Thesis (M.S.)--University of Iowa, 2006. / Supervisor: Lea-Der Chen. Includes bibliographical references (leaves 114-116).

Thesis (M.S.)--Rochester Institute of Technology, 2005. / Typescript. Includes bibliographical references (leaves 78-80).

Thesis (Ph.D.)--University of Tasmania, 2002. / Includes bibliographical references.

Wheel loaders are under the influence of low frequency vibrations that may be harmful for the health of the operator, and for the productivity of the machine. The strong vibrations can significantly impact the operation of the machine since they are not equipped with wheel suspension systems and due to their work environment in rough terrains with uneven surfaces. The risk of spilling or dropping the load is also increased and they can introduce higher mechanical stress that can wear out parts faster. The focus of this thesis work is to develop an approach for damping these vibrations dynamically by improving the functionality of the electrohydraulic system in Volvo's prototype wheel loader LX1. The dynamic damping system controls the cylinder of the lift framework to make it behave as a damper. The system utilizes the lift cylinder pressure and piston position as feedback to adjust the oil flow in the cylinder using the proposed control system. Results indicate that the proposed technique is capable of attenuation that is comparable with the existing boom suspension system based on accumulators through simulations and experimental tests.

In working machines the human operator is essential for the performance of the total system. Productivity and energy efficiency are both dependent not only on inherent machine properties and working place conditions, but also on how the operator manoeuvres the machine. In order to operate energy-efficient the operator has to experience the machine as harmonic. This is important to consider during the development of such working machines. It is necessary to quantify operability and to include this interaction between the human operator and the machine in both the later stages of a development project (where physical prototypes are evaluated by professional test operators) as well as in the earlier stages like concept design (where only virtual prototypes are available). The influence of the human operator is an aspect that is traditionally neglected in dynamic simulations conducted in concept design, because the modelling needs to be extended beyond the technical system. The research presented in this thesis shows two approaches to rule-based simulation models of a wheel loader operator. Both operator models interact with the machine model just as a human operator does with the actual machine. It is demonstrated that both operator models are able to adapt to basic variations in workplace setup and machine capability. A “human element” can thus be introduced into dynamic simulations of working machines, providing more relevant answers with respect to operator-influenced complete-machine properties such as productivity and energy efficiency. While the influence of the human operator is traditionally ignored when evaluating machine properties in the early stages of the product development process, later stages are very reliant on professional test operators using physical prototypes. The presented research demonstrates how the traditional subjective evaluation of a machine’s operability can be complemented by a calculated measure for the operator’s control effort, derived from the recorded control commands of the machine operator. This control effort measure can also be calculated from the control commands of an operator model in a simulation, such as those presented in this thesis. It thus also allows for an assessment of operability already in the concept design phase. In addition, the results of a study of quantifying operator workload by means of measuring psycho-physiological data such as heart rate variability and respiration rate are presented as the first step towards realising workload-adaptive operator assistance functions. Once fully developed, the method itself can also be used as another complement to the traditional subjective evaluations of operability. This approach can then be applied not only in testing of physical prototypes, but also earlier in the product development process in studies on human-in-the-loop simulators. / I arbetsmaskiner spelar föraren en avgörande roll för maskinens prestanda. Såväl produktivitet som energieffektivitet beror inte enbart av maskinens egenskaper och arbetsomgivningen, utan beror också av sättet på vilket föraren manövrerar maskinen. För att främja ett bränslesnålt körsätt ska maskinerna upplevas som harmoniska och det är viktigt att beakta detta vid utvecklingen. Det är nödvändigt att kvantifiera maskinharmonin och att ta hänsyn till interaktionen mellan föraren och maskinen i alla steg av ett utvecklingsprojekt. Detta gäller såväl sena faser, när fysiska prototyper redan har tagits fram och utvärderas av professionella provförare, såväl som tidiga faser som konceptutveckling, när endast virtuella prototyper finns tillgängliga. Förarens inflytande beaktas traditionellt inte i prestandasimuleringar i konceptfasen, eftersom detta innebär att mer än enbart det tekniska systemet måste modelleras. I den forskningen som presenteras här visas två olika regelbaserade modeller av hjullastarförare. Båda förarmodellerna använder maskinmodellen på samma sätt som en verklig förare använder en verklig maskin. Det visas att båda förarmodellerna kan anpassa sig till förändringar både i arbetsomgivningen och i maskinens egenskaper. I och med detta kan man utöka dynamiska simuleringar av arbetsmaskiner med ”ett mänskligt element”. Detta ger bättre resultat vad gäller produktivitet, energieffektivitet och liknande egenskaper som föraren påverkar i kompletta maskiner. Medan man i tidiga faser av produktutvecklingsprocessen traditionellt bortser från förarens inflytande, så är man i senare faser mycket beroende av att professionella provförare testar fysiska prototyper. Den här presenterade forskningen visar hur den traditionella subjektiva förarbedömningen av en maskins körbarhet kan kompletteras med ett mått på förarens ”spakarbete”, som beräknas utifrån en mätning på hur föraren använder sina kontroller för att styra maskinen. Detta mått på ”spakarbete” kan också beräknas utifrån de spaksignaler som genereras av förarmodellerna i en simulering. I och med detta kan en maskins körbarhet undersökas redan under konceptutvecklingen. I avhandlingen redovisas också resultaten från en studie som gjorts i syfte att kvantifiera förarens arbetsbelastning genom att mäta psykofysiologiska mått som variationer i hjärtfrekvens och andningsfrekvens. Studien är ett första steg mot att förverkliga en vision av stödfunktioner i arbetsmaskiner vilka anpassar sig efter förarens momentana arbetsbelastning. En sådan metod att mäta förarens arbetsbelastning kan också användas som ett komplement till den traditionella subjektiva förarbedömningen av en maskins körbarhet. Metoden kan inte bara användas vid provning av fysiska prototyper utan också tidigare i produktutvecklingsprocessen vid studier i avancerade körsimulatorer. / IN ARBETSMASCHINEN spielt der Fahrer eine entscheidende Rolle für die Leistung des gesamten Systems. Produktivität und Energieeffizienz sind nicht nur abhängig von den Grundeigenschaften der Maschine und den Bedingungen am Einsatzort, sondern auch von der Art und Weise wie der Fahrer die Maschine manövreriert. Für eine kraftstoffsparende Fahrweise muss der Fahrer die Maschine als harmonisch erleben. Dies muss bei der Entwicklung beachtet werden. Das Erfassen der Fahrbarkeit und die Berücksichtigung des Zusammenspiels zwischen Fahrer und Maschine ist in allen Phasen der Entwicklung notwendig, sowohl in den späteren Phasen, wenn Prototypen von Erprobungsfahrern ausgewertet werden, als auch in den frühen Phasen wie dem Konzeptentwurf, wenn nur virtuelle Prototypen vorhanden sind. Der Fahrereinfluss wird traditionell in den dynamischen Simulationen während des Konzeptentwurfs vernachlässigt, denn er erfordert die Ausweitung der Modellierung über das technische System hinaus. In dieser Dissertation werden zwei Herangehensweisen zur Erstellung regelbasierter Modelle eines Radladerfahrers aufgezeigt. Beide Fahrermodelle interagieren mit dem Maschinenmodell gleich einem menschlichen Fahrer mit einer realen Maschine. Es wird gezeigt, dass beide Fahrermodelle in der Lage sind, sich auf Änderungen des Einsatzortes und der Maschineneigenschaften anzupassen. Somit kann „ein menschliches Element“ in die dynamische Simulation von Arbeitsmaschinen eingeführt werden, was zu qualitativ besseren Resultaten bezüglich Produktivität, Energieeffizienz und ähnlicher fahrerbeeinflusster Eigenschaften führt. Während man in den frühen Phasen der Produktentwicklung traditionell vom Fahrereinfluss absieht, ist man später sehr auf die Erprobung physischer Prototypmaschinen durch professionelle Testfahrer angewiesen. In dieser Dissertation wird aufgezeigt, wie die traditionell subjektive Bewertung der Fahrbarkeit einer Maschine mit einem Maß der „Steuerungsarbeit“ komplettiert werden kann, berechnet aus der gemessenen Betätigung der dem Fahrer zur Verfügung stehenden Bedienelemente. Dieses Maß der „Steuerungsarbeit“ kann auch aus den Signalen der von uns vorgestellten Fahrermodelle in einer Simulation berechnet werden. Damit kann man die Fahrbarkeit bereits in der Konzeptentwicklung abschätzen. Weiterhin werden die Resultate einer Studie zur Quantifizierung der Fahrerbelastung mithilfe psychophysiologischer Daten wie Veränderungen der Herzfrequenz und Atmungsfrequenz vorgestellt. Diese Studie ist ein erster Schritt zur Entwicklung eines Assistenzsystemes, dass sich an die aktuelle Fahrerbelastung anpasst. Eine solche Messmethode der Fahrerbelastung kan auch zusätzlich zur traditionellen subjektiven Fahrbarkeitseinschätzung angewendet werden – nicht nur bei der Erprobung physischer Prototpyen, sondern auch schon frühzeitig bei Studien auf Fahrsimulatoren.

Submitted by Marco Antonio Oliveira da Silva (maosilva@ipen.br) on 2017-10-27T12:46:47Z No. of bitstreams: 0 / Made available in DSpace on 2017-10-27T12:46:47Z (GMT). No. of bitstreams: 0 / Leishmaniose é uma zoonose desenvolvida por protozoários do gênero Leishmania. A doença se manifesta sob a forma visceral e cutânea cujo tratamento apresenta diversas limitações como alto custo, elevada toxicidade dos fármacos e altos índices de recidiva. A leishmaniose cutânea abrange lesões destrutivas e ulceradas que podem evoluir para condições mais graves culminando em óbito dos hospedeiros acometidos. Tratamentos alternativos tem sido implementados com a finalidade de proporcionar acessibilidade financeira e menores efeitos colaterais aos pacientes. A terapia fotodinâmica se insere nesse contexto devido à praticidade, custo reduzido, mínima toxicidade e sem relatos de resistência descritos na literatura. O objetivo desse trabalho foi avaliar os efeitos da terapia fotodinâmica em leishmaniose cutânea induzida em camundongos BALB/c infectados com leishmaniose cutânea. A otimização da PDT também foi avaliada pela administração de doadores de óxido nítrico (S-nitroso-MSA) encapsulados em nanopartículas de quitosana (CSNPs), já que esse composto é altamente reativo e potencialmente tóxico para o parasito. Camundongos BALB/c foram infectados no membro posterior esquerdo com 1.106 promastigotas de Leishmania (L) amazonensis que expressam o gene da luciferase e acompanhados por 4 semanas até o surgimento da lesão. Após esse período, os animais foram distribuídos em 6 grupos (n=4): Controle (não tratado), PDT1 (submetidos à uma sessão de PDT), PDT2 (duas sessões ), PDT1NPNO e PDT2NPNO (uma sessão e duas sessões de PDT em associação com S-nitroso-MSACPNPS, respectivamente), e NPNO (somente S-nitroso-MSA-CP NPS). A segunda sessão foi realizada 24 h após a primeira. A PDT foi efetuada usando um diodo emissor de luz (LED, λ=660 ± 22 nm) e azul de metileno (100 μM), com densidade de energia de 150 J/cm2. O progresso da doença foi avaliado por meio do tamanho da lesão e escala de dor utilizando um paquímetro e filamentos von Frey, respectivamente. A carga parasitária foi quantificada por intermédio do bioimageamento nas primeiras 96 h após o tratamento e nas 4 semanas seguintes. Os resultados obtidos demonstraram redução na carga parasitária durante o período experimental, com exceção do grupo PDT1NPNO. Houve redução parasitária significante em 72 h e 96 h para os grupos PDT2, PDT2NPNO e NPNO. A maior redução da lesão foi observada para o grupo PDT2 bem como menor sensibilidade ao estímulo doloroso. Nossos resultados indicam efeitos benéficos da PDT em duas sessões, sugerindo que pode ter ocorrido modulação do processo inflamatório. Entretanto, o uso das nanopartículas nas condições utilizadas nesse experimento não foi capaz de otimizar a eficiência da PDT nos animais infectados com Leishmania (L) amazonensis. / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP

Finding new use for the existing railway tracks, which prove themselves as one of the best ways to carry heavy or sizable load. Therefore they have an ability to carry a space. Verification of merging railway with everyday life. Design of a modular units and modifiable structures. Utilization of modern technologies. Demonstration of a proposal of a design using typical examples of railway structure and its surroundings. Taking advantage of railway tracks, unused train stations, neighboring unused industry grounds etc. Description: New possibilities of using railway tracks and surrounded unused sites. Design of modular structures adapted according to selected areas. Utilization of modern technologies.

A growing population is driving automatization in agricultural industry to strive for more productive arable land. Being part of this process, this work is aimed to investigate the possibility to implement sensor-based automation in a particular system called Front End Loader, which is a lifting arms that is commonly mounted on the front of a tractor. Two main tasks are considered here, namely Electronic Self Leveling (ESL) and payload estimation. To propose commercially implementable solutions for these tasks, specific objectives are set, which are: 1) to propose a controller to perform ESL under typical disturbances 2) to propose a methodology for payload estimation considering realistic estimation conditions. Lastly, aligned with these goals, 3) to propose models for the Front End Loader under consideration for derivation of solutions of the specified tasks. The self-leveling task assists farmers in maintaining the angular position of the mounted implements, e.g. a bale handler or a bucket, with respect to the ground when the loader is manually lifted or lowered. Experimental results show that different controllers are required in lifting and lowering motions to maintain the implement's angular position with a required accuracy due to principle differences in gravity impact. The gravity helps the necessary correction in lifting motion, but works against the correction in lowering motions. This led us to propose a controller with a proportional term, a discontinuous term and an on-line disturbance estimation and compensation as well as the tuning procedure to achieve a 2 degrees tracking error for lowering motions in steady state. The proposed controller shows less sensitive performance to lowering velocity, as the main disturbance, in comparison to a linear controller. The second task, payload estimation, assists farmers to work within safety range as well as to work with a weight measurement tool. A mechanical model derived based on equations of motion is improved by a pressure based friction to sufficiently accurately represent the motion of the front end loader under consideration. The proposed model satisfies the desired estimation accuracy of 2\% full scale error in a certain estimation condition domain in constant velocity regions, with off-line calibration step and off-line payload estimation step. An on-line version of the estimation based on Recursive Least Squares also fulfills the desired accuracy, while keeping the calibration step off-line.

This paper discusses an investigation on a novel hydraulic pump concept. The idea aims on a pump principle to be directly connected to highspeed electric motors to build compact highpressure drives [... aus der Einführung]

Volvo Construction Equipment (VCE) manufactures wheel loaders, articulated haulers, and excavators. By the end of 2030, the company hopes to have reduced the carbon footprint of its machines by 30 %. To increase energy efficiency and productivity, VCE is focused on developing futuristic wheel loaders that are both electric and autonomous. VCE has unveiled its latest autonomous wheel loader prototype called Zeux. This thesis work aims to create a simulation setup that includes a vehicle model of Zeux and a driver model that is optimised for the machine to complete a certain drive/load cycle. This simulation setup will be used to examine the machine’s performance, energy usage, and efficiency and compare it to a conventional machine to determine its advantages and limitations. The new vehicle model was created by modifying a conventional electric machine’s vehicle modeland a new four-wheel steering system was developed. A driver model was developed based on a condition-based decision tree and state machines with unique controllers for each driver input. This complete vehicle-driver simulation set-up has been tunedand optimised with respect to energy efficiency and productivity. The simulation results are then compared to the results of a similar conventional electric machine simulation model. According to the comparison study, the autonomous wheel loader concept has better productivity, lower hydraulic energy consumption as well as lower overall energy consumption compared to the conventional machine. It can complete the drive cycle much more efficiently despite having a similar powertrain and loading unit as the conventional machine. / Volvo Construction Equipment (VCE) tillverkar hjullastare, midjestyrda dumprar och grävmaskiner. I slutet av 2030 hoppas företaget ha minskat koldioxidavtrycket för sina maskiner med 30 %. För att öka energieffektiviteten och produktivitet är VCE fokuserade på att utveckla framtida hjullastare som både är elektriska och autonoma. VCE har presenterat sitt senaste autonoma hjullastarprototyp som heter Zeux. Detta examensarbete syftar till att skapa en simuleringsmiljö som innehåller en fordonsmodell av Zeux och en förarmodell som är optimerad för att maskinen ska klara en viss kör-/lastcykel. De framtagna modellerna ska sedan användas för att undersöka maskinens prestanda, energianvändning och effektivitet och jämföra resultaten med en konventionell elektrisk maskin för att fastställa dess fördelar och begränsningar. Den nya fordonsmodellen skapades genom att modifiera en konventionell elektrisk maskins fordonsmodell och ett nytt fyrhjulsstyrningssystem utvecklades. En förarmodell utvecklades baserad på ett tillståndsbaserat beslutsträd och tillståndsmaskiner med unika regulatorer för varje drivrutin. Den kompletta simuleringsmodellen har justerats och optimerats med avseende på energianvändning och produktivitet. Resultaten jämfördes sedan med simuleringsresultat av en liknande konventionell elektrisk hjullastare. Enligt jämförelsestudien, har konceptet med autonoma hjullastare bättre produktivitet, lägre hydrauliskenergiförbrukning samt lägre total energiförbrukning jämfört med den konventionella maskinen. Den kan slutföra körcykeln mycket mer effektivt samtidigt trots att den har en liknande drivlina och lastenhet som den konventionell maskin.