Feedforward and feedback optimal vibration rejection for active suspension discrete-time systems under in-vehicle networks

This paper studies the vibration rejection problem of active suspension discrete-time systems under in-vehicle networks and designs a controller of feedforward and feedback optimal vibration rejection. Based on the ground displacement power spectral density, an discrete-time exosystem is employed to estimate the random road disturbances. A two degree of freedom discrete-time system is introduced to describe the active suspension under in-vehicle networks. Then, the original vibration control is formulated as the optimal control for a linear discrete-time system affected by external disturbances. The feedforward and feedback optimal vibration rejection law (FFOVRL) is designed by solving the Riccate and Stein equations, in which the feedforward term incorporates the information of the random road disturbances and the feedback loop includes the status of suspension system. The feasibility and effectiveness of the proposed approaches are validated by an active suspension structure.