Drop-Then-Recovery: How Redundant Are Vision-Language-Action Models?
Paper • 2606.27755 • Published • 6
Checkpoint for Drop-Then-Recovery: How Redundant Are Vision-Language-Action Models?.
DTR (Drop-Then-Recovery) removes transformer blocks from a pretrained VLA model and recovery-fine-tunes the smaller dense model. Code: https://github.com/s1ghhh/VLADrop
| Paper row | Table 1: OpenVLA-OFT Drop Half Action |
| Dropped blocks | Action head (MLPResNet): reduce hidden dimension 4096 -> 2048. Vision and language backbone untouched. |
| Recovery training | LoRA rank 32 (merged), batch size 16, 100K steps, lr 5e-4 |
| LIBERO success rate | Spatial 92.4 / Object 99.0 / Goal 93.6 / Long 92.8 / Avg 94.5 |
Merged full-weight OpenVLA-OFT checkpoint. The drop lists are baked into
config.json (text_config.drop_attn_list / drop_mlp_list), so evaluation
reconstructs the pruned graph automatically. Requires the VLADrop modified
transformers (transformers-openvla-oft-dropped) from https://github.com/s1ghhh/VLADrop
python -m experiments.robot.libero.run_libero_eval_random_dropped \
--pretrained_checkpoint <this_repo_local_path> \
--task_suite_name libero_spatial \
--num_trials_per_task 50 --center_crop True
Includes action_head--*.pt and proprio_projector--*.pt (L1 regression head, 2 input images + proprio).
@article{sun2026vladrop,
title={Drop-Then-Recovery: How Redundant Are Vision-Language-Action Models?},
author={Sun, Guoheng and Feng, Kaixi and He, Shwai and Gong, Xiaochuan and He, Yexiao and Wang, Ziyao and Shen, Zheyu and Ye, Wanghao and Kompella, Ramana Rao and Liu, Gaowen and Li, Ang},
journal={arXiv preprint arXiv:2606.27755},
year={2026}
}