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arXiv · 2606.16504

APEX: Adaptive Policy Execution for Precise Manipulation

Mengfei Zhao·Chenxi Jiang·Tuo An·Jindou Jia·Jianfei Yang
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Abstract

Modern imitation learning methods, including visuomotor and Vision-Language-Action (VLA) policies, typically output high-level action references that are executed by low-level controllers. However, the absence of higher-order reference signals, together with the policy's lack of awareness of the underlying low-level control dynamics during training, inevitably induces an execution gap. As a result, realized actions deviate systematically from policy-commanded ones, with a critical impact on precision-sensitive manipulation. Prior work either modifies the policy architecture or the low-level controller, both requiring intrusive changes to the pretrained policy or packaged controller. This raises a natural question: when the policy and controller are both treated as inaccessible black boxes, can we bridge the execution gap? We propose Adaptive Policy Execution (APEX), a plug-and-play framework inserted between the policy and the controller that reconstructs a dynamically feasible reference from policy outputs and adapts at test-time according to low-level state feedback, with a provable convergence guarantee. Extensive empirical studies show that APEX reduces controller-induced tracking error by 41.2% on demonstration replay and improves manipulation success by 4.8--25.8 percentage points across four visuomotor and VLA policy classes.

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Mengfei Zhao, Chenxi Jiang, Tuo An, Jindou Jia, Jianfei Yang. 2026-06-15. APEX: Adaptive Policy Execution for Precise Manipulation. https://arxiv.org/abs/2606.16504

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