A TVC based nonlinear rocket controller for contour following

This paper presents a nonlinear controller for rockets with thrust-vector-control (TVC) to perform the contour-following task given a predefined trajectory. A guidance law is designed to produce the "sliding velocity" for the rocket in real-time such that the relative motion between the rocket and the trajectory is minimized. An autopilot system is designed not only to stabilize the rocket but also to realize the guidance law. In order to establish a complete system model, besides the rocket motion dynamics, we also take into account the propellant effort of movable nozzle TVC (MNTVC), aerodynamic influence, the earth's gravitational field and the earth's revolution. Both sliding mode control and nonlinear system analysis theory are employed to design stable control system. Stability and performance of the contour-following control is demonstrated by simulation.