In practice, the time-varying communication delays and actuator failures are the main inevitable issues in nonlinear multilateral teleoperation systems, which can reduce the performance and stability of the considered systems. This article proposed a novel failure-distribution-dependent $H_{\infty }$ fuzzy fault-tolerant control scheme to realize position synchronization and force tracking simultaneously for multilateral teleoperation systems. Firstly, the nonlinear multilateral systems were modeled as a kind of T-S fuzzy systems with multiple time-varying delays. Then, based on the distribution characteristic of failures, by introducing a series of tradeoff coefficients, a novel failure-distribution-dependent fault-tolerant control algorithm was provided to ensure force tracking in spite of failures, and the purpose of position synchronization was achieved (not only the master and slave robot position synchronization but also the position synchronization between each slave robot). Finally, a numerical simulation example was given to show the effectiveness of the proposed method.

This article focuses on the fault-tolerant constrained consensus problem for multiagent systems with communication delays. The communication graphs are first assumed to be directed and fixed. Then, a novel delay-dependent fault-tolerant controller is designed such that, in the presence of communication delays and randomly occurring actuator failures, the influence of the projections and the initial states on the closed-loop system can be attenuated with a prespecified level. Based on the provided performance requirement, the initial state of each agent does not need to be identical. The proposed control algorithms ensure that sufficient conditions are met for the fault-tolerant constrained consensus to be achieved according to the prespecified performance index. After this, the controller gains are computed by employing an iterative linear matrix inequality scheme. Finally, a numerical example is provided to show the effectiveness of the proposed method.

This article studies the non-fragile $H_\infty$ fault-tolerant load frequency control problem for multi-area power systems with actuator failures. At first, considering the distribution characteristics of partial failures, a stochastic distribution model is established for actuator partial failures. Next, for the perturbations of controller gains, not only the additive uncertainties but also the multiplicative uncertainties are incorporated into the fault-tolerant controller design. The coupling items which hardly directly solved have turned into a W-problem in fault-tolerant load frequency control. Furthermore, a novel failure-distribution-dependent non-fragile $H_\infty$ fault-tolerant load frequency control algorithm is given by using linear matrix inequalities technology and Lyapunov-Krasovskii functional method. Finally, a numerical example with a three-area power system is given to show the effectiveness of the proposed methods.

In this paper, the disturbance rejection adaptive fault-tolerant constrained consensus problem of multi-agent with actuator failures is investigated. At first, an auxiliary variable based observer is designed to estimate the disturbance. Then, based on the estimated disturbance, an adaptive law is provided for partial failures. In order to avoid the zero initial condition in the traditional H∞ control approach, a novel performance function is constructed with the considered initial condition. After this, a disturbance rejection adaptive fault-tolerant constrained consensus algorithm is given with the performance requirement. Finally, a simulation example is provided to illustrate the effectiveness of the proposed method.

In this paper, the event-triggered control problem is investigated using backstepping techniques for nonlinear systems with dead-zone input. The external disturbance and unknown parameters are also considered in the controller’s design. It is well known that errors in input signal measurements are inevitable. In event-triggered control, such errors will directly affect whether the control signal is updated. This measurement error can be seen in the form of interference to the threshold. Therefore, unlike traditional event-triggered control, the existence of threshold disturbance is considered in the controller’s design. The proposed controller can not only compensate for the uncertainties caused by external disturbance and unknown parameters but can also suppress the unknown effects caused by threshold interference. In addition, to obtain a continuous controller, a smooth function is constructed to approximate the discontinuous sign function. In this way, Zeno behavior is successfully avoided. The boundedness of all signals and the tracking performance of the system can be guaranteed by the proposed control scheme. Numerical simulation and actual system simulation demonstrate the effectiveness of the proposed control scheme. The comparative simulation results also verify this event-triggered controller’s advantages, including better tracking performance and fewer trigger times.