Stability-assured robust adaptive control of semi-active suspension systems

The paper is concerned with a stable robust adaptive scheme for semiactive control of suspension system installed with MR damper, which can deal with uncertainties in both models of MR damper and suspension mechanism. The proposed scheme consists of two main adaptive controllers: One is an adaptive inverse control for compensating the nonlinear hysteresis dynamics of the MR damper, which can be realized by identifying a forward model of MR damper or by directly adjusting an inverse model of MR damper. The other is an adaptive reference control which gives the desired damping force to match the seat dynamics to a specified reference dynamics, which can also be designed by taking into account the passivity of the MR damper. The stability of the total system including the two adaptive controllers is discussed and its stability condition is explored. Validity of the proposed algorithm is also examined in simulation studies.