# 接线很重要：VLA 策略中可供性头的注入拓扑与初始化

> 原文链接：https://robotics.hellobike.com/papers/2026-10-05-2610-06318
> 频道：papers | 更新日期：2026-10-05 | 标签：arxiv, cs.RO
> 核心摘要：研究VLA中可供性头损害指令遵循的问题，提出stop-gradient读取与桥接重注入，并在LIBERO验证性能。

# 接线很重要：VLA 策略中可供性头的注入拓扑与初始化

::: v-pre
> 原文链接：[Wiring Matters: Injection Topology and Initialization of Affordance Heads in Vision-Language-Action Policies](https://arxiv.org/abs/2610.06318)（arXiv 2610.06318 · 发布日期：2026-10-05）

**Wiring Matters: Injection Topology and Initialization of Affordance Heads in Vision-Language-Action Policies**

研究VLA中可供性头损害指令遵循的问题，提出stop-gradient读取与桥接重注入，并在LIBERO验证性能。

## 核心要点

- 密集可供性监督虽有吸引力，但朴素共训可供性头会严重损害指令遵循。
- 方法以stop-gradient读取骨干，并通过学习桥将中间头特征重注入动作专家。
- 在LIBERO上，允许梯度回传使策略低于无头基线，保护骨干是前提。
- 初始化比注入拓扑更关键；主动初始化残差桥达96.2%，额外参数低于1%。

**验证范围与局限**：验证范围为LIBERO benchmark上的现代VLA，摘要未说明真机实验。

## 英文摘要 (Abstract)

Dense affordance supervision is an appealing auxiliary signal for vision-language-action (VLA) policies, yet naively co-training an affordance head can severely damage instruction following. We present a controlled study of how to wire such a head into a modern VLA on the LIBERO benchmark. Our recipe reads the backbone through a stop-gradient and re-injects an intermediate head feature into the action expert via a learned bridge. The stop-gradient is a precondition: letting affordance gradients reach the backbone drops the policy below the headless base (85.5% vs. 93.1%). With the backbone protected, a same-budget 2*2 ablation over injection topology (concatenation vs. residual) and bridge initialization (zero vs. random) shows initialization is the dominant lever. The best wiring, an actively initialized residual bridge, reaches 96.2%, matching the far more elaborate three-expert AffordanceVLA (95.8%) with under 1% extra parameters. Two probes explain the mechanism: ground-truth affordances fed as an input hurt, and inference-time zeroing shows a lazy bridge acts only as a training-time regularizer while an active bridge becomes load-bearing.

作者：Zijian An, Linhan Wang, Jiayan Wang, Shijie Geng, Ran Yang, Yiming Feng, Lifeng Zhou
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## 原始参考来源 (Sources)

- [arXiv 2610.06318：Wiring Matters: Injection Topology and Initialization of Affordance Heads in Vision-Language-Action Policies](https://arxiv.org/abs/2610.06318)