Cooperative diagnostics for distributed large-scale dimensional metrology systems based on triangulation

In the field of large-scale dimensional metrology, new distributed systems based on different technologies have blossomed over the last decade. They generally include (1) some targets to be localized and (2) a network of portable devices, distributed around the object to be measured, which is often bulky and difficult to handle. The objective of this article is to present some diagnostic tests for those distributed large-scale dimensional metrology systems that perform the target localization by triangulation. Three tests are presented: two global tests to detect the presence of potential anomalies in the system during measurements and one local test aimed at isolating any faulty network device(s). This kind of diagnostics is based on the cooperation of different network devices that merge their local observations, not only for target localization but also for detecting potential measurement anomalies. Tests can be implemented in real time, without interrupting or slowing down the measurement process. After a detailed description of the tests, some practical applications on Mobile Spatial coordinate Measuring System-II (MScMS-II) – a distributed large-scale dimensional metrology system based on infrared photogrammetric technology, recently developed at DIGEP-Politecnico di Torino – are presented.