Original title: Do Better Imagined Rollouts Mean Better Robot Control? A Controlled Study of World-Model Evaluation Under Feedback
Dharini Raghavan, Amritpal Singh · September 2026
Robots often use world models, which are internal simulations that predict the future. Usually, engineers test these models by making them predict many steps ahead without checking real sensor data. But in real life, robots constantly get new sensor measurements to correct their mistakes. Researchers tested whether judging models without sensor updates actually reflects real-world success. They tested six state estimatorsAlgorithms that calculate a robot's position and orientation from sensor data., which track where a robot is, across 24 sensing conditions for a wheeled robot following a path. They found that open-loopA system that acts based on predictions without real-time corrections from sensors. predictions without measurements gave misleading results. Testing models with recorded replays matched real driving much better than test runs that had no sensor checks. When rollouts completely skipped sensor updates, long predictions picked the wrong best model in most setups. However, predictions stayed accurate if the model received regular sensor corrections. Therefore, offline tests must include regular sensor updates to reflect real robot control accurately.
Imagine hiking with a map. If you check your compass often and adjust your path, you stay on course, but if you navigate only from memory without checking, you might get lost. In this paper, testing robot models without simulated sensor checks is like hiking from memory, while actual robot control is like constantly checking the compass, and the study shows that testing without checks gives misleading results about which navigation model is best.
This matters for engineers designing robot control systems. Using the wrong offline tests can lead to choosing models that fail in real conditions, affecting safety and reliability.
The study is limited to a differential-drive robot in a path-tracking task, and results may not generalize to other systems. Improvements from training on longer sensing outages were not consistent across all estimator architectures.
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Do Better Imagined Rollouts Mean Better Robot Control? A Controlled Study of World-Model Evaluation Under Feedback — Dharini Raghavan, Amritpal Singh
Abstract licence: CC0
Explanation generated by Synthesis from the abstract — it is not the original paper. This is a preprint, so it hasn't necessarily been peer reviewed.