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When a Robot is More Capable than a Human: Learning from Constrained Demonstrators

Robotics 2026-05-12 v3 Artificial Intelligence Machine Learning

Abstract

Learning from demonstrations enables experts to teach robots complex tasks using interfaces such as kinesthetic teaching, joystick control, and sim-to-real transfer. However, these interfaces often constrain the expert's ability to demonstrate optimal behavior due to indirect control, setup restrictions, and hardware safety. For example, a joystick can move a robotic arm only in a 2D plane, even though the robot operates in a higher-dimensional space. As a result, the demonstrations collected by constrained experts lead to suboptimal performance of the learned policies. This raises a key question: Can a robot learn a better policy than the one demonstrated by a constrained expert? We address this by allowing the agent to go beyond direct imitation of expert actions and explore shorter and more efficient trajectories. We use the demonstrations to infer a state-only reward signal that measures task progress, and self-label reward for unknown states using temporal interpolation. Our approach outperforms common imitation learning in both sample efficiency and task completion time. On a real WidowX robotic arm, it completes the task in 12 seconds, 10x faster than behavioral cloning, as shown in real-robot videos on https://sites.google.com/view/constrainedexpert .

Keywords

Cite

@article{arxiv.2510.09096,
  title  = {When a Robot is More Capable than a Human: Learning from Constrained Demonstrators},
  author = {Xinhu Li and Ayush Jain and Zhaojing Yang and Yigit Korkmaz and Erdem Bıyık},
  journal= {arXiv preprint arXiv:2510.09096},
  year   = {2026}
}
R2 v1 2026-07-01T06:28:50.543Z