Evaluation of a Haptic Stick Implementation for Enhanced Attitude Control of the Aerial Refueling Boom

Abstract

Advances in aerial refueling automation are expected to reduce operators’ manual boom refueling control skills while remaining insufficiently reliable across all operational conditions. This highlights the need for intuitive interfaces that support effective human intervention. The use of artificially generated haptic cues has proven effective for enhancing human manual control performance. This study investigates the use of continuous haptic feedback based on the state of the controlled element in a realistic two-dimensional aerial refueling boom attitude-control task. For this research, two sticks using a command shaping filter, of which one with haptic feedback, were compared to a conventional implementation. Haptic feedback is implemented by shifting the neutral position of a stick, with otherwise conventional mass-spring-damper characteristics, proportional to the boom's rotational rate. It was found that, compared with non-haptic implementations, the proposed haptic configuration improves tracking performance by 35-50\% without increasing operator control effort. Frequency-domain analysis suggests that the implemented haptic feedback allows for more effective control by redistributing the workload and thereby supporting the operator in managing challenging controlled element dynamic behavior. All participants indicated a preference for the haptic stick implementation. The results indicate that continuous haptic feedback is a highly effective means of supporting operator manual control of aerial refueling boom attitude, particularly as automation increases. Incorporating continuous haptic feedback derived from the controlled element’s state is therefore recommended to enhance human manual control performance in both current and future automated refueling operations.