Mass-adaptive Takagi-Sugeno fuzzy control for semi-active vehicle suspension with a CDC damper and experimental validation

This study proposes a novel mass-adaptive control strategy for Continuous Damping Control (CDC) semi-active suspension systems, operating within the feasible range of the CDC damper’s drive current. To facilitate control design, the suspension system characterized by asymmetric saturation is transformed into an equivalent system with symmetric actuator saturation. A current-based piecewise affine (PWA) model combined with the Takagi-Sugeno (T-S) fuzzy method is utilized to address the CDC damper’s nonlinearity. A mass-adaptive fuzzy controller is developed using switched quadratic Lyapunov functions (SQLFs) and optimized for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>H</mml:mi> <mml:mi>∞</mml:mi> </mml:msub> </mml:mrow> </mml:math> performance. Simulation results show that the proposed controller effectively adapts to variations in vehicle mass: in underloaded conditions, it exhibits soft damping characteristics, while under overloaded conditions, the proportion of damping force in the hard damping region increases by 23.64% compared to underloaded conditions, indicating hard damping characteristics. Bench tests validate its superior performance over existing methods within the operational frequency range.