This paper investigates the recoil control of the deepwater drilling riser system with nonlinear tension force and energy-bounded friction force under the circumstances of limited network resources and unreliable communication. Different from the existing linearization modeling method, a triangle-based polytope modeling method is applied to the nonlinear riser system. Based on the polytope model, to improve resource utilization and accommodate random data loss and communication delay, an asynchronous gain-scheduled control strategy under a hybrid event-triggered scheme is proposed. An asynchronous linear parameter-varying system that blends input delay and impulsive update equation is presented to model the nonlinear networked recoil control system, where the asynchronous deviation bounds of scheduling parameters are calculated. Resorting to the Lyapunov–Krasovskii functional method, some solvable conditions of disturbance attenuation analysis and recoil control design are derived such that the resulting networked system is exponentially mean-square stable with prescribed H ∞ performance. The obtained numerical results verified that the proposed nonlinear networked control method can achieve a better recoil response of the riser system with less transmission data compared with the linear control method.

This article presents an asynchronous distributed interval filtering method for discrete-time positive Markov jump linear systems (MJLSs) with bounded disturbance under the denial-of-service attack. By designing an asynchronous switching-distributed mechanism that depends on a randomly occurred attack, the proposed positive filter can monitor the real-time range of estimated states against the attack. The filtering error systems are modeled as a class of MJLSs with two attack-dependent Markov chains. Some analysis and design results are derived such that the error systems are positive and stochastically internally stable with satisfied$l_{1}$-gain performance. The remote power monitoring in telecommunication systems is used for numerical verification.

In this paper, the optimal control for regulating linear singularly perturbed systems with perturbed quadratic-cost is presented by discussing the singular quadratic-cost control problem for the reduced-order slow subsystem. Under some assumptions, the optimal performance cost of the singularly perturbed system will tend to that of the reduced-order slow subsystem.