TempoFit: Plug-and-Play Layer-Wise Temporal KV Memory for Long-Horizon Vision-Language-Action Manipulation

Fuente: arXiv
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Autori principali: Sun, Jun, Yang, Boyu, Zhang, Jiahao, Ma, Ning, Wu, Chencheng, Zhang, Siqing, Huang, Yiou, Wang, Qiufeng, Liang, Shan, Chen, Yaran
Natura: Preprint
Pubblicazione: 2026
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author Sun, Jun
Yang, Boyu
Zhang, Jiahao
Ma, Ning
Wu, Chencheng
Zhang, Siqing
Huang, Yiou
Wang, Qiufeng
Liang, Shan
Chen, Yaran
author_facet Sun, Jun
Yang, Boyu
Zhang, Jiahao
Ma, Ning
Wu, Chencheng
Zhang, Siqing
Huang, Yiou
Wang, Qiufeng
Liang, Shan
Chen, Yaran
contents Pretrained Vision-Language-Action (VLA) policies have achieved strong single-step manipulation, but their inference remains largely memoryless, which is brittle in non-Markovian long-horizon settings with occlusion, state aliasing, and subtle post-action changes. Prior approaches inject history either by stacking frames, which scales visual tokens and latency while adding near-duplicate pixels, or by learning additional temporal interfaces that require (re-)training and may break the original single-frame inference graph. We present TempoFit, a training-free temporal retrofit that upgrades frozen VLAs through state-level memory. Our key insight is that prefix attention K/V already form a model-native, content-addressable runtime state; reusing them across timesteps introduces history without new tokens or trainable modules. TempoFit stores layer-wise FIFO prefix K/V at selected intermediate layers, performs parameter-free K-to-K retrieval with Frame-Gap Temporal Bias (FGTB), a fixed recency bias inspired by positional biases in NLP, to keep decisions present-dominant, and injects the retrieved context via pre-attention residual loading with norm-preserving rescaling to avoid distribution shift under frozen weights. On LIBERO-LONG, TempoFit improves strong pretrained backbones by up to +4.0% average success rate while maintaining near-real-time latency, and it transfers consistently to CALVIN and real-robot long-horizon tasks.
format Preprint
id arxiv_https___arxiv_org_abs_2603_07647
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle TempoFit: Plug-and-Play Layer-Wise Temporal KV Memory for Long-Horizon Vision-Language-Action Manipulation
Sun, Jun
Yang, Boyu
Zhang, Jiahao
Ma, Ning
Wu, Chencheng
Zhang, Siqing
Huang, Yiou
Wang, Qiufeng
Liang, Shan
Chen, Yaran
Robotics
Pretrained Vision-Language-Action (VLA) policies have achieved strong single-step manipulation, but their inference remains largely memoryless, which is brittle in non-Markovian long-horizon settings with occlusion, state aliasing, and subtle post-action changes. Prior approaches inject history either by stacking frames, which scales visual tokens and latency while adding near-duplicate pixels, or by learning additional temporal interfaces that require (re-)training and may break the original single-frame inference graph. We present TempoFit, a training-free temporal retrofit that upgrades frozen VLAs through state-level memory. Our key insight is that prefix attention K/V already form a model-native, content-addressable runtime state; reusing them across timesteps introduces history without new tokens or trainable modules. TempoFit stores layer-wise FIFO prefix K/V at selected intermediate layers, performs parameter-free K-to-K retrieval with Frame-Gap Temporal Bias (FGTB), a fixed recency bias inspired by positional biases in NLP, to keep decisions present-dominant, and injects the retrieved context via pre-attention residual loading with norm-preserving rescaling to avoid distribution shift under frozen weights. On LIBERO-LONG, TempoFit improves strong pretrained backbones by up to +4.0% average success rate while maintaining near-real-time latency, and it transfers consistently to CALVIN and real-robot long-horizon tasks.
title TempoFit: Plug-and-Play Layer-Wise Temporal KV Memory for Long-Horizon Vision-Language-Action Manipulation
topic Robotics
url https://arxiv.org/abs/2603.07647