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Abstract Resilience of multi-agent systems (MAS) reflects their capability to maintain normal operation, at a prescribed level in the presence of unintended faults. In this paper, we investigate resilient control of MAS under faults on sensors and actuators. We propose four resilient state feedback based leader–follower tracking protocols. For the case of sensor faults, we develop an adaptive compensation protocol and an H ∞ control protocol. For the case of simultaneous sensor and actuator faults, we further propose an enhanced adaptive compensation protocol and an enhanced H ∞ control protocol. We show the duality between the adaptive compensation protocols and the H ∞ control protocols. For adaptive compensation protocols, faults on sensors and actuators are rejected by using local adaptive sensor and actuator compensators, respectively. Moreover, by employing a static output-feedback design technique, we propose H ∞ control protocols that guarantee bounded L 2 gains of certain errors in terms of the L 2 norms of fault signals. This further allows us to prove resilience even if sensor faults are unbounded. Finally, simulation studies validate the effectiveness of the proposed protocols. [ABSTRACT FROM AUTHOR]

Most existing control results for pure-feedback stochastic systems are limited to a condition that tracking errors are bounded in probability. Departing from such bounded results, this paper proposes an asymptotic fuzzy neural network control for pure-feedback stochastic systems. The control goal is realized by proposing a novel semi-Nussbaum function-based technique and employing it in adaptive backstepping controller design. The proposed Nussbaum function is integrated with adaptive control technique to guarantee that the tracking error is asymptotically stable in probability. [ABSTRACT FROM PUBLISHER]

This paper presents a saturated Nussbaum function based approach for robotic systems with unknown actuator dynamics. To eliminate the effect of the control shock from the traditional Nussbaum function, a new type of the saturated Nussbaum function is developed with the idea of time-elongation. Moreover, by exploiting properties of the proposed Nussbaum function, a promising theorem is established to deal with unknown multiple actuator nonlinearities. In what follows, the proposed theorem is integrated with the adaptive control technique such that the stability analysis of the robotic system is completed. It thus guarantees that the state of the robotic system asymptotically converges to the desired trajectory. Finally, comparative studies are carried out to validate the effectiveness and the superiority of the proposed approach. [ABSTRACT FROM PUBLISHER]

To isolate the mounted object from the vibration sources, it is required that the qualities of the actuators in an active vibration isolation system are highly promising. Therefore, it is unreasonable to ignore actuator nonlinearity to realize the excellent performances of the vibration isolation. In this paper, the problem of unknown actuator backlash in the vibration isolation system is investigated. To handle the lines–segments backlash nonlinearity, an adaptive smooth backlash inverse is employed to compensate the deleterious effect. Moreover, a promising controller is proposed to ensure that the motion of the moving platform converges to desired values. Based on Lyapunov’s second method, all of the involved signals in the closed-loop system are proved to be stable. Finally, comparative studies involving active vibration isolation with actuator backlash are constructed and carried out to validate the effectiveness of the proposed control scheme. [ABSTRACT FROM PUBLISHER]