API’s Robot Metrology Solution Improves Accuracy of UR at Cole Tech

20 September 2023 · 2 min read

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Laser Tracker and Software Combination Improved Universal Robot’s Accuracy by 78%

Cole Technologies, Inc, located in Columbus, Indiana, is a certified Universal Robots system integrator supplying automation systems specializing in pick and place, deburring, and plastic part trimming applications. One recent project involved the deflashing of molded parts where a more accurate robot path was deemed necessary. After researching various options, Cole Technologies contracted API Services to perform on-site robot calibration using the API RADIAN 6DoF (6 degrees of freedom) Laser Tracker, in conjunction with its proprietary Robot Metrology Solution (RMS) software, to improve programmed robot motion path accuracy. API was able to:

  • Integrate with their Robo DK software to effortlessly operate the robot
  • Complete the calibration in a single day
  • Improve robot accuracy by 78%

Established in 2003, Cole Tech is a full-service job shop, and a certified integrator of UR (Universal Robots) collaborative robots. Their broad range of capabilities allows them to supply turnkey automation solutions to meet customers’ needs. Cole Tech’s twin facilities are ISO 9001 Certified, with over 25 specialists averaging more than eighteen years’ experience.

For more than fifteen years, Cole Tech has been living up to their mission statement, commitment to meeting or exceeding customer requirements and increasing customer satisfaction through continual improvement of products, services, and quality management system. This spirit of continual improvement for customer satisfaction led Cole Tech to look for ways to improve their robotic performance in deflashing of molded parts. Their research led them API’s RMS software.

RMS uses a multiple SMR tracker target frame (or single automated target) directly mounted onto the robot end-effector allowing for dynamic robot tracking. Recorded measurements are used to determine tracked robot position points revealing true robot position and orientation. RMS meets ISO 9283 guidelines to check accuracy, repeatability, pose, distance, drift, and overshoot by exercising all robot joints. Robotic working envelope can be defined applicable to the planned robot application function.

RMS was able to provide several benefits for Cole Tech. API was able to integrate with their Robo DK software to allow for easier control and programming of the robot. And the ability of RMS to be performed in a single setup meant that the process took less than one day, limiting downtime. By the end of the day, RMS had reduced maximum errors of 4mm to less than one.

“The availability of additional robot accuracy allows us to provide a better outcome for the customer regardless of application” states Steve Richard Director of Engineering at Cole Technologies. “API were able to directly interface with our RoboDK robot programming software for robot calibration making it seamless and efficient to load the new parameters.”

Measuring a free point cloud consisting of 80 points the RMS software generated a new DH (Denavit-Hartenberg) frame model parameter set that was used to correct errors in joint angles and link lengths. The revised DH parameter can be directly input into the robot controller or used to update the robot motion path program as was the case at Cole Technologies resulting in significant improvements to robot accuracy. This process can be repeated at any Universal Robot production facility.

To learn more about API’s RMS software and service offerings, please visit https://services.apimetrology.com/calibration/robot-calibration/. To speak to a metrology expert or request a quote, fill out the form below.

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