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  • 1.
    Delsing, Jerker
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Eliasson, Jens
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Gustafsson, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Kyusakov, Rumen
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Kruglyak, Andrey
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Mcload, Stuart
    University of Warwick, Coventry.
    Harrison, Robert
    University of Warwick, Coventry.
    Colombo, Armando W.
    Schneider Electric, Marktheidenfeld.
    Mendes, J Marco
    Schneider Electric, Marktheidenfeld.
    Building System of Systems with SOA Technology: A Smart House Use Case2014In: Industrial Cloud-Based Cyber-Physical Systems: The IMC-AESOP Approach, Encyclopedia of Global Archaeology/Springer Verlag, 2014, p. 219-230Chapter in book (Refereed)
    Abstract [en]

    The IMC-AESOP architecture has been used to implemente a smart house demonstration. Six different systems has been integrated with local (802.11, 802.15.4) and global (telecom) communication. The six systems integrated are: Car arrival detection system, Garage door opening system, House security system, External house lightning system, External electrical outlet system, House energy control system. The SOA technologies used are CoAP and EXI using SenML to encode the services. Engineering tools have been used to simulate the usage scenario and provide prediction of system behaviour.

  • 2.
    Delsing, Jerker
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    van Deventer, Jan
    Gustafsson, Jonas
    A service oriented architecture to enable a holistic system approach to large system maintenance information2010In: The Seventh International Conference on Condition Monitoring and Machinery Failure Prevention Technologies: 22 - 24 June 2010, Ettington Chase, Stratford-upon-Avon, England ; CM 2010/MFPT 2010, Northampton: Coxmoor Publishing Co. , 2010, Vol. 2, p. 907-914Conference paper (Refereed)
    Abstract [en]

    Heavy machinery in today's process industry is equipped with an increasing number of sensors for control and maintenance purposes. Each sensor is engineered and configured for a dedicated purpose; thus, the data or information provided by each sensor is confined to a specific purpose. Changing this individual approach to a holistic approach for control, operation and maintenance allows the data to be used in new ways, such as new control strategies, operation strategies and maintenance management. The holistic approach is demonstrated for a process of continuous energy generation and distribution: district heating. The purpose-based approach is replaced with the holistic approach, which focuses on system optimization and failure detection. The system was first set up in a Simulink simulation model to capture the thermodynamic behavior of the houses attached to the district heating system. In this model, each sensor is seen as a service that can be accessed for different purposes. Model analysis in this case led to new approaches for control and maintenance of critical parts in a district heating system.The new holistic approach is realized as a service-oriented architecture (SOA)-based wireless sensor network. It is currently installed in a small part of a district heating system in Piteå, Sweden. The system utilizes a wireless sensor network with service-oriented architecture using device profile web services (DPWS). Based on the data and information provided by the SOA wireless sensor network, the system can be identified. For the district heating example, the system identification provides system parameters that can be used to improve the thermodynamic Simulink model. Thus, comparisons can be made over time to determine system degradation. Furthermore, possible maintenance actions can be modeled, which allows prediction of system performance improvements related to specific maintenance actions.

  • 3.
    Delsing, Jerker
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    van Deventer, Jan
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Yliniemi, Kimmo
    Gustafsson, Jonas
    Jomni, Yassin
    Projekt: Fjärrvärme2007Other (Other (popular science, discussion, etc.))
  • 4.
    Gustafsson, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Distributed wireless control strategies for district heating substations2009Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The overall fuel efficiency of district heating could clearly be improved by using new strategies for measurement and control. The potential for improvement is on the order of several percent. Keeping in mind that district heating makes up ~50% of the Swedish heating market (5 billion euro total turnover) which in turn is about 1% of the total world market, such improvements would be of global importance both from financial and environmental viewpoints.The energy transfer from the distribution network to space heating and tap water systems is done at a district heating substation. To maximize energy effciency in the district heating network and minimize primary fuel source usage, it is essential to have maximum utilization of produced heat. This means that a large temperature drop (Delta T) across the substation is of utmost importance. This is related to the fact that the same amount of heat energy can be transferred with a decreased flow, if the temperature difference (Delta T) between incoming and returning water is increased. This makes Delta T a very important factor in making district heating more effcient.Today, substation control systems focuses on indoor comfort and do not generally consider Delta T, since it is not measured by the control system, however, Delta T is measured by the energy meter used for billing.This thesis proposes an alternative way to control a district heating substation, wherein wireless sensor and actuator technology together with a service oriented architecture are used. This technology allows different devices, such as the energy meter, circulation pump, and control valve, to share information without restrictions and thus increase the control possibilities.To test the new control strategies, a complex thermodynamic computer model of a building with an included district heating substation was developed for simulation. The thermodynamic model was complemented with models of battery-powered wireless devices to predict the sensor lifetime. A field experiment was also carried out wherewireless platforms were retrofitted into commercially available components used in district heating substations. The complete setup is currently mounted in a villa for continued research.The results of my research so far have proved that there is great potential for increasingDelta T and for additional services if new sensor technology is applied.

  • 5.
    Gustafsson, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Wireless sensor network architectures as a foundation for efficient district heating2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Our expanding modern society demands more and more energy, and with diminishing fossil fuel supplies and threats of global warming, it has become imperative that we use our energy efficiently. For decades, district heating has proved to be a stable and energy-friendly way of supplying space- and hot-water heating to connected customers. In this thesis, methods to make the technology of district heating (and cooling) even more efficient and competitive are presented and investigated.Most installed district heating substations today do not work at their full potential, meaning that energy is short-circuited and hence wasted. By integrating wireless Internet-enabled embedded devices into district heating substation components, e.g., circulation pump, heat meter and temperature sensors, a Wireless Sensor Network (WSN) is formed. With a Internet enabled WSN in place, the possibility is given to interact and communicate with the substations worldwide. It also enables information sharing between devices that traditionally have not been able to communicate and exchange data,e.g., heat meter and control valve.Frustration is often associated with the introduction of new IT solutions, including their implementation, maintenance and proprietary protocols. To make the embedded devices (sensor platforms) context-aware and support plug-n-play features, an information architecture based on service-oriented architecture (SOA) has been experimentally tested with promising results.When looking at efficiency in district heating systems, ∆T (difference between supply- and return-temperature) is a key indicator, as a large ∆T contributes to lower distribution, fuel and installation costs. A large ∆T can also increase electricity production if the heat is produced in a combined heat and power plant. Using the Internet-enabled WSN architecture described in the thesis, it is possible to increase system ∆T through improved substation control. It is also possible to support a range of new services for both customers and producers that will enhance the quality of service and functionality,both from a system-wide and subsystem perspective.

  • 6.
    Gustafsson, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Delsing, Jerker
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    van Deventer, Jan
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Experimental evaluation of radiator control based on primary supply temperature for district heating substations2011In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 88, no 12, p. 4945-4951Article in journal (Refereed)
    Abstract [en]

    In this paper, we evaluate whether the primary supply temperature in district heating networks can be used to control radiator systems in buildings connected to district heating; with the purpose of increasing the ΔT. The primary supply temperature in district heating systems can mostly be described as a function of outdoor temperature; similarly, the radiator supply temperature in houses, offices and industries can also be described as a function of outdoor temperature. To calibrate the radiator control system to produce an ideally optimal radiator supply temperature that produces a maximized ΔT across the substation, the relationship between the primary supply temperature and outdoor temperature must be known. However, even if the relation is known there is always a deviation between the expected primary supply temperature and the actual temperature of the received distribution media. This deviation makes the radiator control system incapable of controlling the radiator supply temperature to a point that would generate a maximized ΔT. Published simulation results show that it is possible and advantageous to utilize the primary supply temperature for radiator system control. In this paper, the simulation results are experimentally verified through implementation of the control method in a real district heating substation. The primary supply temperature is measured by the heat-meter and is shared with the radiator control system; thus no additional temperature sensors were needed to perform the experiments. However additional meters were installed for surveillance purposes. To maintain a stable indoor temperature at times when the primary supply and outdoor temperatures deviates from their assumed relation, the radiator system flow must be controlled by an additional control-loop. The results confirms that it is possible to control the radiator system based on the primary supply temperature while maintaining comfort; however, conclusions regarding improvements in ΔT were hard to distinguish.

  • 7. Gustafsson, Jonas
    et al.
    Delsing, Jerker
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    van Deventer, Jan
    Improved district heating substation efficiency with a new control strategy2010In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 87, no 6, p. 1996-2004Article in journal (Refereed)
    Abstract [en]

    In this paper, we describe a new alternative control approach for indirectly connected district heating substations. Simulations results showed that the new approach results in an increased ΔT across the substation. Results were obtained for both ideal and non-ideal operation of the system, meaning that less water must be pumped through the district heating network, and a higher overall fuel efficiency can be obtained in the district heating power plants. When a higher fuel efficiency is achieved, the usage of primary fuel sources can be reduced. Improved efficiency also increases the effective heat transfer capacity of a district heating network, allowing more customers to be connected to an existing network without increasing the heating plant or network capacity.Also, if combined heat and power plants are used to produce the heat, the increased ΔT will result in a further improved overall fuel efficiency, as more electricity can be produced with colder cooling water.The idea behind the new control method is to consider the temperature of the water supplying the district heating substation with heat, often referred to as the primary supply temperature. This represents a logical next step, as currently, the only parameter generally taken into account or measured when controlling the temperature level of the radiator circuit is the local outdoor temperature. In this paper we show how the primary supply temperature together with thermodynamic knowledge of the building can be used to maximize the ΔT across the district heating substation.

  • 8. Gustafsson, Jonas
    et al.
    Delsing, Jerker
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    van Deventer, Jan
    Validation of a district heating substation model using a wireless sensor network approach2008Conference paper (Refereed)
    Abstract [en]

    A thermodynamic model of a detached house using district heating has been created in Mathworks Simulink to form a realistic tool to test new control methods to optimize district heating systems. We here present the experimental validation process of the model. Detailed measurements were made using high performance ultrasonic flow-meters with embedded temp sensors. The flow-meters measures e.g. total tap water consumption, total primary energy consumption and radiator energy consumption separately. We show satisfying thermodynamic results of the model versus the real house. We also show that wind and sun exposure play a role in this validation.

  • 9.
    Gustafsson, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Kyusakov, Rumen
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Mäkitaavola, Henrik
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Delsing, Jerker
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Application of service oriented architecture for sensors and actuators in district heating substations2014In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 14, no 8, p. 15553-15572Article in journal (Refereed)
    Abstract [en]

    Hardwired sensor installations using proprietary protocols found in today’s district heating substations limit the potential usability of the sensors in and around the substations. If sensor resources can be shared and re-used in a variety of applications, the cost of sensors and installation can be reduced, and their functionality and operability can be increased. In this paper, we present a new concept of district heating substation control and monitoring, where a service oriented architecture (SOA) is deployed in a wireless sensor network (WSN), which is integrated with the substation. IP-networking is exclusively used from sensor to server; hence, no middleware is needed for Internet integration. Further, by enabling thousands of sensors with SOA capabilities, a System of Systems approach can be applied. The results of this paper show that it is possible to utilize SOA solutions with heavily resource-constrained embedded devices in contexts where the real-time constrains are limited, such as in a district heating substation.

  • 10. Gustafsson, Jonas
    et al.
    Mäkitaavola, Henrik
    Delsing, Jerker
    van Deventer, Jan
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Integration of an IP based low-power sensor network in district heating substations2010In: Proceedings of the 12th International Symposium on District Heating and Cooling: September 5th to September 7th, 2010, Tallinn, Estonia, Tallinn, 2010Conference paper (Refereed)
    Abstract [en]

    In this study, the implementation of a wireless, lowpower, sensor network with IP capabilities in a district heating substation was evaluated. The aim of the study was to show that an open standard solution is technically feasible. Low-power wireless communication was established using IPv6/6LoWPAN on an IEEE 802.15.4 wireless network. An experimental district heating substation was equipped with sensor platforms in vital devices located within or near a district heating substation. As a result, all connected devices could obtain a direct internet connection.A system with open standards facilitates the introduction of new energy services such as individual measurements and improved space heating control. In this study, we found that resource-limited batterypowered devices possess a life expectancy of over 10 years, using small batteries while participating in IPv6 compatible communication.

  • 11.
    Gustafsson, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    van Deventer, Jan
    Delsing, Jerker
    Thermodynamic simulation of a detached house with district heating subcentral2008In: 2nd Annual IEEE Systems Conference, 2008: Montreal, QC, Canada, 7 - 10 April 2008, Piscataway, NJ: IEEE Communications Society, 2008, p. 485-492Conference paper (Refereed)
    Abstract [en]

    A physical thermodynamic model of a detached house connected to a low-tempered district heating network is presented. The model is created in Mathworks Simulink\textregistered\space with a pedagogic approach in mind, e.g. masked subsystems divided in to physical components. The house model is easily modified to any detached house. Provision is also made to make it scalable to multi-family houses. The district heating substation modeled is a parallel coupled plate heat exchanger, which is the most common substation in smaller buildings such as villas. The purpose of creating the model was to provide a platform for test and evaluation of new control methods for district heating system based on wireless sensor networks. Initial validation of the model is presented.

  • 12.
    Hamfelt, Jesper
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Gustafsson, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    van Deventer, Jan
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Löfqvist, Torbjörn
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Häggström, Fredrik
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Delsing, Jerker
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    A passive Barkhausen noise sensor for low-power applications2016In: 2016 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) Proceedings, Piscataway, NJ: IEEE Communications Society, 2016, p. 280-284, article id 7520374Conference paper (Refereed)
    Abstract [en]

    This paper proposes a passive Barkhausen noise sensor design suitable for low power applications. The sensor uses a permanent magnet and the relative motion between itself and a measured specimen instead of the conventional method that uses a fixed sensor and an alternating magnetic field. Since this novel design is passive, the sensor is well suited for low power applications and could potentially be used in e.g. A condition monitoring system integrated into a rolling element bearing. Proof of concept testing has been performed showing that the proposed sensor produces similar results as conventional Barkhausen noise sensors when applied to specimens being cyclically loaded until failure in a rotating bending rig. The results imply that material fatigue detection using the Barkhausen noise can be performed with the proposed sensor at a fraction of the energy cost compared to a conventional sensor. This warrants future research into the development of the proposed sensor, its advantages, disadvantages, and functionality

  • 13.
    Häggström, Fredrik
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Gustafsson, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Delsing, Jerker
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Energy harvesting technologies for wireless sensors in rotating environments2014In: Proceedings of 2014 IEEE 19th International Conference on Emerging Technologies & Factory Automation (ETFA 2014): Barcelona, Spain, 16-19 Sept. 2014, Piscataway, NJ: IEEE Communications Society, 2014, article id 7005364Conference paper (Refereed)
    Abstract [en]

    Using sensors to measure parameters of interest in rotating environments and communicating the measurements in real-time over wireless links, requires a reliable power source. In this paper, we have investigated the possibility to generate electric power locally by evaluating six different energy-harvesting technologies. The applicability of the technology is evaluated by several parameters that are important to the functionality in an industrial environment. All technologies are individually presented and evaluated, a concluding table is also summarizing the technologies strengths and weaknesses. To support the technology evaluation on a more theoretical level, simulations has been performed to strengthen our claims. Among the evaluated and simulated technologies, we found that the variable reluctancebased harvesting technology is the strongest candidate for further technology development for the considered use-case.

  • 14.
    Häggström, Fredrik
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Gustafsson, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Delsing, Jerker
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Interleaved Switch Harvesting on Inductor: Non-linear extraction, action and reaction2016In: 2016 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) Proceedings, Piscataway, NJ: IEEE Communications Society, 2016, p. 642-647, article id 7520439Conference paper (Refereed)
    Abstract [en]

    The circuit presented in this paper provides increased transfer efficiency for the electric charge generated by a piezoelectric element to the storage device, it also enables a simplified active control circuitry required for switched harvesting solutions as the control transistors are referenced to ground. This is achieved by inverting the voltage potential across the piezoelectric element and thereby maintaining a higher voltage while extracting energy. The increased potential allows vibration harvesters to operate over a broader frequency range. For weakly coupled piezoelectric harvesters, the increased potential allows the electrical power output to be increased. In this paper, the circuit is simulated in SPICE using existing models of discrete components in conjunction with a model of a piezoelectric vibration harvester. The power output and mechanical behavior of the harvester using the presented circuit are compared to two existing technologies: Synchronous Switch Harvesting on Inductor (SSHI) and a full-wave rectifying bridge. The comparison demonstrates that the novel Interleaved Switch Harvesting on Inductor (ISHI) circuit outperforms state-of-the-art active harvesting solutions, e.g., SSHI, as a result of the decreased energy losses from diodes. In addition, the ISHI circuit requires fewer components than does the SSHI circuit and solves the floating transistor source issue that arises in SSHI implementations. To achieve the maximum power conversion efficiency, impedance matching is required, which can be achieved by controlling the voltage of the storage device

  • 15.
    Häggström, Fredrik
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Gustafsson, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Delsing, Jerker
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Piezoelectric energy harvesting modeled with SPICE2016In: 2016 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) Proceedings, Piscataway, NJ: IEEE Communications Society, 2016, p. 654-659, article id 7520441Conference paper (Refereed)
    Abstract [en]

    The generation of electricity from vibrations has attracted considerable attention over the past decade. For this purpose, a piezoelectric-type harvester tuned to resonate at a specific frequency is typically used. This paper proposes a SPICE model capable of modeling piezoelectric energy harvesters. The model is parametrized enabling simple introduction of relevant physical parameters. Underlying theory based on Euler-Bernoulli beam theory is presented and modeling simplifications are justified. The SPICE model is verified by comparison to examples for which analytical and experimental solutions has been published. The SPICE model is valid close to the analyzed mode center frequency and delivers results within 1% compared to experimental and analytical data. Furthermore, we also show that the harvester can be electrically tuned to match the excitation frequency. This makes it possible to maximize the power output for both linear and non-linear loads. The here presented model enables efficient analysis of harvester design and changes of harvesting conditions

  • 16.
    Jenvey, Stewart
    et al.
    Monash University, Melbourne, VIC.
    Gustafsson, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Henriksson, Fredrik
    Luleå tekniska universitet.
    A portable monopulse tracking antenna for UAV communications2007In: Unmanned air vehicle systems: 22nd International Conference ; 16 - 18 April 2007, Bristol, United Kingdom ; conference papers, Bristol: Bristol University , 2007Conference paper (Refereed)
    Abstract [en]

    This paper describes a portable tracking antenna system that is used for line of sight communications with the small UAVs being developed by Monash University. The antenna is a wire-frame parabolic antenna that is mechanically rotated in an elevation over azimuth mode in response to tracking signals derived from the UAV video link transmissions. The antenna feed system is arranged in a four channel monopulse format to derive the steering signals for the tracking and a single bore sight channel for the data reception.

  • 17.
    Kyusakov, Rumen
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Eliasson, Jens
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Delsing, Jerker
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    van Deventer, Jan
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Gustafsson, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Integration of wireless sensor and actuator nodes with IT infrastructure using service-oriented architecture2013In: IEEE Transactions on Industrial Informatics, ISSN 1551-3203, E-ISSN 1941-0050, Vol. 9, no 1, p. 43-51Article in journal (Refereed)
    Abstract [en]

    A large number of potential applications for Wireless Sensor and Actuator Networks (WSAN) have yet to be embraced by industry despite high interest amongst academic researchers. This is due to various factors such as unpredictable costs related to development, deployment and maintenance of WSAN, especially when integration with existing IT infrastructure and legacy systems is needed. Service-Oriented Architecture (SOA) is seen as a promising technique to bridge the gap between sensor nodes and enterprise applications such as factory monitoring, control and tracking systems where sensor data is used. To date, research efforts have focused on middleware software systems located in gateway devices that implement standard service technology, such as Devices Profile for Web Services (DPWS), for interacting with the sensor network. This paper takes a different approach - deploying interoperable Simple Object Access Protocol (SOAP)-based web services directly on the nodes and not using gateways. This strategy provides for easy integration with legacy IT systems and supports heterogeneity at the lowest level. Two-fold analysis of the related overhead, which is the main challenge of this solution, is performed; Quantification of resource consumption as well as techniques to mitigate it are presented, along with latency measurements showing the impact of different parts of the system on system performance. A proof-of-concept application using Mulle - a resource-constrained sensor platform - is also presented.

  • 18.
    Sandin, Fredrik
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Gustafsson, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Delsing, Jerker
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Fault detection with hourly district energy data: Probabilistic methods and heuristics for automated detection and ranking of anomalies2013Report (Other academic)
    Abstract [en]

    This project is motivated by the difficulties experienced by district energy utilities to detect faults in large-scale district energy systems. Faults that remain undetected can be costly and the industry loose credibility when customers detect faults and receive incorrect bills. Faults are common in district energy systems due to the high number of substations and instrumentation components. Also, the standard energy-metering instrumentation is designed for low cost and billing, not for automated fault detection. Large variations in building dynamics, building subsystems, human behaviour and the environment make the system complex to model and analyse. Therefore, conventional methods for fault detection are not applicable and the use of ad hoc methods for fault detection often result in numerous false alarms that are costly to analyse and manage. There is a growing interest among the utilities to develop services and functions that are based on data with high temporal resolution. Energy metering regulations are also expected to become more demanding in the future, which drives technology standards towards high-resolution data. This trend results in high rates of streaming data at the management level, which is more challenging to validate. Therefore, more efficient methods for fault detection are needed.This project deals with probabilistic methods for automated anomaly detection that are useful for the identification of faults in large-scale district energy systems. These methods are compatible with the information that is available in modern energy meter data management systems. We focus on methods and heuristics that can be applied automatically with a minimum of human assistance to enable cost-efficient analysis of data. With these methods, operators do not have to rely on ad hoc tests or manual inspection of graphs to detect anomalies in the data. Instead, operators can focus on the analysis of a subset of substations that are identified as abnormal. Intraday and intraweek variations in the thermal load are accounted for by automatically grouping hours of the week with similar thermal load characteristics. Alternatively, intraweek cycles can be accounted for by grouping days of the week with similar characteristics. Robust regression is used to model variable relationships with historical data. A robust outlier detection method is used to determine if variables deviate from the expectation defined by a regression model. Robust statistical methods are used to score outliers, so that outstanding substations can be identified automatically with a ranking procedure. The regression models can also be used for imputation of missing energy metering data, which is a common problem that is not always solved in an accurate way. We also present methods for the detection of long-term drift, which can be costly and otherwise difficult to detect, and the detection of poor precision in measurement data, which for example can result from oversized flow valves, misconfiguration and noise. In addition to fault detection, the proposed methods can be useful also for maintenance scheduling because substations that behave in a way that is consistent with the historical record can be given a lower maintenance priority compared to substations with abnormal behaviour.The proposed methods are studied using hourly data from a population of about one thousand district heating substations. Sample code of key functions is provided. We find that substations with documented faults, unknown faults and abnormal characteristics can be identified in about 5% of the substations. The lack of a well-defined dataset makes the development and evaluation of methods for fault detection challenging, and the fact that historical energy metering data includes abnormal data is often ignored in the literature. The proposed methods need to be implemented in a full-scale district energy management system under the supervision of experienced operators before the effects on the fault detection rate and cost efficiency can be properly evaluated. However, we are convinced that the proposed algorithms can be implemented in present data management systems and that they offer significant advantages over the methods that are commonly used today.

  • 19.
    Sandin, Fredrik
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Gustafsson, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Delsing, Jerker
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Eklund, Robert
    Södertörns Fjärrvärme AB, Box 3073, 145 03 Norsborg, Sweden.
    Basic methods for automated fault detection and energy data validation in existing district heating systems2012In: 13th international symposium on district heating and cooling: 3rd of September - 4th of September Copenhagen, Denmark, District Energy Development Center , 2012Conference paper (Refereed)
    Abstract [en]

    Fault detection and diagnostics (FDD) of district heating substations (DHS) are important activities because malfunctioning components can lead to incorrect billing and waste of energy. Although FDD has been an activate research area for nearly two decades, only a few simple tools are commonly deployed in the district energy industry. Some of the methods proposed in the literature are promising, but their complexity may prevent broader application. Other methods require sensor data that are not commonly available, or cannot be expected to function well in practice due to oversimplification. Here we present two basic methods for improved FDD and data validation that are compatible with the data acquisition systems that are commonly used today. We propose that correlation analysis can be used to identify substations with similar supply temperatures and that the corresponding temperature difference is a useful quantity for FDD. The second method is a limit- checking approach for the validation of thermal power usage, which is sensitive to faults affecting both the primary flow and temperature sensors in a DHS. These methods are suitable for automated FDD and are demonstrated with hourly data provided by a Swedish district energy company.

  • 20.
    Törngren, Martin
    et al.
    Mechatronics/Machine Design, KTH, Stockholm .
    Edin Grimheden, Martin
    Mechatronics/Machine Design, KTH, Stockholm .
    Birk, Wolfgang
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Gustafsson, Jonas
    Strategies and considerations in shaping cyber-physical systems education2016In: ACM SIGBED Review, ISSN 1551-3688, Vol. 14, no 1, p. 53-60Article in journal (Refereed)
    Abstract [en]

    Embedded and Cyber-Physical Systems education faces several challenges as well as opportunities as every-"thing" becomes connected, and as technology development accelerates. Initiatives such as CDIO, as well as several other academic and industry initiatives to create new CPS programs illustrate strong interests and awareness of these challenges. We provide an overview of foreseen educational needs, existing state of the art in education and an analysis of the subject of CPS with the purpose of understanding the implications for education. The investigation points to key issues in curriculum design regarding balancing depth and breadth, theory and practices, academic and industrial needs, and core technical skills with complementary skills. Curricula in CPS could, if the right balance is achieved, educate CPS engineers of the future that are "ready to engineer". We conclude by synthesizing high level guidelines in terms of strategies and considerations for CPS curriculum development.

  • 21.
    van Deventer, Jan
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Gustafsson, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Delsing, Jerker
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Controlling district heating load through prices2011In: 2011 IEEE International Systems Conference, IEEE Communications Society, 2011, p. 461-465Conference paper (Refereed)
    Abstract [en]

    This paper shows that the price of the kilo Watt hour can be used to level off daily peak demands of heat energy in district heating without compromising the end customer’s comfort. A 5 days simulation of a building at an outdoor temperature of -15°C shows a 20% power consumption reduction causing only a 1°C variation of indoor temperature when the price is raised as a function of heat energy demand. This control scheme is made possible when using Internet communication between the heat supplier and the buildings’ substation when the latter is equipped with a wireless sensor network to share internal information.

  • 22.
    van Deventer, Jan
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Gustafsson, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Delsing, Jerker
    Eliasson, Jens
    Wireless infrastructure in a district heating substation2009In: 3rd Annual IEEE Systems Conference, 2009: 23 - 26 March 2009, Marriott Vancouver Pinnacle Hotel, Vancouver, British Columbia, Canada, IEEE Communications Society, 2009, p. 139-143Conference paper (Refereed)
    Abstract [en]

    A new wireless sensor and actuator network architecture for a district heating substation is presented. The implementation allows for new control algorithms to save substancial amounts of energy and therefore reduce waste and indirectly CO2 emissions. The wireless network uses TCP/IP all the way to the sensor level, which can enable a standardized Service Oriented Architecture and the possibility to upgrade software of each node remotely over the Internet. New diagnostic services are also available to improve service and maintenance.

  • 23.
    van Deventer, Jan
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Gustafsson, Jonas
    Eliasson, Jens
    Delsing, Jerker
    Mäkitaavola, Henrik
    Independence and interdependence of systems in district heating2010In: 2010 IEEE International Systems Conference proceedings: April 5-8th, 2010, Hyatt Regency Mission Bay Spa and Marina, San Diego, California., Piscataway, NJ: IEEE Communications Society, 2010, p. 267-271Conference paper (Refereed)
    Abstract [en]

    In this paper, a fully operational wireless sensor and actuator network is presented. The network has the ability to control a district heating substation to ensure indoors comfort while minimizing energy waste by maximizing heat extraction from the distribution network. Introduced here is the foundation for a systems of systems approach within a district heating application, where several substations cooperate with the heat production plant. Presented are also the first steps to a service oriented architecture (SOA) where sensor nodes in the district heating network can cooperate with other nodes and systems, for example a ventilation control network.

1 - 23 of 23
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