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BEGIN:VEVENT
UID:1b3b713f1e245722d248ca905cfa606f
DTSTAMP:20260614T230207Z
SUMMARY:Improved Joint Zero Offset Calibration for Industrial Cobot Arms
DESCRIPTION:Contact: yiannis.karayiannidis@control.lth.se\n\nTitle:&nbsp\; 
 Improved Joint Zero Offset Calibration for Industrial Cobot ArmsAuthor:&nb
 sp\;Dante NeckmarDate &amp\; Time:&nbsp\;June 4th\, 9:15–10:00Location:&
 nbsp\;Seminar Room M 3170-73 in the M-building\, LTHSupervisor: Yiannis Ka
 rayiannidis\,&nbsp\;Kristian KassowExaminer:&nbsp\; Bo BernhardssonOpponen
 ts: Jacob Heyden and Georg Emmanouilidis&nbsp\;Abstract:Collaborative robo
 ts\, or cobots\, are increasingly used in industrial automation\, where th
 ey work in flexible\, semi-modular configurations while still being expect
 ed to meet demanding positioning-accuracy requirements. After a joint is r
 eplaced on such a robot\, the resulting zero offset typically forces a ful
 l kinematic recalibration before the robot can return to service\, causing
  downtime and requiring specialized equipment. Existing solutions are eith
 er simple manual references that lack the accuracy needed\, or external op
 tical systems that are expensive and complex to set up. This thesis develo
 ps a low-complexity\, joint-level zeroing method for the cobot arms produc
 ed by Kassow Robots\, with the goal of avoiding that recalibration step. A
  sensitivity analysis showed that a pin-level repeatability of around 20μ
 m is enough to keep the tool center point (TCP) positioning error below 1 
 mm across the full product range. Three concepts were considered: a mechan
 ical fixture\, a laser triangulation system\, and a vision-based solution.
  The mechanical concept was chosen for its lower complexity and cost\, and
  was designed and built as a cup-shaped fixture with a self-locking block 
 that engages the joint output through well-defined contact. A 3D-printed p
 rototype was used to validate the principle\, and a machined stainless ste
 el version was then tested over 96 zeroing cycles. The proposed prototype 
 achieved a TCP standard deviation of 0.18 mm and a pin-level repeatability
  of about 3μm\, well within the requirement. The results show that a pass
 ive mechanical fixture can deliver the precision needed for joint replacem
 ent without optical hardware or firmware modifications\, removing the need
  for full kinematic recalibration after joint maintenance.\n\nMore informa
 tion about the event: https://www.control.lth.se/calendar/improved-joint-z
 ero-offset-calibration-industrial-cobot-arms
DTSTART;TZID=GMT:20260604T071500
DTEND;TZID=GMT:20260604T080000
LOCATION:Seminar Room M 3170-73 in the M-building\, LTH
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