Virtual Distances Methodology as Verification Technique for AACMMs with a Capacitive Sensor Based Indexed Metrology Platform

This paper proposes a quick and efficient methodology of uncertainty estimation on measurement results provided by an articulated arm coordinate measuring machine (AACMM). The methodology is highly adapted to industrial applications—a frequent use of these devices—but can also be performed in laboratories. The study stems from an actual need among coordinate measuring arm users to estimate the uncertainty associated with their equipment in specific conditions on the shop floor. It is important to mention that no simple and quick test exists currently to estimate the measurement uncertainty of results obtained with an AACMM in the conditions of the measurement site. In fact, the guidelines and studies addressing measuring machines propose protocols to verify performance or to evaluate uncertainties associated with measurement results, but these protocols are laboratory-type tests (carried out after purchase, re-calibration, etc) and usually take hours to complete.

Section: Related Workmentioning

confidence: 99%

Rapid and robust on-site evaluation of articulated arm coordinate measuring machine performance

Asmai

Hennebelle

Coorevits

et al. 2018

“…However, the probe is only suitable for calibration. Recently, Acero and Brau-Avila et al [19][20][21][22] designed an indexed metrology platform, which adjusts the direction of the AACMM through the rotation of the platform. This reduces the time for placing and adjusting the position of the calibration artifact, and thus improves the calibration efficiency.…”

Section: Introductionmentioning

confidence: 99%

On-site calibration method of the AACMM based on a high-precision CNC machine tool

Wang

Sun²,

Sun³

et al. 2022

An articulated arm coordinate measuring machine (AACMM) is a kind of instrument used to test workpieces in the industrial field, and its measurement uncertainty depends on the on-site environmental factors to a certain extent. If there is a problem with the AACMM during on-site testing, it needs to be re-calibrated to ensure the measurement uncertainty. In this work, a fast on-site calibration method of the AACMM is proposed using a high-precision CNC machine tool. The AACMM is fixed on the machine tool table. A calibration artifact is clamped on the machine tool spindle. This calibration artifact could move to any point in the global space of the AACMM along with the operation of the spindle. Then, a virtual calibration artifact with calibration points is achieved using the CNC machine tool. The positions of these points are calculated by the improved Hammersley sequence. The calibration method using a high-precision CNC machine tool is experimentally verified through the single-point articulation performance test of ASME B89.4.22-2004 and the length measurement test of ISO 10360-12. The calibration method proposed in this work only uses an on-site high-precision CNC machine tool, one of the common machines in many industrial fields, as the calibration instrument for the AACMM calibration. No extra equipment is required, which is convenient and beneficial to calibrate the AACMM. And the CNC machine tool could construct different kinds of virtual structures for the AACMM calibration, such as virtual rods, virtual circles, virtual balls, and even non-uniform three-dimensional artifacts with complex curved surfaces. This may arouse many novel calibration methods and further improve the calibration accuracy.

“…The calibration accuracy is not high enough. Acero [26][27][28] proposed a method to obtain the virtual distance by adjusting the direction of the AACMM. Instead of rotating the gauge around the AACMM, multiple standard lengths of different lengths and positions were obtained in multiple quadrants.…”

Section: Introductionmentioning

confidence: 99%

Research on the calibration method of a new multifunctional calibrator based on AACMM

Huang

Chen

et al. 2021

Calibrators can effectively improve the calibration accuracy of articulated coordinate measuring machine (AACMM). However, the traditional calibration method of a calibrator is usually cumbersome. To study the influence of sampling strategies of various calibration methods on the calibration effect of AACMM, we design a new multifunctional calibrator for AACMM kinematics parameters, and propose three calibration methods with high accuracy and high efficiency. In the multifunctional calibrator, 84 different calibration points are provided by changing the rotation angle of calibration bar and the inclination angle of calibration plate. Compared with previous calibrators, the calibrator can obtain more positions and directions. The length calibration, multi-point calibration and virtual center distance calibration methods are proposed to calibrate kinematic parameter of AACMM. In addition, the sampling strategy for the three calibration methods is explored. Finally, the consistency of single-axis coordinate measurement is verified based on the three calibration methods. The results show that the three calibration methods can effectively improve the measurement accuracy of AACMM. Especially, the length calibration method has the highest accuracy of the three methods. The multi-point calibration method can significantly improve the calibration efficiency.