Reaction Templates: A Formal Approach to Realize Reactivity in Task and Motion Planning-Based Action Execution

Abstract

Recent advancements in artificial intelligence have broadened the spectrum of tasks that robots can effectively tackle. However, the seamless execution of prolonged action sequences continues to pose a considerable challenge, attributed to limitations in the abilities of today's robots to react to unforeseen situations or failures. In response, we introduce Reaction Templates (RTs), a formal approach for integrating reactivity into task and motion planning. Operating concurrently with the primary execution logic, RTs enable a clear differentiation between planned actions and the necessary recovery strategies for handling unexpected events. This design promotes scalability by establishing reusable building blocks and customizable parameters, thereby enhancing flexibility in application. We provide a thorough introduction to the RT concept, elucidating its principles, mechanisms, and the rationale behind its design decisions. The resulting benefits of the approach are demonstrated through experimental validation with the humanoid robot Rollin’ Justin.