Longitudinal attitude control of a hypersonic vehicle with angle of attack constraints

An adaptive dynamic surface control algorithm is proposed for longitudinal attitude of the hypersonic vehicle in the presence of angle of attack constraints. The angle of attack constraints are firstly converted into the tracking error constraints, and then a weighted performance function and an error transformation technique are introduced, which guarantee a prescribed performance of tracking error as well as prevent the angle of attack from transgressing the constraints, and the original nonlinear system with constrained tracking error is transformed into an equivalent unconstrained one. An adaptive dynamic surface control algorithm is subsequently proposed to stabilize this transformed error system. It is proved that asymptotic tracking of the longitudinal attitude is achieved without violation of the angle of attack constraints, and all the other signals in the closed loop are uniformly ultimately bounded. The Monte-Carlo simulation results show the effectiveness of the proposed method.