Kaivoslastauskoneen hybridisointianalyysi virtuaali- ja in-loop -simuloinnin avulla

Työssä tutkitaan raskaiden työkoneiden hybridisointimitoitusta simuloimalla. Työssä esitetään simulation-in-the-loop-simulointiin perustuva järjestelmä, jolla esimerkkitapauksena oleva kaivoslastauskone työympäristöineen voidaan mallintaa mekaaniselta osaltaan monikappaledynamiikkaan perustuvalla ohjelmistolla ja hybridijärjestelmän osalta Simulinkissa. Yhdistetty simulointi mahdollistaa hybridityökoneen virtuaalimallin ohjaamisen käyttäjän toimesta reaaliajassa. Simuloinnista saadaan tuloksena mm. työsykli, jota voidaan käyttää hybridisointimitoitukseen. Hybridisointi toteutetaan kahdella erilaisella kokoonpanolla, joista analysoidaan suorituskykyä sekä polttoaineen kulutusta. Tuloksia verrataan pelkästään dieselmoottoria voimanlähteenä käyttävään lastauskoneeseen. Työssä tehty tutkimus osoittaa, että (sarja-) hybridisoinnilla voidaan saavuttaa merkittäviä etuja raskaiden työkoneiden polttoainetehokkuudessa. Dieselmoottoria voidaan ajaa sellaisessa staattisessa toimintapisteessä, jonka hyötysuhde on korkea riippumatta työkoneen kuormituksesta. Saavutettu hyöty on toteutetussa tutkimuksessa parhaimmillaan jopa 56 % vähennys polttoaineenkulutuksessa. Lisäksi tarvittava dieselin nimellisteho pienenee huomattavasti. Tutkimuksen osana esitellään myös Hardware-in-the-Loop -laitteisto, jonka avulla voidaan liittää oikea sähkömoottori ja taajuudenmuuttaja osaksi virtuaalisesti simuloitua työkonetta.

Energy Efficiency of a Diesel-Electric MobileWorking Machine

The power demand of many mobile working machines such as mine loaders, straddle carriers and harvesters varies significantly during operation, and typically, the average power demand of a working machine is considerably lower than the demand for maximum power. Consequently, for most of the time, the diesel engine of a working machine operates at a poor efficiency far from its optimum efficiency range. However, the energy efficiency of dieseldriven working machines can be improved by electric hybridization. This way, the diesel engine can be dimensioned to operate within its optimum efficiency range, and the electric drive with its energy storages responds to changes in machine loading. A hybrid working machine can be implemented in many ways either as a parallel hybrid, a series hybrid or a combination of these two. The energy efficiency of hybrid working machines can be further enhanced by energy recovery and reuse. This doctoral thesis introduces the component models required in the simulation model of a working machine. Component efficiency maps are applied to the modelling; the efficiency maps for electrical machines are determined analytically in the whole torque–rotational speed plane based on the electricalmachine parameters. Furthermore, the thesis provides simulation models for parallel, series and parallel-series hybrid working machines. With these simulation models, the energy consumption of the working machine can be analysed. In addition, the hybridization process is introduced and described. The thesis provides a case example of the hybridization and dimensioning process of a working machine, starting from the work cycle of the machine. The selection and dimensioning of the hybrid system have a significant impact on the energy consumption of a hybrid working machine. The thesis compares the energy consumption of a working machine implemented by three different hybrid systems (parallel, series and parallel-series) and with different component dimensions. The payback time of a hybrid working machine and the energy storage lifetime are also estimated in the study.

Value added logistics in supply and demand chain : COSTFIX : New operation model for maintenance material logistics in paper industry

This research report illustrates and examines new operation models for decreasing fixed costs and transforming them into variable costs in the field of paper industry. The report illustrates two cases – a new operation model for material logistics in maintenance and an examination of forklift truck fleet outsourcing solutions. Conventional material logistics in maintenance operation is illustrated and some problems related to conventional operation are identified. A new operation model that solves some of these problems is presented including descriptions of procurement and service contracts and sources of added value. Forklift truck fleet outsourcing solutions are examined by illustrating the responsibilities of a host company and a service provider both before and after outsourcing. The customer buys outsourcing services in order to improve its investment productivity. The mechanism of how these services affect the customer company’s investment productivity is illustrated.

Virtual technology and haptic interface solutions for design and control of mobile working machines

Commercially available haptic interfaces are usable for many purposes. However, as generic devices they are not the most suitable for the control of heavy duty mobile working machines like mining machines, container handling equipment and excavators. Alternative mechanical constructions for a haptic controller are presented and analysed. A virtual reality environment (VRE) was built to test the proposed haptic controller mechanisms. Verification of an electric motor emulating a hydraulic pump in the electro-hydraulic system of a mobile working machine is carried out. A real-time simulator using multi-body-dynamics based software with hardware-in-loop (HIL) setup was used for the tests. Recommendations for further development of a haptic controller and emulator electric motor are given.

Speed Control of an Autonomous Mobile Robot: Comparison between a PID Control and a Control Using Fuzzy Logic

An Autonomous Mobile Robot battery driven, with two traction wheels and a steering wheel is being developed. This Robot central control is regulated by an IPC, which controls every function of security, steering, positioning localization and driving. Each traction wheel is operated by a DC motor with independent control system. This system is made up of a chopper, an encoder and a microcomputer. The IPC transmits the velocity values and acceleration ramp references to the PIC microcontrollers. As each traction wheel control is independent, it's possible to obtain different speed values for each wheel. This process facilities the direction and drive changes. Two different strategies for speed velocity control were implemented; one works with PID, and the other with fuzzy logic. There were no changes in circuits and feedback control, except for the PIC microcontroller software. Comparing the two different speed control strategies the results were equivalent. However, in relation to the development and implementation of these strategies, the difficulties were bigger to implement the PID control.

A Test Bed Applied Mobile Robot Navigation

It is presented a test bed applied to studies on dynamics, control, and navigation of mobile robots. A cargo ship scale model was chosen, which can be radio-controlled or operated autonomously through an embedded control system. A control program, which manages on board mission execution, is implemented on a microcontroller. Navigation is based on an electronic compass, which includes automatic compensation for pitch and roll motions. Heading control loop is based on this sensor, and on a rudder positioning system. A propulsion control system is also implemented. Typical manoeuvres as the turning test and "zig-zag", were implemented and tested. They are included on a manoeuvre library, and can be accessed independently or in combined modes. The embedded system is also in charge of signal acquisition and storing during the missions. It is possible to analyse experiments on identification of ship dynamics, control, and navigation, through the data transferred to a PC by serial communication. Navigation is going to be improved by including inertial sensors on board, and a DGPS. Preliminary tests are aimed to ship identification, and manoeuvrability, using free model tests. Future steps include extending this system for developing other mobile robots as, ROVs, AUVs, and aerial vehicles.

Design and testing of an armature-reaction-compensated permanent magnet synchronous generator for island operation

At present, permanent magnet synchronous generators (PMSGs) are of great interest. Since they do not have electrical excitation losses, the highly efficient, lightweight and compact PMSGs equipped with damper windings work perfectly when connected to a network. However, in island operation, the generator (or parallel generators) alone is responsible for the building up of the network and maintaining its voltage and reactive power level. Thus, in island operation, a PMSG faces very tight constraints, which are difficult to meet, because the flux produced by the permanent magnets (PMs) is constant and the voltage of the generator cannot be controlled. Traditional electrically excited synchronous generators (EESGs) can easily meet these constraints, because the field winding current is controllable. The main drawback of the conventional EESG is the relatively high excitation loss. This doctoral thesis presents a study of an alternative solution termed as a hybrid excitation synchronous generator (HESG). HESGs are a special class of electrical machines, where the total rotor current linkage is produced by the simultaneous action of two different excitation sources: the electrical and permanent magnet (PM) excitation. An overview of the existing HESGs is given. Several HESGs are introduced and compared with the conventional EESG from technical and economic points of view. In the study, the armature-reaction-compensated permanent magnet synchronous generator with alternated current linkages (ARC-PMSG with ACL) showed a better performance than the other options. Therefore, this machine type is studied in more detail. An electromagnetic design and a thermal analysis are presented. To verify the operation principle and the electromagnetic design, a down-sized prototype of 69 kVA apparent power was built. The experimental results are demonstrated and compared with the predicted ones. A prerequisite for an ARC-PMSG with ACL is an even number of pole pairs (p = 2, 4, 6, …) in the machine. Naturally, the HESG technology is not limited to even-pole-pair machines. However, the analysis of machines with p = 3, 5, 7, … becomes more complicated, especially if analytical tools are used, and is outside the scope of this thesis. The contribution of this study is to propose a solution where an ARC-PMSG replaces an EESG in electrical power generation while meeting all the requirements set for generators given for instance by ship classification societies, particularly as regards island operation. The maximum power level when applying the technology studied here is mainly limited by the economy of the machine. The larger the machine is, the smaller is the efficiency benefit. However, it seems that machines up to ten megawatts of power could benefit from the technology. However, in low-power applications, for instance in the 500 kW range, the efficiency increase can be significant.

Mapping the Value Network Potential in Cross-sector Collaboration: Case welfare Services for Elderly in Finland

Value network has been studied greatly in the academic research, but a tool for value network mapping is missing. The objective of this study was to design a tool (process) for value network mapping in cross-sector collaboration. Furthermore, the study addressed a future perspective of collaboration, aiming to map the value network potential. During the study was investigated and pondered how to get the full potential of collaboration, by creating new value in collaboration process. These actions are parts of mapping process proposed in the study. The implementation and testing of the mapping process were realized through a case study of cross-sector collaboration in welfare services for elderly in the Eastern Finland. Key representatives in elderly care from public, private and third sectors were interviewed and a workshop with experts from every sector was also conducted in this regard. The value network mapping process designed in this study consists of specific steps that help managers and experts to understand how to get a complex value network map and how to enhance it. Furthermore, it make easier the understanding of how new value can be created in collaboration process. The map can be used in order to motivate participants to be engaged with responsibility in collaboration and to be fully committed in their interactions. It can be also used as a motivator tool for those organizations that intend to engage in collaboration process. Additionally, value network map is a starting point in many value network analyses. Furthermore, the enhanced value network map can be used as a performance measurement tool in cross-sector collaboration.

Mobile clinics in public health care: Integrated service offerings for rural elderly

This research is an analysis of the value and content of local service offerings that enable longer periods of living at home for elderly people. Mobile health care and new distribution services have provided an interesting solution in this context. The research aim to shed light on the research question, ‘How do we bundle services based on different customer needs?’ A research process consisting of three main phases was applied for this purpose. During this process, elderly customers were segmented, the importance of services was rated and service offerings were defined. Value creation and service offering provides theoretical framework for the research. The target group is South Karelia’s 60 to 90-year old individuals and the data has been acquired via a postal questionnaire. Research has been conducted as exploratory research utilizing the methods of quantitative and social network analysis. The main results of the report are identified customer segments and service packages that fits to the segments’ needs. The results indicate the needs of customers and the results are additionally analysed from the producer’s point of view. In addition to the empirical results, the used theory framework has been developed further in order for the service-related theories to be seen from the customer’s point of view and not just from the producer’s point of view.

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.

[Aaria La donna e mobile oopperasta Rigoletto]

Soitinnus: lauluääni (tenori), orkesteri.

Kysyntä-toimitusketjun synkronointi epävarman kysynnän ja tarjonnan toimintaympäristössä

Kysynnän ja tarjonnan epävarmuudet ovat nykyisin arkipäivää useilla toimialoilla. Elämme epävarmuuden suhteen ennen näkemättömiä aikoja, minkä on arvioitu jatkuvan myös tulevaisuudessa. Yritysten tilauskannat ovat lyhyitä, ja tilaukset viivästyvät tai peruuntuvat kokonaan. Toisaalta tarjonnan epävarmuudet aiheuttavat asiakasyrityksille haasteita esimerkiksi toimitusmyöhästymisten muodossa. Tuotannon ollessa hajaantunut verkostoihin yksittäisten yritysten toiminta ja päätökset vaikuttavat toisten verkostoyritysten toimintaan. Tämän takia epävarmuuden aiheuttamista muutoksista ja poikkeamista tulisi tiedottaa kumppaniyrityksiä, jotta kaikki pysyisivät samalla kellotaajuudella. Operatiivisen ja taktisen tiedon jakaminen on nykyisissä toimitusketjuissa jo arkipäivää, mutta yritysten välisistä rajapinnoista löytyy edelleen kehitettävää. Riittävästä ei kiinnitetä huomiota vastaanottajan kykyyn ja tapaan hyödyntää informaatiota – varsinkaan muutostilanteissa. Ajan/nopeuden ollessa yhä tärkeämpi kilpailutekijä informaation ajoituksella on kriittinen merkitys kysyntä-toimitusketjujen kokonaissuorituskykyyn. Toisin sanoen, millä ajanhetkellä tietoa tulisi jakaa, jotta kumppani pystyisi hyödyntämään saamaansa tietoa mahdollisimman hyvin. Kysyntä-toimitusketjun synkronoinnilla tarkoitetaan tässä väitöstutkimuksessa nimenomaan aikatekijään keskittymistä yritysten välisessä päätöksenteossa ja informaation jakamisessa toimitusketjun kokonaissuorituskyvyn parantamiseksi. Tutkimus kytkeytyy toimitusketjukoordinoinnin tieteelliseen keskusteluun. Koordinointiteorian keskeinen osa ovat riippuvuussuhteet, joita johdetaan koordinointimekanismien avulla. Kysyntätoimitusketjun synkronointia on mallinnettu aikaisemmin VOP-OPP-mallin (Value Offering Point – Order Penetration Point) ja sen johdannaisten avulla. Näissä malleissa asiakasyrityksen kysyntäketju ja toimittajayrityksen toimitusketju ovat keskinäisessä riippuvuussuhteessa, jota johdetaan päätöksenteon synkronoinnin ja informaation jakamisen koordinointimekanismeilla. VOP-OPP-malli johdannaisineen eivät kuitenkaan huomioi epävarman toimintaympäristön vaikutuksia synkronointiin. Näissä malleissa informaation ainoana laatudimensiona tarkasteltava aikatekijä on liian kapea-alainen näkökulma synkronointiin epävarmassa ympäristössä. Lisäksi nämä mallit keskittyvät vain yksisuuntaiseen, kysyntälähtöiseen, synkronointiin jättäen huomioimatta tarjontalähtöisen synkronoinnin. Aikatekijä- ja kokonaissuorituskykypainotustensa takia VOP-OPP-malli tarjosi kuitenkin hyvän lähtöfilosofian uusien synkronointimallien kehittämiseen. Väitöstutkimus toteutettiin hypoteettis-deduktiivisena tapaustutkimuksena, jossa ensin luotiin kirjallisuuden perusteella uudet teoreettiset synkronointimalliehdotukset. Tämän jälkeen ehdotusten toimivuutta arvioitiin käytännön kysyntä-toimitusketjuissa. Tutkimuksen uutuusarvo liittyy kysyntä-toimitusketjun synkronoinnin keskeisten piirteiden systeemiseen mallintamiseen epävarmassa toimintaympäristössä. Kontribuutiona esitetään kysyntä-toimitusketjun synkronoinnin moniulotteinen kokonaismalli, joka sisältää koordinointimekanismeina päätöksenteon synkronoinnin, informaation läpinäkyvyyden sekä asiakas- ja toimittajapään joustot. Tiedon vaihtoa mallissa tarkastellaan kaksisuuntaisesti – kysyntä- ja tarjontalähtöisesti. Informaation laatudimensioina mallissa ovat informaation ajoitus, luotettavuus ja tarkkuus. Kokonaismalli sisältää kolme alimallia: Demand Visibility Point – Demand Penetration Point (DVP-DPP) on kysyntälähtöisen synkronoinnin malli, Supply Visibility Point – Supply Information Penetration Point (SVP-SIPP) on tarjontalähtöisen synkronoinnin malli ja Integroitu DVP-DPP - SVP-SIPP-malli kytkee edellä mainitut mallit toisiinsa. Näissä alimalleissa informaation eri luokkia ovat tilausta edeltävä, tilaukseen liittyvä, tilauksen jälkeinen ja sovitun toimitusajankohdan jälkeinen kysyntä- ja tarjontatieto. Käytännön hyödyntämisen näkökulmasta mallit toimivat ns. mentaalitason koordinointimekanismeina, joiden tarkoitus on herättää toimitusketjukumppanit tavoittelemaan kokonaissuorituskyvyn parantamista oman edun tavoittelemisen sijasta. Tutkimuksen päärajoitteena on sen keskittyminen ainoastaan kahdenvälisiin yhteistyösuhteisiin, mikä tarjoaa nykyisessä verkostoituneessa toimintaympäristössä varsin kapean kuvan käytännön synkronointihaasteisiin.

Open Preservation: Community Approaches to Ensuring Long-Term Access to Digital Collections

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014