Sight Over Site: Perception-Aware Reinforcement Learning for Efficient Robotic Inspection

*Equal Contribution,
1Robotic Systems Lab, ETH Zurich, 2Computer Vision and Geometry Group, ETH Zurich 3Robotics and Perception Group, University of Zurich 4Microsoft

Sight Over Site presents a novel approach to perception-aware reinforcement learning for efficient robotic inspection tasks.

Abstract

Autonomous inspection is a central problem in robotics, with applications ranging from industrial monitoring to search-and-rescue. Traditionally, inspection has often been reduced to navigation tasks, where the objective is to reach a predefined location while avoiding obstacles. However, this formulation captures only part of the real inspection problem. In real-world environments, the inspection targets may become visible well before their exact coordinates are reached, making further movement both redundant and inefficient.

What matters more for inspection is not simply arriving at the target’s position, but positioning the robot at a viewpoint from which the target becomes observable. In this work, we revisit inspection from a perception-aware perspective. We propose an end-to-end reinforcement learning framework that explicitly incorporates target visibility as the primary objective, enabling the robot to find the shortest trajectory that guarantees visual contact with the target without relying on a map. The learned policy leverages both perceptual and proprioceptive sensing and is trained entirely in simulation, before being deployed to a real- world robot. We further develop an algorithm to compute ground-truth shortest inspection paths, which provides a ref- erence for evaluation. Through extensive experiments, we show that our method outperforms existing classical and learning- based navigation approaches, yielding more efficient inspection trajectories in both simulated and real-world settings.

Method

Method

To obtain visual access to a given target, the inspection policy (green path) results in a shorter trajectory compared to the navigation policy (red path). Our proposed RL-based policy (bottom right) takes egocentric depth input along with the target and robot state to achieve efficient inspection.

Video

Video demonstration coming soon.

Methodology

Stay tuned, coming soon!

Results

Stay tuned, coming soon. Spoiler: We are efficient!

Future Directions

Future work will explore extensions to non-planar movement and 3D dynamics.

BibTeX

@article{sightoversite2025,
  author    = {Kuhlmann, Richard and Wolfram, Jakob and Sun, Boyang and Xing, Jiaxu and Scaramuzza, Davide and Pollefeys, Marc and Cadena, Cesar},
  title = {Sight Over Site: Perception-Aware Reinforcement Learning for Efficient Robotic Inspection},
  journal   = {ArXiv},
  year      = {2025},
}