HiVLA: A Visual-Grounded-Centric Hierarchical Embodied Manipulation System

Tianshuo Yang1,2,*, Guanyu Chen3,*, Yutian Chen2,4, Zhixuan Liang1,2, Yitian Liu3, Zanxin Chen2,3,
Chunpu Xu2, Haotian Liang2, Jiangmiao Pang2, Yao Mu2,3, Ping Luo1
1HKU, 2Shanghai AI Lab, 3SJTU, 4CUHK
* indicates equal contributions, † indicates corresponding author
HiVLA teaser figure

(a) Overview of our proposed HiVLA framework. (b) Success rate comparison on RoboTwin benchmark.

Abstract

While end-to-end Vision-Language-Action (VLA) models offer a promising paradigm for robotic manipulation, fine-tuning them on narrow control data often compromises the profound reasoning capabilities inherited from their base Vision-Language Models (VLMs). To resolve this fundamental trade-off, we propose HiVLA, a visual-grounded-centric hierarchical framework that explicitly decouples high-level semantic planning from low-level motor control. In high-level part, a VLM planner first performs task decomposition and visual grounding to generate structured plans, comprising a subtask instruction and a precise target bounding box. Then, to translate this plan into physical actions, we introduce a flow-matching Diffusion Transformer (DiT) action expert in low-level part equipped with a novel cascaded cross-attention mechanism. This design sequentially fuses global context, high-resolution object-centric crops and skill semantics, enabling the DiT to focus purely on robust execution. Our decoupled architecture preserves the VLM's zero-shot reasoning while allowing independent improvement of both components. Extensive experiments in simulation and the real world demonstrate that HiVLA significantly outperforms state-of-the-art end-to-end baselines, particularly excelling in long-horizon skill composition and the fine-grained manipulation of small objects in cluttered scenes.

Pipeline

HiVLA pipeline figure

(a) Our decoupled framework utilizes a VLM to decompose user instructions into explicit structured plans, yielding a skill-level subtask and a bounding box used to extract a high-resolution target crop. (b) To execute this plan, the DiT action expert employs a cascaded cross-attention block. This design sequentially conditions the noisy action latents on global visual context, position-aware local features, and language tokens, bridging high-level reasoning with low-level control.

Results

Task π0 π0.5 StarVLA H-RDT Oursw/o Skill Ours
Easy Tasks
Click Bell 45% 65% 71% 88% 95% 94%
Click Clock 53% 66% 83% 93% 97% 97%
Press Stapler 60% 69% 63% 89% 98% 97%
Lift Pot 59% 21% 18% 92% 96% 96%
Average 54.3% 55.3% 58.8% 90.5% 96.5% 96.0%
Hard Tasks
Place Shoe 75% 68% 61% 88% 94% 95%
Move Stapler 15% 17% 15% 34% 42% 60%
Stamp Seal 61% 42% 25% 43% 68% 76%
Stack 3 Blocks 1% 1% 16% 20% 26% 37%
Click 3 Bells 41% 54% 66% 88% 92% 98%
Average 38.6% 36.4% 36.6% 54.6% 64.4% 73.2%
Total Average 45.6% 44.8% 46.4% 70.6% 78.7% 83.3%

Main success rates across 9 tasks in the RoboTwin simulator. HiVLA demonstrates superior performance, particularly in long-horizon and visually demanding tasks. Best and second-best results are bold and underlined.

BibTeX

@article{yang2026hivla,
  title   = {{HiVLA}: A Visual-Grounded-Centric Hierarchical Embodied Manipulation System},
  author  = {Yang, Tianshuo and Chen, Guanyu and Chen, Yutian and Liang, Zhixuan and Liu, Yitian and Chen, Zanxin and Xu, Chunpu and Liang, Haotian and Pang, Jiangmiao and Mu, Yao and Luo, Ping},
  journal = {arXiv preprint arXiv:2604.14125},
  year    = {2026}
}