This paper focuses on the tracking problem for airbreathing hypersonic vehicles, and proposes a new control method on the basis of not canceling, but using, aeropropulsive, as well as elevator-to-lift, couplings to design controllers without strategically avoiding or reducing the nonminimum-phase characteristic. The controllers and the external reference trajectories are simultaneously obtained by solving a system of linear algebraic equations. The altitude error is shown to be asymptotically stable. The velocity, flight-path angle, angle-of-attack, and pitch-rate errors all exponentially converge to zero with the proposed tracking controllers. The suppression of the flexible dynamics is achieved by integrating the new control method with H∞ control. To enhance the robustness of the controllers with respect to the uncertainties of the aerodynamic parameters, a nonlinear disturbance observer is proposed to estimate the variations of the aerodynamic parameters for airbreathing hypersonic vehicles during cru...

The exponential stabilisation problem of nonlinear parameter-varying (NPV) systems with input constraints is investigated. Unlike the existing NPV-related works, this paper directly addresses NPV models to conduct the stabilisation problem, without hiding nonlinearities or ignoring the time-varying nature. Existence conditions of a nonlinear time-varying (NTV) controller to render the uniformly exponential stability of an NPV system are given in terms of state-and-parameter-dependent linear matrix inequalities (SPLMIs). Specifically, a new controller structure and a novel Lyapunov functional are adopted such that the exact variation rates of the state and parameters can be incorporated into the SPLMIs. The generalised S-procedure is used to convexify the input constraints such that the resulting closed-loop system satisfies input constraints for any state starting from an admissible set. The derived SPLMIs can then be efficiently solved via sum-of-squares programming. The proposed approach is applied to the conversion flight control of a tilt rotor aircraft.

This brief analyzes the robust secure consensus control problem for linear multi-agent systems under random Denial-of-Service (DoS) attacks and external disturbances. When agents communicate with its neighbors, a malicious attacker randomly carries out DoS attacks to certain communication channels in the network, thereby causing the communication topology to be Markovian switching. Solely depending on the immediate partial information per node rather than global information, a fully distributed robust secure consensus protocol is put forward under DoS attacks and external disturbances by using the Lyapunov function analysis. A simulation case of leader-follower formation is taken to explain the efficiency of the consensus algorithm.