Physical Parametric Model of an Automotive Electrohydraulic Semiactive Damper

A full mathematical model is developed to formulate the nonlinear characteristics of an automotive electrohydraulic semiactive damper. This multidisciplinary physical parametric model considers the force equilibrium, flow continuity with flow losses due to the volumetric change and pressure difference, total flow through the valve system under different control modes, and dynamics of the floating piston which are balanced by the pressures of the fluid and gas. Both computer simulation and bench testing of the damper demonstrate that the damper has four levels of damping characteristics: "hardmode", "hard rebound and medium-soft compression mode", "medium-hard rebound and soft compression mode" and "soft mode". The considerable consistency between the simulation and experimental results verifies that the mathematical model accurately captures the physical damping characteristics of the damper. Thus, the developed physical damper model is experimentally validated. The obtained full parametric damper model with mode controls is valuable for accurate and reliable damper development and crucial for the next step in vehicle system dynamics simulation and suspension control system synthesis.