Nonlinear Backstepping Based Trajectory Tracking Control of a Gun Launched Micro Aerial Vehicle

Abstract

This paper considers the question of obtaining a nonlinear trajectory tracking control law for a comprehensive design of a Gun Launched Micro Aerial Vehicle (GLMAV), a new Micro Aerial Vehicle (MAV) concept using two bladed coaxial contra-rotating rotors. The MAV packaged in a projectile is launched using the energy delivered by a portable weapon. When it reaches the apogee, the projectile is transformed in such a way that the MAV becomes operational over the zone to be observed. A detailed GLMAV nonlinear mathematical model, taking into consideration external wind, is presented for hover and near hover flight conditions. The problem is di cult due to that external wind and to the presence of small body forces that can not be directly incorporated into the control design. A control Lyapunov function, used to analyze the closed loop performance of the system, is then derived for an approximate model using standard backstepping techniques. The whole design procedure of the backstepping based control law is conducted within the paper. This control law is then applied to the whole model of the GLMAV and a numerical simulation is used to demonstrate the control law's nominal performance. Following this, other numerical simulations are used to demonstrate the control law performance in presence of noise measurement and external wind. Finally, the designed nonlinear control law succeeds in enforcing the desired trajectories robustly with respect to noise measurement, external wind and approximations made in the modeling of the GLMAV.