Design and Experimental Validation of a Quarter-Car Pseudo-Active Suspension for Body-on-Frame Vehicles

Suspension architecture has long been a central topic in vehicle chassis research and development. Passive, active, and semi-active suspensions provide different trade-offs in performance, complexity, and energy use. The pseudo-active actuator (PAA) is a newly emerging concept that delivers near active-level performance with semi-active-level energy input, which opens a new direction for suspension architecture design. In this work, a pseudo-active suspension (PAS) based on a PAA is developed. Along with the structural investigation, the corresponding dynamic model and control system are established and experimentally validated. Taking a suspension of a body-on-frame (BoF) vehicle as the application platform, an engineering-feasible PAS configuration is proposed, and design/optimization principles are presented for key geometric parameters and components. A quarter-car three-mass PAS dynamic model is derived, in which the equivalent coupling introduced by the mechanical compensation mechanism is explicitly characterized, leading to a complete state-space representation. To address the multi-objective performance requirements of the PAS, a conventional H∞ controller and a finite-frequency H∞ controller with a specified target band are designed, respectively. A quarter-car PAS experimental rig and a real-time control platform are built, and experiments are conducted under various displacement excitation scenarios. Both simulations and experiments demonstrate that the proposed PAS and controllers meet the multi-objective design objectives and provide robust performance, supporting practical implementation.