Modelling and control of a semi-active dual-chamber hydro-pneumatic inerter-based suspension system

This study develops a new type of semi-active dual-chamber hydro-pneumatic inerter-based suspension (SADHPIS) based on the ‘inerter–spring–damping’ vibration isolation system and semi-active control. The mathematical model of SADHPIS is linearised to match the nonlinear SADHPIS system with a linear control strategy, and the equivalent parameters are calculated. A linear–quadratic–Gaussian (LQG) controller that matches the nonlinear characteristics of the SADHPIS system is designed. Furthermore, the performance of a quarter-vehicle model with SADHPIS is analysed and compared with that with normal semi-active hydro-pneumatic suspension (SAHPS). Simulation results show that the performance of SADHPIS is better than that of SAHPS, indicating that ride comfort and handle stability are improved greatly in SADHPIS. A prototype is also developed, and a comparative bench test is conducted to verify the accuracy of the simulations. SADHPIS can realise adjustable inertia with a small space and low energy consumption. This work provides new insights for research on variable inertia, promotes the matching of inerters and hydro-pneumatic suspension systems and further proves the practical application value of hydro-pneumatic inerter-based suspension.