Abstract:

At present， the assembly ratio of air suspension in different vehicle models is increasing， however， the air suspension matching of vehicle performance is mainly carried out based on the constant ambient temperature， and the control performance of air suspension in wide temperature range is rarely considered. For the problem of air suspension height control of passenger cars in wide temperature range， this paper proposes a wide temperature range air spring characterization model from the static characteristics of air springs， and simulates the height control of the suspension system of passenger cars in the non-motion state to carry out simulation and experiments， so as to realize the improvement of the service performance of the vehicle in the wide temperature range. Firstly， a wide temperature domain air spring model is established by wide temperature domain test data， which fully considers the influence of temperature on rubber and on gas. Secondly， an air suspension control algorithm based on the online linear quadratic regulator method （LQR） is proposed， which takes into account of the influence of temperature on airbag parameters. Finally， the robustness of the controller is verified under wide temperature domain conditions. Simulation and experiments show that the controller can control the body height to reach the target height and avoid oscillations under wide temperature range， with good stability and robustness.

Key words: air suspension, wide temperature domain, online linear quadratic regulator method, height control