python
Run under repository: https://github.com/thu-ml/RDT2


import torch
from transformers import AutoProcessor, Qwen2_5_VLForConditionalGeneration

from vqvae import MultiVQVAE
from models.normalizer import LinearNormalizer
from utils import batch_predict_action

assuming using gpu 0
device = "cuda:0"


processor = AutoProcessor.from_pretrained("Qwen/Qwen2.5-VL-7B-Instruct")
model = Qwen2_5_VLForConditionalGeneration.from_pretrained(
    "robotics-diffusion-transformer/RDT2-VQ"
    torch_dtype=torch.bfloat16,
    attn_implementation="flash_attention_2",
    device_map=device
).eval()
vae = MultiVQVAE.from_pretrained("robotics-diffusion-transformer/RVQActionTokenizer").eval()
vae = vae.to(device=device, dtype=torch.float32)

valid_action_id_length = (
    vae.pos_id_len + vae.rot_id_len + vae.grip_id_len
)
TODO: modify to your own downloaded normalizer path
download from http://ml.cs.tsinghua.edu.cn/~lingxuan/rdt2/umi_normalizer_wo_downsample_indentity_rot.pt
normalizer = LinearNormalizer.from_pretrained("umi_normalizer_wo_downsample_indentity_rot.pt")  


result = batch_predict_action(
    model,
    processor,
    vae,
    normalizer,
    examples=[
        {
            "obs": {
                
NOTE: following the setting of UMI, camera0_rgb for right arm, camera1_rgb for left arm
                "camera0_rgb": ..., 
RGB image in np.ndarray of shape (1, 384, 384, 3) with dtype=np.uint8
                "camera1_rgb": ..., 
RGB image in np.ndarray of shape (1, 384, 384, 3) with dtype=np.uint8
            },
            "meta": {
                "num_camera": 2
            }
        },
        ...,    
we support batch inference, so you can pass a list of examples
    ]，
    valid_action_id_length=valid_action_id_length,
    apply_jpeg_compression=True,
    
Since model is trained with mostly jpeg images, we suggest toggle this on for better formance
    instruction="Pick up the apple."
    
We suggest using Instruction in format "verb + object" with Capitalized First Letter and trailing period 
)

get the predict action from example 0
action_chunk = result["action_pred"][0] 
torch.FloatTensor of shape (24, 20) with dtype=torch.float32
action_chunk (T, D) with T=24, D=20
  T=24: our action_chunk predicts the future 0.8s in fps=30, i.e. 24 frames
  D=20: following the setting of UMI, we predict the action for both arms from right to left
  
[0-2]: RIGHT ARM end effector position in x, y, z (unit: m)
  
[3-8]: RIGHT ARM end effector rotation in 6D rotation representation
  
[9]: RIGHT ARM gripper width (unit: m)
  
[10-12]: LEFT ARM end effector position in x, y, z (unit: m)
  
[13-18]: LEFT ARM end effector rotation in 6D rotation representation
  
[19]: LEFT ARM gripper width (unit: m)


rescale gripper width from [0, 0.088] to [0, 0.1]
for robot_idx in range(2):
    action_chunk[:, robot_idx * 10 + 9] = action_chunk[:, robot_idx * 10 + 9] / 0.088 * 0.1

bibtex
@article{liu2026rdt2,
  title={RDT2: Exploring the Scaling Limit of UMI Data Towards Zero-Shot Cross-Embodiment Generalization},
  author={Liu, Songming and Li, Bangguo and Ma, Kai and Wu, Lingxuan and Tan, Hengkai and Ouyang, Xiao and Su, Hang and Zhu, Jun},
  journal={arXiv preprint arXiv:2602.03310},
  year={2026}
}