Haptic Interface for UAV Teleoperation

The feedback upon which operators in teleoperation tasks base their control actions, differs substantially from the feedback to the driver of a vehicle. On the one hand, there is often a lack of sensory information; on the other hand, there is additional status information presented via the visual channel. Haptic feedback could be used to unload the visual channel and to compensate for the lack of feedback in other modalities. For collision avoidance, haptic feedback could provide repulsive forces via the control inceptor. It allows operators to interpret the repulsive forces as impedance to their control deflections, when a potential for collision exists. Haptic information can be generated from an artificial force field that maps environmental constraints to repulsive forces. This paper describes the design and theoretical evaluation of a novel artificial force field, the parametric risk field, for teleoperation of an uninhabited aerial vehicle (UAV). The field allows adjustments of the size, shape and force gradient by means of parameter settings, which determine the sensitivity of the field. Computer simulations were conducted to evaluate the effectiveness of the field for collision avoidance, for various parameter settings. Results indicate that the novel artificial force field more effectively performs the collision avoidance function than potential fields known from literature. Because of its smaller size, the field yields lower repulsive forces, results in less force cancellation effects, and allows for larger UAV velocities. This indicates less operator control demand and more effective UAV operations, both expected to lead to lower operator workload, while at the same time increasing safety.