Nonlinear flight navigation controller for an octorotor unmanned aerial vehicle

In this research, a feedback nonlinear controller for an unmanned aerial vehicle octorotor is developed. The proposed controller scheme is designed with a Nonlinear Proportional Velocity (NLPV) term, plus a Linear Integral (LI) term. The tracking controller NLPV plus LI is based on a two layer bounded controller with saturation approach. The Newton Euler formulation is applied to obtain a mathematical model of the octorotor Unmanned Aerial Vehicle (UAV). This modeling approach is applied to obtain the motion equations coupling moments and forces by extracting two sets of interconnected attitude and translational equations. In the design of a flight navigation controller with two layers, the inner layer consists of NLPV plus LI controller that is applied to the attitude dynamics, obtaining the references for the coupling outer layer NLPV plus LI controller, which manipulates the translational dynamics. The navigation NLPV plus LI controller is saturated for bounding in translational forces, to avoid large deviations of commands to Euler angles pitch and roll , another saturated controller is applied for the bounded thrust rotor to avoid the excessive speed of the propellers. The simulation of the flight navigation of an octorotor is performed to test the tracking control of a cylindrical trajectory, which is presented as a validation for the proposed control scheme.