A new dynamic stiffness model with hysteresis of air springs based on thermodynamics

A new theoretical model of the dynamic stiffness of air springs based on thermodynamics is proposed for determining the precise algorithm for air suspension control systems. The complex stiffness formula comprehensively considers the external heat exchange equivalent damping characteristics and air spring stiffness and damping characteristics with clear physical meaning and precise mathematical expressions for each contribution. Compared with the traditional air spring model, this model is universal because it does not restrict the gas change process inside air springs. Based on the new model, a set of identification methods for key nonlinear parameters are given. The indicator experiment was carried out to validate the dynamic stiffness model and parameter identification methods under various frequencies and strokes. Finally, the influence of key parameters and their dynamic characteristics are analysed. This theory and experiment identify air spring nonlinear parameter frequency dependence and change characteristics.