Laser Tracker and 6 DoF measurement strategies in industrial robot applications

In this paper, the usage of the Leica Laser Tracker, including especially 6dof products is presented in the field of industrial robot applications. Hereby, a major need of modern production cells is to increase the efficiency of robot programming in quality and time consumption. Copying and mirroring of complex robot movement paths on symmetrical objects is a non-avoidable step in today’s flexible automation processes. But for this, a set of critical information about the robot cell has to be acquired and calculated. Identified by special measurement procedures, this information is integrated into the duplication process of the programs to deliver the needed accuracy of the real application results. In this process, the robot and optional adapted linear tracks, which are used to increase the robots working range, can be analyzed separately. The robot for itself is used for passing the DIN EN ISO 9283, a test concerning the identification of robot accuracy. Also various transformation corrections for the integration of the robot into the working cell help to increase the robots final accuracy behavior. The linear track is analyzed by a special method using the laser tracker and the robot to identify a continuous 6-dimensional mathematical description of the whole linear track. After all identification and optimization procedures are completed, a set of created input data is used in a software tool to calculate the appropriate robot point corrections for each constructed robot tool position in the copied or mirrored robot program. A sample program in comparison to a non-corrected application presents the final resulting accuracy after duplication of a constructed robot program including all corrections. The main focus of the paper is on the various measurement strategies and also on the improvements and new possibilities by using 6dof measurement products. The introduction of 6dof measurements in the field of robotic applications gives more flexibility and efficiency, as shown in special examples.