A novel method of vehicle height control utilizing semi-active actuator

Inspired by the physical phenomenon that the balance position of the vehicle body changes due to a suspension system with asymmetric damping, this paper presents a novel method to control the vehicle height utilizing semi-active actuators. The proposed vehicle height control method uses the asymmetric damping of the semi-active actuator to control the raising and lowering of the vehicle body, which essentially harnesses the energy from the vehicle's driving vibrations and has the characteristics of low cost, energy saving and fast response. Aiming at the strong nonlinearity and discontinuity of the piecewise linear nonlinear system of the vehicle body vibration, the homotopy analysis method (HAM) is used to solve the high-order analytical solution, the nonsmooth terms are processed through Fourier series expansion, and the iteration method is combined to treat the iteration result as the initial guess solution for the next iteration, improving the convergence accuracy of the series solution and expands the application scope of the HAM. The feasibility of the presented method is investigated from an analytical point of view and the influences of some critical parameters on the responses of the system are analyzed. Finally, the magnetorheological damper (MRD) produced by LORD company is utilized as the actuator, and the vehicle height control experiments system is established by using NI-Labview software and NIPXI hardware platform, The experiments are performed to verify the feasibility of the proposed vehicle height control method and the system response laws. The proposed method realizes the functions of active actuators using semi-active actuators, and tries a new method and approach for vehicle height control under specific working conditions, such as short-term obstacle surmounting, high-speed steering, emergency avoidance, and rollover prevention.