Run Time Assurance for Autonomous Spacecraft Inspection

Abstract: As autonomous systems become more prevalent in the real world, it is critical to ensure they operate safely. One approach is the use of Run Time Assurance (RTA), which is a real-time safety assurance technique that monitors a primary controller and intervenes to assure safety when necessary. As these autonomous systems become more complex, RTA is useful because it can be designed completely independent of the primary controller. This paper develops several translational motion safety constraints for a multi-agent autonomous spacecraft inspection problem, where all of these constraints can be enforced with RTA. A comparison is made between centralized and decentralized control, where simulations of the inspection problem then demonstrate that RTA can assure safety of all constraints. Monte Carlo analysis is then used to show that no scenarios were found where the centralized RTA cannot assure safety. While some scenarios were found where decentralized RTA cannot assure safety, solutions are discussed to mitigate these failures.