This application example shows a drilling fixture built from BoxJoint components. The fixture was designed by DELFOi and physically built by Nikon Metrology. It was demonstrated in Nikon Metrology's booth at the CONTROL 2010 fair in Stuttgart. Nikon needed a fixture to locate a small demo component during drilling. You robot users out there understand that robots are not accurate machines. Even if some robots today are accurate down to +/-0,3 mm once a robot comes in contact with an object, such as drilling, the robot can deflect and skid along the surface of the part on contact. One way to maintain high accuracy in a robot is to measure its TCP (Tool Center Point) each time the accuracy is required, such as just before engaging the drilling. The idea is to integrate the robot controller with the metrology controller.

Nikon Metrology provide just such a solution by integrating their K600 photogrammetry camera with the robot controller. The metrology system sees infrared LEDs, and measures their spatial locations using photogrammetry . One set of LEDs where glued to the robot drill, and one set of leds where glued to the BoxJoint fixture framework. By measuring the tooling pins relative to the framework LEDs the system will know the position of the part. When the robot moves along its programmed drilling positions the robot will go into a measurement loop and ask the metrology system about the location of the Iterations are performed where the robot updates its position until it meets the accuracy requirements. The accuracy settings for this cell was better than +/- 0,1 mm.

Drilling fixture demo with BoxJoint