Time-delayed vibration control and parameter optimization of semi-active vehicle suspension designed for random road excitation

Under the influence of road excitations, the acquisition of optimal time-delayed feedback control parameters is deemed crucial for the improvement of the vibration reduction effect of semi-active vehicle suspension systems. Moreover, different effects on vibration reduction are generally exhibited by vehicle suspension systems based on different time-delayed state feedback control. Therefore, the mechanical model of time-delayed feedback control in semi-active vehicle suspension systems is chosen as the research focus in this paper. Firstly, the optimal values of time-delayed feedback control parameters are derived through an optimization algorithm based on “equivalent harmonic excitation.” Secondly, driven by the optimal values derived from optimization, this study is primarily focused on the investigation of the vibration reduction effect of time delay in a vehicle’s semi-active suspension system under road excitation, thereby revealing the optimal time-delayed feedback control strategy. Finally, the study suggests that a stable state with full time delay within the effective vibration frequency range is more likely to be achieved by the semi-active vehicle suspension system based on time-delayed state feedback control of wheel vertical displacement. Additionally, the optimization efficiencies for vertical seat acceleration, vertical body acceleration, suspension travel, and tire displacement are reported as 97.73%, 98.95%, 47.30%, and 46.38%, respectively.