Alenna Spiro
← All papersPreprint · 2025 · In preparation

ENCORE: Environment-aware Cost-optimal Fault Recovery

When a robot detects a hardware fault mid-mission, ENCORE recommends the repair that minimizes expected mission cost, using a learned model of repair effectiveness and risk-aware rollouts.

A. Spiro, M. Everett

Part ofHybrid models

Robots often develop faults partway through a mission: a tire goes soft, a sensor drifts, a joint stiffens. The usual responses are to stop and wait for a human or to repair everything possible, and both can waste time. This paper looks at a narrower question: given where the robot is and what remains of its mission, which repair is actually worth doing?

ENCORE keeps a learned model of how well each repair tends to work and what it costs, rather than assuming every fix fully restores the robot. For each candidate repair, including doing nothing, it rolls the rest of the mission forward in the current environment and estimates the total cost. These rollouts are risk-aware, so a repair that is usually fine but occasionally disastrous does not win on its average alone.

ENCORE architecture: an offline repair effectiveness model feeding an online fault recovery pipeline
ENCORE architecture. Offline, past repairs train a per-component model of how effective each repair tends to be. Online, when a fault is detected, ENCORE samples repair effectiveness, predicts the robot's post-repair state and dynamics, simulates mission rollouts, and recommends the cheapest safe repair to the control loop.

The figure shows an example. After a tire fault, the robot compares no repair, a patch, a fill, or both. Here, skipping the repair is the cheapest way to finish, because the route ahead is forgiving.

Example mission comparing repair options after a tire fault
Example: after a tire fault, the robot compares repair options against the rest of its route.

The paper is in preparation, and a preprint link will be added once it is available.

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