MScMS-II: an innovative IR-based indoor coordinate measuring system for large-scale metrology applications

According to the current great interest concerning large-scale metrology applications in many different fields of manufacturing industry, technologies and techniques for dimensional measurement have recently shown a substantial improvement. Ease-of-use, logistic and economic issues, as well as metrological performance are assuming a more and more important role among system requirements. This paper describes the architecture and the working principles of a novel infrared (IR) optical-based system, designed to perform low-cost and easy indoor coordinate measurements of large-size objects. The system consists of a distributed network-based layout, whose modularity allows fitting differently sized and shaped working volumes by adequately increasing the number of sensing units. Differently from existing spatially distributed metrological instruments, the remote sensor devices are intended to provide embedded data elaboration capabilities, in order to share the overall computational load. The overall system functionalities, including distributed layout configuration, network self-calibration, 3D point localization, and measurement data elaboration, are discussed. A preliminary metrological characterization of system performance, based on experimental testing, is also presente

Modelling Eurasian beaver foraging habitat and dam suitability, for predicting the location and number of dams throughout catchments in Great Britain

This is the final version. Available from Springer via the DOI in this record.Eurasian beaver (Castor fiber) populations are expanding across Europe. Depending on location, beaver dams bring multiple benefits and/or require management. Using nationally available data, we developed: a Beaver Forage Index (BFI), identifying beaver foraging habitat, and a Beaver Dam Capacity (BDC) model, classifying suitability of river reaches for dam construction, to estimate location and number of dams at catchment scales. Models were executed across three catchments, in Great Britain (GB), containing beaver. An area of 6747 km2 was analysed for BFI and 16,739 km of stream for BDC. Field surveys identified 258 km of channel containing beaver activity and 89 dams, providing data to test predictions. Models were evaluated using a categorical binomial Bayesian framework to calculate probability of foraging and dam construction. BFI and BDC models successfully categorised the use of reaches for foraging and damming, with higher scoring reaches being preferred. Highest scoring categories were ca. 31 and 79 times more likely to be used than the lowest for foraging and damming respectively. Zero-inflated negative binomial regression showed that modelled dam capacity was significantly related (p = 0.01) to observed damming and was used to predict numbers of dams that may occur. Estimated densities of dams, averaged across each catchment, ranged from 0.4 to 1.6 dams/km, though local densities may be up to 30 dams/km. These models provide fundamental information describing the distribution of beaver foraging habitat, where dams may be constructed and how many may occur. This supports the development of policy and management concerning the reintroduction and recolonisation of beaver.Wellcome TrustUniversity of ExeterDWTNERCScottish Natural Heritag

Mobile Spatial coordinate Measuring System (MScMS) and CMMs: a structured comparison

In many branches of industry, most of manufacturing efforts are directed toward producing objects of specific forms and dimensions. Dimensional measurement is an important part of the production cycle, to check products compliance with specifications. For this, many substantial improvements in the existing technologies have been made, and new measuring systems have been introduced. This paper briefly introduces a recent measuring system—mobile spatial coordinate measuring system (MScMS)—which is suitable for performing dimensional measurements of large-size objects (dimension on the order of tens of meters). MScMS, thanks to its distributed wireless sensor network nature, is portable and can be easily arranged around the measured object. Furthermore, it does not require complex setup operations before being ready to perform measurements. After describing how the system works, we will compare it with well-tested and widespread instruments such as traditional coordinate measuring machines (CMMs), showing analogies and differences. The comparison is structured on the basis of different criteria, which are analyzed in detail in the first part of the paper. Although being able to perform similar measurements, CMMs and MScMS are different in technological features. CMMs are able to achieve higher level of accuracy, while MScMS is more flexible, cheap, and can be important to simplify the current measuring practices within large-scale industrial metrology. It can be concluded that these systems can easily coexist, as each system is suitable for specific applications. Keywords Mobile measuring system . Dimensional metrology . Large-scale metrology.Wireless sensor network . Coordinate measuring machine (CMM

An unmanned aerial vehicle-based system for large scale metrology applications

International audienceDifferent manufacturing environments, such as aerospace, automotive, shipbuilding, and railway, reveal their interest in Large Scale Metrology (LSM) instruments, to provide a support in assembly, alignment, inspection, and robot tracking tasks. Notwithstanding different levels of portability granted by existing systems, the overall measurement procedure actually involves a direct interaction between the measuring equipment and the operator, as well as a strong dependence on human skills. This paper presents a novel metrological system, scaling down this interaction to a mission management task and aimed at uniforming system performance. The proposed architecture entrusts an unmanned aerial vehicle (UAV) with the task of carrying the sensor equipment and of moving the measuring probe. The design process of the proposed system is detailed and faced with a two-level approach. The first level is directed to identify the available start-up technology, its limitations and sensitivity to the design parameters, while the second level is focused on the experimental testing of a preliminary test-bed to investigate the overall system performance. An actual implementation of the proposed architecture is herein discussed, focusing on system feasibility and presenting some preliminary experimental results

Where Wolves Kill Moose: The Influence of Prey Life History Dynamics on the Landscape Ecology of Predation

The landscape ecology of predation is well studied and known to be influenced by habitat heterogeneity. Little attention has been given to how the influence of habitat heterogeneity on the landscape ecology of predation might be modulated by life history dynamics of prey in mammalian systems. We demonstrate how life history dynamics of moose (Alces alces) contribute to landscape patterns in predation by wolves (Canis lupus) in Isle Royale National Park, Lake Superior, USA. We use pattern analysis and kernel density estimates of moose kill sites to demonstrate that moose in senescent condition and moose in prime condition tend to be wolf-killed in different regions of Isle Royale in winter. Predation on senescent moose was clustered in one kill zone in the northeast portion of the island, whereas predation on prime moose was clustered in 13 separate kill zones distributed throughout the full extent of the island. Moreover, the probability of kill occurrence for senescent moose, in comparison to prime moose, increased in high elevation habitat with patches of dense coniferous trees. These differences can be attributed, at least in part, to senescent moose being more vulnerable to predation and making different risk-sensitive habitat decisions than prime moose. Landscape patterns emerging from prey life history dynamics and habitat heterogeneity have been observed in the predation ecology of fish and insects, but this is the first mammalian system for which such observations have been made