In this study, a multi-objective dynamic output-feedback robust H ₂ / H _∞ 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.

In this paper, constrained memory state-feedback H_∝ control for a half-car model of an active vehicle suspension system with input time-delay in the presence of external disturbance has been investigated. Its prime goal is to improve the inherent trade-offs among power consumption, handling performance, ride quality, and suspension travel. The tire deflections and the suspension deflections are constrained by their peak response values in time domain using the generalized H₂ ( GH_∝) norm (energy-to-peak) performance, while the ride comfort performance of the suspension system is optimized by notion of the H_∝ control (energy-to-energy) to measure the body accelerations including both the heaving and the pitching motions. Similar to the well-known prediction-based methods, the prediction vector of the system is achieved to construct the memory state-feedback controller. Using the prediction vector, sufficient conditions guaranteeing closed-loop system stability as well as disturbance attenuation are obtained as some delay-dependent linear matrix inequalities (LMIs). In addition, some LMIs are added to limit the gain of the controller. In the case of feasibility, obtained LMIs provide the stabilizing gain of the memory controller. The proposed approach is applied to a half-car model of an active suspension system considering the actuator time-delay to illustrate the effectiveness of the proposed method.

In this study, we investigate a robust $H_{\infty }$ controller for a quarter-car model of an active inerter-based suspension system under parameter uncertainties and road disturbance. Its main objective is to improve the inherent compromises between ride quality, handling performance, suspension stroke, and energy consumption. Inerters have been extensively used to suppress unwanted vibrations from various kinds of mechanical structures. The advantage of inerter is that the realized ratio of equivalent mass (inertance relative to the mass of the primary structure) is greater than its actual mass ratio, resulting in higher performance for the same effective mass. First, the dynamics and state space of the active inerter-based suspension system were achieved for the quarter-car model with parameter uncertainties. In order to attain the defined objectives, and ensure that the closed-loop system achieves the prescribed disturbance attenuation level, the Lyapunov stability function, and linear matrix inequality (LMI) techniques have been utilized to satisfy the robust $H_{\infty }$ criterion. Furthermore, to limit the gain of the controller, some LMIs have been added. In the case of feasibility, sufficient LMI conditions by solving a convex optimization problem afford the stabilizing gain of the robust state-feedback 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.

In this study, a multi-objective robust H 2 /H ∞ controller for a half-car model of an active inerter-based suspension system in the presence of 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 energy consumption. Inerters have been widely used to suppress undesirable vibrations of various types of 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 have been achieved. In order to attain the defined objectives, and ensure that the closed-loop system achieves the prescribed disturbance attenuation level, the Lyapunov stability function, and linear matrix inequality (LMI) techniques have been utilized to satisfy the multi-objective robust H 2 /H ∞ criterion. Furthermore, to limit the gain of the controller, some LMIs have been added. In the case of feasibility, sufficient LMI conditions by solving a convex optimization problem afford the stabilizing gain of the constrained robust state-feedback controller. Numerical simulations show that the active inerter-based suspension system performs much better than a passive suspension with inerter and active suspension without inerter