ProRet-VLA: Bridging Prospection and Retrospection for Long-Horizon Robotic Manipulation

Enhua Cheng, Xiaoyuan Fang, Yuxuan Wang, Piji Li


Abstract
Vision-Language-Action (VLA) models map visual observations and language instructions to low-level control actions, but their reliance on the current observation often limits temporal continuity in long-horizon manipulation. We propose ProRet-VLA, a temporal reasoning framework that links prospection and retrospection through predictive consistency. ProRet-VLA maintains compact episodic memories and predicts future observations from temporally enriched context. Rather than using future prediction only as an auxiliary target, we use its prediction error as a self-supervised deviation signal to train a lightweight Deviation Predictor. During inference, the predicted deviation conditions token-wise fusion between current context and retrieved memory, allowing memory usage to vary across decision stages without accessing future observations. Experiments on CALVIN ABC-D and LIBERO show that ProRet-VLA improves long-horizon task completion, achieving an average length of 4.50 on CALVIN and a 96.7% average success rate on LIBERO. Real-world experiments on two long-horizon manipulation tasks further indicate improved temporal progress tracking over strong VLA baselines.
Anthology ID:
2026.findings-emnlp.620
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
13029–13047
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URL:
https://aclanthology.org/2026.findings-emnlp.620/
DOI:
Bibkey:
Cite (ACL):
Enhua Cheng, Xiaoyuan Fang, Yuxuan Wang, and Piji Li. 2026. ProRet-VLA: Bridging Prospection and Retrospection for Long-Horizon Robotic Manipulation. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 13029–13047, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
ProRet-VLA: Bridging Prospection and Retrospection for Long-Horizon Robotic Manipulation (Cheng et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.620.pdf