VLAC: A Vision-Language-Action-Critic Model for Robotic Real-World Reinforcement Learning

[paper] [code] [model]

🚀 Interactive Demo & Homepage

Try Interactive & Homepage

Online Demo is available now in Homepage, Try as you like!!!

VLAC-2B

VLAC is a general-purpose pair-wise critic and manipulation model which designed for real world robot reinforcement learning and data refinement.

It provides robust evaluation capabilities for task progress prediction and task completion verification base one images and task description.

VLAC trained on 3000h+ human egocentric data, 1200h+ comprehensive public robotic manipulation data, and 15h+ self-collected manipulation data.

VLAC-8B is coming soon! Now the 8B model can be used on Homepage.

✨ Key Features

• Pair-wise comparison mechanism for improved progressing dense critic accuracy, better recognition of state changes, and each step can be the start of the trajectory.

• Multi-modal capabilities - Supports process tracking, task completion judgment, task description estimation, visual question answering, and even embodied action output, equipped with VLA capabilities.

• Flexible zero-shot and one-shot - in-context capabilities, maintaining excellent performance across entities, scenarios, and tasks.

• Human-task synesthesia - Based on the ego4D human dataset, model understands common tasks and build synesthesia for real-world human tasks and embodied tasks.

• Trajectory quality screening - VLAC can evaluate the collected trajectories and filters out low score trajectories based on the VOC value and mask the action with negative pair-wise score, that is, data with low fluency and quality, improving the effect and efficiency of imitation learning.

Framework & Performance

Details about the model's performance and evaluation metrics can be found in the Homepage.

🛠️ Installation

To install from source:

git clone https://github.com/InternRobotics/VLAC.git
cd VLAC
pip install -e .

Running Environment:

	Range	Recommended	Notes
python	>=3.9	3.10
cuda		cuda12	No need to install if using CPU, NPU, MPS
torch	>=2.0
transformers	>=4.51	4.51.3
peft	>=0.15.2
ms-swift		3.3

🚀 Quick Start

from evo_vlac import GAC_model
from evo_vlac.utils.video_tool import compress_video
import os
#Consistent with the web interface, the value and citic rewards of video input can be evaluated.


#assign local model path
model_path="set to your local model path"
#download model form https://huggingface.co/InternRobotics/VLAC

#assign video path and task description
test_video='evo_vlac/examples/videos/pick-bowl-test.mp4'
ref_video='evo_vlac/examples/videos/pick-bowl-ref.mov'
task_description='Put up the bowl and place it back in the white storage box.'

#init model
Critic=GAC_model(tag='critic')
Critic.init_model(model_path=model_path,model_type='internvl2',device_map=f'cuda:0')
Critic.temperature=0.5
Critic.top_k=1
Critic.set_config()
Critic.set_system_prompt()

# transform video
test_video_compressed = os.path.join(os.path.dirname(test_video),"test.mp4")
_,output_fps=compress_video(test_video, test_video_compressed,fps=5)
reference_video_compressed = None
if ref_video:
    reference_video_compressed = os.path.join(os.path.dirname(ref_video),"ref.mp4")
    compress_video(ref_video, reference_video_compressed,fps=5)


# generate Critic results
result_path,value_list,critic_list,done_list = Critic.web_trajectory_critic(
    task_description=task_description,
    main_video_path=test_video_compressed,
    reference_video_path=reference_video_compressed,#if None means no reference video, only use task_description to indicate the task
    batch_num=10,#batch number
    ref_num=6,#image number used in reference video
    think=False,# whether to CoT
    skip=5,#pair-wise step
    rich=False,#whether to output decimal value
    reverse_eval=False,#whether to reverse the evaluation(for VROC evaluation)
    output_path="results",
    fps=float(output_fps),
    frame_skip=True,#whether to skip frames(if false, each frame while be evaluated, cost more time)
    done_flag=False,#whether to out put done value
    in_context_done=False,#whether use reference video to generate done value
    done_threshold=0.9,#done threshold
    video_output=True#whether to output video
)


print("=" * 100)
print(">>>>>>>>>Critic results<<<<<<<<<<")
print(" ")

print(f"result path: {result_path}")
print(f"task description: {task_description}")
print("=" * 50)

print("value_list:")
print(value_list)
print("=" * 50)

print("critic_list:")
print(critic_list)
print("=" * 50)

print("done_list:")
print(done_list)
print("=" * 100)

More examples of

• pair-wise image inputs critic. Please check this example

• vla action generation. Please check this example

• data refinement. Please check this example

For training code, please refer to InternVL2.

🔗 Citation

If you find our work helpful, please cite:

@misc{VLAC2025,
    title = {A Vision-Language-Action-Critic Model for Robotic Real-World Reinforcement Learning},
    author = {Shanghai AI lab},
    year = {2025},
    booktitle={arXiv},
}

🙏 Acknowledgments

• SWIFT
• InternVL