Comparison of a VR-based and a rule-based robot control method for assistance in a physical human-robot collaboration scenario

Many physically demanding tasks require the help of a second person to avoid the otherwise harmful effects of musculoskeletal disorders when performing the task alone. The workforce in many domains, such as nursing care, is rapidly declining. Furthermore, complex repositioning tasks during patient care make it all the more difficult to find a simple solution. Therefore, robotic assistance could be a perfect fit to support this scenario. For this purpose, we conducted a study where 12 caregivers were given the task of repositioning a patient simulator (80 kg) within a nursing bed with the help of a robotic assistant. We measured the physical relief potential using muscle activity and force data while examining this human-robot collaboration problem with two different control approaches, namely a virtual reality-based and a rule-based robot control method. The results show that both methods effectively supported the chosen task with varied strengths and weaknesses. The main advantage of VR-based control is the ability to adapt to the situation and execute quickly (6.61 s), but this also results in higher acting robot forces (35.70 N). With the rule-based control variant, a lower speed of support can be noted on average (10.84 s), but better robot interaction forces (14.95 N) can be discovered in return.