Geometry Control On SE(3) For A Small Size Unmanned Helicopter

This paper presents a new geometry based attitude and position controller for a small size unmanned helicopter, which is able to achieve the agile flight maneuvers in a large flight envelope. The controller is designed on SE(3) by using the geometry control technology, which avoids the singularity inherented in the Euler angles based attitude representation, and unwinding behaviours existed in the quaternion based attitude representation. Moreover, the effects associated with the unknown external disturbances are compensated via the disturbance observers in the attitude loop and the position loop. By using the precise estimate values combined with the geometry controller, it achieves the strongly robustness to the external disturbances. Then, the Lyapunov based stability analysis is employed to prove that the proposed control algorithm can guarantee the convergence of the UAV’s position and attitude tracking errors. Finally, numerical simulations are included to show the effectiveness of the proposed control algorithm.