Collaborative robots (cobots) are widely used in industrial applications, yet extensive research is still needed to enhance human-robot collaborations and operator experience. A potential approach to improve the collaboration experience involves adapting cobot behavior based on natural cues from the operator. Inspired by the literature on human-human interactions, we conducted a wizard-of-oz study to examine whether a gaze towards the cobot can serve as a trigger for initiating joint activities in collaborative sessions. In this study, 37 participants engaged in an assembly task while their gaze behavior was analyzed. We employ a gaze-based attention recognition model to identify when the participants look at the cobot. Our results indicate that in most cases (84.88\%), the joint activity is preceded by a gaze towards the cobot. Furthermore, during the entire assembly cycle, the participants tend to look at the cobot around the time of the joint activity. To the best of our knowledge, this is the first study to analyze the natural gaze behavior of participants working on a joint activity with a robot during a collaborative assembly task.

翻译：协作机器人（cobots）已在工业应用中得到广泛使用，但提升人机协作与操作员体验仍需大量研究。一种改善协作体验的潜在方法是根据操作员的自然线索调整协作机器人的行为。受人类交互文献启发，我们开展了一项"巫师之奥兹"研究，旨在探究对协作机器人的凝视是否能作为触发协作会话中联合活动的信号。本研究分析了37名参与者在装配任务中的凝视行为，并采用基于凝视的注意力识别模型来检测参与者何时注视协作机器人。结果表明，在84.88%的案例中，联合活动发生前存在对协作机器人的凝视。此外，在整个装配周期中，参与者倾向于在联合活动发生前后注视协作机器人。据我们所知，这是首项在协作装配任务中分析参与者与机器人联合活动时自然凝视行为的研究。