LM-vesiturbiinin tuotteistaminen

Tämän työn tarkoituksena on kehittää LM-vesiturbiini tuotantoon soveltuvaksi, käytöltään pitkäikäiseksi ja helposti huollettavaksi tuotesarjaksi. Työn ohjaavana runkona on käytetty VDI-Richtlinie 2221: 'Kehitystyön ja konstruoinnin yleinen kulku', mukaista järjestelmää. Lisäksi on käytetty valmistuksellista modulointia tuotteen osien suunnittelussa. Erityisesti on huomioitu tuotteen koko elinkaaren aikaiset kustannukset (LCC) ja sen vaatimukset mitoitukseen. LM-vesiturbiinistaon kehitetty kolmen erikokoisen laitteiston tuotesarja. Tuoteperheen yksittäisistä sylinteriryhmistä voidaan koota joustavasti erikokoisia ja -tehoisia energiantuotantoyksiköitä, jotka soveltuvat käyttöön hyvin pieniinkin virtauksiin ja putouskorkeuksiin. Piensarjatuotantoon hyvin soveltuvat materiaalit on valittu silmälläpitäen mahdollisimman edullista kokonaiskustannusta. Kiertomäntä laitteiston toiminnan kannalta tärkeimpänä ja siten vaativimpana osana on edellyttänyt laserhitsausta ja -leikkausta sekä koekappaleiden valmistusta, joiden perusteellalopulliseen rakenteeseen on päädytty. Mitoitus perustuu perinteisiin lujuuslaskentamenetelmiin, joiden avulla eri osien kestävyys käyttöolosuhteissa on pyrittysaamaan luotettavaksi vähintään 20 vuoden kestoiälle ja väsymiskestävyyteen käytön aikaisissa vaihtelevissa olosuhteissa. Kiertomäntä on ns. kevytrakenne koostuen ohutlevykennorakenteesta ja täytteenä olevasta kompound-materiaalista.

Computational Analysis and Optimization of Real Gas Flow In Small Centrifugal Compressors

Small centrifugal compressors are more and more widely used in many industrialsystems because of their higher efficiency and better off-design performance comparing to piston and scroll compressors as while as higher work coefficient perstage than in axial compressors. Higher efficiency is always the aim of the designer of compressors. In the present work, the influence of four partsof a small centrifugal compressor that compresses heavy molecular weight real gas has been investigated in order to achieve higher efficiency. Two parts concern the impeller: tip clearance and the circumferential position of the splitter blade. The other two parts concern the diffuser: the pinch shape and vane shape. Computational fluid dynamics is applied in this study. The Reynolds averaged Navier-Stokes flow solver Finflo is used. The quasi-steady approach is utilized. Chien's k-e turbulence model is used to model the turbulence. A new practical real gas model is presented in this study. The real gas model is easily generated, accuracy controllable and fairly fast. The numerical results and measurements show good agreement. The influence of tip clearance on the performance of a small compressor is obvious. The pressure ratio and efficiency are decreased as the size of tip clearance is increased, while the total enthalpy rise keeps almost constant. The decrement of the pressure ratio and efficiency is larger at higher mass flow rates and smaller at lower mass flow rates. The flow angles at the inlet and outlet of the impeller are increased as the size of tip clearance is increased. The results of the detailed flow field show that leakingflow is the main reason for the performance drop. The secondary flow region becomes larger as the size of tip clearance is increased and the area of the main flow is compressed. The flow uniformity is then decreased. A detailed study shows that the leaking flow rate is higher near the exit of the impeller than that near the inlet of the impeller. Based on this phenomenon, a new partiallyshrouded impeller is used. The impeller is shrouded near the exit of the impeller. The results show that the flow field near the exit of the impeller is greatly changed by the partially shrouded impeller, and better performance is achievedthan with the unshrouded impeller. The loading distribution on the impeller blade and the flow fields in the impeller is changed by moving the splitter of the impeller in circumferential direction. Moving the splitter slightly to the suction side of the long blade can improve the performance of the compressor. The total enthalpy rise is reduced if only the leading edge of the splitter ismoved to the suction side of the long blade. The performance of the compressor is decreased if the blade is bended from the radius direction at the leading edge of the splitter. The total pressure rise and the enthalpy rise of thecompressor are increased if pinch is used at the diffuser inlet. Among the fivedifferent pinch shape configurations, at design and lower mass flow rates the efficiency of a straight line pinch is the highest, while at higher mass flow rate, the efficiency of a concave pinch is the highest. The sharp corner of the pinch is the main reason for the decrease of efficiency and should be avoided. The variation of the flow angles entering the diffuser in spanwise direction is decreased if pinch is applied. A three-dimensional low solidity twisted vaned diffuser is designed to match the flow angles entering the diffuser. The numerical results show that the pressure recovery in the twisted diffuser is higher than in a conventional low solidity vaned diffuser, which also leads to higher efficiency of the twisted diffuser. Investigation of the detailed flow fields shows that the separation at lower mass flow rate in the twisted diffuser is later than in the conventional low solidity vaned diffuser, which leads to a possible wider flow range of the twisted diffuser.

Ilmakehan hiukkasmaisten ioniyhdisteiden online-mittaus

Ilmakehän hiukkaset aiheuttavat merkittäviä ympäristö- ja terveyshaittoja, joihin vaikuttaa hiukkasten kemiallinen koostumus. Hiukkasten kemiallisesta koostumuksesta voidaan hankkia tietoa hiukkasmittauksilla. Työn tavoitteena oli rakentaa jatkuvatoiminen mittausjärjestelmä, jolla voidaan mitata ilmakehän aerosolihiukkasten ionipitoisuuksia. Mittausjärjestelmä koostuu virtuaali-impaktorista, denuderputkista, PILS-laitteesta ja ionikromatografista. Näyteilmavirtaus kulkee ensin esierottimena toimivan virtuaali-impaktorm lävitse, joka poistaa aerodynaamiselta halkaisijaltaan 1,3 um:a suuremmat hiukkaset ilmavirtauksesta. Näyte, joka sisältää 1,3 um:a pienemmät hiukkaset kulkee virtuaali-impaktorin jälkeen kahden 1 % KOH-liuoksella käsitellyn denuderputken lävitse, joilla poistetaan hiukkasmääritystä häiritsevät happamat kaasut näytevirtauksesta. Denuderputkien jälkeen ilmavirtaus saapuu PILS-laitteeseen, jossa hiukkaset kasvatetaan vesihöyryn avulla aerosolipisaroiksi, törmäytetään keräyslevyyn ja sekoitetaan sen jälkeen sisäistä standardiainetta (NaBr) sisältavään kuljetusliuokseen. Kuljetusliuoksen ja aerosolipisaroiden seoksesta koostuva näyteliuos johdetaan PILS-laitteesta ionikromatografille analysoitavaksi. Mittausjärjestelmään liitetyllä ionikromatografilla voidaan analysoida neljä näytetta tunnissa. Näytteistä määritettävät anionit olivat sulfaatti, nitraatti ja kloridi. PILS-mittausjärjestelmää testattiin keräämällä hiukkasnäytteitä samanaikaisesti PILS-laitteella sekä virtuaali-impaktorilla tai suodatinkeräimellä ja vertaamalla saatuja aerosolihiukkasten sulfaattipitoisuuksia keskenään. Testeissa kerättiin joko VOAG-laitteella tuotettuja ammoniumsulfaattihiukkasia tai laboratorion huoneilmaa. PILS-mittausjärjestelmällä mitatut sulfaattipitoisuudet olivat 2-20 % pienempia kuin suodatinkeraimella mitatut, kun kerättiin keinotekoisesti tuotettuja ammoniumsulfaattihiukkasia. Huoneilmaa kerättäessä PILS-mittausjärjestelmällä saadut pitoisuudet olivat noin 10 % pienempiä kuin suodatinkeräystulokset. Koetulokset osoittivat, että mittausjärjestelmällä saadaan analysoiduksi luotettavasti hiukkasten sulfaattipitoisuudet.

Advanced control methods for reducing nitrogen oxides in a fluidized bed boiler

Tämän työn tarkoituksena oli löytää keinoja erään leijukerroskattilan typenoksidipäästöjen vähentämiseksi. Koska päästöt olivat jo alunperin alhaiset leijukerrostekniikan ja hybridin SNCR/SCR –typenpoistolaitteiston ansiosta, päätettiin päästöjä lähteä vähentämään parantamalla ammoniakkiruiskutuksen säätöä. Alkuperäinen ammoniakkiruiskutuksen säätö oli liian hidas, jotta satunnaisten häiriöiden aiheuttamat typenoksidipiikit olisi pystytty poistamaan. Ammoniakkiruiskutusta parannettiin lisäämällä jokaiseen ammoniakkilinjaan mäntäpumput, joiden avulla ammoniakkia voidaan syöttää sinne, missä sitä eniten tarvitaan. Ammoniakkiruiskutuksen säätöön kehitettiin uusi sumeaan logiikkaan perustuva säätäjä. Myös muita kehittyneitä säätömenetelmiä kuten neuroverkkoa hyödynnettiin säätäjän kehityksessä. Ammoniakkiruiskutuksen säätäjää testattiin menestyksekkäästi Ruotsissa Brista Kraftin Märstassa sijaitsevalla voimalaitoksella

Hakevirrasta otettavan näytteen luotettavuus ja näytteenottimen kehittäminen

Työn tavoitteena oli saada tietoa yleisesti partikkelivirtauksessa tapahtuvasta näytteenotosta ja näytteenottomenetelmistä. Työssä tutkittiin UPM-Kymmenen Kaukaan tehtaan nykyisen ostohakkeen automaattisen näytteenottimen toimintaa sekä sen ottamien näytteiden luotettavuutta kokeellisesti ja tilastollisesti. Lopuksi tutkimuksessa ideoitiin uusi näytteenottimen konstruktio. Uuden konstruktion suunnittelun lähtökohtana oli, että näytteenottimen konstruktiolla tulisi voida ottaa toistuvasti ja turvallisesti luotettavia hakenäytteitä aiheuttamatta muulle vastaanottoaseman toiminnalle häiriöitä Tutkimusta varten tehtiin eri haketoimittajien kanssa koenäytteenottoja. Hakenäytteet otettiin kolmessa eri haketoimituksen vaiheessa niiden keskinäistä vertailua varten. Hakenäytteistä määritettiin kuiva-ainepitoisuus ja laatuanalyysin tekoa varten palakokojakauma koeseulonnoilla. Palakokojakauma-analyysistä saatuja jakaumapainoprosenttiosuuksien ja niistä laskettujen laatuarvojen pohjalta tutkittiin automaattisen näytteenottimen ottaman näytteen luotettavuutta ja näytteenottimen toimintaa. Konstruointityössä noudatettiin pääpiirteittäin ohjeistoa VDI 2221. Uuden näytteenottimen suunnittelutyön tavoitteet määriteltiin tutkimuksessa tehtyjen päätelmien ja kokeiden pohjalta. Uudelle näytteenottimen konstruktiolle etsittiin toteutuskelpoisia ratkaisuja jo olemassa olevista laitteistoista ja uusista ideoista. Uudet konstruktiovaihtoehdot suunniteltiin noudattamaan näytteenottoteoriaa ja sijoituspaikan asettamia vaatimuksia.

Kakun rakenteen vaikutus pesutulokseen

Tässä työssä tutkittiin suodatukseen vaikuttavien tekijöiden vaikutusta suodatuksessa syntyvän kakun ominaisuuksiin sekä kakun ominaisuuksien vaikutusta syrjäytyspesun tehokkuuteen. Lisäksi määritettiin tärkeimmät suodatusparametrit sekä niiden riippuvuudet suodatusolosuhteista. Toissijaisena tavoitteena oli lisäksi tutkia, miten suodatusolosuhteita ja suodatettavan lietteen ominaisuuksia muuttamalla voidaan vaikuttaa suodatusjakson kestoon. Työn kirjallisuusosassa käsiteltiin aluksi yleisesti kiintoaineen erotusta nesteestä. Tämän jälkeen käsiteltiin yleisimmät suodatustekniikat ja tarkasteltiin yksityiskohtaisemmin painesuodatusta ja varsinkin syntyvän kakun rakenteeseen vaikuttavia tekijöitä. Lopuksi käytiin läpi kakulle suodatuksen jälkeen suoritettavat jälkikäsittelymenetelmät ja selvitettiin varsinkin syrjäytyspesun tehokkuuteen vaikuttavia tekijöitä tarkemmin. Kokeellisessa osassa tehtiin koesuodatuksia lietteellä joka sisälsi hienojakoista pigmenttiä. Koesuodatukset tehtiin kahdella eri kankaalla panostoimisella piston press- laboratoriopainesuodattimella johon oli liitetty tiedonkeruuohjelmisto, joka keräsi tiedostoon paineet suodatuskammiossa, kankaan alapuolella ja työsylinterin syöttölinjassa sekä lisäksi männän korkeuden, lietteen lämpötilan ja suodosvaakalukeman. Lietteiden ominaisuuksia seurattiin analysoimalla niiden kiintoainepitoisuuksia, kloridipitoisuuksia, z-potentiaaleja ja partikkelikokojakau-mia siten että jokaisessa suodatuksessa käytetyn lietteen ominaisuudet olivat tiedossa. Suodatusten jälkeen syntyneistä kakuista määritettiin kiintoaine- sekä joissain tapauksissa myös kloridipitoisuudet. Suodatus- ja puristuspaineiden havaittiin vaikuttavan kakkujen huokoisuuksiin ja ominaisvastuksiin selvästi, joskin muutokset olivat melko pieniä. Vaikutus näkyi selvästi myös suodatusten kestoissa ja muutosten havaittiin olevan merkittävän suuruisia. Myös lietteen pH:n havaittiin vaikuttavan merkitsevästi suodatusten kestoihin ja kakkujen ominaisuuksiin. Pesutuloksen ja kakun ominaisuuksien välille löydettiin riippuvuus heikoksi jääneestä pesutuloksesta huolimatta. Myös koesuodatuksissa käytettyjen kankaiden välillä havaittiin selviä eroavaisuuksia.

Cardan Gear Mechanism versus Slider-Crank Mechanism in Pumps and Engines

In machine design we always want to save space, save energy and produce as much power as possible. We can often reduce accelerations, inertial loads and energy consumption by changing construction. In this study the old cardan gear mechanism (hypocycloid mechanism) has been compared with the conventional slider-crank mechanism in air pumps and four-stroke engines. Comprehensive Newtonian dynamics has been derived for the both mechanisms. First the slidercrank and the cardan gear machines have been studied as lossless systems. Then the friction losses have been added to the calculations. The calculation results show that the cardan gear machines can be more efficient than the slider-crank machines. The smooth running, low mass inertia, high pressures and small frictional power losses make the cardan gear machines clearly better than the slider-crank machines. The dynamic tooth loads of the original cardan gear construction do not rise very high when the tooth clearances are kept tight. On the other hand the half-size crank length causes high bearing forces in the cardan gear machines. The friction losses of the cardan gear machines are generally quite small. The mechanical efficiencies are much higher in the cardan gear machines than in the slider-crank machines in normal use. Crankshaft torques and power needs are smaller in the cardan gear air pumps than in the equal slider-crank air pumps. The mean crankshaft torque and the mean output power are higher in the cardan gear four-stroke engines than in the slider-crank four-stroke engines in normal use. The cardan gear mechanism is at its best, when we want to build a pump or an engine with a long connecting rod (≈ 5⋅crank length) and a thin piston (≈ 1.5⋅crank length) rotating at high angular velocity and intermittently high angular acceleration. The cardan gear machines can be designed also as slide constructions without gears. Suitable applications of the cardan gear machines are three-cylinder half-radial engines for motorcycles, sixcylinder radial engines for airplanes and six-cylinder double half-radial engines for sport cars. The applied equations of Newtonian dynamics, comparative calculations, calculation results (tables, curves and surface plots) and recommendations presented in this study hold novelty value and are unpublished before. They have been made and written by the author first time in this study.

High pressure compression of filter cakes

The purpose of this thesis was to investigate the compression of filter cakes at high filtration pressures with five different test materials and to compare the energy consumption of high pressure compression with the energy consumption of thermal drying. The secondary target of this study was to investigate the particle deformation of test materials during filtration and compression. Literature part consists of basic theory of filtration and compression and of the basic parameters that influence the filtration process. There is also a brief description about all of the test materials including their properties and their industrial production and processing. Theoretical equations for calculating the energy consumptions of the filtrations at different conditions are also presented. At the beginning of the experiments at experimental part, the basic filtration tests were done with all the five test materials. Filtration tests were made at eight different pressures, from 6 bars up to 100 bars, by using piston press pressure filter. Filtration tests were then repeated by using a cylinder with smaller slurry volume than in the first series of filtration tests. Separate filtration tests were also done for investigating the deformation of solid particles during filtration and for finding the optimal curve for raising the filtration pressure. Energy consumption differences between high pressure filtration and ideal thermal drying process were done partly experimentally and partly by using theoretical calculation equations. By comparing these two water removal methods, the optimal ranges for their use were found considering their energy efficiency. The results of the measurements shows that the filtration rate increased and the moisture content of the filter cakes decreased as the filtration pressure was increased. Also the porosity of the filter cakes mainly decreased when the filtration pressure was increased. Particle deformation during the filtration was observed only with coal particles.

Holocene Varved Lake Sediments as Records of Palaeoenvironmental Change and Geomagnetic Palaeosecular Variation in Eastern Finland

This dissertation discusses Holocene palaeoenvironmental and palaeomagnetic secular variation (PSV) records reconstructed from sediments preserved in Lake Lehmilampi (63º37´N, 29º06´E) and Lake Kortejärvi (63º37´N, 28º56´E) in eastern Finland. Several piston and freeze cores were obtained from both lakes for varve and magnetic analyses. Sediment samples were impregnated in low-viscosity epoxy and physical parameters of varves, including varve thickness and relative grey-scale values, were recorded using x-ray densitometry combined with semiautomatic digital image analysis. On average, varve records of Lehmilampi and Kortejärvi cover 5122 and 3902 years, respectively. Past solar activity, as estimated by residual ₁₄C data, compares favourably with varve thicknesses from Lehmilampi during the last 2000 years. This indicates the potential of clastic-organic varves to record sensitively climatic variations. Bulk magnetic parameters, including magnetic susceptibility together with natural, anhysteretic and isothermal remanent magnetizations, were measured to describe mineral magnetic properties and geomagnetic palaeosecular variation recorded in the sediments. Main stages in the development of the investigated lakes are reflected in the variations in the mineral magnetic records, sediment lithology and composition. Similar variations in magnetic parameters and sediment organic matter suggest contribution of bacterial magnetite in the magnetic assemblages of Lehmilampi. Inclination and relative declination records yielded largely consistent results, attesting to the great potential of these sediments to preserve directional palaeosecular variation in high resolution. The PSV data from Lehmilampi and Kortejärvi were stacked into North Karelian PSV stack, which may be used for dating homogenous lake sediments in the same regional context. Reconstructed millennial variations in relative palaeointensity results are approximately in agreement with those seen in the absolute palaeointensity data from Europe. Centennial variations in the relative palaeointensity, however, are influenced by environmental changes. Caution is recommended when using varved lake sediments in reconstructing relative palaeointensity.

Online Ultrasound Measurements of Membrane Compaction

There are several filtration applications in the pulp and paper industry where the capacity and cost-effectiveness of processes are of importance. Ultrafiltration is used to clean process water. Ultrafiltration is a membrane process that separates a certain component or compound from a liquid stream. The pressure difference across the membrane sieves macromolecules smaller than 0.001-0.02 μm through the membrane. When optimizing the filtration process capacity, online information about the conditions of the membrane is needed. Fouling and compaction of the membrane both affect the capacity of the filtration process. In fouling a “cake” layer starts to build on the surface of the membrane. This layer blocks the molecules from sieving through the membrane thereby decreasing the yield of the process. In compaction of the membrane the structure is flattened out because of the high pressure applied. The higher pressure increases the capacity but may damage the structure of the membrane permanently. Information about the compaction is needed to effectively operate the filters. The objective of this study was to develop an accurate system for online monitoring of the condition of the membrane using ultrasound reflectometry. Measurements of ultrafiltration membrane compaction were made successfully utilizing ultrasound. The results were confirmed by permeate flux decline, measurements of compaction with a micrometer, mechanical compaction using a hydraulic piston and a scanning electron microscope (SEM). The scientific contribution of this thesis is to introduce a secondary ultrasound transducer to determine the speed of sound in the fluid used. The speed of sound is highly dependent on the temperature and pressure used in the filters. When the exact speed of sound is obtained by the reference transducer, the effect of temperature and pressure is eliminated. This speed is then used to calculate the distances with a higher accuracy. As the accuracy or the resolution of the ultrasound measurement is increased, the method can be applied to a higher amount of applications especially for processes where fouling layers are thinner because of smaller macromolecules. With the help of the transducer, membrane compaction of 13 μm was measured in the pressure of 5 bars. The results were verified with the permeate flux decline, which indicated that compaction had taken place. The measurements of compaction with a micrometer showed compaction of 23–26 μm. The results are in the same range and confirm the compaction. Mechanical compaction measurements were made using a hydraulic piston, and the result was the same 13 μm as obtained by applying the ultrasound time domain reflectometry (UTDR). A scanning electron microscope (SEM) was used to study the structure of the samples before and after the compaction.

Tooth-Coil Permanent Magnet Synchronous Machine Design for Special Applications

This doctoral thesis presents a study on the design of tooth-coil permanent magnet synchronous machines. The electromagnetic properties of concentrated non-overlapping winding permanent magnet synchronous machines, or simply tooth-coil permanent magnet synchronous machines (TC-PMSMs), are studied in details. It is shown that current linkage harmonics play the deterministic role in the behavior of this type of machines. Important contributions are presented as regards of calculation of parameters of TC-PMSMs,particularly the estimation of inductances. The current linkage harmonics essentially define the air-gap harmonic leakage inductance, rotor losses and localized temporal inductance variation. It is proven by FEM analysis that inductance variation caused by the local temporal harmonic saturation results in considerable torque ripple, and can influence on sensorless control capabilities. Example case studies an integrated application of TC-IPMSMs in hybrid off-highway working vehicles. A methodology for increasing the efficiency of working vehicles is introduced. It comprises several approaches – hybridization, working operations optimization, component optimization and integration. As a result of component optimization and integration, a novel integrated electro-hydraulic energy converter (IEHEC) for off-highway working vehicles is designed. The IEHEC can considerably increase the operational efficiency of a hybrid working vehicle. The energy converter consists of an axial-piston hydraulic machine and an integrated TCIPMSM being built on the same shaft. The compact assembly of the electrical and hydraulic machines enhances the ability to find applications for such a device in the mobile environment of working vehicles.Usage of hydraulic fluid, typically used in working actuators, enables direct-immersion oil cooling of designed electrical machine, and further increases the torque- and power- densities of the whole device.

Flexible multibody dynamics and intelligent control of a hydraulically driven hybrid redundant robot machine

The assembly and maintenance of the International Thermonuclear Experimental Reactor (ITER) vacuum vessel (VV) is highly challenging since the tasks performed by the robot involve welding, material handling, and machine cutting from inside the VV. The VV is made of stainless steel, which has poor machinability and tends to work harden very rapidly, and all the machining operations need to be carried out from inside of the ITER VV. A general industrial robot cannot be used due to its poor stiffness in the heavy duty machining process, and this will cause many problems, such as poor surface quality, tool damage, low accuracy. Therefore, one of the most suitable options should be a light weight mobile robot which is able to move around inside of the VV and perform different machining tasks by replacing different cutting tools. Reducing the mass of the robot manipulators offers many advantages: reduced material costs, reduced power consumption, the possibility of using smaller actuators, and a higher payload-to-robot weight ratio. Offsetting these advantages, the lighter weight robot is more flexible, which makes it more difficult to control. To achieve good machining surface quality, the tracking of the end effector must be accurate, and an accurate model for a more flexible robot must be constructed. This thesis studies the dynamics and control of a 10 degree-of-freedom (DOF) redundant hybrid robot (4-DOF serial mechanism and 6-DOF 6-UPS hexapod parallel mechanisms) hydraulically driven with flexible rods under the influence of machining forces. Firstly, the flexibility of the bodies is described using the floating frame of reference method (FFRF). A finite element model (FEM) provided the Craig-Bampton (CB) modes needed for the FFRF. A dynamic model of the system of six closed loop mechanisms was assembled using the constrained Lagrange equations and the Lagrange multiplier method. Subsequently, the reaction forces between the parallel and serial parts were used to study the dynamics of the serial robot. A PID control based on position predictions was implemented independently to control the hydraulic cylinders of the robot. Secondly, in machining, to achieve greater end effector trajectory tracking accuracy for surface quality, a robust control of the actuators for the flexible link has to be deduced. This thesis investigates the intelligent control of a hydraulically driven parallel robot part based on the dynamic model and two schemes of intelligent control for a hydraulically driven parallel mechanism based on the dynamic model: (1) a fuzzy-PID self-tuning controller composed of the conventional PID control and with fuzzy logic, and (2) adaptive neuro-fuzzy inference system-PID (ANFIS-PID) self-tuning of the gains of the PID controller, which are implemented independently to control each hydraulic cylinder of the parallel mechanism based on rod length predictions. The serial component of the hybrid robot can be analyzed using the equilibrium of reaction forces at the universal joint connections of the hexa-element. To achieve precise positional control of the end effector for maximum precision machining, the hydraulic cylinder should be controlled to hold the hexa-element. Thirdly, a finite element approach of multibody systems using the Special Euclidean group SE(3) framework is presented for a parallel mechanism with flexible piston rods under the influence of machining forces. The flexibility of the bodies is described using the nonlinear interpolation method with an exponential map. The equations of motion take the form of a differential algebraic equation on a Lie group, which is solved using a Lie group time integration scheme. The method relies on the local description of motions, so that it provides a singularity-free formulation, and no parameterization of the nodal variables needs to be introduced. The flexible slider constraint is formulated using a Lie group and used for modeling a flexible rod sliding inside a cylinder. The dynamic model of the system of six closed loop mechanisms was assembled using Hamilton’s principle and the Lagrange multiplier method. A linearized hydraulic control system based on rod length predictions was implemented independently to control the hydraulic cylinders. Consequently, the results of the simulations demonstrating the behavior of the robot machine are presented for each case study. In conclusion, this thesis studies the dynamic analysis of a special hybrid (serialparallel) robot for the above-mentioned special task involving the ITER and investigates different control algorithms that can significantly improve machining performance. These analyses and results provide valuable insight into the design and control of the parallel robot with flexible rods.

Simulation of wind powered hydraulic heating system

The objective of this master’s thesis was to design and simulate a wind powered hydraulic heating system that can operate independently in remote places where the use of electricity is not possible. Components for the system were to be selected in such a way that the conditions for manufacture, use and economic viability are the as good as possible. Savonius rotor was chosen for wind turbine, due to its low cut in speed and robust design. Savonius rotor produces kinetic energy in wide wind speed range and it can withstand high wind gusts. Radial piston pump was chosen for the flow source of the hydraulic heater. Pump type was selected due to its characteristics in low rotation speeds and high efficiency. Volume flow from the pump is passed through the throttle orifice. Pressure drop over the orifice causes the hydraulic oil to heat up and, thus, creating thermal energy. Thermal energy in the oil is led to radiator where it conducts heat to the environment. The hydraulic heating system was simulated. For this purpose a mathematical models of chosen components were created. In simulation wind data gathered by Finnish meteorological institute for 167 hours was used as input. The highest produced power was achieved by changing the orifice diameter so that the rotor tip speed ratio follows the power curve. This is not possible to achieve without using electricity. Thus, for the orifice diameter only one, the optimal value was defined. Results from the simulation were compared with investment calculations. Different parameters effecting the investment profitability were altered in sensitivity analyses in order to define the points of investment profitability. Investment was found to be profitable only with high average wind speeds.