Study on Sliding Mode Variable Structure Control Strategy of Semi-Active Suspension Based on Power-Flow Analysis

To comprehensively improve vehicle ride comfort and body attitude stability, as well as to enhance the robustness and disturbance rejection capability of the suspension system under uncertain operating conditions, this paper first establishes a full vehicle suspension dynamic model. On this basis, an improved SH-ADD controlled suspension is proposed as a reference model through the analysis of power flow characteristics within the suspension system, and a sliding mode control (SMC) strategy is subsequently designed based on this reference model. Simulation results indicate that, compared with conventional control strategies, the proposed algorithm offers a clear advantage in reducing the root mean square (RMS) values of sprung mass acceleration, thereby effectively suppressing body vibration and improving ride comfort. In addition, both roll and pitch angular accelerations are notably reduced, contributing to enhanced body attitude stability. Moreover, when subjected to parameter uncertainties such as variations in vehicle speed and sprung mass, the proposed controller maintains excellent robustness and stable control performance, demonstrating its overall effectiveness in improving suspension system performance under complex operating conditions.