Analysis and compensation for absolute positioning error of robot in automatic drilling

Due to the relatively low absolute positioning accuracy of robot, the required accuracy of drilled holes could not be directly met without compensation during robot automatic drilling. In order to improve the accuracy, the absolute positioning error of robot is researched. Firstly,this article discusses the error sources and generating processes. And through theoretical analysis and relevant experiment, we found that the absolute positioning error would have different influences on translation component and rotation component of calibration result of robot base coordinate system. Secondly, in order to compensate for the coordinate converted error caused by calibration inaccuracy of base coordinate system, a new method based on constructing error Coons surface function is proposed from the standpoint of aircraft surface construction principle. And the validity of the new method is experimentally verified through robot automatic drilling. Results show that the average error of holes is 0.205 mm and the maximum error is less than 0.343 mm, which must be controlled under 0.5 mm. The required accuracy of robot automatic drilling is realized. ©, 2015, AAAS Press of Chinese Society of Aeronautics and Astronautics. All right reserved.