Adaptive Backstepping Control Design for Active Suspension Systems with Output Feedback

The paper focuses on designing an output-feedback adaptive controller which maintains the comfort and safety of the vehicle body. The road disturbance is modelled as a finite sum of sinusoidal waves with unknown frequencies, amplitudes and phases. The road disturbance is parametrized and estimation of the derivative of the unknown road profile as well as the unmeasured system states are achieved. An adaptive controller is proposed using a backstepping approach. It is shown that the equilibrium of the closed loop system is exponentially stable. The effectiveness of the observer and controller designs is illustrated with a simulation of a road test.