This paper presents the results of a wideband channel measurement campaign carried out in an indoor environment with representative inventory of a factory. The measurements were carried out using a frequency domain channel sounder from 3.4 - 3.8 GHz and the virtual array method was adopted for averaging small-scale fading effects. From the average power delay profile (APDP), parameters for the Saleh-Valenzuela (S-V) model were extracted for line-of-sight (LoS) and non line-of-sight (NLoS) sites. The ray decay from the S-V model increased with cluster delay for all LoS sites and the delay spread for NLoS sites were higher than LoS locations. The NLoS delay spread was also higher than the results obtained at 2.4 GHz for the same measurement locations. The APDPs from both LoS and NLoS sites showed clustering effects with a mean cluster number of 8/7 for LoS/NLoS sites.

This paper presents a new way to estimate delay spread in machine workspaces by using fractal geometry. In this way, inventories can be created quickly and used within a ray tracing software to estimate the radio environment of machine workspaces as part of the planning process. Delay spread is an important metric in assessing the performance of wireless technologies. Predicted 5G cyber-physical systems in workplaces will require high-density use of wirelessly connected machine-to-machine RF modules. In workshops, the surfaces and edges of machines, shelves, and furniture influence the multipath/power delay profile of the space. However, with the fast construction pace and high occupancy of buildings, it is impractical to characterize the location as building work progresses. Consequently, it becomes more probable that the radio communication system deployed will perform suboptimally. In this work, the Wi-Fi band was investigated. In addition, representative simulations were also carried out at millimetre wave frequencies of 28 GHz and 60 GHz. (C) 2019 Elsevier B.V. All rights reserved.

Fuel cell stack compression is a vital part of the manufacturing process, however limited research exists in predicting the optimal compression force to maximise fuel cell performance. This paper validates a spring equivalent model proposed in a previous publication which, when coupled with literature derived gas diffusion layer (GDL) optimal compression data, can predict the compression force required based on gas diffusion layer and gasket properties. The error between the model and the optimal performance of the stack is a maximum of 6.4%. This is a positive indication as to the model's validity. In addition, the compression homogeneity applied by the compression system to the flow field plate is measured to confirm the GDL is experiencing the predicted compression force. The impact of this research is a reduction in development time and cost as less empirical testing will be required to identify optimal fuel cell stack compression.

Various tools and methods exists for arriving at an optimised assembly sequence with most using a soft computing approach. However, these methods have issues including susceptibly to early convergence and high computational time. The typical objectives for these methods are to minimise the number of assembly change directions, orientation changes or the number of tool changes. This research proposes an alternative approach whereby an assembly sequence is measured based on its complexity. The complexity value is generated using design for assembly metrics and coupled with considerations for product performance, component precedence and material handling challenges to arrive at a sequence solution which is likely to be closest to the optimum for cost and product quality. The case presented in this study is of the assembly of a single proton exchange membrane fuel cell. This research demonstrates a practical approach for determining assembly sequence using data and tools that are used and available in the wider industry. Further work includes automating the sequence generation process and extending the work by considering additional factors such as ergonomics.

Proton Exchange Membrane Fuel Cells (PEMFCs) offer numerous advantages over combustion technology but they remain economically uncompetitive except for in niche applications. A portion of this cost is attributed to a lack of assembly expertise and the associated risks. To solve this problem, this research investigates the assembly systems that do exist for this product and systematically decomposes them into their constituent components to evaluate reconfigurability and suitability to product. A novel method and set of criteria are used for evaluation taking inspiration from heuristic approaches for evaluating manufacturing system complexity. It is proposed that this can be used as a support tool at the design stage to meet the needs of the product while having the capability to accept potential design changes and variants for products beyond the case study presented in this work. It is hoped this work develops a new means to support in the design of reconfigurable systems and form the foundation for fuel cell assembly best practice, allowing this technology to reduce in cost and find its way into a commercial space.

This paper evaluates the suitability of existing 2D interpolation techniques to estimate RF power density levels within an automobile manufacturing plant in the UK. This analysis is based on a measurement campaign carried out at five locations within the plant. Using widely accepted interpolation techniques, a power density grid that provides an estimate of power density distribution for the plant can be created. The interpolation techniques evaluated are: Inverse distance weighting, Kriging and Spline. The analytical results showed that the Kriging technique was more suitable for estimating power density across the entire band (0.2 GHz - 3 GHz). Using the power density grid obtained, an energy profile for a pallet traveling in a predefined production loop was estimated. As a result, it becomes essential to carefully select the estimation technique to adopt, particularly when the measurement dispersion points are sparse.

Global market pressures and the rapid evolution of technologies and materials force manufacturers to constantly design, develop and produce new and varied products to maintain a competitive edge. Although virtual design and engineering tools have been key to supporting this fast rate of change, there remains a lack of seamless integration between and within tools across the domains of product, process, and resource design - especially to accommodate change. This research examines how changes to designs within these three domains can be captured and evaluated within a component based engineering tool (vueOne, developed by the Automation Systems Group at the University of Warwick). This paper describes how and where data within these tools can be mapped to quickly evaluate change (where typically a tedious process of data entry is required) decreasing lead times and cost and increasing productivity. The approach is tested on a sub-assembly of a hydrogen fuel cell, where an assembly system is modelled and changes are made to the sequence which is translated through to control logic. Although full implementation has not yet been realized, the concept has the potential to radically change the way changes are made and the approach can be extended to supporting other change types provided the appropriate rules and mapping.

This paper investigates the opportunities of deploying distributed sensors within the manufacturing environment of a large scale automobile plant using energy harvesting techniques. Measurements were taken in three domains at the plant in order to characterize ambient energy. Due to the location of the plant, the RF power density for radio access technologies present varied between -127 dBm/cm2 and -113 dBm/cm2. The maximum temperature difference measured within accessible distance from machine parts on the production lines surveyed was 10°C. Indoor lighting was dominant at the plant via fluorescent tubes, with average irradiance of 1 W/m2. The results obtained from this measurement campaign showed that indoor lighting was the most suitable ambient source for energy harvesting.

This paper presents RF power density measurements carried out at an automobile manufacturing plant in the UK. This measurement campaign was carried out in order to quantify the amount of ambient RF power available within the plant. Due to the location of the plant, low power density measurements were recorded in the base-station downlink. The dominant frequencies at the plant were GSM-1800 and 3G. Average input RF power density for horizontal and vertical polarizations showed few variations in amplitude compared to the maximum hold technique for the frequency band surveyed. The measurement campaign showed that at some locations at the plant, the input RF power density for 3G mobile transmit band was more than the base-station downlink.

Unpredictable and dynamic markets are driven by an ever more informed customer base and rapid technological evolution. In order stay competitive, organisations producing physical products need to be agile. To realise a product, an organisation must go through several phases including product design, process planning and manufacturing system design. These phases can exist within and across organisations, spanning the globe and utilizing an enormous range of information and communication standards. So as to understand the requirements of the predominantly sequential phases, resources are exhausted in converting information into a language which upstream and downstream phases can understand. This research paper aims to reduce this effort by capturing knowledge in a core ontology which is formed by product, process and resource domain ontologies. The vision is that phase or domain experts input information into this ontology, which then infers requirements for the adjacent phases based on predefined relationships. The presented approach permits the insertion of additional information as it becomes available because ontologies are extensible and scalable. This supports a concurrent engineering approach and accommodates the needs of modern businesses. This research paper presents a proof of concept based on a Proton Exchange Membrane Fuel Cell (PEMFC). The rationale for the choice of classes and properties in the model are described. The model is successfully proved by describing liaison precedence and the selection of appropriate assembly equipment.

Optimising the compression process during assembly improves the performance of fuel cells. Sufficient and uniform compression across the x, y and z axes ensures uniform current distribution contributing to stack longevity, minimisation of mechanical stresses and optimisation of the well-recognised compromise between mass transport and ohmic losses. In addition, the sealing media experience the necessary forces required to prevent the leakage of reactant gases and thus increase the efficiency of the system. This research paper evaluates the compression characteristics of a test version of a fuel cell compression rig, designed by Horizon Fuel Cell UK, to inform future assembly line design. A MATLAB code was used to assess the compression homogeneity presented on Fuji Prescale Low pressure films. A spring equivalent model is developed to approximate required compressive force for optimal performance. Optimisation of this model is expected to facilitate the development of a compression process which lends itself to the mass production of fuel cells. Recommendations for improving the current process include the use of electronically controlled cyclic compression and an increase in the number of compression pistons. The key finding of this study is a lack of compression symmetry which is associated with the alignment of the jig or component manufacturing and assembly tolerances.

Information availability and data transparency are key requirements from manufacturers when supporting products throughout the life cycle, for example, when implementing product service systems. The application of embedded wireless technologies into printed circuit boards can help by bridging current knowledge gaps in order to minimise both technical and financial risk through: reduced product downtime, improved quality of tracking, and enhanced end-of-life decision making. The application of an embedded radio frequency identification device into printed circuit boards for life cycle monitoring of electronic products to support product service systems is discussed in this article.

Real time visibility of product-centric data has become increasingly important to original equipment manufacturers in order to optimise supply chain operations, increase quality, reduce resource usage and increase the retained value at the end-of-life of the product. The development of a system capable of supporting collection and visualisation of product-centric data that is used in life-cycle monitoring systems for electronic products is described in this article. The concepts behind intelligent products in the electronics manufacturing domain are discussed. In particular the research is focused on which product-related information is needed throughout the supply chain and how business processes can be optimised if this knowledge is available. A review of intelligent products is outlined and product information that is generated and travels with the product through the supply chain is described by analysis of business processes and identification of those processes, which could be made redundant if product-related data were available. A survey of manufacturing experts within this domain has been undertaken to determine what information should travel with the product, what opportunities exist for embedded information and what barriers for the implementation exist with regard to the specific constraints and needs in the electronics manufacturing domain. The results of this survey are discussed with conclusions drawn and future research derived and described.

Businesses rely on information being accessed, processed, transferred and stored in order to support decision making activities. When any of these activities is poorly supported the ability to adapt to unexpected changes is reduced resulting in risk during decision activities. If these risks were to materialize consequences can be considerable from an economic, quality or time point of view. In this study, we discuss the development of a Radio Frequency Identification (RFID) system to manage the information and state of both secure printed documents and physical assets which loss or misplacement has considerable economic consequences. Discrete event simulation and enterprise modeling was used to evaluate various implementation scenarios. Initial trials of the proposed automated documents and assets management tool showed a reduction in cost partly due to a reduction in management time of 59% and 45% of manager and staff respectively.

A comprehensive system is required to monitor numerous variables of a swimmer's performance. Current methods of analysis do not offer solutions which record and analyse multiple performance parameters simultaneously. The research presented in this paper provides an overview of an integrated system which has been developed to monitor several components of a swimmer's start, free swimming and turn concurrently. The integrated system is comprised of a wearable wireless sensor, vision components, force platform, pressure pad. LED markers and audio communication.

An overview of the development of a wireless sensor network (WSN) used to monitor swimmers performance is presented in this paper. The WSN is based on the functional and non-functional requirements of the user. It has been designed to monitor multiple swimmers performance simultaneously, providing feedback to the coaches and swimmers in real-time. The effect the embedded real-time processing has on available bandwidth in the network is discussed.

The research outlined in this paper was conducted to allow real-time processing, transmission and presentation of data to swimming coaches and subsequently their swimmers in a training environment, focused on providing information relevant to strokes in free swimming. This was achieved using a wearable wireless sensor and embedded programming techniques, using accelerations involved in the swimming stroke to provide relevant features for coaches. Current methods used do not offer real-time response to coaches, which results in the lack of real-time feedback and significantly increased post-session analysis time. Filtering and signal processing algorithms are described here, which allow real-time data analysis to be embedded within a wireless sensor node. The system significantly reduces the time for processing acquired data and has delivered a novel monitoring device suitable for operation within the harsh environment of the pool.

Reliable manufacture depends among other aspects on the supply of correct parts to the different manufacturing processes. In this paper a Radio Frequency Identification (RFID) system used for material handling in harsh environments is presented. The system enforces business rules to guarantee that only correct parts are supplied to the assembly line also registering unexpected manual overrides of the system (e.g. Operator manually retracting the solenoid at the entrance of the lane at the assembly station). Resulting benefits allowed include an ergonomically smoother loading operation and a reduction in misbuild levels in a flexible manufacturing environment.

Radio Frequency Identification (RFID) is a powerful tool used in several application areas. In this paper a method to embed a passive Ultra High Frequecy (UHF) RFID chip within Printed Circuit Boards (PCB) is presented, along with how this can be used to improve the quality and tracking of boards along the electronics supply chain. Embedding of the RFID tag at the very beginning of the supply chain aims to widen the visibility of the product from a very early stage. The embedding of the tag is performed during the bonding process when the multi-layer board is assembled. From this stage onwards it is possible to visualize, record and trace every movement and operation the board goes through along the supply chain.

PurposeThe purpose of this paper is to present an update of and the latest results from work on a project aimed at monitoring electronic products during the whole life cycle with embedded wireless components.Design/methodology/approachBusiness processes of the electronic manufacturing supply chain were analysed. A business case and the system opportunities for life cycle monitoring, based on embedded wireless components system were developed. Radio frequency identification (RFID) assembly technology was adapted for the integration of components into a multi‐layer printed circuit board (PCB).FindingsBy storing product‐related information into electronic products, tracing of components, monitoring of processes, operations and costs, environmentally optimised recycling can be enhanced.Research limitations/implicationsThe research undertaken so far relates to the embedding of RFID tags into PCBs. Wireless components with more processing power will be used in the next project phase.Originality/valueThe paper details how wireless components can be embedded into multi‐layer PCBs and how a business case for a life cycle monitoring system can be established.