This feature makes cobots an attractive means of performing flexible and efficient tasks through interaction with human operators [4]. However, since such interactions involve unwanted collisions or potential hazards between humans and robots, research has been conducted to prevent them [5; 6]. Furthermore, standards such as ISO 10218-2 [7] and ISO/TS 15066 [8] have been developed. ISO 10218-2 and ISO/TS 15066 define the safety requirements for robotic systems and provide methods for risk assessment and reduction. However, due to the nature of the standards, they are rather general, and they indicate that a risk assessment for robotic applications is essential. Therefore, various risk assessments are required for the utilization of cobots, and research in this area is being emphasized [9; 10]. Despite the critical importance of risk assessment for occupational safety, current research has mainly focused on stationary robots applied to assembly lines [11; 12]. However, with the demand for full automation of smart manufacturing systems, mobile robots such as AMRs have been increasingly studied, with applications in various environments beyond fixed workstations [13]. Along with this, research is being conducted on the safety requirements for each application domain [14]. Recent advances in robotics technology have expanded from familiar wheeled mobile robots to various forms of mobile robots, which are used in different applications depending on their movement characteristics. Among them, quadruped robots are gaining attention as an alternative to overcome the limitations of wheeled robots. Quadruped robots can climb stairs and navigate dangerous or unstructured terrain autonomously, making them suitable for inaccessible areas such as narrow pipelines and nuclear power plant inspection sites. Their feasibility has been studied for collaborative work across industries, including mineral exploration in high-temperature and high-pressure environments, automotive plants, and steel mills [15; 16; 17]. However, research into safety in environments where quadruped robots and humans collaborate is still in its infancy, and existing risk assessment methodologies may not be appropriate for these new technologies [18]. Therefore, there is a need for systematic risk assessment and analysis of stakeholders' risk perceptions for the safe industrial application of quadruped robots [19; 20; 21]. Given this context, the aim of this study is to identify the possible risk factors in the industrial application of quadruped robots and to contribute to the development of safety management strategies by analyzing the differences in risk perceptions among different stakeholders. To this end, the following research questions were set:  
1. What are the perceived safety issues of stakeholders in collaborative mobile robot environments, with specific insights from a quadruped robot case study? 2. What are the differences in risk perceptions among stakeholders regarding the hazards of quadruped robots? This study is based on a real-world example of a company that uses quadruped robots for safety management patrols in factories with confined environments. A survey of risk cases was conducted among workers with experience in collaborative work, and the risk factors were classified into major and minor factors. Traditional risk assessment methods rely mostly on accident cases or statistical data to analyze potential risks. However, industrial applications of quadruped robots are scarce, and the complexity of the technology limits existing methodologies [22; 23]. The Delphi method can leverage the collective intelligence of experts to build a reliable consensus and is an effective approach in situations where objective data is scarce [23; 24]. Therefore, in this study, the Delphi method was applied to collect the opinions of experts from various backgrounds and to achieve consensus [25]. Based on this, the Delphi method was applied, dividing the experts into four groups with different levels of knowledge, experience, and expertise.