Assessment of Influence of Sample Averaging on Accuracy of Point Coordinates Measurement Performed Using Laser Tracking Systems

Abstract

Laser Tracking systems are commonly used in all brunches of industry which requires accurate large-scale measurements for instance aviation, space and shipbuilding industries. Laser Trackers belong to the group of non-Cartesian Coordinate Measuring Systems. The determination of measured point coordinates involves measurements of distance using laser beam and two angles recorded by horizontal and vertical encoders. Additionally environmental conditions are monitored and used for compensation of measured distance. The coordinates of single measured point are estimated using results obtained from series of samples taken in a short time period. The average value obtained from sample is given as a result, additionally dispersion parameters are calculated which can be used to evaluate the probing process. This paper presents research procedure which allows to assess the influence of chosen dispersion parameter related to sample averaging on accuracy of measurements performed with laser tracking devices. The procedure involves standard elements measurements during which the points with similar level of RMS parameter are used for calculation of measurement result. Such approach allows to simulate the increasing dispersion of points taken into account during sample probing. The results presented in the article can be helpful to operators of laser tracking systems to assess the influence of probing process on measurement accuracy.

Keywords

• accuracy
• measurement uncertainty
• laser tracker