Indoor hovering flight of a nano-scale helicopter by markerless visual servo control

This paper addresses the visual servo control problem of a nano-scale quadcopter with a monocular onboard camera. The total weight of the helicopter with the camera is 48 g, and the helicopter belongs to a class of nano-scale aerial vehicles. The camera is a wireless device, and it is installed beneath the helicopter. The camera looks downward, and it captures an image of the ground at each time step. The captured image data are transferred via a receiver to a computer at a ground station. The computer processes the image data, and it generates a control signal by the markerless visual servo control algorithm proposed in our previous paper. The control signal is then supplied through a transmitter to the helicopter. It is demonstrated that five-minutes hovering flight can be achieved by markerless visual servo control. The controller is not new. The contribution of this paper is to confirm that the markerless visual servo controller is also valid for a nano-scale quadcopter, while a coaxial counter-rotating micro helicopter has been controlled by markerless visual servo control in our previous paper.