In this paper, the issue of adaptive neural event-triggered control (ETC) is studied for uncertain block-structure multi-input multi-output (MIMO) constrained non-affine nonlinear systems with unmodeled dynamics. A dynamic signal produced by the auxiliary system based on the property of unmodeled dynamics is employed to solve the dynamical disturbances. The unknown continuous function obtained at each step of recursion is estimated by using radial basis function neural networks (RBFNNs). Utilizing logarithmic function as an invertible mapping, the uncertain constrained MIMO non-affine system is changed into a novel unconstrained block-structure MIMO nonaffine system. Using improved dynamic surface control (DSC) strategy, adaptive event-triggered control scheme is developed for the transformed non-affine system based on relative threshold mechanism. According to the Lyapunov method, all the signals in the closedloop system are shown to be semi-globally uniformly ultimately bounded (SGUUB). Output constraint requirements are not triggered, and Zeno behavior is avoided. A constrained pure-feedback system and a kind of 2-DOF flexible manipulator system are used to illustrate the theoretical findings. INDEX TERMS Event-triggered control, dynamic surface control, block-structure nonlinear systems, unmodeled dynamics, output constraints.

Proper signal structure is very important in the navigation, positioning, and time services of a satellite navigation system. In this paper, the carrier wave characteristics, ranging code functions, BOC modulation, navigation data rate, the error-correcting methods, and signal channel resource allocation are discussed in terms of the technical characteristics of the transforming satellite navigation system and the resources of communication satellites. The results show that dual-frequency of C band in the Chinese Area Positioning System (CAPS), compound ranging code, a combination of the coarse code and precise code, BOC modulation, separate-channel transmission of different users are compatible with the satellite navigation system at present. The experiments show that the current signal structure can meet the demand of CAPS.

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In this article, a unified adaptive neural event‐triggered control strategy is presented for uncertain multi‐input multi‐output (MIMO) nonlinear systems with dynamic and static constraints in the presence of unmodeled dynamics. By introducing an invertible nonlinear mapping based on hyperbolic tangent function, the constrained original system is transformed into an equivalent unconstrained MIMO pure‐feedback system. A dynamic signal is employed to dispose of the dynamical uncertainties in the novel system. Based on the transformed system, unified adaptive event‐triggered controller is formed by using modified dynamic surface control technique and the bounded characteristic of Gaussian function. Using the introduced compact set in stability analysis and Lyapunov function method, all signals in the closed‐loop system are proved to be the semiglobal uniform ultimate boundedness. Furthermore, all states and output signals can strictly comply with the defined constraint conditions. Simulations of two numerical examples including 2‐link rigid manipulator are provided to verify and clarify the theoretical results.