Calibration technique of articulated arm coordinate measuring machines based on large scale multilateration system gauges

In this work we present a novel kinematic parameter identification procedure of an articulated arm coordinate measuring machine (AACMM). This procedure is based on a geometric multilateration system constructed from four Laser Trackers (LT's) that allow us to determine the spatial localization of a retroreflector target. Then, from the captured nominal data obtained by the LT's (used as a gauge instrument) and the data obtained by the AACMM, an objective function based on Euclidean distances and standard deviations is proposed. Hence, the self-calibration algorithm of the LT's positions and the coordinates calculated by means of multilateration, as well as the nonlinear optimization algorithm proposed for the identification procedure of the AACMM are explained. Finally, we show how the obtained results show the effectiveness of this procedure in terms of using the measurements of the LT's as gauge instrument and in the final error committed by the measuring arm.