The measurement process of three-dimensional shapes has recently assumed a relevant role in various industrial applications due to its wide field of application such as reverse engineering or coordinate metrology in dimensional control. The acquisition of 3D geometrical data generally requires three main steps: planning the number and the right sequence of all the range scans, acquiring the single data sets and aligning the collected data in a common reference frame. The overall measurement accuracy directly depends on the planned strategy, the sensor precision and the alignment methodology used. Among these, the point cloud alignment phase represents the task having the main influence on the reliability of the measurement process and on required time. This paper describes an integration between a 3D stereo vision system and 5 motorized axes with the aim at the definition of a no-contact Coordinate Measurement Machine (CMM) system for fast and accurate digital representations of target objects with minimum human intervention. An automatic alignment methodology, based on a calibration procedure of the vision system with respect to the 5 axes, allows rapid and high-precision 3D shape measurements with minimum human intervention.
Validation of a No-Contact CMM System for Fast and Accurate 3D Shape Measurements
BARONE, SANDRO;PAOLI, ALESSANDRO;RAZIONALE, ARMANDO VIVIANO
2007-01-01
Abstract
The measurement process of three-dimensional shapes has recently assumed a relevant role in various industrial applications due to its wide field of application such as reverse engineering or coordinate metrology in dimensional control. The acquisition of 3D geometrical data generally requires three main steps: planning the number and the right sequence of all the range scans, acquiring the single data sets and aligning the collected data in a common reference frame. The overall measurement accuracy directly depends on the planned strategy, the sensor precision and the alignment methodology used. Among these, the point cloud alignment phase represents the task having the main influence on the reliability of the measurement process and on required time. This paper describes an integration between a 3D stereo vision system and 5 motorized axes with the aim at the definition of a no-contact Coordinate Measurement Machine (CMM) system for fast and accurate digital representations of target objects with minimum human intervention. An automatic alignment methodology, based on a calibration procedure of the vision system with respect to the 5 axes, allows rapid and high-precision 3D shape measurements with minimum human intervention.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
