Trajectory optimization and adaptive fuzzy based Launch Vehicle attitude control

This paper presents a methodology based on direct adaptive fuzzy controller to control the pitch attitude of Satellite Launch Vehicle (SLV). To generate reference trajectories of a four-stage Launch Vehicle, Trajectory Optimization has been performed offline using Genetic Algorithms. The optimization routine takes into account the maximum angle of attack along with normal and lateral overload constraints. To efficiently follow the reference pitch profile, a fuzzy based controller is proposed in which an adaptation law is devised which automatically adjusts the tunable parameter. This tunable parameter is the consequent part of fuzzy IF-THEN rules. Lyapunov principle is incorporated in the adaptation law for ensuring system´s stability. It is observed that although the Lyapunov approach make sure that the system is asymptotically stable, it is very critical to select appropriately the value of semi positive definite matrix. To analyze the performance of proposed control scheme, 6DOF simulation model is developed in Simulink.