Hovering control of a nano quadrotor unmanned aerial vehicle using optical flow

In this paper, a PD controller which uses optical flow to obtain position and velocity feedback is proposed for the autonomous hovering flight control of a nano quadrotor unmanned aerial vehicle (UAV). The nano quadrotor UAV has a mass less than 100 g and is comparatively much smaller than the micro vehicles utilized in previous research. Due to the limited size and payload ability, a wireless camera is employed as the onboard visual device to obtain the position and translational velocity of the UAV. Experiment results are included to demonstrate the good control performance of the proposed design.