Study on noises influencing the accuracy of CNC machine straightness measurements methods based on beam position detection

Abstract

Fast, easy and accurate measurement of geometry of numerically controlled machines has always been challenging. With the use of a laser interferometer, it can be precise but it is complex. On the other side, the use of granite reference blocks is fairly easy yet quite limited for many machine types and sizes. Nowadays the improvements in technology open a new waythe instruments based on the detection of laser beam spot position. Those instruments are accurate and easy to use yet, comparing to the laser interferometers and granite blocks, they are sensitive to parameters of a laser source and to changing environmental conditions. In the paper, we analyse experimentally the influence of the type and parameters of laser source on the accuracy of straightness measurements. The most commonly met in practical applications a free space and fibre based laser sources are studied and compared. The influence of environmental conditions on measurement accuracy is also shown. Finally, the conclusions about optimal methods of improving the accuracy of beam position detection methods are drawn.

Analysis of Laser Interferometer Measurement Uncertainty by Simulating Error Sources

“…This phenomenon has been extensively evaluated and described in [13,14], yet mostly for very large distances and applications in astronomy or communication. Recently published tests [15] performed on shorter distances are showing great dependence of the laser beam position on the air density fluctuations over the laser paths.…”

Matrix data analysis methods for applications in laser beam position measurement modules

“…This is possible due to the wide availability of various laser sources with parameters tailored to users' requirements, and due to the great convenience of using laser equipment. One of the areas in which laser sources are commonly used is the measurement of the geometry of numerically controlled machines and the quality of movement in the individual axes of the machine [1][2][3]. A laser source with a good quality and stable output beam position establishes a reference line in space to which the actual movement of the machine is compared.…”