Indirect multisignal monitoring and diagnosis of drill wear

A machine tool utilisation rate can be improved by an advanced condition monitoring system using modern sensor and signal processing techniques. A drilling test and analysis program for indirect tool wear measurement forms the basis of this thesis. For monitoring the drill wear a number of monitoring methods such as vibration, acoustic emission, sound, spindle power and axial force were tested. The signals were analysed in the time domain using statistical methods such as root mean square (rms) value and maximum. The signals were further analysed using Fast Fourier Transform (FFT) to determine their frequency contents. The effectiveness of the best sensors and analysis methods for predicting the remaining lifetime of a tool in use has been defined. The results show that vibration, sound and acoustic emission measurements are more reliable for tool wear monitoring than the most commonly used measurements of power consumption, current and force. The relationships between analysed signals and tool wear form a basis for the diagnosis system. Higher order polynomial regression functions with a limited number of terms have been developed and used to mimic drill wear development and monitoring parameters that follow this trend. Regression analysis solves the problem of how to save measuring data for a number of tools so as to follow the trend of the measuring signal; it also makes it possible to give a prognosis of the remaining lifetime of the drill. A simplified dynamic model has been developed to gain a better understanding of why certain monitoring methods work better than others. The simulation model also serves the testing of the developed automatic diagnostic method, which is based on the use of simplified fuzzy logic. The simplified fuzzy approach makes it possible to combine a number of measuring parameters and thus improves the reliability of diagnosis. In order to facilitate the handling of varying drilling conditions and work piece materials, the use of neural networks has been introduced in the developed approach. The scientific contribution of the thesis can be summarised as the development of an automatically adaptive diagnostic tool for drill wear detection. The new approach is based on the use of simplified fuzzy logic and higher order polynomial regression analysis, and it relies on monitoring methods that have been tested in this thesis. The diagnosis program does not require a lot of memory or processing power and consequently is capable of handling a great number of tools in a machining centre.reviewe

Development of a Maintenance System Based on Web and Mobile Technologies

The paper reports the development of an e-monitoring and maintenance system based on web technology and mobile device, PDA. Rarity of experts led to the application of artificial intelligence and later, distributed artificial intelligence for condition monitoring and diagnosis of machine condition. Recently, web technology along with wireless communication is emerging as a potent tool in maintenance. It facilitates obtaining of the desired information by the relevant personnel at any time wherever he may be. The paper first describes the web and mobile architecture that formed the basis of the system and ICT tools used to communicate among the different layers in the architecture/system and its various client machines. It is followed by the demonstration of the use of the system with a faulty bearing simulated signal. A mobile emulator was used to perf ect the system for different requirements and the same was then tested on the PDA

Identifying Organisational Requirements for the Implementation of an Advanced Maintenance Strategy in Small to Medium Enterprises (SME)

In many organisations the production equipment represents the majori-ty of invested capital, and deterioration of these facilities and equipment increases production costs, reduces product quality and has a significant impact on energy consumption. Over recent years the importance of maintenance, and therefore maintenance management within manufacturing organisations has grown. The maintenance function has become an increasingly important and complex, activity – particularly as automation increases. The opportunity exists for many organisa-tions to benefit substantially through improvements to their competitiveness and profitability by adopting a new approach to maintenance management. Several tools and technologies including Condition Based Maintenance, Reliability Cen-tred Maintenance and more recently E-Maintenance have developed under the heading of Advanced Maintenance Strategies. However, the adoption of advanced maintenance strategies and their potential benefits are usually demonstrated in large organisations. Unfortunately, the majority of organisations, classified as Small and Medium Sized Enterprises (SMEs), are constrained by the lack of knowledge and understanding on the requirements which need to be in place be-fore adopting an advanced maintenance strategy. This paper will present the find-ings from an extensive literature review and an ex-amination of multiple case studies. The results show that there is a set of key requirements which strongly in-fluence the implementation of an Advanced Maintenance Strategy (AMS) within SMEs

Mobile Maintenance Management

The paper gives a short overview of the enabling tools and technology available to the maintenance engineer in manufacturing industry, in relation to the emergence of e-maintenance practices and the introduction of mobile computing devices. An analysis of the main characteristics of the e- maintenance concepts and the associated challenges is provided, highlighting the lack of use of condition-based maintenance strategies. The potential of using ubiquitous computing in industrial maintenance practice is then examined, followed by an original vision for the adoption of mobile maintenance management solutions, which can facilitate the implementation of condition-based- maintenance. This vision is supported today by the European Integrated Project DYNAMITE 017498 (Dynamic Decisions in Maintenance)

Blockchain Technology Helps Maintenance to Stop Climate Change

The development and interest in Industry 4.0 together with rapid development of Cyber Physical Systems has created magnificent opportunities to develop maintenance to a totally new level. The Maintenance 4.0 vision considers massive exploitation of information regarding factories and machines to improve maintenance efficiency and efficacy, for example by facilitating logistics of spare parts, but on the other hand this creates other logistics issues on the data itself, which only exacerbate data management issues that emerge when distributed maintenance platforms scale up. In fact, factories can be delocalized with respect to the data centers, where data has to be transferred to be processed. Moreover, any transaction needs communication, be it related to purchase of spare parts, sales contract, and decisions making in general, and it has to be verified by remote parties. Keeping in mind the current average level of Overall Equipment Efficiency (50%) i.e. there is a hidden factory behind every factory, the potential is huge. It is expected that most of this potential can be realised based on the use of the above named technologies, and relying on a new approach called blockchain technology, the latter aimed at facilitating data and transactions management. Blockchain supports logistics by a distributed ledger to record transactions in a verifiable and permanent way, thus removing the need for multiple remote parties to verify and store every transaction made, in agreement with the first “r” of maintenance (reduce, repair, reuse, recycle). Keeping in mind the total industrial influence on the climate change, we can expect that with the aid of the new advancements the climate change can be if not totally stopped at least reduced, and contribute to the green economy that Europe aims for. The paper introduces the novel technologies that can support sustainability of manufacturing and industry at large, and proposes an architecture to bind together said technologies to realise the vision of Maintenance 4.0.info:eu-repo/semantics/publishedVersio

Problems with using Fast Fourier Transform for rotating equipment: Is it time for an update?

Condition-Based Maintenance (CBM) is widely used to manage the condition of rotating machinery. They require a number of CBM tools to detect acous-tic and vibration signals. One such method is the Fast Fourier Transform (FFT). FFT converts a vibration signal from time domain to its equivalent fre-quency domain representation. Unfortunately, there are dramatic assumptions made related to the proper use of FFT. The paper will provide evidence that this approach may not be the perfect tool for fault detection and diagnosis. The paper celebrates with the limitations of FFT and does not muffle the culpa-bilities of our developed diagnosis culture. The aim is to challenge researchers to come up with something more developed to eventually take use of the processing power we have today

ANALISIS PERBANDINGAN KUALITAS LAYANAN ANTARA BANK PEMERINTAH DAN BANK SWASTA

Persaingan yang terjadi dalam bisnis perbankan dewasa ini mendorong pihak bank berlomba-Iombamemberikan kualitas pelayanan yang terbaik kepada masing-masing nasabahnya. Dengan memberikankualitas layanan yang sesuai dengan apa yang diharapkan oleh nasabahnya pada akhirnya akan memberikankepuasan yang nantinya akan meningkatkan foyalitas mereka terhadap bank yang bersangkutan.Lima dimensi kualitas layanan yang dikemukakan oleh Parasuraman menjadi acuan untuk mengukurapakah ada perbedaan antara kualitas layanan yang diterima oleh nasabah dan ekspektasi nasabah pada bankBUMN dengan bank swasta, disamping itu untuk mengetahui apakah ada perbedaan kualitas layanan yangditerima oleh nasabah, harapan nasabah serla kesenjangan (gap) antara bank BUMN dan bank swasta. Alatanalisis yang digunakan adalah dengan melakukan uji sampel bebas t serla uji sampel berpasangan t.Disamping itu penulis juga ingin mengetahui apakah ada pengaruh faktor individu, kesan dan alasanpemilihan suatu bank terhadap ekspektasi nasabah akan kualitas layanan pada kedua jenis bank tersebut. Alatanalisis yang digunakan adalah analisis varian (ANOVA).Hasilnya memperlihatkan bahwa ekspektasi atau perkiraan nasabah mengenai kualitas fayanan perbankanyang baik rupanya tidak ada perbedaan yang signifikan antara kedua jenis bank tersebut. Pandangan yangnasabah miliki mengenai kualitas layanan yang diberikan oleh suatu bank, meskipun demikian, menampilkanbeberapa perbedaan yang signifikan. Menurut nasabah, bank swasta dinilai unggul dalam dimensi tamplan fisik(tangibles), sedangkan empat dimensi lainnya yaitu kemampuan mewujudkan janji, ketanggapan memberikanpelayanan, kemampuan memberikan jaminan pelayanan, dan kemampuan memahami kebutuhan nasabahdipegang oleh bank pemerintah.Secara keseluruhan, kualitas layanan yang diberikan oleh kedua jenis bank tersebut ternyata belum dapatmemuaskan nasabah, namun bila dilakukan perbandingan antara keduanya ternyata kualitas layanan yangdiberikan oleh bank pemerintah menurut persepsi nasabah lebih baik dibandingkan dengan kualitas layananyang diberikan oleh bank swasta, hal ini ditunjukkan dengan rata-rata skor kesenjangan bank pemerintahsebesar-1,02 sedangkan bank swasta sebesar-1,29.Kata Kunci : bank BUMN, bank swasta, kualitas layanan, servqua