Constrained Dynamic Output-Feedback Robust H8 Control of Active Inerter-Based Half-Car Suspension System With Parameter Uncertainties

In this study, a multi-objective dynamic output-feedback robust H-2/H-8 controller for an active inerter-based half-car suspension system in the presence of parameter uncertainty and external disturbance has been investigated. Its main goal is to improve the inherent trade-offs between ride quality, handling performance, and suspension travel and to guarantee the allowable level for suspension stroke and input constraint. Inerters have been widely used to suppress undesirable vibrations in various mechanical structures. The advantage of inerters is that the realized equivalent mass ratio (inertance over primary structure mass) is greater than its actual mass ratio, leading to higher performance for the same effective mass. First, the dynamics and state space of the active inerter-based suspension system for a half-car model with parameter uncertainties have been achieved. To meet the specified objectives, and guarantee the prescribed disturbance attenuation level of the closed-loop system, the Lyapunov stability function and linear matrix inequality (LMI) technique have been used to fulfill the proposed approach. In the case of feasibility, sufficient LMI conditions by solving a convex optimization problem afford the stabilizing gain of the controller. According to numerical simulations, the active inerter-based suspension system in the presence of parameter uncertainties and external disturbance performs much better than both a passive suspension with inerter and active suspension without inerter.