Jywe W.Liu C.H.Lin B.J.Hsu T.H.Wen-Yuh Jywe2022-05-242022-05-242006https://www.scopus.com/inward/record.uri?eid=2-s2.0-34247173614&doi=10.1243%2f09544054JEM254&partnerID=40&md5=bd97b61b3a27a5a3f629a0f718fa858ehttps://scholars.lib.ntu.edu.tw/handle/123456789/611975The accuracy of machine tools restricts the dimensional accuracy of parts processed thereon. It is, therefore, necessary to monitor the errors of machine tools constantly. Normally, it takes a long set-up time before one can observe the machine tool and monitor its errors. The cost of such delays is inevitably high. As for CNC, the conventional measurement system is capable of measuring one-dimensional signals, as a laser interferometer does, and two-dimensional signals, as a grid encoder does. Three-dimensional measurement techniques, however, are far from being well developed and are not yet well known. This paper proposes a triangulation method incorporating three built-in linear-scale ball bars that requires less set-up time and lower costs than the laser ball bar system, and is capable of acquiring threedimensional signals with greater accuracy with the extension bars, so that large volumes can be checked. ? IMechE 2006.Ball barGrid encodesMachine tool errorsVolume errorCalibrationComputer controlError analysisNumerical control systemsTriangulationMachine toolsjournal article10.1243/09544054JEM2542-s2.0-34247173614