In this paper, a new n-step fuzzy adaptive output tracking prescribed performance control problem is investigated for a class of non-triangular structure nonlinear systems. In the control design process, the Mean Value Theorem is used to separate the virtual state variables needed for the control design, and the Implicit Function Theorem is exploited to assert the existence of the continuous desired control. The fuzzy logic systems are used to identify the unknown nonlinear functions and ideal controller, respectively. By constructing a novel iterative Lyapunov function, a new n-step adaptive backstepping control design algorithm is established. The prominent characteristics of the proposed adaptive fuzzy backstepping control design algorithm are as follows: one is that it can ensure the control system is the semi-globally uniformly ultimately boundedness (SGUUB) and the tracking error can converge with the prescribed performance bounds (PPBs). The other is it solves design problem for the non-triangular structure nonlinear systems that the previous adaptive backstepping design techniques cannot deal with. Two examples are provided to show the effectiveness of the presented control method.

This article investigates the adaptive event-triggered secure control design problem for a class of stochastic nonlinear high-order multiagent systems (MASs) subject to denial-of-service (DoS) attacks and actuator faults. The considered systems contain not only unknown random interference terms but also general nonlinear functions that are not required to be globally Lipschitz, in contrast to most of the existing results in the area. To solve the problem of wasted communication resources, the control signal with the relative threshold strategy is designed via the event-triggered control technique. As a class of cyber–physical systems, the securities of MASs are vulnerable to actuator faults and DoS attacks. When the system suffers from coupled DoS attacks and actuator failures, its performance will deteriorate rapidly and even the controlled system will collapse. To overcome this difficulty, a novel fault-tolerant and antiattack control method is proposed, which enables the system to achieve the security control objective even in an insecure network and physical environment. The stability analysis of the system is given by combining the adaptive backstepping recursive design process with stochastic Lyapunov stability theory. It is demonstrated that all the signals of the closed-loop systems are semiglobally uniformly ultimately bounded in probability. Finally, a simulation example is given to illustrate the effectiveness and advantages of the presented scheme.

This article studies the adaptive fault-tolerant consensus tracking control problem for a class of stochastic nonlinear high-order MASs under stochastic FDI attacks. Based on the FLSs and backstepping design technique, a novel adaptive fuzzy fault-tolerant consensus tracking control strategy is proposed to guarantee that the closed-loop stochastic high-order MASs are semi-globally stable in probability via stochastic Lyapunov stability theory and It $\hat{o}$ lemma. In order to relieve the communication pressure of MASs, a novel high-order dynamic event-triggered mechanism (DETM) based on user-set parameters is developed. Compared with the traditional event-triggered mechanism, this DETM has larger triggering time intervals, effectively reduces communication frequency, and has greater flexibility in balancing system performance and communication bandwidth resource constraints. Finally, the actual simulation and comparative simulation are given to verify the effectiveness and superiority of the proposed scheme.