Design and implementation of in-arm hydro-pneumatic suspension control system based on multi-objective output feedback

Abstract

The in-arm hydro-pneumatic suspension unit (ISU), comprising mainly a hydro-pneumatic spring and vane damper units, is a typical suspension system. Owing to the excellent damping properties of its hydro-pneumatic suspension unit, the ISU has not only been applied to tracked vehicles but can also be adopted in various other vehicle types. In this study, we evaluate the applicability of the ISU in enhancing tank maneuverability and turret stability during dynamic operations. Specifically, a mathematical model is first established for kinematic analysis of the tank’s internal suspension elbow structure, followed by an adjustable damper flow orifice design to improve the stability of the tank chassis. Using the linear matrix inequality (LMI) approach, this orifice design is modeled as a multi-objective $H_{\infty }$ /generalized H₂ output feedback control system, which satisfies multiple hardware constraints while reducing the disturbance channel gain. Both simulations and experiments are conducted to evaluate the effectiveness of the LMI-based control system design. Results demonstrate that the proposed system effectively reduces vertical vehicle acceleration caused by external road disturbances, while system stiffness can be optimized within the operational disturbance range. Additionally, the suspension stroke, dynamic-static load ratios, and vane damper output forces remain within predefined constraints.