Calibration and uncertainty budget analysis of a high precision telescopic instrument for simultaneous laser multilateration

Abstract

The precision manufacturing industry depends on precision measurement instruments capable of tracing the measurement results to national and international standards. This paper presents a calibration model for a high precision telescopic instrument (HPTI) for machine tool verification together with its estimated uncertainty budget. The instrument tracks autonomously a target using an interferometric sensor to measure distances and allows the simultaneous use of three HPTIs for multilateration, decreasing data capture time and improving measurement accuracy. A calibrating ball beam artefact, previously calibrated with a coordinate measurement machine, is used to trace the calibration results. The uncertainty of the HPTI is estimated in laboratory conditions. The uncertainty budget of the HPTI, as well as the uncertainty of simultaneous multilateration, in workshop conditions are analysed and estimated with Monte Carlo. The calibration model defined gives traceability to the measurement results obtained with the HPTI allowing its use in machine tool verification processes.