Wearable supernumerary robotic limbs (SRLs) sit at the intersection of human augmentation and embodied AI, transforming into extensions of the human body. However, their movements within the intimate near-body space raise unresolved challenges for perceived safety, user control, and trust. In this paper, we present results from a Wizard-of-Oz study (n=18), where participants completed near-body collaboration tasks with SRLs to explore these challenges. We collected qualitative data through think-aloud protocols and semi-structured interviews, complemented by physiological signals and post-task ratings. Findings indicate that greater autonomy did not inherently enhance perceived safety or trust. Instead, participants identified near-body zones and paired them with clear coordination rules. They also expressed expectations for how different arm components should behave, shaping preferences around autonomy, perceived safety, and trust. Building on these insights, we introduce SRL Proxemics, a zone- and segment-level design framework showing that autonomy is not monolithic: perceived safety hinges on spatially calibrated, legible behaviors, not higher autonomy.

翻译：可穿戴超数机械臂（SRLs）处于人体增强与具身人工智能的交叉领域，正逐渐演化为人体延伸部分。然而，其在亲密近身空间内的运动引发了感知安全性、用户控制与信任等尚未解决的挑战。本文通过一项巫师实验研究（n=18）呈现相关结果，参与者与SRLs协作完成近身任务以探索上述挑战。我们通过有声思维报告与半结构化访谈收集定性数据，辅以生理信号与任务后评分。研究发现，更高的自主性并未本质提升感知安全性或信任度。相反，参与者识别出近身交互区域，并将其与明确的协调规则相匹配。他们还对不同机械臂组件的行为模式提出预期，由此形成对自主性、感知安全性与信任度的偏好取向。基于这些发现，我们提出SRL近体交互空间学——一个区域与分段层级的设计框架，该框架表明自主性并非单一概念：感知安全性的核心在于空间校准的明晰行为模式，而非更高的自主性水平。