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arXiv · 2603.21635

RTD-RAX: Fast, Safe Trajectory Planning for Systems under Unknown Disturbances

Evanns Morales-Cuadrado·Long Kiu Chung·Shreyas Kousik·Samuel Coogan
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Abstract

Reachability-based Trajectory Design (RTD) is a provably safe, real-time trajectory planning framework that combines offline reachable-set computation with online trajectory optimization. However, standard RTD implementations suffer from two key limitations: conservatism induced by worst-case reachable-set overapproximations, and an inability to account for real-time disturbances during execution. This paper presents RTD-RAX, a runtime-assurance extension of RTD that utilizes a non-conservative RTD formulation to rapidly generate goal-directed candidate trajectories, and utilizes mixed monotone reachability for fast, disturbance-aware online safety certification. When proposed trajectories fail safety certification under real-time uncertainty, a repair procedure finds nearby safe trajectories that preserve progress toward the goal while guaranteeing safety under real-time disturbances.

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Evanns Morales-Cuadrado, Long Kiu Chung, Shreyas Kousik, Samuel Coogan. 2026-03-23. RTD-RAX: Fast, Safe Trajectory Planning for Systems under Unknown Disturbances. https://arxiv.org/abs/2603.21635

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