Charles Xu

I am currently a PhD student at UC Berkeley, advised by professor Sergey Levine. I recently interned at Physical Intelligence, where I built a system for real-world online RL with VLA's. Before this, I finished my undergrad at UC Berkeley in EECS in May 2024, where I also conducted research with professor Sergey Levine. I've also had the pleasure of working with Stefan Schaal from Intrinsic. My research interest is learning from real-world experience through on-robot online reinforcement learning for scalable and deployable robot systems.

xuc [at] berkeley [dot] edu  /  GitHub  /  Google Scholar  

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Research

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Test-Time Gradient Guidance of Flow Policies in Reinforcement Learning


Zhiyuan Zhou, Andy Peng, Charles Xu, Qiyang Li, Jost Tobias Springenberg, Kevin Frans, Sergey Levine
arXiv preprint, 2026
website / paper / code

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π0.7: a Steerable Model with Emergent Capabilities


Physical Intelligence Team
arXiv preprint, 2026
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RL Token: Bootstrapping Online RL with Vision-Language-Action Models


Charles Xu, Jost Tobias Springenberg, Michael Equi, Ali Amin, Adnan Esmail, Sergey Levine, Liyiming Ke
arXiv preprint, 2026
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RLDG: Robotic Generalist Policy Distillation via Reinforcement Learning


Charles Xu, Qiyang Li, Jianlan Luo, Sergey Levine
Robotics: Science and Systems 2025
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Precise and Dexterous Robotic Manipulation via Human-in-the-Loop Reinforcement Learning


Jianlan Luo†, Charles Xu†, Jeffrey Wu, Sergey Levine
Science Robotics, 2025
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Octo: An Open-Source Generalist Robot Policy


Dibya Ghosh*, Homer Walke*, Karl Pertsch*, Kevin Black*, Oier Mees*, Sudeep Dasari, Joey Hejna, Tobias Kreiman, Charles Xu, Jianlan Luo, You Liang Tan, Dorsa Sadigh, Chelsea Finn, Sergey Levine
Robotics: Science and Systems 2024
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SERL: A Software Suite for Sample-Efficient Robotic Reinforcement Learning


Jianlan Luo*, Zheyuan Hu*, Charles Xu, Siri Gadipudi, Archit Sharma, Rehaan Ahmad, Stefan Schaal, Chelsea Finn, Abhishek Gupta, Sergey Levine
IEEE International Conference on Robotics and Automation (ICRA) 2024
website / paper / video / code

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Open X-Embodiment: Robotic Learning Datasets and RT-X Models


Open X-Embodiment Collaboration
IEEE International Conference on Robotics and Automation (ICRA) 2024
ICRA 2024 Best Paper Award
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FMB: A Functional Manipulation Benchmark for Generalizable Robotic Learning


Jianlan Luo*, Charles Xu*, Fangchen Liu, Liam Tan, Zipeng Lin, Jeffrey Wu, Pieter Abbeel, Sergey Levine
The International Journal of Robotics Research
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Multi-Stage Cable Routing through Hierarchical Imitation Learning


Jianlan Luo*, Charles Xu*, Xinyang Geng, Gilbert Feng, Kuan Fang, Liam Tan, Stefan Schaal, Sergey Levine
IEEE Transactions on Robotics, 2024
website / paper / video / code / data




Teaching

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EECS C106A/206A: Introduction to Robotics


Lab Assistant: Fall 2023

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CS 189: Introduction to Machine Learning


Tutor: Spring 2023





Design and source code from Jon Barron's website