Human-Robot-Interaction with Parallel Robots

• Applicant: Professor Dr.-Ing. Thomas Seel, since 5/2023
• Subject Area: Automation, Mechatronics, Control Systems, Intelligent Technical Systems, Robotics ; Human Factors, Ergonomics, Human-Machine Systems
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 444769341

Methods of human robot interaction (HRI/MRK) have the potential to simplify the operation of robots and make them more efficient. In addition, higher safety standards open up new areas of application. Methods such as safety-related stops, manual guidance based on force/torque sensing or monitoring speed of and distance from the user can be implemented independently of the robot kinematics under consideration, but require additional components in addition to the actual robot. The highest intrinsic safety level through force and power limitation has so far only been achieved with a few serial robots specially designed for this purpose. Due to the large moving mass of serial robots, these are operated in HRI mode at low speed, which makes the use of this technology uneconomical in some cases due to the long cycle time. In contrast, parallel robots or parallel kinematic machines (PKM) can be characterized by a low moving mass. Since the HRI standard (ISO/TS 15066) indirectly limits the maximum energy, using PKM in principle allows for higher speeds in HRI operation. Thus HRI-PKM can compensate restrictions of serial HRI robots. However, no PKM is yet known which is used in HRI workplaces or which has dedicated HRI operating modes. HRI capability is advantageous to reduce the effort and expertise required to set up parallel robots: it makes PKM setup more intuitive through manual guidance and haptic interaction. The time-consuming programming part is reduced. Their use is then also profitable for small batch sizes and in small and medium-sized companies. The aim of this proposition is therefore to develop methods for enabling parallel robots to perform HRI. The main focus is on the research of methods for the avoidance of clamping hazards in the parallel leg struts of the robot by evaluation and avoidance strategies. For this purpose, the kinematics analysis is no longer carried out in relation to the platform as before, but at any points on the structure that can represent a risk of jamming or collision. In addition, controller and observer concepts already tested in serial HRI robotics will be adapted for HRI-PKM. These include in particular impedance control, model-based disturbance observers and heuristics for estimating the location and force of collisions. The results of the project are safety functions for the ongoing operation of PKM as well as design guidelines for increasing HRI capability in principle. In addition, there will be an evaluation of how HRI concepts can be implemented on existing, established systems.

• DFG Programme: Research Grants
• Ehemaliger Antragsteller: Professor Dr.-Ing. Tobias Johannes Ortmaier, until 5/2023