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Recent studies show that the combined use of Large-Volume Metrology (LVM) systems (e.g., laser trackers, rotary-laser automatic theodolites (R-LATs), photogrammetric cameras, etc.) can lead to a systematic reduction in measurement uncertainty and a better exploitation of the available equipment. Unfortunately, the sensors of a specific LVM system are usually able to localize only specific targets (i.e., active/passive elements positioned in the measurement volume) and not necessarily those related to other systems (e.g., the reflective markers for photogrammetric cameras cannot be used for R-LATs or laser trackers); this represents an obstacle when using combinations of different LVM systems. This paper describes the design of a new modular probe, with different typologies of targets and integrated sensors, which allows to simplify the measurement process. The probe is versatile as the number of targets, their typology and spatial position can be customized depending on the combination of LVM systems in use. A detailed analysis of the technical and functional characteristics of the probe is followed by the presentation of a mathematical/statistical model for the real-time probe localization. Description is supported by realistic application examples.

Quality function deployment (QFD) is a consolidated management tool for supporting the design of new products/services and the relevant production/supply processes, starting from the so-called voice of the customer (VoC). QFD includes several operative phases, ranging from the VoC collection to the definition of the technical features of production/supply processes. The first phase entails the construction of the so-called house of quality (HoQ), i.e., a planning matrix, which translates the customer requirements (CRs) into measurable engineering characteristics (ECs) of the product/service. One of the main goals of this phase is the definition of relationships between CRs and ECs, and the prioritization of these ECs, taking account of (i) their relationships with CRs and (ii) the importance of the related CRs. Given that data are collected from customers through questionnaires or interviews, both of these inputs are based on linguistic/ordinal scales. In the traditional approach, represented by the independent scoring method (ISM), ordinal data are arbitrarily enriched with cardinal properties. The current scientific literature encompasses a number of alternative approaches but, even for most of them, cardinal properties are mistakenly attributed to data collected on ordinal scales. This paper proposes a method based on a consolidated ME-MCDM (multi expert / multiple criteria decision making) technique, which is able to perform the EC prioritization without incurring in the aforementioned issue. This method is able to aggregate data evaluated on ordinal scales, overcoming controversial assumptions of data cardinality and avoiding any arbitrary and/or artificial “scalarization” of the data. On the other hand, its application is relatively simple and intuitional, compared to other proposed approaches alternative to the ISM, which often are conceptually complicated and difficult to implement. Furthermore, the proposed method can be effectively used when both CR importances and relationship matrix coefficients are rated on different ordinal scales and, being easily automatable, it can be effortlessly integrated into existing QFD software applications. In the paper, after a general description of the theoretical principle of the method, several application examples are presented and discussed.

Quality function deployment (QFD) is a useful tool to improve the design/development process of products and services. The initial phases of the QFD process—that is, those concerning the collection and analysis of the so-called voice of the customer—are..

Recent studies show that the combined use of Large-Volume Metrology (LVM) systems can lead to a systematic reduction in measurement uncertainty and a better exploitation of the available equipment. This is actually possible using a recently developed modular probe, which is equipped with different typologies of targets and integrated inertial sensors. The goal of this paper is to present a new mathematical/statistical model for the real-time localization of this probe. This model is efficient, as it is based on a system of linearized equations, and effective, as the equations are weighed with respect to their uncertainty contribution.

The focus of this paper is on the prioritization of customer requirements (CRs) in the quality function deployment (QFD) process. There are numerous techniques for this task, which are based on different types of judgements (e.g., in the form of preference orderings, relative importance ratings, paired comparisons), generally collected by questionnaires/interviews. Unfortunately, many of these techniques violate some properties of the scales on which judgements are defined and/or are not flexible and user-friendly for respondents. This paper introduces a prioritization technique based on a recent algorithm—denominated as generalized Yager’s algorithm—aimed at fusing the preference orderings by multiple respondents into a single ordering. This technique can be applied even when (1) some CRs are tied or omitted in the individual preference orderings, and (2) respondents have a hierarchical importance ranking. Also, the procedure is automatable and relatively robust and provides a solution which is consistent with the preference orderings. The description is supported by a realistic application example, concerning the prioritization of QFD’s CRs in the design of an aircraft seat.

Last decades witness an increasing interest in Large-Scale/Large-Volume Dimensional Metrology (LSDM). Many fields of application, ranging from construction to shipbuilding and aerospace, have shown more and more accurate and versatile systems for geometric control and tolerancing. Especially in the last ten years, optical technology has registered a fundamental step forward both in terms of metrological performances, versatility and convenience of use. This is further demonstrated by the current large diffusion of laser tracker and photogrammetric systems. The growth is also complemented by the development of new standards, even though a comprehensive body specific for LSDM is still lacking. The twofold aim of the present survey is to present a bibliographical and bibliometric analysis of the field and to propose a scheme of classification of the main current approaches. As an output of this paper, a “LSDM Multi-perspective Model” is introduced, according to which dominant technologies and restrictions are analyzed with the aim of individuating current lacks and defining the roadmap for future development of new instruments and systems.

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.

In the last two decades, there has been a great development of the measuring systems in the field of large-scale dimensional metrology (LSDM), as also proved by the significant growth of the scientific literature. The aim of this paper is to analyze the LSDM scientific literature, from the dual perspective of scientific articles and patents, and estimate their impact in terms of amount of documents and relevant citations. In detail, this study investigates similarities and differences between articles and patents, as regards their dominant technologies and temporal distribution, and identifies (1) the major scientific journals and conference proceedings containing LSDM articles and (2) the major assignees of LSDM patents. Two main results emerge from the analysis: (a) important inventions concerning new LSDM systems were deposited before the end of twentieth century, while scientific articles have “bloomed” only in the last decade, and (b) the vast majority of patents concern inventions related to the laser-interferometry technology, while articles are divided more evenly among available technologies, with an important role played by the less accurate but more affordable ones, such as photogrammetry or structured-light scanning.

PurposeThe goal of this paper is to suggest a new incentive model that is capable of creating the conditions for the autonomous growth of diffusion and credibility of the ISO 9000 national quality certification system.Design/methodology/approachThe first part of this work contains some considerations about the general interest of organisations in quality certification systems, emphasising the advantages and the drawbacks in being certified. Next, the attention shifts to future scenarios. Specifically, a new model is proposed that is capable of encouraging certified organisations (COs) and certification bodies (CBs) that operate blamelessly and seriously, while at the same time penalising those that do not.FindingsThe suggested model consists of two inter‐connected sub‐models relative to COs and CBs, respectively. Each sub‐model includes different states with different incentives/penalties. The switch‐over from one state to another depends on the practical results recorded in recent years by the CO/CB of interest. The switching rules are based on a set of objective, transparent, and non‐manipulable indicators.Research limitations/implicationsOn‐site analyses and simulations are necessary so as to tune optimal switching rules to balance the whole model.Practical implicationsThe (possible) future implementation of the model could have great impact on COs' and CBs' modi operandi, promoting the real implementation of quality management practices but – at the same time – not requiring significant additional effort from the state and the authorities accrediting/controlling CBs.Originality/valueThe proposed model is absolutely new and may represent a proper way to combine the interests and expectations of COs and CBs into a unique “virtuous circle” for improving the real implementation of quality management.

PurposeOne of the stated goals behind the formation of the International Organization for Standardization was to develop standards to facilitate international trade in goods and services. This goal has caused different country‐group trends in the diffusion of ISO certification. The purpose of this paper is to create a taxonomy of ISO 9000 certification diffusion in Europe.Design/methodology/approachThe diffusion of ISO certificates in Europe was analyzed using the single linkage clustering algorithm. Then the features of each cluster were highlighted.FindingsEuropean nations were found to belong to three macro areas which differ for patterns of ISO 9000 certification diffusion: the constant growth area, the saturation area and the decline area.Research limitations/implicationsThe present study deals with European nations, focusing on ISO 9000 standards. Future research will be addressed toward the analysis of other standards in a wider geographical area in order to see if the results found for the European reality may be extended. In addition the outcomes of such analysis may be used to enhance the existing models for the diffusion of ISO 9000 certification.Practical implicationsThe analysis of the evolution of the certification market may arouse the interest of both companies and certification bodies that, from this study, may gain an insight into the future possible demand of certification. Furthermore, this study can be interesting from a legislature point of view, providing an answer to a more general question: “What is the general life cycle of standards or regulations?”Originality/valueThe novelty of the paper is the clustering approach that allows the grouping of different nations according to similar diffusion dynamics.

Wireless sensor networks (WSNs) typically consist of a large number of densely populated sensor nodes. Due to important advances in integrated circuits and radio technologies, the use of distributed sensor networks is becoming increasingly widespread for a variety of applications, e.g. indoor navigation, environmental monitoring, people and object tracking, logistics, industrial diagnostics, quality control, and other manufacturing activities. In many cases, such as in objects tracking, knowing the physical location of network nodes is essential. Locating elements of WSNs is not a trivial task. Manual methods are wearisome and may be inaccurate, especially for large-scale networks. Therefore, many self-locating methods – where nodes cooperate with each other without human involvement – have recently been studied and implemented. The purpose of this work is to analyse the most significant methods for automatic location of distributed WSNs. The first part of the paper provides a description of the most comm...

Advances in the area of industrial metrology have generated new technologies that are capable of measuring components with complex geometry and large dimensions. However, no standard or best-practice guides are available for the majority of such systems. Therefore, these new systems require appropriate testing and verification in order for the users to understand their full potential prior to their deployment in a real manufacturing environment. This is a crucial stage, especially when more than one system can be used for a specific measurement task. In this paper, two relatively new large-volume measurement systems, the mobile spatial co-ordinate measuring system (MScMS) and the indoor global positioning system (iGPS), are reviewed. These two systems utilize different technologies: the MScMS is based on ultrasound and radiofrequency signal transmission and the iGPS uses laser technology. Both systems have components with small dimensions that are distributed around the measuring area to form a network of sensors allowing rapid dimensional measurements to be performed in relation to large-size objects, with typical dimensions of several decametres. The portability, reconfigurability, and ease of installation make these systems attractive for many industries that manufacture large-scale products. In this paper, the major technical aspects of the two systems are briefly described and compared. Initial results of the tests performed to establish the repeatability and reproducibility of these systems are also presented.

Acceptance sampling is a statistical procedure for accepting or rejecting production lots according to the result of a sample inspection. Formalizing the concept of assisted acceptance sampling, this article suggests the use of consolidated tools for reducing the risk of human errors in acceptance sampling activities. To this purpose, the application of augmented reality techniques may represent a profitable and sustainable solution. An augmented reality–based prototype system is described in detail and tested by an experimental plan. The major original contributions of this work are (a) introducing the new paradigm of assisted acceptance sampling and (b) developing a preliminary application in an industrial-like environment. This application is a first step towards the realization of a complete assisted acceptance sampling system.

Distributed Large-Volume Metrology (LVM) systems are mainly used for industrial applications concerning assembly and dimensional verification of large-sized objects. These systems generally consist of a set of network devices, distributed around the measurement volume, and some targets to be localized, in contact with the measured object's surface or mounted on a hand-held probe for measuring the points of interest. Target localization is carried out through several approaches, which use angular and/or distance measurements by network devices. This paper presents a new methodology to support the design of networks of devices, for distributed LVM systems based on triangulation (i.e., systems in which network devices perform angular measurements only). It is assumed that these systems use multi-sensor networks including two typologies of devices: some are accurate but expensive and other ones are less accurate but cheaper. The goal of the methodology is establishing a link between the following parameters: (i) density of network devices, (ii) mix between the two typologies of network devices, (iii) measurement uncertainty, and (iv) cost. The methodology allows to estimate the most appropriate density and mix between the two typologies of network devices, so that the distributed LVM system is conforming with the required measurement uncertainty and cost. The methodology relies on a large number of simulated experiments, defined and implemented using a dedicated routine; feasibility and practicality is tested by preliminary experiments on a multi-sensor photogrammetric system, developed at Politecnico di Torino—DIGEP.

Large Volume Metrology (LVM) tasks can require the concurrent use of several measuring systems. These systems generally consist of set of sensors measuring the distances and/or angles with respect to a point of interest so as to determine its 3D position. When combining different measuring systems, characterized by sensors of different nature, competitive or cooperative methods can be adopted for fusing data. Competitive methods, which are by far the most diffused in LVM, basically perform a weighted mean of the 3D positions determined by the individual measuring systems. On the other hand, for cooperative methods, distance and/or angular measurements by sensors of different systems are combined together in order to determine a unique 3D position of the point of interest. This paper proposes a novel cooperative approach which takes account of the measurement uncertainty in distance and angular measurements of sensors of different nature. The proposed approach is compared with classical competitive approaches from the viewpoint of the metrological performance. The main advantages of the cooperative approach, with respect to the competitive one, are: (i) it is the only option when the individual LVM systems are not able to provide autonomous position measurements (e.g., laser interferometers or single cameras), (ii) it is the only option when only some of the sensors of autonomous systems work correctly (for instance, a laser tracker in which only distance – not angular – measurements are performed), (iii) when using systems with redundant sensors (i.e. photogrammetric systems with a large number of distributed cameras), point localization tends to be better than that using the competitive fusion approach.

Distributed systems for Large-Scale-Metrology applications generally include a set of angular and/or distance sensors, distributed around the measurement volume, and some targets to be localized, in contact with the measured object's surface. For these systems, estimating the uncertainty in target localization is far from trivial, as it may be affected by several factors: uncertainty in sensor calibration and angular/distance measurements, relative position between targets and sensors, etc. This paper proposes a novel approach based on the combined use of the Multivariate Law of Propagation of Uncertainty and Monte Carlo method. Preliminary results and experimental tests are presented and discussed.

PurposeAnalysis and comparison of three existing indicators of the air quality: the American air quality index, the French Atmo, and the Italian Indice di Qualità dell'Aria.Design/methodology/approachInternational general and organic regulations to control air quality do not exist yet. Consequently many countries have independently implemented specific indicators to monitor the air pollution and then alert people of resulting health risks. The paper focuses on three of them. Each one is independently presented showing the peculiarities. Therefore, these indicators are compared to identify the features they have in common, as well as those that set them apart, and to figure out which are either restrictive or permissive, and what are their qualities and drawbacks.FindingsThe three mentioned indicators convert the real health risk due to air pollution into numerical information, in different ways. Doing this, they carry out some simplifications or assumptions, which can be questionable. The main difficulty is to understand if the indicators aggregate the different pollutant concentrations consistently with the real effects on human health.Research limitations/implicationsThis paper analyses only three specific indicators of the air quality, selected among the existing ones.Practical implicationsIndicators should carefully be analysed to understand if they properly represents the real effects of pollutants on human health. The most critical aspect to consider is the aggregation of the different pollutant concentrations in one information.Originality/valueThis paper analyses the efficacy of representation of some air quality indicators. It discusses if indicators aggregation is consistent with the real effects on human health.

A B S T R A C T Large Volume Metrology (LVM) tasks often require the concurrent use of several distributed systems. Competitive or cooperative methods can be adopted for fusing multiple system data. Nowadays, competitive methods are by far the most diffused in LVM; these methods basically perform a weighted mean of 3D position measurements carried out by individual systems, with respect to the relevant uncertainties. This paper proposes a cooperative approach relying on the combination of angular and distance measurements (and relevant uncertainties) yielded by the sensors of each individual system. Preliminary simulations and experimental results concerning the application of this method are presented and discussed. 2015 CIRP.

Quality Function Deployment is an effective tool to orient the design of a product and related production processes towards the real exigencies of the end-user. Its first phase – the house of quality – is aimed at translating customer requirements (CRs) into engineering characteristics (ECs) of the product of interest, also determining an ECs’ prioritisation. All of the techniques proposed for tackling this problem are based on the assumption that the importance of each CR is expressed on interval or ratio scales (i.e. cardinal scales). To this end, customer evaluations – naturally expressed on ordinal scales – are artfully turned into numbers. This study introduces a novel technique – denominated as ordinal prioritisation method – that can be applied to prioritise ECs. The method addresses the problem of the prioritisation of ECs when the importance of CRs is given on an ordinal scale. The description of the method is supported by some application examples.

The automotive industry has always shown a particular interest in quality management systems, which resulted in the development of several different specific standards. As a result of this, by the mid-1980s, automotive suppliers were subject to numerous national and customer-specific regulations. The proliferation of these standards and the need to create a single reference model led to Technical Specification (TS) 16949, an International Organization for Standardization (ISO) technical specification aimed at representing a comprehensive quality management system for the global automotive industry. Since its early introduction, TS 16949 has encountered a certain success thanks to its feature of unifying and harmonizing the already existing standards. This paper studies the global evolution and diffusion of this technical specification, observing its impact on local economies. The findings are supported by empirical data.

The Mobile Spatial coordinate Measuring System (MScMS) is a distributed wireless-sensor-network-based system used to perform dimensional measurements of large-scale objects. The system consists of a wireless mobile probe with ultrasonic (US) transceivers, the position of which is determined using a distributed constellation of US transceivers arranged around the measuring area. These US transceivers, which are known as Crickets, transmit US signals to each other and measure their time of flight (TOF) to determine the mutual distances. The MScMS is able to calculate the Cartesian coordinates of the object surface points touched by the wireless mobile probe. This paper aims to experimentally evaluate the performance of the US transducers on each of the MScMS Crickets. The experiments are designed and performed by means of a statistical factorial plan to identify the most important factors affecting the transducers' performance on TOF measurements. Particular attention is given to the error derived by the US signal attenuation and the method of US pulse detection. The results are analyzed in detail and fully interpreted. Finally, some considerations about possible actions to improve the MScMS measuring system are given.

Large scale metrology refers to dimensional measurement of objects or features of perhaps a ten of meters or more in size. Alternatively, large scale metrology could be said to apply to any dimensional measurement where the metrology instrument has to be brought to the object rather than vice versa. Recent approaches seem to turn their attention towards distributed metrology systems made of multiple components with small dimensions spread around the measuring area. In general, these components are able to form a wireless network of sensors that allows rapid dimensional measurements to be performed in relation to large-size objects, with typical dimensions of several decametres. The portability, flexibility, and ease of installation of wireless sensor networks (WSNs) make these systems attractive for many industries manufacturing large scale products. This paper proposes different WSN localization procedures designed for the mobile spatial coordinate measuring system, a distributed metrology system developed at the industrial metrology and quality laboratory of DISPEA—Politecnico di Torino.

The mobile spatial coordinate measuring system (MScMS) is a system to perform dimensional measurements of large-scale objects. It consists of a wireless measuring probe with ultrasonic (US) transceivers, the position of which is determined using a distributed constellation of analogous transceivers arranged around the measuring area. The principle is to measure the time-of-flight (TOF) of the US signals exchanged between pairs of transceivers and, consequently, to obtain an estimate of their distances. The accuracy of TOF measurements can be attributed to many factors; the most influential are those associated with US signal attenuation. The purpose of this paper is to build an experimental correction model to reduce the MScMS’ error in TOF measurements. First, a two-way block design, which is based on exploratory experiments, is created to show that transmitter—receiver distance and relative orientation between US transceivers have significant effects on TOF measurement error. Next, an empirical regressive model is constructed on the basis of additional detailed experiments. After performing an extensive experimental validation, the model is automatically implemented by MScMS, with an iterative procedure. The most important benefit of such a model is an important reduction in the dispersion and an improved accuracy associated with TOF measurements.

Mobile Spatial coordinate Measuring System (MScMS) is a wireless-sensor-network based system developed at the industrial metrology and quality engineering laboratory of DISPEA – Politecnico di Torino. It has been designed to perform simple and rapid indoor dimensional measurements of large-size volumes (large-scale metrology). It is made up of three basic parts: a “constellation” of wireless devices (Crickets), a mobile probe, and a PC to store and elaborate data. Crickets and mobile probe utilize ultrasound (US) transceivers in order to evaluate mutual distances. The system makes it possible to calculate the position – in terms of spatial coordinates – of the object points “touched” by the probe. Acquired data are then available for different types of elaboration (determination of distances, curves or surfaces of measured objects). In order to protect the system against causes of error such as, for example, US signal diffraction and reflection, external uncontrolled US sources (key jingling, neon blinking, etc.), or software non-acceptable solutions, MScMS implements some statistical tests for on-line diagnostics. Three of them are deeply analyzed in this paper: “energy model-based diagnostics”, “distance model-based diagnostics”, and “sensor physical diagnostics”. For each measurement, if all these tests are satisfied at once, the measured result may be considered acceptable with a specific confidence coefficient. Otherwise, the measurement is rejected. After a general description of the MScMS, the paper focuses on the description of these three on-line diagnostic tools. Some preliminary results achieved by the system prototype are also presented and discussed.

International audience; In many industrial fields (for example, automotive and aerospace) dimensional measurements of large size objects should be easily and rapidly taken. Nowadays, the problem can be handled using many metrological systems, based on different technologies (optical, mechanical, electromagnetic etc..). Each of these systems is more or less adequate, depending on measuring conditions, user's experience and skill, or other factors like time, cost, dimensions, accurateness, portability etc.. In general for measuring medium-large size objects, portable systems can be preferred to fixed ones. Transferring the measuring system to the measured object place is often more practical than the vice-versa. The purpose of this paper is to introduce a new system called Mobile Spatial coordinate Measuring System (MScMS). The system has been designed to perform dimensional measurements of medium-large size objects. MScMS is made up of three basic parts: a “constellation” of wireless devices, liberally distributed around the working area; a mobile probe to register the coordinate points of the measured object; a PC to store data sent by the mobile probe – via Bluetooth – and to process them by means of an ad hoc application software. MScMS is easily adaptable to different measuring environments and does not require complex procedures for installation, start-up or calibration.

Indoor GPS (iGPS) is a newly developed laser based measuring system for large scale metrology. The relative portability, reconfigurability and ease of installation make the iGPS suitable for many industries manufacturing large scale products. The system performance depends on both the components characteristics and their physical configuration. Hence, an important consideration for the iGPS is to characterise its real capabilities, pointing out how they can be influenced by the system's configuration and setup. In this paper, the system is introduced and the technical aspects are briefly described. Then, an initial test is performed to establish its repeatability, reproducibility and accuracy.

Mobile Spatial coordinate Measuring System (MScMS) is a wireless-sensor-network based system developed at the Industrial Metrology and Quality Engineering Laboratory of DISPEA – Politecnico di Torino. It has been designed to perform simple and rapid indoor dimensional measurements of medium-large size objects (large scale metrology). It is made up of three basic parts: a “constellation” of wireless devices (Crickets), a mobile probe, and a PC to store and elaborate data. Crickets and mobile probe use ultrasound (US) transceivers in order to evaluate mutual distances. Each US device has a communication range limited by a cone of transmission within a nominal opening angle of about 170° and a maximum distance of no more than 8 m. The mobile probe location in the working volume is obtained by a trilateration, consequently it should communicate with at least 4 constellation devices at once. The system makes it possible to calculate the position — in terms of spatial coordinates — of the object points “touched” by the probe. Acquired data are then available for different types of elaboration (determination of distances, curves or surfaces of measured objects). During the system set-up, the constellation Crickets (beacons) are manually placed in the working volume (we define this operation as “positioning”). After that, their coordinates are determined as much precisely as possible (this operation is said “location”). The positioning of constellation devices is one of the most critical aspects in the system set-up. In principle, Crickets can be arranged without restrictions all around the measured object. However, the number and position of network devices are strongly related to the dimensions and shape of both the measuring volume and the measured object. The accuracy in the location of constellation devices is fundamental for the accuracy of the coordinates of the touched points during measurement operation. It is important to assure a full coverage of the space served by network devices by a proper alignment of US transmitters. For that reason, an ad hoc software “pre-processor” has been developed in order to help the operator in positioning and locating constellation devices in the working volume, according to the measuring space and the measured object dimensional characteristics. The aim of the paper is to introduce and describe this computer-assisted approach. Some preliminary results of experimental tests carried out on the system prototype are also presented and discussed.Copyright © 2008 by ASME