Kyoto University Graduate School of Engineering Department of Micro Engineering
Machining Measurement and Control Laboratory

Metrology for Machine Tools

An accurate, and efficient measurement of motion accuracies of a machine tool is a key to further improve it.

The importance of the calibration of volumetric errors, or the measurement of three-dimensional positioning error over the entire three-dimensional workspace, has been recognized for the error calibration of machine tools. These projects are related to the calibration of volumetric errors.

Laser Trackers Laser Trackers
The laser tracker can follow the moving target, in order to continuously measure the distance to the target. We study its application to the evaluation of three-dimensional volumetric errors of a machine tool. (March 2008)

Laser Step Diagonal Measurement Laser Step Diagonal Measurement
The laser step diagonal measurement can evaluate all the volumetric errors by using a laser interferometer only. Critical issues with its conventional formulation were addressed. (March 2008)

Self-calibration of Cross Grid Encoder Self-calibration of Cross Grid Encoder
We proposed a self-calibration scheme to identify measurement errors of a cross grid encoder (KGM). Based on it, a methodology to measure two-dimensional kinematic errors such as the straightness error or the squareness error of a high-precision machine tool has been established (March, 2005).