Adaptive Sliding Mode Controller Design For Attitude Small UAV

The dynamic of Unmanned Aerial Vehicle (UAV) is nonlinear, strongly coupled, multi-input multi-output (MIMO), and subject to uncertainties and external disturbances. In this paper, an adaptive sliding mode controller (ASMC) is integrated to design the attitude control system for an inner loop fixed wing UAV. In the proposed scheme, sliding mode control law parameters due to uncertainty are assumed to be unknown and are estimated via adaptation laws. The synthesis of the adaptation laws is based on the positivity and Lyapunov design principle. Navigation outer loop parameters are regulated via PID controllers. Simulation results indicate that the proposed controller design can stabilize the nonlinear system, and it is robust to parametric model uncertainties and external disturbance.