  Run Time Assurance (RTA) systems are online safety verification techniques
that filter the output of a primary controller to assure safety. RTA approaches
are used in safety-critical control to intervene when a performance-driven
primary controller would cause the system to violate safety constraints. This
paper presents four categories of RTA approaches based on their membership to
explicit or implicit monitoring and switching or optimization interventions. To
validate the feasibility of each approach and compare computation time, four
RTAs are defined for a three-dimensional spacecraft docking example with safety
constraints on velocity.

Systems and Control;Systems and Control