Farbod Zorriassatine

A survey of virtual prototyping techniques for mechanical product development

Abstract Repeated, efficient, and extensive use of prototypes is a vital activity that can make the difference between successful and unsuccessful entry of new products into the competitive world market. In this respect, physical prototyping can prove to be very lengthy and expensive, especially if modifications resulting from design reviews involve tool redesign. The availability and affordability of advanced computer technology has paved the way for increasing utilization of prototypes that are digital and created in computer-based environments, i.e. they are virtual as opposed to being physical. The technology for using virtual prototypes was pioneered and adopted initially by large automotive and aerospace industries. Small-to-medium enterprises (SMEs) in the manufacturing industry also need to take virtual prototyping (VP) technology more seriously in order to exploit the benefits. VP is becoming very advanced and may eventually dominate the product development process. However, physical prototypes will still be required for the near future, albeit less frequently. This paper presents a general survey of the available VP techniques and highlights some of the most important developments and research issues while providing sources for further reference. The purpose of the paper is to provide potential SME users with a broad picture of the field of VP and to identify issues and information relevant to the deployment and implementation of VP technology.

A Survey on Condition Monitoring Systems in Industry

Advances in networking technologies are opening integration opportunities for Condition Based Monitoring (CBM) systems, presenting further possibilities for increasing CBM system functionality. This paper presents the results of a CBM Survey designed to determine present applications of CBM system within industry. Understanding how industry applies practices such as CBM in the work place offers valuable research results for CBM system providers, consultants and business users alike. The survey acts as a CBM application indicator for 2004. It targets 6 key areas: 1) Respondents’ company information, 2) The type of CBM technique/s applied by the respondents’ company, 3) Incentives that led the respondents’ company to implement their CBM system, 4) Technological and integration issues associated with respondents’ application of CBM, 5) Implementation issues associated with the respondents’ CBM system, and 6) Reliability and consequential maintenance awareness issues following implementation. An international response shows CBM to be a globally accepted maintenance practice. In addition to the survey results, the paper discusses developments in remote CBM systems using the Internet, with particular regard for developing suitable user interface designs.Copyright

A new project scheduling approach for improving multi-product multi-period production planning problems

The problem of matching production levels for individual products to demand fluctuations during multiple periods is known in the production planning literature as the multi-product multi-period (MPMP) problem. Linear programming (LP)-based solutions have been extensively reported in this respect. MPMP problems are commonly solved by using either analytic or simulation methods. More recently, hybrid solutions consisting of both analytical models and simulation analysis have been proposed where some operational criteria, e.g. the order of visit to machining centres, are taken into account. In this paper, results related to some of the literature based on hybrid solutions are used as the initial feasible solutions and then examined in the context of project scheduling by considering the influences of resource constraints. After converting the MPMP to a project network problem and assigning resources to activities and consequently levelling the resource profiles, it is discovered that machine utilization can be further improved by applying unused machine capacities. A LP model is therefore developed in order to maximize feasible production rates over all the production planning periods. The proposed approach results in improvements on the results of earlier hybrid solutions reported in the literature. Finally, three different planning problems are suggested for further applications of the proposed approach in the context of manufacturing environments.

Application of infrared technology for quality control of diesel engine glow plugs

Abstract In recent years, the diesel engine has increasingly become a more popular choice with manufacturers and car buyers owing to its high fuel and power efficiencies. The research into diesel engine and its components is driven by the desire to meet strict emission standards and improving performance. This paper describes the application of infrared technology for quality control of diesel engine glow plugs. It is not sufficient to measure the resistance of glow plugs to assess their conformance to the performance specifications on account of the irregularity of the heat patterns produced. Moreover, the full power testing of glow plugs is not practical for quality control owing to the consumption of power, the considerable length of time, and the extreme temperatures generated. This paper describes a novel approach using low-cost infrared technology and a limited power-consuming experiment in order to test 100 per cent conformance of manufactured glow plugs. The results show that the technology can be utilized for quality control inspection of glow plugs.

Smarter maintenance through internet-based condition monitoring with indirect sensing, novelty detection, and XML

Abstract In engineering, combining a number of solutions and technologies can result in more effective systems than using only one approach on its own. In particular, it has been shown that in condition monitoring (CM), smarter maintenance systems may be obtained by integrating various sensors together. This paper extends this idea by integrating various non-homogeneous technologies horizontally. The proposed system is an internet-based condition monitoring (e-CM) prototype that can identify abnormal tension in moving belts. It is shown that by applying a classification technique, known as novelty detection, it is possible to decide the status of belt tension by processing the belt vibration signals from an optical sensor (i.e. an indirect sensing approach). A novel method for industrial network communication using XML to create a single standard format for sensor information is also used to link the sensor to the process controller via the internet using the flexible CAN bus technology; this is used together with low-cost microcontrollers with a built-in ethernet link for data acquisition and transmission. The resulting integrated approach is more efficient because: (a) it can reduce waste by minimizing process interruptions caused by direct belt inspection methods while obtaining high detection accuracy (99.67 per cent) and (b) it can provide on-line remote CM that is cost-effective, simple, standardized, and scalable across a wide area and for a relatively large number of sensors. This improvement is especially important when applied to bottleneck processes and critical components.

Application of FPGAs to High-Speed Condition Based Maintenance of Rolling Element Bearings

Field-Programmable Gate Array (FPGA) technology has been applied widely in electronic engineering and computing industries, but it has not had the same level of reception in other disciplines including mechanical engineering [1]. The purpose of this paper is to examine FPGA implementations of signal processing techniques that are used in the context of bearing condition monitoring. As the number of bearings can be large sparse sensor arrays are used to locate and detect their condition. The demands of realtime process monitoring [2] [3] can place a heavy burden upon the monitoring system. Field-Programmable Gate Array (FPGA) technology [4] in this application makes it possible to implement more sophisticated algorithms. These exploit its high-speed, parallel, reconfigurable architecture. Bring forth the advantages of FPGA technology to condition monitoring. The techniques covered are: cross-correlation, digital signal processing (DSP) Infinite Impulse Response (IIR) filters, neural networks and signature matching. The implemented designs are optimised for both execution time and the amount of logic area consumed. Results were obtained from each technique and were assessed and compared in terms of execution time and also the amount of logic consumed on the FPGA. Over the past 15 years FPGA technology has been applied extensively in electronic engineering but its scope has not been as vastly in mechanical engineering. The objective of this paper was to examine an application in mechanical engineering. Ideally this would be done with a mechanical engineering compatible approach, giving rise to a methodology, which would allow FPGA programming [5] to become a transferable skill.Copyright

The Smart Parcel Concept for Condition Monitoring of Materials Handling Machinery

Complex machinery which bears loads over large distances requires a large capital outlay to monitor condition at many points. Hand-held monitoring units necessitate knowledgeable operators and are of limited use when applications involve areas inaccessible during operation. This paper presents the idea of deploying a ‘smart parcel’ to navigate the process, reporting on performance. Equipment was mounted on a receptacle belonging to such a machine, and sound data was recorded for later analysis. Frequencies present were compared with component characteristic frequencies in order to ascertain robustness of method as compared to traditional installations. The presence of common information and also some that are not obtainable by other means has rendered the theory a viable proposal.Copyright

A Novel Approach for Extracting Sensor Information From Different Industrial Networks for Internet Based Condition Monitoring Applications

Automated Condition Monitoring (ACM) has become a necessity for complex modern day systems. The advent and ever increasing popularity of Internet has given a new dimension to ACM. Many Internet Based Condition Monitoring (IBCM) solutions have since been implemented. There are many types of Industrial Networks that are used in the industry to implement ACM. The protocols and information sent through these networks are very different from one another. Sharing information between industrial networks and presenting it for consolidated monitoring can be a daunting task. This paper describes a novel way for extracting sensor information from different industrial networks into a single standard format using Extensible Markup Language (XML). Implementation of the solution with an Industrial Network, Controller Area Network (CAN), is also shown. The results demonstrate that by using this approach communication between automated systems and mechatronic devices will become more integrated, more efficient and less complex.Copyright