Repeated positioning accuracy is one of the important performance indicators of industrial robots. Position reproducibility is a positioning performance index specified by industrial robot manufacturers. The range in the manual is between 0.010 mm and 0.100 mm. The measurement standard has changed. Gauge reference ball is particularly important. Learn more below How to measure the repeated positioning accuracy of the reference ball of the inspection tool for the industrial robot.

The basic method proposed by ISO/TR 13309:1995 depends on the installation of three orthogonal position sensors, which are wireless, light in weight, and have a measurement uncertainty of about It is 0.001mm, and the measurement range is 3.5mm. The use of eddy current sensors requires a special reference ball for the inspection tool, which is easy to damage.

In a very important part, the 3D detector is the new component calibration board. The latter is basically based on the principle of three balls moving on a three-v-groove sports table. A custom-made axis table was used when testing our 3D detector with an industrial robot (leased to General Electric) and an ABB IRB 120 robot. Consists of 3 0.5" reference spheres with about 300mm spacing between each pair. Using very simple matlab code, position data can be obtained from each digital indicator and sent to the robot controller via ethernet. Execute the program for each robot controller and perform an automatic test, the test steps are as follows:

For the given end position of the reference ball of the inspection tool, the robot automatically aligns the three reference balls of the three-dimensional probe, and adjusts to zero 0.002 mm after several times, and then records The position of the end effector (actually the placement of the robot), the robot moves each reference ball forward 30 times, then clockwise and counterclockwise, we tested five different orientations of the end effector and compared them placed at the same location on each robot.