Weighted multilateration in volumetry of CNC machine tools

Abstract

Our research study describes utilization of a weighted multilateration principle in the multi axis machine error modeling. Multilateration plays on of the most important role in the identification of the exact position of the point in the machine tool work space. Using laser tracer, the measured data were obtained in spherical coordinates. The multilateration attempts to improve data accuracy using only a radial component. Each of measurements has a different quality of the laserTRACER signal. According to this information, three ways of the weight assignment are presented. The weight of each value of the measurement distance was given as a ration of each signal quality to: the best signal quality that was obtained during the measurement; the sum of all signal quality for each position of the measuring device; the norm of vector of total signal quality for each position of the measuring device. All of our results were compared with the data that were obtained by the original software TRAC-CAL.