Human Machine Interface Design to Support Safety Risk Monitoring of Autonomous Small Unmanned Aircraft Systems - Results from a Mock-Up Evaluation

Numerous research papers propose the operation of highly automated or autonomous small Unmanned Aircraft Systems (UAS) in low-altitude urban airspace. However, the operation of autonomous UAS introduces safety risks, such as unsafe proximity to people and property or collision with other traffic and obstacles. In order to approach these safety risks, technical means were proposed, including geo-fencing systems and autonomous collision avoidance systems. Humans will most likely stay an essential component in assuring safety during autonomous UAS operations, analyzing and supervising the output of the technical safety assurance systems. In a previous study, a Human Machine Interface (HMI) was developed, aiming to comprehensively visualize information stemming from the aforementioned safety assurance systems. The HMI enables an operator to simultaneously supervise multiple autonomous UAS in low-altitude urban airspace. An evaluation of the HMI was conducted with an online study using mock-ups of the HMI. Seven UAS pilots took part in the evaluation study and completed four experimental scenarios. This paper focuses on the usability and acceptability of the HMI. Further, its main advantages, disadvantages and suggestions for improvement obtained in an online questionnaire are presented. The findings of the evaluation show satisfying results for usability and acceptability. Even though, various suggestions for improvement of the HMI were obtained. Based on the results, the HMI will be improved for future studies and will ultimately be integrated into a simulation environment