Booster stage adaptive backstepping tracking control for interceptor

An adaptive backstepping tracking controller in the presence of uncertain parameters and external disturbance is designed for the thrust vector-controlled interceptor during its booster stage. The dynamic equation is formulated into a parametric-strict-feedback form under reasonable assumption. The controller design is decomposed into two loops, which are aerodynamic angle loop and angular rate loop. The whole closed system is proved to converge into a compact set asymptotically by employing feedback control laws and adaptive estimate laws designed in this paper. The controller proposed here has two main advantages. First, it can deal with the disturbances whose bounds have the expression of all system states. Second, there is no chattering in the tracking process by using continuous hyperbolic tangent function in place of sign function. Simulation results demonstrate that the proposed method in this paper not only afford strong capability but also achieve a fast and accurate response of resistance to parameters uncertainty and external disturbances.