FLUX: Accelerating Cross-Embodiment Generative Navigation Policies via Rectified Flow and Static-to-Dynamic Learning

Zeying Gong1       Yangyi Zhong1       Yiyi Ding1       Tianshuai Hu2      
Guoyang Zhao1       Lingdong Kong3       Rong Li1       Jiadi You1       Junwei Liang1,2,✉

1 The Hong Kong University of Science and Technology (Guangzhou)    
2 The Hong Kong University of Science and Technology    
3 National University of Singapore    
Under Review

  Main Video

The first FLow-based U policy for X-platform navigation.


  Real-World Demonstrations

Testing our method in real-world environments.

  Humanoid Robot Navigation

  Quadrupedal Robot Navigation

  Wheeled Robot Navigation



  Simulation Demonstrations

Evaluating our method on fundamental navigation tasks in dynamic scenarios via our proposed benchmark DynBench.

  Dynamic PointNav

  Warehouse

  Hospital

  Office

  Jetracer

  SocialNav

  Warehouse

  Hospital

  Office

  Jetracer

  Dynamic Exploration

  Warehouse

  Hospital

  Office

  Jetracer


  Abstract

Autonomous navigation requires a broad spectrum of skills, from static goal-reaching to dynamic social traversal, yet evaluation remains fragmented across disparate protocols. We introduce DynBench, a dynamic navigation benchmark featuring physically valid crowd simulation. Combined with existing static protocols, it supports comprehensive evaluation across six fundamental navigation tasks. Within this framework, we propose FLUX, the first flow-based unified navigation policy. By linearizing probability flow, FLUX replaces iterative denoising with straight-line trajectories, improving per-step inference efficiency by 47% over prior flow-based methods and 29% over diffusion-based ones. Following a static-to-dynamic curriculum, FLUX initially establishes geometric priors and is subsequently refined through reinforcement learning in dynamic social environments. This regime not only strengthens socially-aware navigation but also enhances static task robustness by capturing recovery behaviors through stochastic action distributions. FLUX achieves state-of-the-art performance across all tasks and demonstrates zero-shot sim-to-real transfer on wheeled, quadrupedal, and humanoid platforms without any fine-tuning.


  Overview

Fig. 1. FLUX : A Flow-Based Unified Policy for Cross-Embodiment Navigation. Our static-to-dynamic training curriculum enables efficient, socially-aware navigation, which transfers zero-shot across three heterogeneous platforms in the real world without platform-specific fine-tuning.


  Framework

Fig. 2. Overview of FLUX framework. FLUX follows a static-to-dynamic training paradigm. Stage 1 (Top): Given egocentric visual observations and a goal, the flow policy head is pre-trained via imitation learning on static expert trajectories. It generates diverse candidate paths, which are evaluated by the critic head. Stage 2 (Bottom): The framework is post-training using Group Relative Policy Optimization via on-policy rollouts. This stage optimizes for both goal-reaching efficiency and social compliance in dynamic environments.


  Quantitative Results

Metrics:
SR (Success Rate) / SPL (Success weighted by Path Length) / ET (Exploration Time) / EA (Exploration Area)
S-TL (Success Time Length) / Coll. (Collision) / SC (Safety Cost) / MinDist. (Minimum Distance).


Methods Static Scenes Dynamic Scenes
PointNav Exploration ImageNav Dyn. PointNav Dyn. Exploration SocialNav
SR SPL ET EA SR SPL SR S-TL ET EA SR Coll SC MinDist
Traditional Planning Methods
DWA 33.532.4---- 38.218.5-- 41.8107.34.1
FBE --4.311.2-- --20.339.5 ----
Reinforcement Learning Methods
DD-PPO 19.519.2---- 8.47.7-- 1.5184.33.4
Falcon 40.033.6---- 19.016.4-- 13.8174.23.6
Hybrid Modular Methods
iPlanner 66.865.1---- 30.815.4-- 35.3136.34.3
ViPlanner 63.462.4---- 27.517.2-- 37.0125.94.3
Imitation Learning Methods
GNM --22.127.816.315.7 --29.765.5 ----
ViNT --24.436.212.611.8 --31.973.2 ----
Generative Modeling Methods
NoMaD --35.562.58.57.6 --34.975.0 ----
FlowNav --36.064.19.28.5 --35.875.7 ----
NavDP 77.874.872.5167.243.443.4 38.731.943.693.7 59.3215.53.5
Ours 80.978.673.7172.844.044.4 42.420.655.1128.7 64.0164.44.0

Tab: Performance Comparison Across Six Fundamental Navigation Tasks. This table presents quantitative comparisons of six core navigation tasks in both static and dynamic scenes, covering traditional planning, reinforcement learning, hybrid modular, imitation learning, and generative modeling methods. Our approach achieves state-of-the-art performance across all metrics, demonstrating superior effectiveness in both static and dynamic navigation scenarios.



  Qualitative Results


Qualitative analysis of generative navigation policies. Compared to prior methods, FLUX generates trajectories with higher safety in both static and dynamic obstacle avoidance.