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This paper is concerned with the modelling and vibration control problem for networked nonlinear vehicle active suspension (NNVAS) with actuator time delay. Inserting in-vehicle communication network to active suspension, a novel model for NNVAS is established based on the Takagi-Sugeno fuzzy fusion technology first. By introducing a transformation vector, NNVAS with actuator time delay is reformed as a delay-free nonlinear system. Then, an approximation optimal vibration controller (AOVC) is proposed by using an iterative algorithm, which consists of suspension state item, a road disturbance state item, and a compensated item for nonlinear response. Dependant on the control performance in each iteration, the computability of proposed AOVC is realized. A reduced-order observer is designed to solve the physical unrealizable problem of road disturbances. Finally, compared with the open-loop system and [ABSTRACT FROM AUTHOR]

The study is concerned with problem of optimal disturbance rejection for a class of discrete-time systems with multiple delayed inputs. In order to avoid the two-point boundary value (TPBV) problem with items of time-delay and time-advance caused by multiple delayed inputs, the discrete-time system with multiple delayed inputs is transformed into a delay-free system by introducing a variable transformation, and the original performance index is reformulated as a corresponding form without the explicit appearance of time-delay items. Then, the approximate optimal disturbance rejection controller (AODRC) is derived from Riccati equation and Stein equation based on the reduced system and reformulated performance index, which is combined with feedback item of system state, feedforward item of disturbances, and items of delayed inputs. Also, the existence and uniqueness of AODRC are proved, and the stability of the closed-loop system is analysed. Finally, numerical examples of disturbance rejection for jacket-type offshore structure and pure mathematical model are illustrated to validate the feasibility and effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]