Investigation on a System for Positioning of Industrial Robots Based on Ultra-Broadband Millimeter Wave FMCW Radar

Industrial robots are the key components of most automated manufacturing systems, but exhibit a low intrinsic accuracy and precision. To overcome this disadvantage, a measurement system to estimate the 3D position of the tool center point (TCP) is presented. The measurement system is based on four FMCW radar systems operating from 68 GHz to 93 GHz, each measuring the 1D distance to a recognizable target mounted at the TCP, which is 3D printed and coated with copper spray paint. To estimate the 3D position of the target from the 1D measurements, two algorithms based on the Taylor series method and the two-stage maximum likelihood method are implemented. After testing the algorithms in a simulator, the measurement system was demonstrated and verified in an experimental setup. The system could successfully estimate the 3D position of the target by means of both algorithms.