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Rongxuan Zhou

Robotics — from hardware to learning algorithms.
safety-constrained robot learning. multi-modal sensing & fusion. real-time manipulation & deployment. physically grounded autonomy.

Portrait of Rongxuan Zhou

About

I am currently a graduate research assistant at the CRAFT Lab, Northeastern University, advised by Prof. Gilbert Yang Ye. My research focuses on safe, physically-grounded robot manipulation — building learned policies that respect safety constraints and genuinely exploit the sensory inputs they are given.

Before joining CRAFT Lab, I worked as a research assistant at SJTU IWIN-FINS Lab advised by Prof. Jianping He, where I co-designed the full-stack Fines robotic platform, covering hardware architecture, embedded control framework, and perception pipeline.

On the industry side, I built production robotics and automation systems. At Dinnar Automation, I designed automated optical inspection (AOI) equipment for Texas Instruments semiconductor products. At CloudMinds Robotics, I co-designed standardized multi-robot assembly workstations for harmonic-reducer production, with EtherCAT real-time control and digital-twin systems. At NIO Automobile, I developed sim-to-real transfer pipelines for autonomous driving.

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Publications

PRISM: PRior-guided Imagination Sampling in World Models

Yuhai Wang, Jiawei Xia, Rongxuan Zhou, Xiao Hu, Yongliang Shi, Jing Du, and Yang Ye
arXiv preprint, 2026
[Abstract] [Paper] [Website] [Code]

A learned world model provides a powerful physical intuition for evaluating future states. But its effectiveness in continuous control also depends critically on how candidate actions are generated for model-based planning. Rather than solely asking how accurately a model can simulate the future, we ask: which candidate actions are worth evaluating in the first place? Existing planners typically search arbitrarily or use expert demonstrations only to initialize a sampling mean, discarding the expert's state-conditioned confidence. Properly guiding this search requires a robust action prior, yet current approaches often rely on independent visual encoders or large-scale VLMs to obtain one. We argue that this architectural bloat is unnecessary: the exact same data — and the learned representations of the world model itself — inherently encode the agent's action intuition. We introduce PRISM, a task-agnostic framework that extracts both from a single dataset while maintaining strict architectural simplicity. Building on a standard JEPA-style latent world model, PRISM attaches a lightweight MLP directly to its frozen encoder to predict a state-conditioned Gaussian prior. At plan time, PRISM fuses this prior into the planner's sampling distribution via a precision-weighted Product-of-Gaussians update. This parameter-free, closed-form integration steers the sampling process, making the prior confident where it is and ceding control where it is not. PRISM improves success rates by 35 percentage points over vanilla world-model-based MPC on Cube and 32 percentage points on PushT, without introducing significant inference overhead.

Deploying...

Is Your Policy Actually Using Force? Why Concatenation Fails for Contact-Force Integration in Sequential Robot Policies

Rongxuan Zhou and Yang Ye
[Abstract] [Paper] [Code]

Multi-modal sequential policies fuse proprioception, vision, and auxiliary modalities by concatenating them into a shared processing sequence — yet on a contact-rich nut-threading task, naïve raw-force concatenation reduces success rate by 32 percentage points compared to ignoring force entirely. We show that FiLM side-channel conditioning bypasses competitive normalization in self-attention and LSTM gating layers, restoring force utility (+17 pp on NutThread, non-overlapping 95% CIs). To diagnose suppression post-hoc without retraining, we introduce Rcontact, a contact-sensitivity ratio via Integrated Gradients that reliably distinguishes suppressed (≈1×) from functional (3.0–3.7×) architectures. Validated across 5 contact-rich tasks on two simulators (robosuite imitation learning + Isaac Lab Factory reinforcement learning).

TACS: Training-Free Safety Guidance for Action-Space Diffusion Policies via Tweedie-Adaptive Constrained Sampling

Rongxuan Zhou and Gilbert Yang Ye
IEEE Robotics and Automation Letters (RA-L)
[Abstract] [Paper] [Code]

Diffusion policies have become the dominant paradigm for learned robotic manipulation, yet they offer no intrinsic mechanism to enforce workspace safety constraints. TACS is a training-free method that injects barrier-function guidance into the DDIM denoising loop of action-space diffusion policies, applying repulsive guidance on the Tweedie-predicted end-effector positions; subsequent denoising steps coherently adapt rotation and gripper dimensions, achieving effective obstacle avoidance at 10× smaller guidance scales than post-hoc potential-field projection. On three robosuite manipulation tasks, TACS Pareto-dominates post-hoc filtering, with a statistically significant win-win on Lift (violations 6.6% → 0.32%, 20× reduction; p=0.015 across 5 seeds × 250 episodes) and zero measurable inference overhead versus the unmodified diffusion policy.

Fines Robot Platform Steerable Wheel Kinematics Trajectory Results

A Robust Distributed Odometry for Mobile Robots with Steerable Wheels

Wang Xi, Jiaming Guo, Chenyang Wang, Shukun Wu, and Jianping He
IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)
Lead designer of mechanical architecture and simulation environment for the “Fines” steerable wheeled mobile robot platform
[Abstract] [Paper] [Code]

Odometry estimation remains a critical challenge for wheeled robots, as reducing its drift directly mitigates dependency on external localization systems. This paper proposes a distributed odometry framework for steerable wheels, named ICF-DO, which is applicable to both Steerable Wheeled Mobile Robots (SWMRs) and cooperative multi-single-wheel robot systems. The proposed method features low computational complexity and reduced drift, while demonstrating strong robustness in communication-restricted scenarios. Additionally, singularity can be processed in a distributed manner in the proposed framework. Experimental validation on a real physical SWMR platform demonstrates the effectiveness and practicality of the proposed method.

Mandrel Cross-section Stress Nephogram von Mises Residual Stress Circumferential Residual Stress

Simulation Research on Residual Stress of Swage Autofrettage-processed High-Pressure Cylinder

Lihua Sun, Rongxuan Zhou, Guiqin Li, Jianing Li, and Peter Mitrouchev
Journal of Physics: Conference Series.
Proceedings of the 2023 9th International Conference on Applied Materials and Manufacturing Technology (ICAMMT-2023).
[Abstract] [Paper] [BibTeX]

The vital component of the high-pressure pump is the high-pressure cylinder, which undergoes pulsating cyclic loads during operation. This exposure can lead to fatigue cracking and limit the pump’s overall performance. To address this issue, a swage autofrettage treatment method for the high-pressure cylinder is proposed based on the principles of autofrettage technology. The structure parameters of the mandrel are designed to optimize its role in the treatment process. Subsequently, a swage autofrettage simulation model is established, considering the Bauschinger effect to analyze the distribution of residual stress about the mandrel interference percentage. The results demonstrate that the swage autofrettage treatment improves the stress distribution in the high-pressure cylinder, causing the inner wall surface to undergo a circumferential residual compressive stress. Within a specific range, the Bauschinger effect becomes more significant as the mandrel interference percentage increases. This study provides insights for enhancing the durability and performance of high-pressure cylinders while adhering to mechanical engineering standards.

@article{sun2023simulation,
  title={Simulation Research on Residual Stress of Swage
         Autofrettage-processed High-Pressure Cylinder},
  author={Sun, Lihua and Zhou, Rongxuan and Li, Guiqin and Li, Jianing and Mitrouchev, Peter},
  journal={J. Phys.: Conf. Ser.},
  volume={2587},
  pages={012088},
  year={2023}
}

Selected Projects

AOI Slide 1 AOI Slide 2 AOI Slide 3 AOI Slide 4 AOI Slide 5 AOI Slide 6

Automated Optical Inspection System for Texas Instrument

Sole engineer on 4-CCD multi-angle visual inspection system for TI semiconductor CSE products. 19 defect categories, 100% detection rate, >85K units/day production throughput. Full mechanical design of 1800×1600×2000 mm equipment with 18-step automated process flow.
Machine Vision AOI CAD ANSYS Semiconductor
85K+ units/day 100% detection 19 defect types
[Project] [Code]

Designed and delivered a production AOI (Automated Optical Inspection) system for Texas Instruments CSE semiconductor products at Dinnar Automation. The system uses 4 industrial CCD cameras (MV-GE501GC) with multi-angle illumination to inspect 19 defect categories including epoxy exposure, pin missing, contamination, and marking defects, achieving 100% detection rate at >85K units/day throughput.

Robot Workstation Layout CAD Top View Multi-Station Layout

EtherCAT Real-Time Manipulator Control

Developed EtherCAT master module with 1 kHz F/T sensor synchronization, reducing joint control cycle from 20 ms to 12 ms (40%). Deployed data-driven impedance controller on UR5e with 42% vibration reduction, validated through 72-hour aging test.
C++ EtherCAT CODESYS Real-Time UR5e
[Project] [Code]

Developed EtherCAT master module with 1 kHz F/T sensor synchronization at CloudMinds Robotics, reducing joint control cycle from 20 ms to 12 ms (40%). Co-designed standardized multi-robot assembly workstations for harmonic reducer production with digital twin systems. Deployed data-driven impedance controller on UR5e with 42% vibration reduction.

Fines Robot CAD ROS2 Node Flow Camera Calibration Terrain Construction LiDAR Navigation LiDAR Loop

Fines Full-Stack Robotic Platform

Co-designed hardware architecture, embedded control framework (FineMote), and perception pipeline (FineVision) for steerable wheeled mobile robot at SJTU. Platform enabled experimental validation for IROS 2025 distributed odometry paper.
C++ ROS2 LiDAR Embedded MoveIt!
1 ms control cycle IROS 2025 validated
[Project] [Code]

Co-designed the full-stack "Fines" robotic platform at SJTU IWIN-FINS Lab: hardware architecture (steerable wheeled chassis), embedded control framework (FineMote, 1 ms cycle), and perception pipeline (FineVision with LiDAR + IMU fusion). The platform enabled experimental validation for the IROS 2025 paper on distributed odometry.

NIO ET5

Autonomous Driving Sim-to-Real Transfer

Built GAN-based CAN FD signal synthesizer (5× augmented data, +35% ECU test coverage) and gradient reversal domain adaptation (CARLA→NIO ET5) reducing lateral control error by 37% in production vehicle road tests.
PyTorch GAN CARLA Sim-to-Real
37% error reduction Production validated
[Project] [Code]

Built GAN-based CAN FD signal synthesizer (5× augmented data, +35% ECU test coverage) and gradient reversal domain adaptation pipeline (CARLA→NIO ET5) at NIO Autonomous Driving, reducing lateral control error by 37% in production vehicle road tests.

MuJoCo MCP Server — AI-Driven Robotics Simulation

65-tool server connecting MuJoCo physics simulation to AI assistants via natural language. Supports trajectory optimization (iLQR, MPPI), inverse kinematics, domain randomization, and RL environment integration for 50+ robot models from MuJoCo Menagerie.
Python MuJoCo MCP Robotics Sim RL
[Project] [Code]

Open-source 65-tool MCP server bridging MuJoCo physics simulation with AI assistants via natural language. Supports trajectory optimization (iLQR, MPPI), inverse kinematics, domain randomization, and RL environment integration for 50+ robot models from MuJoCo Menagerie.

Loop Closure Feature System Overview 3D Map EXP Building

LiDAR-Inertial SLAM Benchmarking

Benchmarked FAST-LIO vs. LIO-SAM on real-world driving datasets collected with Northeastern’s NUance platform. Integrated FAST-LIO-LC for loop closure drift correction over long trajectories.
C++ ROS SLAM LiDAR
[Project] [Code]

Benchmarked FAST-LIO vs. LIO-SAM on real-world driving datasets collected with Northeastern's NUance autonomous vehicle platform. Integrated FAST-LIO-LC for loop closure drift correction over long trajectories, achieving consistent sub-meter accuracy.

Rongxuan Zhou © 2026  ·  zhou.rongx@northeastern.edu