions systems.
The main changing parameters are