Haptic interface in UAV tele-operation using force-stiffness feedback

This study investigates the use of force-stiffness feedback, i.e., a combination of force offset and extra spring load, in UAV tele-operation with transmission time delay. The goal was to further increase the level of safety of tele-operation with a reduction in operator workload with respect to force feedback, i.e., using force offset alone. A theoretical analysis is given of using force-stiffness feedback to improve collision avoidance. Wave variables are included to reduce time delay effects. An experiment was conducted to investigate the effects of force-stiffness feedback on safety of operation, operator performance, control activity, and workload. Results indicate that force-stiffness feedback improves the haptic interface with respect to force feedback alone. Safety of tele-operation increases without increasing operator workload with respect to force feedback.