Research On Control Method Of Active Suspension For A Heavy Vehicle

As a new type of passive suspension system, hydro-pneumatic suspension is based on the inert gas (usually nitrogen) as the elastic medium, and the oil as the transfer medium, at the same time, It has good nonlinear damping and stiffness characteristics, and can ensure that vehicles get a good ride comfort and handling stability; it not only has the features of traditional passive suspension, but also can use the hydraulic drive and control algorithms to improve the performance became active suspension. Therefore, it has important practical significance for improving the performance of the vehicle by studying active pneumatic suspension system.This article is based on a single-chamber heavy vehicles pneumatic suspension for the study, the working principle of the actuator (hydro-pneumatic spring) is analyzed and the nonlinear mathematical model of hydro-pneumatic spring is established by using the flow orifice and the ideal gas equation theory. In the AMESim software environment, the performance of hydro-pneumatic spring under different excitation frequency and amplitude is studied, and by comparing the simulation results with the experimental data to verify the correctness of the mathematical model. The key part of the active control system of hydro-pneumatic suspension, the electro-hydraulic servo valve is modeled, and based on this, the vehicle vibration model of two degree of freedom active hydro-pneumatic suspension is established. In view of the characteristics of the heavy vehicle hydro-pneumatic suspension system, the fuzzy PID control strategy is established based on the AMESim and Simulink. The performance improvement of the active hydro-pneumatic suspension system with the same random road input is analyzed.