Pelican-Sim 1.0: A General World Model Simulator for Embodied Intelligence
Shilong Zou, Shilin Zhang, Yingji Zhang, Yuhang Huang, Yi Zhang, Zeyuan Ding, Han Dong, Junwei Liao and 3 others
Beijing Innovation Center of Humanoid Robotics (X-Humanoid)
Published September 10, 2026 · on the feed September 14, 2026 · ▲ 22 · arXiv 2609.12036
The abstract
In this technical report, we propose Pelican-Sim 1.0, a general world model simulator for embodied intelligence that predicts future observations from visual context and robot actions to support downstream learning and decision making. The model incorporates four key design features: (1) Unified action representation: a 28-dimensional action value space covering most mainstream embodiments, keeping one model valid across heterogeneous devices. (2) Action-visual injection: URDF- and camera-rendered action videos bridge actions and pixels, giving markedly better controllability across embodiments, scenes, and tasks (PSNR +0.904 over alternative fusion baselines). (3) Sparse mixture-of-experts (MoE): sparse MoE layers add capacity for heterogeneous dynamics and absorb the action modality while reducing inter-modality conflict (FVD -6.530 vs. the dense backbone). (4) Efficient rollout generation: causal adaptation and few-step distillation yield a four-step autoregressive simulator, achieving a 5.67-fold speedup over the 35-step model. Benefiting from these designs, we train on approximately one million real-world and simulated trajectories and obtain large gains in action controllability and video quality: PSNR improves over the strongest evaluated baselines by 4.636 on AgiBotWorld Beta, 2.080 on RoboMIND, and 10.343 on RoboTwin, with the adapted EWMBench DYN score up 0.426 on RoboTwin. Relying on this, four downstream applications on RoboTwin succeed: 500 generated trajectories added to 50 demonstrations per task raise policy success from 70% to 93%; policy evaluation reaches a Pearson correlation of 0.994 across five checkpoints; and relative success gains reach 47.7% for action selection and 20.3% for policy improvement. Qualitative generalization across trajectory, scene, object, embodiment, and viewpoint shifts highlights its potential as a general-purpose world model simulator.
The Brief
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Transcript
Pelican-Sim 1.0. A General World Model Simulator for Embodied Intelligence. By Shilong Zou and ten others, from the Beijing Innovation Center of Humanoid Robotics. Published on the tenth of September. Its code repository is a placeholder: a readme, and nothing to run yet.
Embodied intelligence needs a way to predict what comes next. A world model simulator takes visual context and robot actions, and predicts future observations that can support downstream learning and decision making. Making one general runs into several obstacles: robots differ in how their actions are represented, actions and pixels are different kinds of signal, dynamics vary widely, and rolling a video model forward takes many steps.
Pelican-Sim 1.0 is a general world model simulator for embodied intelligence, presented as a technical report and built around four design features that answer those obstacles one at a time. The goal is one model that can stand in for the real world across many robots and many tasks: given what a camera sees and which actions a robot takes, show what would happen next, well enough that policies can be trained and evaluated against it.
First, a unified action representation: a twenty-eight dimensional action value space that covers most mainstream embodiments, so that one model remains valid across heterogeneous devices. Second, action-visual injection. Action videos, rendered through URDF and through cameras, bridge actions and pixels, giving markedly better controllability across embodiments, scenes and tasks. Against alternative fusion baselines, that is a PSNR gain of zero point nine zero four.
Third, sparse mixture-of-experts layers add capacity for heterogeneous dynamics, and absorb the action modality while reducing conflict between modalities. That improves FVD by six point five three against the dense backbone. Fourth, efficient rollout generation. Causal adaptation and few-step distillation yield a four-step autoregressive simulator, five point six seven times faster than the thirty-five step model.
Trained on approximately one million real-world and simulated trajectories, the model shows large gains in action controllability and video quality. Over the strongest baselines evaluated, PSNR improves by four point six three six on AgiBotWorld Beta, two point zero eight on RoboMIND, and ten point three four three on RoboTwin. The adapted EWMBench DYN score rises by zero point four two six on RoboTwin.
The downstream tests ask whether the simulator is useful, not just accurate, and four applications on RoboTwin succeed. Adding five hundred generated trajectories to the fifty demonstrations per task raises policy success from seventy percent to ninety-three. Policy evaluation reaches a Pearson correlation of zero point nine nine four across five checkpoints. And relative success gains reach forty-seven point seven percent for action selection, and twenty point three percent for policy improvement. Put together, the simulator is used four ways: to make training data, to rank policies, to choose actions, and to improve a policy.
Qualitative tests across shifts in trajectory, scene, object, embodiment and viewpoint point to its potential as a general-purpose simulator. The design puts generality into the interface first. A shared action space and rendered action videos let one model address many robots, and the remaining features give it the capacity and the speed to be put to use.
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Learn it by doing: make the calls the authors made, guess the result before you see it, and defend it in a viva graded on your own words. Chapter 1 is right here.
Chapter 1 🧩 · The problem
Many robots, one simulator. The trouble starts with how to tell it what each robot is doing.
You want one learned simulator that shows what a robot's camera would see next, given the actions the robot takes. It should work for single-arm and two-armed robots, grippers and dexterous hands alike.
The road ahead
- 1 · The problem ~7 min A learned robot simulator must understand actions from many different robots, but numbers and image cues each tell it only part of the story.
- 2 · What came before ~3 min
- 3 · The key idea ~9 min Give each action twice, as shared-layout numbers and as a rendered arm video, and feed the two into alternating blocks of one video model.
- 4 · Choose your own research ~3 min
- 5 · Build the method ~8 min Unify actions, render them as videos, train on mixed real and simulated data, distill to a fast simulator, then use its rollouts for policies.
- 6 · The experiment ~6 min You’ll guess: After causal adaptation and few-step distillation, how much faster was the four-step simulator than the 35-step model?
- 7 · The viva ~5 min Three questions from the examiners, answered in your own words. Win it for the paper’s trophy.
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