Experiments are conducted on a polishing industrial robot using the CompuGauge robot performance analysis system. The aim of this experiment is to explore the influences of link dimension errors and joint torsional angle errors on the positional accuracy reliability for single coordinate, single point, multipoint and trajectory accuracy of industrial robots.
Experiments are conducted on a polishing industrial robot to derive the influence of uncertain variables on the positional accuracy reliability. The experimental setup of positional performance for industrial robot. The control signals of the industrial robot are generated by the control cabinet, which designates the robot for predetermined motions. The 3D measurement adaptor, which is installed at the end of the load, pulls the four red lines. Thus, the lengths of the four red lines, which come out from the cable decoder, is changed. The length variation of lines is recorded by the cable decoder and transformed into electrical signals. The electrical signals are then transmitted to the computer through the USB data acquisition to derive thex,yandzcoordinates of the end-effector.
In order to measure the positional accuracy of a single point for the industrial robot, point A (750, −200, 230) is defined as a referenced point. All the units of coordinates are in millimeters in this study. The end-effector of the industrial robot is controlled to repeatedly move to the reference point A with similar speed and posture. Totally, 6664 experiments are carried out.
The positional accuracy test of multipoint is also conducted by defining four referenced points according to the GB/T 12642-2013. The four referenced points are A (750, −200, 230), B (750, 200, 230), C (1150, 200, 630) and D (1150, −200, 630), respectively. The end-effector of the industrial robot sequentially moves to the reference points A, B, C and D with a same speed and posture. The test times in this experiment is also 6664 for each point.
The positional accuracy test is also carried out to measure the accuracy of kinematic trajectory for this industrial robot. The positional points and kinematic trajectory are selected based on GB/T 12642-2013. The end-effector of the industrial robot sequentially moves to the reference points A (750, −200, 230), B (750, 200, 230), C (1150, 200, 630) and D (1150, −200, 630) with a same speed and posture. The test times in this experiment is run 6664 times for each point. The industrial robot is driven by the servo motor to move along the rectangular trajectory with a same speed and posture. In total, the trajectory experiment is carried out 6000 times.
All the datas can be analyzed in MATLAB software.