Admittance mode framework for haptic teleoperation of hovering vehicles with unlimited workspace

This paper discusses a new approach to haptic feedback for teleoperation of hovering vehicles. Traditionally airplane and helicopter controls use the displacement of a joystick as the main supervisory control input. It is common to overlay force feedback to convey additional information about forces occuring in the controlled craft. However, there are some fundamental problems when trying to feed back information about obstacles, position, velocity or inertia of the craft in this mode of control. This paper proposes to use an admittance control mode for flying a hovering vehicle such as a quad-rotor, which enables a more direct mapping from vehicle position to haptic feedback. Furthermore it is discussed how to overcome the problem of controlling a vehicle with unlimited workspace from a haptic joystick with limited workspace in admittance mode. Experiments were performed in a virtual 3D simulation to evaluate the feasibility of admittance control with position feedback, and to compare two different types of admittance mode feedback with impedance mode feedback.