Automated Identification and Qualitative Characterization of Safety Concerns Reported in UAV Software Platforms

Unmanned Aerial Vehicles (UAVs) are nowadays used in a variety of applications. Given the cyber-physical nature of UAVs, software defects in these systems can cause issues with safety-critical implications. An important aspect of the lifecycle of UAV software is to minimize the possibility of harming humans or damaging properties through a continuous process of hazard identification and safety risk management. Specifically, safety-related concerns typically emerge during the operation of UAV systems, reported by end-users and developers in the form of issue reports and pull requests. However, popular UAV systems daily receive tens or hundreds of reports of varying types and quality. To help developers timely identify and triage safety-critical UAV issues, we (i) experiment with automated approaches (previously used for issue classification) for detecting the safety-related matters appearing in the titles and descriptions of issues and pull requests reported in UAV platforms and (ii) propose a categorization of the main hazards and accidents discussed in such issues. Our results (i) show that shallow machine learning (ML)-based approaches can identify safety-related sentences with precision, recall, and F-measure values of about 80%; and (ii) provide a categorization and description of the relationships between safety issue hazards and accidents.