Human–Robot Collaboration in Occupational Settings: An Introduction to the Special Issue

Welcome to this special issue of the IISE Transactions on Occupational Ergonomics and Human Factors! Our interest in compiling this special issue stems from the increasing use of human–robot collaboration (HRC) in workplace environments. HRC refers to scenarios in which human(s), robot(s), and the environment interact to accomplish tasks as a tightly coupled dynamic system (Bauer et al., 2008). In HRC, humans and robots coexist and cooperate within a shared workspace, aiming to enhance productivity while prioritizing human health and safety. With the growing demand for HRC in occupational settings, research on HRC that is relevant to the workplace is essential to enhance safety and health risk management, while in parallel mitigating any adverse effects or unintended risks resulting from overlooking key ergonomics and human factors considerations.

We initiated an invitation for papers for this special issue in August 2022. We sought papers with a specific emphasis on understanding the “human” element within HRC, broadly considered, with topics to encompass a wide array of perspectives on HRC, including insights and perceptions from both workers and organizations. A total of 10 papers have been published in this special issue, covering various theoretical, experimental, and perceptual approaches to HRC in occupational settings. Specifically, there is one review paper (Haney & Liang, 2024), four papers based on interviews or surveys (Georgadarellis et al., 2024; Johnson et al., 2024; Kim et al., 2024; Rahmani & Weckman, 2024), four papers that report experimental studies (Probst et al., 2023; Ramadurai et al., 2024; Xie et al., 2023; Zolotas et al., 2024), and one modeling paper (Allemang--Trivalle et al., 2024).

Common themes presented among the papers published in this special issue include worker performance during interactions with robots, as well as organizational considerations regarding HRC adoption in occupational settings. Various types of industries and HRC were discussed, including manufacturing, recycling, healthcare/nursing, and general industries using mobile robots, drones, soft growing robots, robotic arms, teleoperation, and medical/care/healthcare service robots. Clearly, there is a diverse range of industry areas and collaboration types covered in this special issue. We found it effective, though, to capture diversity with the broad themes of “Benefits” and “Concerns and Barriers” regarding HRC, with a specific focus on the physical, cognitive, and organizational aspects of ergonomics, following the International Ergonomics and Human Factors Association’s definition (IEA, 2000).

In the Benefits sections below, we highlight the actual or potential positive outcomes observed in the interaction between workers and robots, summarizing improvements in physical and cognitive performance achieved through HRC. Additionally, we explored the organizational benefits associated with the implementation of HRC, such as increased productivity and efficiency. Conversely, in the sections addressing Concerns and Barriers, we review the challenges and potential drawbacks associated with HRC in terms of the physical and cognitive performance of workers, as well as organizational concerns. Concerns and Barriers include topics related to safety hazards, inefficiency, job displacement, resistance to technological change, and the current technical limitations. By summarizing these concerns and barriers, we aimed to provide a more comprehensive understanding of the potential barriers that organizations may encounter when implementing HRC initiatives. We conclude this introduction by offering suggestions for future research directions that can help optimize HRC implementation in occupational settings.

Physical Ergonomics in HRC

Benefits

Several studies addressed enhanced safety, ergonomics (e.g., reduced physical workload and increased motion variability), and accessibility as the actual or anticipated benefits of HRC in occupational settings. In a survey with 100 manufacturing facilities either using or not using robotization of industrial processes, Johnson et al. (2024) identified improvements in worker safety and physical ergonomics, along with economic aspects, as the major justifications for implementing robotic processes, regardless of company size or geographic location. In the healthcare domain, HRC was considered potentially beneficial for enhancing the efficiency and safety of healthcare workers (Georgadarellis et al., 2024). Another unique physical ergonomic benefit of HRC was identified by Zolotas et al. (2024), who showed the benefits of manipulating variability in robot object transfer location (i.e., handover position) to improve the motion variation of workers. The authors found ergonomic benefits of imposing variability in a cobots actions on a worker’s responsive behavior, which improved their postural exposures.

Teleoperation, a type of HRC involving remote robot control, was the focus of an interview study by Kim et al. (2024), in which stakeholders from different domains identified anticipated benefits of teleoperated HRC, with specific distinctive benefits for both teleoperators and on-site workers. For example, on-site workers could benefit from teleoperated robots assisting with heavy or repetitive material handling and dangerous work. Meanwhile, teleoperators can be completely isolated from potential safety hazard environments, minimizing any physical ergonomic concerns stemming from the workplace environment. Having fewer on-site workers due to increased robot implementation was also identified as a benefit toward increased safety.

Concerns and Barriers

Most of the papers published in this special issue identified safety as the critical concern to workers in HRC, especially in situations with close worker proximity to robots. While several papers addressed improved physical ergonomics as a benefit of HRC, they also identified potential injuries and fatalities caused by robots as safety concerns. Collision detection and avoidance systems were discussed as technologies to reduce the possibility of harmful physical contact during HRC. Xie et al. (2023) developed a proof-of-concept scheme for human–robot collision avoidance, using a camera-based motion tracking method and providing visual and auditory alarms to workers while retracting robot arms. The tradeoff between reduced physical workload and increased cognitive workload is not yet thoroughly investigated in HRC, though. Regarding this issue, Allemang--Trivalle et al. (2024) highlighted the importance of investigating all aspects of human factors and ergonomics in potential HRC scenarios to prevent adverse impacts.

Cognitive Ergonomics in HRC

Benefits

Improved workflow, especially under short staffing conditions in the healthcare domain, was discussed as a strong motivation for HRC among healthcare workers, along with a potential positive impact on mitigating worker burnout (Georgadarellis et al., 2024). In many existing HRC reports of industrial applications, the development of trust with robots is discussed as an essential component for a successful collaboration, particularly in risky and uncertain environments (e.g., Charalambous et al., 2015). Papers published in this special issue also addressed trust and safety perception as important cognitive ergonomic aspects to consider and measure, along with fluency and engagement (Ramadurai et al., 2024). During a recycling sorting task, Ramadurai et al. (2024) found enhanced fluency and engagement of humans in simultaneous HRC rather than sequential collaboration. Georgadarellis et al. (2024) found a positive perception of robotics integration in healthcare after exposure to educational videos. Using non-rigid manipulators could reduce worker resistance to using HRC in occupational settings (Probst et al., 2023). Prior exposure to HRC tasks also improved robot-related attitudes, such as perceived safety hazards, fear, anxiety, technology-related job insecurity, and social hesitancy (Probst et al., 2023). Haney and Liang (2024) provided a thorough overview of factors affecting safety perception and trust during HRC with autonomous mobile robots. They identified robot traits (e.g., physical appearance and personality attributes), comfort, movement intention, perceived safety, and trust as the most studied cognitive concepts in this area of research.

Concerns and Barriers

Safety perceptions and trust were discussed as concerns and barriers in multiple papers, if not addressed properly. For example, industry stakeholders identified lack of trust and safety as potential limitations in teleoperated HRC, while the same were discussed as potential benefits of teleoperated HRC compared to autonomous robots (Kim et al., 2024). Specific to drones, a lack of situational awareness, decision-based errors, skill-based errors, risk-taking behavior, communication errors, and inefficient information presentation were identified as potential cognitive ergonomic concerns (Rahmani & Weckman, 2024). Cognitive fatigue and negative learning curve were also identified as concerning factors (Allemang--Trivalle et al., 2024).

Organizational Ergonomics in HRC

Benefits

Industry stakeholders or workers in managerial positions identified increased productivity and efficiency, product quality, and reduced time and cost savings as the major benefits of HRC in occupational settings. In addition, flexibility and accessibility of work, especially if robot operation involves teleoperation, were deemed beneficial (Kim et al., 2024), given the significant present and projected labor shortages in U.S. industry (Bureau of Labor Statistics, U.S. Department of Labor, 2023). Similarly, robot implementation was considered a good solution to short staffing and improving work performance and efficiency in the healthcare domain (Georgadarellis et al., 2024).

Concerns and Barriers

Implementation-related costs, downtime, worker training, and qualification were considered organizational barriers to HRC in general manufacturing industries, as well as costs associated with robot failure (Allemang--Trivalle et al., 2024; Johnson et al., 2024). In healthcare, the quality of care or patient satisfaction were concerns with HRC, and the lack of personal touch and empathy were perceived as barriers (Georgadarellis et al., 2024). Workplace optimization was discussed, emphasizing concerns regarding the ambiguity surrounding the roles and responsibilities of teleoperators and teleoperated robots within the current workplace (Kim et al., 2024), which is also a concern in overall HRC scenarios beyond teleoperation. Accommodating teleoperated HRC might also present challenges in complying with specific Occupational Safety and Health Administration (OSHA) standards, as there are no defined OSHA requirements for such a new form of HRC in occupational settings.

Considerations for Future Development and Implementation of HRC in Occupational Settings

Many potential technological improvements for seamless HRC integration in occupational settings were discussed. Among them, robot and human sensing technology as well as network connectivity were mentioned across papers as primary required technological enhancements, particularly given that the lack of reliable sensing and networks can adversely affect communication and control, and thus worker safety. Control interfaces for robots could also substantially influence worker performance (Kim et al., 2024).

In terms of robotics implementation, prior exposures to HRC tasks seem to positively change worker perceptions of robots (Georgadarellis et al., 2024; Probst et al., 2023) by enhancing perceived safety, trust, and comfort (You et al., 2018). Robot speed and appearance affected acceptance of the workers in HRC tasks but interacted with prior exposure, as faster robot movement was not perceived as fearful or anxious compared to people with less prior exposure (Probst et al., 2023). Thus, gradual or prior exposure to robots and HRC scenarios could aid in successful robotics implementation in occupational settings. Alternatively, using different types of robot manipulators, such as soft types, could alleviate potential worker anxiety.

Potential HRC Research Topics in Occupational Settings

In the domain of HRC, several compelling research topics warrant exploration due to their timeliness, complexity, or distinctive applicability in occupational settings. Some notable examples include:

• Optimization of HRC efficiency and safety: Particularly in dynamic occupational landscapes such as construction sites and agricultural settings, where the interplay between humans and robots is intricate and safety is crucial.

• Mitigating risks of wearable robots: This involves investigating concerns such as joint hyperextension and inadequate accommodation for users, necessitating the development of proper mitigation strategies.

• Cultural acceptance of robots: Understanding and assessing the acceptance of robots across diverse demographic and cultural spectra, including factors such as economic status, ­religious beliefs, and societal norms. The introduction of humanoid robots will further complicate this aspect of research.

• Advancement in Robot Sensor Technologies: Enhancing sensors to bolster human safety and improve applications pertaining to health, with a focus on hazard assessment and control in various environments.

• Enhancing Robot Mobility and Flexibility: Enabling robots to effectively assess and navigate hazardous conditions across different work environments, thereby enhancing workplace safety.

• Development of Adaptive and Self-Learning Systems: These are essential for augmenting worker protection and safety protocols. Continued improvement in HRC designs holds promise for enhancing workplace safety and human protection. Nonetheless, challenges persist in developing adaptive and self-learning systems to ensure worker safety, necessitating sustained efforts in advancing the field of HRC.

The exploration of additional applications linked to workplace safety, human health, and overall well-being would be highly beneficial to enhance HRC in occupational settings.

Acknowledgments

The authors thank Ms. Dawn N. Castillo for her important contributions to this special issue.

Conflict of Interest

The authors declare no conflict of interest.