BEGIN:VCALENDAR PRODID:-//eluceo/ical//2.0/EN VERSION:2.0 CALSCALE:GREGORIAN BEGIN:VEVENT UID:4b56934f42c8e3bedecdcbc86b98161e DTSTAMP:20260720T163557Z SUMMARY:Robot Self-Calibration of Nonlinear Joint Dynamics DESCRIPTION:Contact: bjorn.olofsson@control.lth.se\n\nTitle: \;Robot Se lf-Calibration of Nonlinear Joint DynamicsAuthor: \;Axel TiredDate &am p\; Time: June 8th\, 11:00-12:00Location: \;Seminar Room M 3170-73 in the M-building\, LTHSupervisor: Björn Olofsson\, \;Denis Störkle (Co gnibotics)Examiner: \; Yiannis KarayiannidisAbstract:The demand for ac curate industrial robots has driven an increasing need for accessible and reliable calibration methods. Robot manipulators operating in environments where large external forces are present\, or carrying heavy tools\, suffe r from inaccuracies caused by joint elasticities\, both from external load s and from gravity acting on the robot links themselves. Calibration metho ds for identifying joint stiffnesses are therefore of great importance to compensate for these effects and ultimately obtain more accurate robot mod els.The clamping method\, where a robot arm is attached to a rigid point i n the environment and torques are exerted on the joints using the robot's own motors\, provides a straightforward approach to joint stiffness identi fication. However\, the assumption of a completely rigid attachment point is not always valid\, which may corrupt the identified joint stiffnesses. To address this limitation\, a flexible clamping device extends the idea o f clamping by serving as both a rigid attachment point and a measuring dev ice. This thesis investigates a method for identifying joint stiffnesses u sing the flexible clamping device\, evaluated through MapleSim simulations . The feasibility of the method is further assessed by applying the identi fication method to experimental data collected from a physical experiment. Under idealized conditions in simulations\, the method correctly recovers the relationship between torque and joint deflections\, but does not show consistent accuracy when using a different configuration of the flexclamp \, where a lower stiffness results in increased motion at the end-effector . When other joint uncertainties such as passive joint elasticities are in cluded\, the identification deteriorates. Furthermore\, when translating t he method to a physical experiment\, additional complexity arises from pra ctical challenges\, such as torque limitations in the robot arm. The resul ts suggest that while the method shows promise as an extension of the clam ping method\, further work is needed to investigate the flexclamp's full a bility to identify additional joint properties. In particular\, utilizing force measurements from the flexclamp for identification of passive joint elasticities\, and more thoroughly investigating how different clamping co nfigurations can aid the identification procedure\, are identified as prom ising directions for future work.\n\nMore information about the event: htt ps://www.control.lth.se/calendar/robot-self-calibration-nonlinear-joint-dy namics DTSTART;TZID=GMT:20260608T090000 DTEND;TZID=GMT:20260608T100000 LOCATION:Seminar Room M 3170-73 in the M-building\, LTH END:VEVENT END:VCALENDAR