Study on the impedance of active suspension drive unit under transverse slope condition based on track sensitivity

To improve the safety and stability of active suspension during slope conditions, sensitivity optimization is performed on the active suspension lift control system. A mathematical model of the active suspension under slope conditions is established, and the first-order trajectory sensitivity method is employed to analyze the trajectory sensitivity of the suspension lift under slope conditions. The sensitivity of each parameter corresponding to the displacement response is obtained, and sensitivity metrics are established to quantitatively analyze the degree of influence of parameter original-variations on the output dynamic characteristics. Next, a mathematical model of the position-based impedance for the suspension lift drive unit and the impedance lift sensitivity equations are established. The equations are solved to obtain the sensitivity curves and sensitivity metrics after impedance optimization. A comparison is made between the sensitivity before and after optimization, and the degree to which the parameters of the system affect the suspension lift output displacement dynamic characteristics is quantitatively analyzed after impedance optimization. The research results indicate that the variation of parameters such as the effective area of the hydraulic cylinder piston, the equivalent total volume of the hydraulic cylinder, the hydraulic oil elasticity coefficient, the pressure-flow coefficient of the proportional servo valve, the total leakage coefficient of the hydraulic cylinder, and the maximum load had a significant impact on the dynamic performance of the suspension lift drive unit. After impedance control optimization, the influence of these parameters on the dynamic performance was effectively reduced. Finally, the accuracy of the sensitivity before and after optimization was verified through semi-physical simulation experiments.