Implementing gateway monitoring service for infrastructure sensor networks

Wireless sensor networks and its applications have been widely researched and implemented in both commercial and non commercial areas. The usage of wireless sensor network has developed its market from military usage to daily use of human livings. Wireless sensor network applications from monitoring prospect are used in home monitoring, farm fields and habitant monitoring to buildings structural monitoring. As the usage boundaries of wireless sensor networks and its applications are emerging there are definite ongoing research, such as lifetime for wireless sensor network, security of sensor nodes and expanding the applications with modern day scenarios of applications as web services. The main focus in this thesis work is to study and implement monitoring application for infrastructure based sensor network and expand its usability as web service to facilitate mobile clients. The developed application is implemented for wireless sensor nodes information collection and monitoring purpose enabling home or office environment remote monitoring for a user.

Monitoring of centrifugal pump operation by a frequency converter

Centrifugal pumps are widely used in industrial and municipal applications, and they are an important end-use application of electric energy. However, in many cases centrifugal pumps operate with a significantly lower energy efficiency than they actually could, which typically has an increasing effect on the pump energy consumption and the resulting energy costs. Typical reasons for this are the incorrect dimensioning of the pumping system components and inefficiency of the applied pump control method. Besides the increase in energy costs, an inefficient operation may increase the risk of a pump failure and thereby the maintenance costs. In the worst case, a pump failure may lead to a process shutdown accruing additional costs. Nowadays, centrifugal pumps are often controlled by adjusting their rotational speed, which affects the resulting flow rate and output pressure of the pumped fluid. Typically, the speed control is realised with a frequency converter that allows the control of the rotational speed of an induction motor. Since a frequency converter can estimate the motor rotational speed and shaft torque without external measurement sensors on the motor shaft, it also allows the development and use of sensorless methods for the estimation of the pump operation. Still today, the monitoring of pump operation is based on additional measurements and visual check-ups, which may not be applicable to determine the energy efficiency of the pump operation. This doctoral thesis concentrates on the methods that allow the use of a frequency converter as a monitoring and analysis device for a centrifugal pump. Firstly, the determination of energy-efficiency- and reliability-based limits for the recommendable operating region of a variable-speed-driven centrifugal pump is discussed with a case study for the laboratory pumping system. Then, three model-based estimation methods for the pump operating location are studied, and their accuracy is determined by laboratory tests. In addition, a novel method to detect the occurrence of cavitation or flow recirculation in a centrifugal pump by a frequency converter is introduced. Its sensitivity compared with known cavitation detection methods is evaluated, and its applicability is verified by laboratory measurements for three different pumps and by using two different frequency converters. The main focus of this thesis is on the radial flow end-suction centrifugal pumps, but the studied methods can also be feasible with mixed and axial flow centrifugal pumps, if allowed by their characteristics.

Spectroscopic monitoring during laser welding of aluminium alloy

The mechanical properties of aluminium alloys are strongly influenced by the alloying elements and their concentration. In the case of aluminium alloy EN AW-6060 the main alloying elements are magnesium and silicon. The first goal of this thesis was to determine stability, repeatability and sensitivity as figures of merit of the in-situ melt identification technique. In this study the emissions from the laser welding process were monitored with a spectrometer. With the information produced by the spectrometer, quantitative analysis was conducted to determine the figures of merit. The quantitative analysis concentrated on magnesium and aluminium emissions and their relation. The results showed that the stability of absolute intensities was low, but the normalized magnesium emissions were quite stable. The repeatability of monitoring magnesium emissions was high (about 90 %). Sensitivity of the in-situ melt identification technique was also high. As small as 0.5 % change in magnesium content was detected by the spectrometer. The second goal of this study was to determine the loss of mass during deep penetration laser welding. The amount of magnesium in the material was measured before and after laser welding to determine the loss of magnesium. This study was conducted for aluminium alloy with nominal magnesium content of 0-10 % and for standard material EN AW-6060 that was welded with filler wire AlMg5. It was found that while the magnesium concentration in the material changed, the loss of magnesium remained fairly even. Also by feeding filler wire, the behaviour was similar. Thirdly, the reason why silicon had not been detected in the emission spectrum needed to be explained. Literature research showed that the amount of energy required for silicon to excite is considerably higher compared to magnesium. The energy input in the used welding process is insufficient to excite the silicon atoms.

Spectrometrical Monitoring of Laser Sintering Process of Ceramic Material

This thesis is done as a part of project called FuncMama that is a project between Technical Research Centre of Finland (VTT), Oulu University (OY), Lappeenranta University of Technology (LUT) and Finnish industrial partners. Main goal of the project is to manufacture electric and mechanical components from mixed materials using laser sintering. Aim of this study was to create laser sintered pieces from ceramic material and monitor the sintering event by using spectrometer. Spectrometer is a device which is capable to record intensity of different wavelengths in relation with time. In this study the monitoring of laser sintering was captured with the equipment which consists of Ocean Optics spectrometer, optical fiber and optical lens (detector head). Light from the sintering process hit first to the lens system which guides the light in to the optical fibre. Optical fibre transmits the light from the sintering process to the spectrometer where wavelengths intensity level information is detected. The optical lens of the spectrometer was rigidly set and did not move along with the laser beam. Data which was collected with spectrometer from the laser sintering process was converted with Excel spreadsheet program for result’s evaluation. Laser equipment used was IPG Photonics pulse fibre laser. Laser parameters were kept mainly constant during experimental part and only sintering speed was changed. That way it was possible to find differences in the monitoring results without fear of too many parameters mixing together and affecting to the conclusions. Parts which were sintered had one layer and size of 5 x 5 mm. Material was CT2000 – tape manufactured by Heraeus which was later on post processed to powder. Monitoring of different sintering speeds was tested by using CT2000 reference powder. Moreover tests how different materials effect to the process monitoring were done by adding foreign powder Du Pont 951 which had suffered in re-grinding and which was more reactive than CT2000. By adding foreign material it simulates situation where two materials are accidently mixed together and it was studied if that can be seen with the spectrometer. It was concluded in this study that with the spectrometer it is possible to detect changes between different laser sintering speeds. When the sintering speed is lowered the intensity level of light is higher from the process. This is a result of higher temperature at the sintering spot and that can be noticed with the spectrometer. That indicates it could be possible to use spectrometer as a tool for process observation and support the idea of having system that can help setting up the process parameter window. Also important conclusion was how well the adding of foreign material could be seen with the spectrometer. When second material was added a significant intensity level raise could be noticed in that part where foreign material was mixed. That indicates it is possible to see if there are any variations in the material or if there are more materials mixed together. Spectrometric monitoring of laser sintering could be useful tool for process window observation and temperature controlling of the sintering process. For example if the process window for specific material is experimentally determined to get wanted properties and satisfying sintering speed. It is possible if the data is constantly recorded that the results can show faults in the part texture between layers. Changes between the monitoring data and the experimentally determined values can then indicate changes in the material being generated by material faults or by wrong process parameters. The results of this study show that spectrometer could be one possible tool for monitoring. But to get in that point where this all can be made possible much more researching is needed.

Techno-Economic Feasibility of Novel On-Line Condition Monitoring Methods in Low Voltage Distribution Networks

The focus in this thesis is to study both technical and economical possibilities of novel on-line condition monitoring techniques in underground low voltage distribution cable networks. This thesis consists of literature study about fault progression mechanisms in modern low voltage cables, laboratory measurements to determine the base and restrictions of novel on-line condition monitoring methods, and economic evaluation, based on fault statistics and information gathered from Finnish distribution system operators. This thesis is closely related to master’s thesis “Channel Estimation and On-line Diagnosis of LV Distribution Cabling”, which focuses more on the actual condition monitoring methods and signal theory behind them.

Development of a measuring-control system for energy monitoring in low power

In this thesis a control system for an intelligent low voltage energy grid is presented, focusing on the control system created by using a multi-agent approach which makes it versatile and easy to expand according to the future needs. The control system is capable of forecasting the future energy consumption and decisions making on its own without human interaction when countering problems. The control system is a part of the St. Petersburg State Polytechnic University’s smart grid project that aims to create a smart grid for the university’s own use. The concept of the smart grid is interesting also for the consumers as it brings new possibilities to control own energy consumption and to save money. Smart grids makes it possible to monitor the energy consumption in real-time and to change own habits to save money. The intelligent grid also brings possibilities to integrate the renewable energy sources to the global or the local energy production much better than the current systems. Consumers can also sell their extra power to the global grid if they want.

Practical Framework for Monitoring the Performance of Agile IT Projects in an Output-Based Outsourcing Context

Over the past decade, organizations worldwide have begun to widely adopt agile software development practices, which offer greater flexibility to frequently changing business requirements, better cost effectiveness due to minimization of waste, faster time-to-market, and closer collaboration between business and IT. At the same time, IT services are continuing to be increasingly outsourced to third parties providing the organizations with the ability to focus on their core capabilities as well as to take advantage of better demand scalability, access to specialized skills, and cost benefits. An output-based pricing model, where the customers pay directly for the functionality that was delivered rather than the effort spent, is quickly becoming a new trend in IT outsourcing allowing to transfer the risk away from the customer while at the same time offering much better incentives for the supplier to optimize processes and improve efficiency, and consequently producing a true win-win outcome. Despite the widespread adoption of both agile practices and output-based outsourcing, there is little formal research available on how the two can be effectively combined in practice. Moreover, little practical guidance exists on how companies can measure the performance of their agile projects, which are being delivered in an output-based outsourced environment. This research attempted to shed light on this issue by developing a practical project monitoring framework which may be readily applied by organizations to monitor the performance of agile projects in an output-based outsourcing context, thus taking advantage of the combined benefits of such an arrangement Modified from action research approach, this research was divided into two cycles, each consisting of the Identification, Analysis, Verification, and Conclusion phases. During Cycle 1, a list of six Key Performance Indicators (KPIs) was proposed and accepted by the professionals in the studied multinational organization, which formed the core of the proposed framework and answered the first research sub-question of what needs to be measured. In Cycle 2, a more in-depth analysis was provided for each of the suggested Key Performance Indicators including the techniques for capturing, calculating, and evaluating the information provided by each KPI. In the course of Cycle 2, the second research sub-question was answered, clarifying how the data for each KPI needed to be measured, interpreted, and acted upon. Consequently, after two incremental research cycles, the primary research question was answered describing the practical framework that may be used for monitoring the performance of agile IT projects delivered in an output-based outsourcing context. This framework was evaluated by the professionals within the context of the studied organization and received positive feedback across all four evaluation criteria set forth in this research, including the low overhead of data collection, high value of provided information, ease of understandability of the metric dashboard, and high generalizability of the proposed framework.

On Dynamic Monitoring Methods for Networks-on-Chip

Rapid ongoing evolution of multiprocessors will lead to systems with hundreds of processing cores integrated in a single chip. An emerging challenge is the implementation of reliable and efficient interconnection between these cores as well as other components in the systems. Network-on-Chip is an interconnection approach which is intended to solve the performance bottleneck caused by traditional, poorly scalable communication structures such as buses. However, a large on-chip network involves issues related to congestion problems and system control, for instance. Additionally, faults can cause problems in multiprocessor systems. These faults can be transient faults, permanent manufacturing faults, or they can appear due to aging. To solve the emerging traffic management, controllability issues and to maintain system operation regardless of faults a monitoring system is needed. The monitoring system should be dynamically applicable to various purposes and it should fully cover the system under observation. In a large multiprocessor the distances between components can be relatively long. Therefore, the system should be designed so that the amount of energy-inefficient long-distance communication is minimized. This thesis presents a dynamically clustered distributed monitoring structure. The monitoring is distributed so that no centralized control is required for basic tasks such as traffic management and task mapping. To enable extensive analysis of different Network-on-Chip architectures, an in-house SystemC based simulation environment was implemented. It allows transaction level analysis without time consuming circuit level implementations during early design phases of novel architectures and features. The presented analysis shows that the dynamically clustered monitoring structure can be efficiently utilized for traffic management in faulty and congested Network-on-Chip-based multiprocessor systems. The monitoring structure can be also successfully applied for task mapping purposes. Furthermore, the analysis shows that the presented in-house simulation environment is flexible and practical tool for extensive Network-on-Chip architecture analysis.

Pasvik Water Quality Report Environmental Monitoring Programme in the Norwegian, Finnish and Russian Border Area

The Pasvik monitoring programme was created in 2006 as a result of the trilateral cooperation, and with the intention of following changes in the environment under variable pollution levels. Water quality is one of the basic elements of the Programme when assessing the effects of the emissions from the Pechenganikel mining and metallurgical industry (Kola GMK). The Metallurgic Production Renovation Programme was implemented by OJSC Kola GMK to reduce emissions of sulphur and heavy metal concentrated dust. However, the expectations for the reduction in emissions from the smelter in the settlement Nikel were not realized. Nevertheless, Kola GMK has found that the modernization programme’s measures do not provide the planned reductions of sulfur dioxide emissions. In this report, temporal trends in water chemistry during 2000–2009 are examined on the basis of the data gathered from Lake Inari, River Pasvik and directly connected lakes, as well as from 26 small lakes in three areas: Pechenganikel (Russia), Jarfjord (Norway) and Vätsäri (Finland). The lower parts of the Pasvik watercourse are impacted by both atmospheric pollution and direct wastewater discharge from the Pechenganikel smelter and the settlement of Nikel. The upper section of the watercourse, and the small lakes and streams which are not directly linked to the Pasvik watercourse, only receive atmospheric pollution. The data obtained confirms the ongoing pollution of the river and water system. Copper (Cu), nickel (Ni) and sulphates are the main pollution components. The highest levels were observed close to the smelters. The most polluted water source of the basin is the River Kolosjoki, as it directly receives the sewage discharge from the smelters and the stream connecting the Lakes Salmijarvi and Kuetsjarvi. The concentrations of metals and sulphates in the River Pasvik are higher downstream from the Kuetsjarvi Lake. There has been no fall in the concentrations of pollutants in Pasvik watercourse over the last 10 years. Ongoing recovery from acidification has been evident in the small lakes of the Jarfjord and Vätsäri areas during the 2000s. The buffering capacity of these lakes has improved and the pH has increased. The reason for this recovery is that sulphate deposition has decreased, which is also evident in the water quality. However, concentrations of some metals, especially Ni and Cu, have risen during the 2000s. Ni concentrations have increased in all three areas, and Cu concentrations in the Pechenganickel and Jarfjord areas, which are located closer to the smelters. Emission levels of Ni and Cu did not fall during 2000s. In fact, the emission levels of Ni compounds even increased compared to the 1990s.

Variable speed drive in fan system monitoring

Fan systems are responsible for approximately 10% of the electricity consumption in industrial and municipal sectors, and it has been found that there is energy-saving potential in these systems. To this end, variable speed drives (VSDs) are used to enhance the efficiency of fan systems. Usually, fan system operation is optimized based on measurements of the system, but there are seldom readily installed meters in the system that can be used for the purpose. Thus, sensorless methods are needed for the optimization of fan system operation. In this thesis, methods for the fan operating point estimation with a variable speed drive are studied and discussed. These methods can be used for the energy efficient control of the fan system without additional measurements. The operation of these methods is validated by laboratory measurements and data from an industrial fan system. In addition to their energy consumption, condition monitoring of fan systems is a key issue as fans are an integral part of various production processes. Fan system condition monitoring is usually carried out with vibration measurements, which again increase the system complexity. However, variable speed drives can already be used for pumping system condition monitoring. Therefore, it would add to the usability of a variablespeed- driven fan system if the variable speed drive could be used as a condition monitoring device. In this thesis, sensorless detection methods for three lifetime-reducing phenomena are suggested: these are detection of the fan contamination build-up, the correct rotational direction, and the fan surge. The methods use the variable speed drive monitoring and control options for the detection along with simple signal processing methods, such as power spectrum density estimates. The methods have been validated by laboratory measurements. The key finding of this doctoral thesis is that a variable speed drive can be used on its own as a monitoring and control device for the fan system energy efficiency, and it can also be used in the detection of certain lifetime-reducing phenomena.

Capillary electrophoresis for monitoring of carboxylic, phenolic and amino acids in bioprocesses

Bioprocess technology is a multidisciplinary industry that combines knowledge of biology and chemistry with process engineering. It is a growing industry because its applications have an important role in the food, pharmaceutical, diagnostics and chemical industries. In addition, the current pressure to decrease our dependence on fossil fuels motivates new, innovative research in the replacement of petrochemical products. Bioprocesses are processes that utilize cells and/or their components in the production of desired products. Bioprocesses are already used to produce fuels and chemicals, especially ethanol and building-block chemicals such as carboxylic acids. In order to enable more efficient, sustainable and economically feasible bioprocesses, the raw materials must be cheap and the bioprocesses must be operated at optimal conditions. It is essential to measure different parameters that provide information about the process conditions and the main critical process parameters including cell density, substrate concentrations and products. In addition to offline analysis methods, online monitoring tools are becoming increasingly important in the optimization of bioprocesses. Capillary electrophoresis (CE) is a versatile analysis technique with no limitations concerning polar solvents, analytes or samples. Its resolution and efficiency are high in optimized methods creating a great potential for rapid detection and quantification. This work demonstrates the potential and possibilities of CE as a versatile bioprocess monitoring tool. As a part of this study a commercial CE device was modified for use as an online analysis tool for automated monitoring. The work describes three offline CE analysis methods for the determination of carboxylic, phenolic and amino acids that are present in bioprocesses, and an online CE analysis method for the monitoring of carboxylic acid production during bioprocesses. The detection methods were indirect and direct UV, and laser-induced frescence. The results of this work can be used for the optimization of bioprocess conditions, for the development of more robust and tolerant microorganisms, and to study the dynamics of bioprocesses.

Energy-efficient control strategies for variable speed driven parallel pumping systems based on pump operation point monitoring with frequency converters

The pumping processes requiring wide range of flow are often equipped with parallelconnected centrifugal pumps. In parallel pumping systems, the use of variable speed control allows that the required output for the process can be delivered with a varying number of operated pump units and selected rotational speed references. However, the optimization of the parallel-connected rotational speed controlled pump units often requires adaptive modelling of both parallel pump characteristics and the surrounding system in varying operation conditions. The available information required for the system modelling in typical parallel pumping applications such as waste water treatment and various cooling and water delivery pumping tasks can be limited, and the lack of real-time operation point monitoring often sets limits for accurate energy efficiency optimization. Hence, alternatives for easily implementable control strategies which can be adopted with minimum system data are necessary. This doctoral thesis concentrates on the methods that allow the energy efficient use of variable speed controlled parallel pumps in system scenarios in which the parallel pump units consist of a centrifugal pump, an electric motor, and a frequency converter. Firstly, the suitable operation conditions for variable speed controlled parallel pumps are studied. Secondly, methods for determining the output of each parallel pump unit using characteristic curve-based operation point estimation with frequency converter are discussed. Thirdly, the implementation of the control strategy based on real-time pump operation point estimation and sub-optimization of each parallel pump unit is studied. The findings of the thesis support the idea that the energy efficiency of the pumping can be increased without the installation of new, more efficient components in the systems by simply adopting suitable control strategies. An easily implementable and adaptive control strategy for variable speed controlled parallel pumping systems can be created by utilizing the pump operation point estimation available in modern frequency converters. Hence, additional real-time flow metering, start-up measurements, and detailed system model are unnecessary, and the pumping task can be fulfilled by determining a speed reference for each parallel-pump unit which suggests the energy efficient operation of the pumping system.

Development of remote monitoring process tools for biomass fired bubbling fluidized bed boilers

Remote monitoring of a power boiler allows the supplying company to make sure that equipment is used as supposed to and gives a good chance for process optimization. This improves co-operation between the supplier and the customer and creates an aura of trust that helps securing future contracts. Remote monitoring is already in use with recovery boilers but the goal is to expand especially to biomass-fired BFB-boilers. To make remote monitoring possible, data has to be measured reliably on site and the link between the power plant and supplying company’s server has to work reliably. Data can be gathered either with the supplier’s sensors or with measurements originally installed in the power plant if the plant in question is not originally built by the supplying company. Main goal in remote monitoring is process optimization and avoiding unnecessary accidents. This can be achieved for instance by following the efficiency curves and fouling in different parts of the process and comparing them to past values. The final amount of calculations depends on the amount of data gathered. Sudden changes in efficiency or fouling require further notice and in such a case it’s important that dialogue toward the power plant in question also works.