Vision based flight control of 3-DOF helicopter

In this paper, a new solution to the flight control problem of a 3-degree of freedom (DOF) helicopter is presented. The sensor required is only an onboard monocular camera, but any artificial marker is not required. Firstly, the proposed approach employs the parallel tracking and mapping (PTAM), a technique of visual simultaneous localization and mapping (vSLAM), to estimate the attitude angles of the 3-DOF helicopter. Then the nonlinear optimization technique is applied to solve the puzzle, calibration of the relative attitude angles between the onboard camera and helicopter coordinates. Finally, in order to alleviate the influence of nonlinearity, a controller incorporating the feedback linearization (FL) and linear quadratic regulation (LQR) techniques is designed. Experimental results on the laboratory helicopter demonstrate the effectiveness of the proposed technique.