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）广泛应用于工业场景，但提升人机协作体验及操作员体验仍需大量研究。一种改善协作体验的潜在方法涉及根据操作员的自然信号调整协作机器人行为。受人际互动文献启发，我们开展了一项"绿野仙踪"实验，探究注视协作机器人能否作为协作会话中启动联合活动的触发信号。本研究招募37名参与者完成组装任务，并分析其注视行为。我们采用基于注视的注意力识别模型，在参与者注视协作机器人时进行识别。结果表明，在84.88%的案例中，联合活动启动前均出现对协作机器人的注视。此外，在整个组装周期中，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，这是首项在协作组装任务中分析参与者与机器人进行联合活动时自然注视行为的研究。