<p dir="ltr">Fretting wear occurs when two contacting bodies under load are subjected to small amplitude oscillatory motion. Depending on the applied normal load, displacement amplitude, coefficient of friction and resulting shear force, two types of fretting wear regimes exist – (i) partial slip and (ii) gross slip. At displacement amplitudes higher than gross slip condition, sliding wear regime prevails. Fretting wear becomes dominant in machine components subject to vibrations such as bearings, dovetail joints, etc. whereas sliding wear is observed in brakes, piston-ring applications, etc. The work in this dissertation primarily focuses on characterizing the material response of various machine components subjected to fretting and sliding wear regimes.</p><p dir="ltr">At first, the friction and fretting wear behavior of inlet ring and spring clip components used in land-based gas turbines was investigated at elevated (<a href="" target="_blank">500°C</a>) temperature. In order to achieve this objective, a novel high-temperature fretting wear apparatus was designed and developed to simulate the conditions existing in a gas turbine. The test apparatus was used to investigate fretting wear of atmospheric plasma sprayed (APS) Cr₃C₂-NiCr (25% wt.), high-velocity oxy-fuel (HVOF) sprayed Cr₃C₂-NiCr (25% wt.), HVOF sprayed T-800 and APS sprayed PS400 coated inlet rings against HVOF-sprayed Cr₃C₂-NiCr (25% wt.) coated spring clip. The PS400 coated inlet rings demonstrated a significant reduction in friction and wear. A finite element (FE) framework was also developed to simulate fretting wear in HVOF-sprayed Cr₃C₂-NiCr composite cermet coating. The material microstructure was modelled using Voronoi tessellations with a log-normal distribution of grain size. Moreover, the individual material phases in the coating were randomly assigned to resemble the microstructure from an actual SEM micrograph. A damage mechanics based cohesive zone model with grain deletion algorithm was used to simulate debonding of the ceramic carbide phase from the matrix and resulting degradation from repeated fretting cycles. The specific wear rate obtained from the model for the existing material microstructure was benchmarked against experiments. Novel material microstructures were also modeled and demonstrated to show less scatter in wear rate.</p><p dir="ltr">Following, a three-dimensional (3D) continuum damage mechanics (CDM) FE model was developed to investigate the effects of fretting wear on rolling contact fatigue (RCF) of bearing steels. In order to determine the fretting scar geometry, a 3D arbitrary Lagrangian-Eulerian (ALE) adaptive mesh (AM) FE model was developed to simulate fretting wear between two elastic bodies for different initially pristine fretting pressures (0.5, 0.75 and 1 GPa) and friction coefficients (0.15, 0.175 and 0.25) resulting in stick zone to contact width ratios, c/a = 0.35, 0.55 and 0.75. The resulting wear profiles were subjected to various initially pristine RCF pressures (1, 2.2 and 3.4 GPa). The pressure profiles for RCF were determined by moving the contact over the fretted wear profiles in 21 steps. These pressure profiles were then used in the CDM-FE model to predict the RCF life of fretted surfaces. The results indicate that increased fretting pressure leads to more wear on the surface, thereby reducing RCF life. As the RCF pressure increases (P_RCF ≥ 2.2 GPa), the effect of fretting on RCF life decreases for all fretting pressures and c/a values, indicating that life is primarily governed by the RCF pressure. The results from CDM-FE model were used to develop a life equation for evaluating the L₁₀ life of fretted M-50 bearing steel for the range of tested conditions.</p><p dir="ltr">Lastly, the sliding wear characteristics of pitch and poly-acrylonitrile based carbon-carbon (C/C) composites were investigated in air and nitrogen environment by designing and developing a disc brake test rig. It was found that the temperature of the disc, the surrounding environment, the supplied energy flux as well as the type of composite play a critical role in determining whether C/C composites operate in normal wear or dusting wear regime. Further analysis of wear mechanisms revealed interface and matrix cracking with fiber breakage from tests in air environment, whereas in nitrogen environment, particulate and layered debris played a prominent role.</p>

Kommersiella tunga transporter står för en stor del av utsläppen av växthusgaser. För att minska det globala fotavtrycket hos kommersiella fordon är det vanligt att använda biodrivmedel som ”drop in” bränslen. De avancerade motorer som för närvarande finns på marknaden är känsliga för olösliga föroreningarna, vilka benämns ”mjuka partiklar” av Scania. Dessa partiklar bildas som ett resultat av att biodieseln åldras, p.g.a. oxidationsinstabilitet, och en växelverkan med metalltillsatser i bränslet. Mjuka partiklar orsakar interna dieselinjektoravlagringar (IDID) och ett snabbt åldrande av bränslefilters genom igensättning. Avsikten med denna studie var att analysera det sistnämnda problemet genom att undersöka bränslefiltrets filtreringseffektivitet av oönskade mjuka partiklar. Ett protokoll över utförandet av feltreringstesterna utvecklades och skalades upp från en småskalig filterrestrigg vid KTH (Fas 1) till en fullskalig filtertestrigg på Scania (fas 2). Den experimentella uppställningen var ett försök att reproducera fältscenarier för filtrering i verkliga lastbilar. Tyngdpunkten i fas 1 riktades mot accelererade tester i den småskaliga testriggen med höga koncentrationer av tvålmjuka partiklar av zinkneodekanoat och syntetiskt producerade mjuka kalciumpartiklar. Separationseffektiviteten hos bränslefilter undersöktes med hjälp av GC-MS-analys. ICP mätningar gjordes för att upptäcka Zn2+ och Ca2+-joner i tvålämnena. Dessa tvålämnen identifierades tidigare på igensatta bränslefiltren och värden från dessa konventionella bränslefilter jämfördes med resultat från en absorptionsfiltreringsprocess med hjälp av ler(silikat)filter. Syftet med jämförelsen var att studera en alternativ bränslefiltreringsteknik för fordonstillämpningar. Mätningar med SEM-EDS gav rimliga förklaringar angående effektivitetsvärden för Zn-och Ca-tvålämnen för olika filtren, som används i försöken. Adsorptionsfiltret av lera hade 99 % filtreringseffektivitet och är en intressant lösning för framtida studier. Fas 2 fokuserade på en uppskalning av försöksprotokoll för filtreringstester med biobränslen och inkluderade sex olika riggförsök. Resultaten visade på tillförlitliga och exakta värden av tryckvariationer och filtereffektiviteten med en maximal effektivitet på 63,3 % för huvudfiltret och 75 % för förfiltret, som ett resultat av GC-MS-analysen. De uppmätta tryckvariationerna visar att förfiltret fångar in en majoritet (över 70 %) av de mjuka partiklarna, vilket resulterar i en ökning av tryckfallet över tiden. Med hänsyn till resultaten så rekommenderas försöksförfarandet för fortsatta framtida studier. / Commercial heavy duty transportation accounts for a major share of greenhouse gas emissions. In order to reduce the global footprint, commercial vehicles are widely known to use biodiesel as drop in fuels. The advanced engines, currently on the market, are sensitive to the insoluble contaminants, termed as soft particles in Scania. They are formed because of aging of biodiesel and the interaction with metal additives in the fuel. This is a common problem associated with the fuel due to high oxidation instability. Soft particles are responsible for causing Internal Diesel Injector Deposits (IDIDs) and premature fuel filter clogging. This report deals with the analysis of the latter problem. The purpose of the project is to investigate the fuel filter efficiencies against desired soft particles. A protocol of experiments was developed and scaled up from a small-scale filter rig at KTH (Phase 1) to a full-scale filter test rig at Scania (Phase 2) at ambient temperatures. The experimental campaign in this project is an attempt to replicate on field scenarios of filtration in real trucks. In Phase 1, the emphasis of the accelerated tests (higher concentrations) was on using soap soft particles, zinc neodecanoate and synthetically produced calcium soft particles for the small-scale filter rig. Separation efficiencies of fuel filters were examined using GC-MS analysis. Whereas ICP measurements were done to detect Zn2+ and Ca2+ ion in these soaps. These soaps were successfully identified to be present on the clogged fuel filters. Values from conventional fuel filters were compared with results from absorption filtration process using clay (silicate) filters. The purpose of the comparison was to study an alternate fuel filtration technique for vehicle application. Furthermore, SEM-EDS provided reasonable explanations about the efficiency values of the filters against Zn and Ca soaps used in the operation. The adsorption clay filter as had 99% of filtration efficiency proving an interesting solution for future investigations. Phase 2 started with an initiation of the scaling up or the protocol for test fuels, including six different rig operations. The maximum efficiencies of the filters (63.3% for main filters and 75% for pre filters) were noted as a result of quantification of the GC-MS results of the samples obtained from the rig. The pressure variations recorded proved, that the pre filters were trapping majority (over 70%) of the soft particles showing a rise in pressure drops over time. According to the results, the full-scale filter rig gave reliable and accurate values of pressure variations and filter efficiencies. Thus, it is suggested to use in the future investigations.

Gears are the heart of many machines, being its function transform and transmit torque. This work is a study of adequate design requirements, in particular, the best methodology to early detect gear fatigue failure using a gear test rig, an FZG test machine. The study used the widely proved QFD analysis technique that introduces the client in the design process by using a matrix system. All available relevant literature on the subject and interviews with relevant people in the field were sources of information for the development of this technique. In that way, a mapping is presented, showing the most common fatigue failure modes and available detection methods.  As a result of the investigation, the most suitable technique for the early gear failure detection in the FZG rig to be a combination of vibration analysis and acoustic emissions analysis, these techniques present the best practice at the moment and also possible to implement. However, other technologies are also presented in the report. / Kuggväxlar uppfyller en viktig funktion i många system. I det här arbetet studerades de viktigaste konstruktionskraven hos en tetstrigg för kugg, en FZG-rigg, för att kunna detektera tidiga tecken på kuggskador. Litteraturstudier tillsammans med intervjuer av personer från industrin lade grunden till en jämförelse av produktegenskaper som uppfyller kundkraven med hjälp av en så kallad Quality Function Deployment matrix (QFD-matris). I en QFD omvandlas kundkrav till funktion- och konstruktionskrav, i och med den kunde också de vanligaste kuggskadorna och detekteringsmetoderna kartläggas.  De mest relevanta teknikerna för att detektera tidiga tecken på skador i en FZG-rigg idag visade sig vara en kombination av vibrationsmätningar och akustiska emissionsmätningar. Lösningen är möjlig att implementera. Även andra teknologier finns presenterade i rapporten. / Los engranajes son el corazón de muchas máquinas, siendo su función transformar y transmitir par. En este trabajo se realizó un estudio de los requisitos de diseño más adecuados, en particular, la mejor metodología para detección anticipada de fallo a fatiga de engranajes testeados en un banco de pruebas de engranajes FZG. Durante el estudio se utilizó la técnica de análisis QFD que introduce al cliente en el proceso de diseño mediante el uso de un sistema matricial. Toda la literatura relevante disponible sobre el tema, así como entrevistas a personas relevantes en el campo fueron utilizadas como fuente de información para el desarrollo de dicha técnica. También se realizó un mapeo de los diferentes modos y mecanismos de fallo por fatiga más comunes, así como los métodos de detección disponibles.  Como resultado de la investigación se concretó como metodología más adecuada para la detección anticipada de fallo de engranajes en los bancos de prueba FZG, una combinación de análisis de vibraciones y análisis de emisiones acústicas, estas técnicas presentan las mejores características en función de la dificultad de implementación. Sin embargo, en el informe también se presentan otras tecnologías.

The wheel-rail contact mechanics and dynamics that are of great importance to the railroad industry are evaluated by applying statistical methods to the large volume of data that is collected on the VT-FRA state-of-the-art roller rig. The intent is to use the statistical principles to highlight the relative importance of various factors that exist in practice to longitudinal and lateral tractions and to develop parametric models that can be used for predicting traction in conditions beyond those tested on the rig. The experiment-based models are intended to be an alternative to the classical traction-creepage models that have been available for decades. Various experiments are conducted in different settings on the VT-FRA Roller Rig at the Center for Vehicle Systems and Safety at Virginia Tech to study the relationship between the traction forces and the wheel-rail contact variables. The experimental data is used to entertain parametric and non-parametric statistical models that efficiently capture this relationship. The study starts with single regression models and investigates the main effects of wheel load, creepage, and the angle of attack on the longitudinal and lateral traction forces. The assumptions of the classical linear regression model are carefully assessed and, in the case of non-linearities, different transformations are applied to the explanatory variables to find the closest functional form that captures the relationship between the response and the explanatory variables. The analysis is then extended to multiple models in which interaction among the explanatory variables is evaluated using model selection approaches. The developed models are then compared with their non-parametric counterparts, such as support vector regression, in terms of "goodness of fit," out-of-sample performance, and the distribution of predictions. / Master of Science / The interaction between the wheel and rail plays an important role in the dynamic behavior of railway vehicles. The wheel-rail contact has been extensively studied through analytical models, and measuring the contact forces is among the most important outcomes of such models. However, these models typically fall short when it comes to addressing the practical problems at hand. With the development of a high-precision test rig—called the VT-FRA Roller Rig, at the Center for Vehicle Systems and Safety (CVeSS)—there is an increased opportunity to tackle the same problems from an entirely different perspective, i.e. through statistical modeling of experimental data. Various experiments are conducted in different settings that represent railroad operating conditions on the VT-FRA Roller Rig, in order to study the relationship between wheel-rail traction and the variables affecting such forces. The experimental data is used to develop parametric and non-parametric statistical models that efficiently capture this relationship. The study starts with single regression models and investigates the main effects of wheel load, creepage, and the angle of attack on the longitudinal and lateral traction forces. The analysis is then extended to multiple models, and the existence of interactions among the explanatory variables is examined using model selection approaches. The developed models are then compared with their non-parametric counterparts, such as support vector regression, in terms of "goodness of fit," out-of-sample performance, and the distribution of the predictions. The study develops regression models that are able to accurately explain the relationship between traction forces, wheel load, creepage, and the angle of attack.

The electromechanical design and development of a sophisticated roller rig testing facility at the Railway Technologies Laboratory (RTL) of Virginia Polytechnic and State University (VT) is presented. The VT Roller Rig is intended for studying the complex dynamics and mechanics at the wheel-rail interface of railway vehicles in a controlled laboratory environment. Such measurements require excellent powering and driving architecture, high-performance motion control, accurate measurements, and relatively noise-free data acquisition systems. It is critical to accurately control the relative dynamics and positioning of rotating bodies to emulate field conditions. To measure the contact forces and moments, special care must be taken to ensure any noise, such as mechanical vibration, electrical crosstalk, and electromagnetic interference (EMI) are kept to a minimum. This document describes the steps towards design and development of all electromechanical subsystems of the VT Roller Rig, including the powertrain, power electronics, motion control systems, sensors, data acquisition units, safety and monitoring circuits, and general practices followed for satisfying the local and international codes of practice. The VT Roller Rig is comprised of a wheel and a roller in a vertical configuration that simulate the single-wheel/rail interaction in one-fourth scale. The roller is five times larger than the scaled wheel to keep the contact patch distortion that is inevitable with a roller rig to a minimum. This setup is driven by two independent AC servo motors that control the velocity of the wheel and roller using state-of-the-art motion control technologies. Six linear actuators allow for adjusting the simulated load, wheel angle of attack, rail cant, and lateral position of the wheel on the rail. All motion controls are performed using digital servo drives, manufactured by Kollmorgen, VA, USA. A number of sensors measure the contact patch parameters including force, torque, displacement, rotation, speed, acceleration, and contact patch geometry. A unified communication protocol between the actuators and sensors minimizes data conversion time, which allows for servo update rates of up to 48kHz. This provides an unmatched bandwidth for performing various dynamics, vibrations, and transient tests, as well as static steady-state conditions. The VT Roller Rig has been debugged and commissioned successfully. The hardware and software components are tested both individually and within the system. The VT Roller Rig can control the creepage within 0.3RPM of the commanded value, while actively controlling the relative position of the rotating bodies with an unprecedented level of accuracy, no more than 16nm of the target location. The contact force measurement dynamometers can dynamically capture the contact forces to within 13.6N accuracy, for up to 10kN. The instantaneous torque in each driveline can be measured with better than 6.1Nm resolution. The VT Roller Rig Motion Programming Interface (MPI) is highly flexible for both programmers and non-programmers. All common motion control algorithms in the servo motion industry have been successfully implemented on the Rig. The VT Roller Rig MPI accepts third party motion algorithms in C, C++, and any .Net language. It successfully communicates with other design and analytics software such as Matlab, Simulink, and LabVIEW for performing custom-designed routines. It also provides the infrastructure for linking the Rig's hardware with commercial multibody dynamics software such as Simpack, NUCARS, and Vampire, which is a milestone for hardware-in-the-loop testing of railroad systems. / Ph. D.

This study presents the design and optimization of a test rig tailored for upcoming wind turbine design applications. Initial decisions were made regarding component selection, focusing on a gearbox, electric motor, and motor controller. Requirements included continuous power output of 300 kW from the electric motor and the gearbox's ability to handle specified torque and reduce input speed to match the structural limitations. Key challenges revolved around gearbox design and performance, necessitating a right-angle configuration for converting horizontal to vertical torque efficiently. To meet the rotational speed requirements, a 30 to 1 ratio gearbox was selected, ensuring compatibility with the maximum structural rotational speed of 50 revolutions per minute. The electric motor, pivotal in the drivetrain, was chosen based on a balance between economic viability and rotational speed, resulting in a four-pole motor configuration. Coupling mechanisms were employed to connect the motor and gearbox, facilitating energy transfer between shafts. A motor controller was integrated to regulate current flow, voltage application, and frequency modulation, enhancing operational control and adaptability to specific requirements. Radial ball bearings were selected to minimize energy expenditure during rotation, particularly due to downward compressive forces. The test rig setup, situated indoors on a concrete floor, mandated a metal plate foundation to ease component attachment without drilling into the floor. Data simulations were conducted to determine bolt specifications capable of withstanding motor-induced forces. Furthermore, collaboration with industry experts facilitated component selection and quotation analysis, ensuring an optimized drivetrain solution meeting both technical and economic criteria. This research contributes to the advancement of wind turbine design testing methodologies, providing insights into component selection, integration, and optimization for enhanced performance and reliability.

Sammanfattning Syftet med studien var att skapa en deskriptiv bild över de tre utvalda sårbarhetsfaktorer (tävlingsoro, sömnsvårigheter och fysiska skador) samt undersöka eventuella samband och skillnader mellan dessa gällande elever som läser specialidrott på Riksidrottsgymnasium (RIG). Studiens frågeställningar var: 1) Vilken fysisk skadefrekvens (överbelastning respektive traumatisk skada) har RIG-elever haft under det senaste året? 2) I vilken grad upplever RIG-elever tävlingsoro inför och under tävling/match? 3) I vilken grad upplever RIG-elever sömnsvårigheter? 4) Vilka samband eller skillnader finns mellan de tre valda sårbarhetsfaktorerna? 5) Vilka skillnader i skadefrekvens, skadetyp, sömnsvårigheter och tävlingsoro finns mellan årskurserna? Metod Elektronisk enkätundersökning användes som verktyg för mätbara data genom slutna enkätfrågor. De formulär som använts för den elektroniska enkätundersökningen var CSAI-2 (tävlingsoro), ISI (Sömnsvårigheter) samt fysisk skadefrånvaro enligt definition av Tranæus (2013). Inbjudan till att delta i studien skickades ut till samtliga RIG i Sverige, totalt 40 skolor. Av dessa tackade 18 skolor ja till deltagande, 8 tackade nej och 14 svarade inte på inbjudan. Av den totala populationen deltog 336 riksidrottsgymnasieelever från 24 olika idrotter. Svaren från enkäten presenteras dels i deskriptiv kvantitativ karaktär och dels i en analytisk del. Resultat Inom populationen hade 70 procent varit frånvarande på grund av fysiska skador under året (48 procent på grund av en överbelastnings- och 22 procent på grund av en traumatisk skada), varav 41 procent var frånvarande från träning, tävling eller match längre än en vecka.  Markanta sömnbesvär rapporterades hos 15 procent av eleverna. På CSAI-2 skalan hade självförtroende ett medelvärde på 22,3 ± 5,9 poäng, somatisk oro 18,6 ± 5,6 poäng, kognitiv oro 17,6 ± 4,8 poäng. Statistiska analysen visade signifikanta samband mellan skadefrånvaro, ISI och CSAI-2, förutom mellan somatisk oro och skadefrånvaro. Inga signifikanta skillnader i någon aspekt fanns mellan årskurserna. Slutsats Studiens slutsats är att fysiska skador har ett samband med sömnstörningar och att tävlingsoro korrelerar med både fysiska skador och sömnen negativt. Resultatet kan hjälpa lärare och tränare att få förståelse för dessa faktorer kan behöva uppmärksammas i starten av unga elitidrottares uppväxt. / Abstract The aim of this study was to get a descriptive view of the area and to investigate possible relationships/differences between the three selected vulnerability factors for students who study sports at a Riksidrottsgymnasium (RIG). The study aimed to answer the following questions: 1) To what physical injury rate (overload or traumatic injury) have RIG students had in the past year? 2) To what extent do RIG students experience anxiety before and during competition / match? 3) To what extent do RIG students experience sleep difficulties? 4) What are the relationships or differences between the three selected vulnerabilities? 5) What differences in rate of injury, type of injury, insomnia and anxiety are between grades? Method Electronic survey was used as a tool for measurable data through closed questionnaires. The form that the study used for the electronic survey was CSAI-2 (Anxiety), ISI (Injury) and physical injury severity according to the same definition as Tranæus (2013). The invitation to participate in the study was sent to all RIGs in Sweden, a total of 40 schools. Out of these 40 schools 18 schools accepted to participate in the study, 8 schools voted to not participate and 14 did not respond. Of the total population, 336 high school athletics students participated in 24 different sports. The answers from the questionnaire are presented in a descriptive quantitative character and an analytical part. Results In the population, 70 percent were absent due to physical injuries, of which 41 percent were absent from training, competition or match longer than one week. 48 percent of all students had an overload injury and 22 percent traumatic injury in the past year. 15 percent showed significant sleep disorders. Self-confidence had an average of 22.3 ± 5.9 points, somatic concern, 18.6 ± 5.6 points, cognitive concern, 17.6 ± 4.8 points. Statistical analysis showed significant results between injury absence, ISI and CSAI-2 aside from somatic concern and injuries. Regarding differences between grades, the results showed no diferences in any aspects. Conclusion The conclusion of this study is that physical injuries are associated with sleep disorders and that anxiety is correlated negatively with both physical injuries and sleep. The result can help teachers and coaches to understand these factors may need to be noted at the start of young elite athletes.

The goal of this 15 hp thesis in computer engineering was to develop a tool for monitoring and analyzing the data flow on a Controller Area Network (CAN) called Rig Control System (RCS) that is used by Atlas Copco. Atlas Copco develops and manufactures machines for Mining and Rock Excavation. The Rocktec division is responsible for the Rig Control System platform used on machines in all division within the Mining and Rock Excavation Technique (MR) business area. The tool’s primary purpose is monitor and analyze data from the RCS network and present the analyzed data in an easy way to help with development and maintenance of RCS and machines that use RCS. The advantages and how data is sent over the CAN bus are presented as well as the CANopen protocol which is a higher layer protocol based on CAN. Two ways of data acquisition from RCS are presented, a simulated environment and real hardware. Different types of interprocess communication are presented as well as the pros and cons of each of these types. The creation of the tool required a Graphical User Interface (GUI) so different frameworks for this task are also presented and discussed. A version of the tool is presented and discussed in detail. The result of the project is a tool that with further development can be of great use to developers and service engineers working with RCS. / Målet med detta 15 hp examensarbete inom datateknik var att utveckla ett verktyg för att övervaka och analysera dataflödet på ett Controller Area Network (CAN) kallat Rig Control System (RCS) som används av Atlas Copco. Atlas Copco utvecklar och tillverkar maskiner för gruvdrift och bergbrytning. Rocktec-divisionen är ansvarig för Rig Control System-plattformen som används i maskiner från alla avdelningar inom affärsområdet Mining and Rock Excavation Technique (MR). Verktygets primära uppgift är att övervaka och analysera data från RCS-nätverket och presentera den analyserade datan på ett lättöverskådligt sätt för att vara till hjälp vid utveckling och underhåll av RCS och maskiner som använder RCS. Fördelar, hur data skickas över CAN-bussen och även CANopen-protokollet, som är ett högnivåprotokoll baserat på CAN, presenteras. Två olika sätt att samla in data från RCS presenteras, en simulerad miljö och riktig hårdvara. Olika typer av interprocesskommunikation och deras respektive fördelar och nackdelar presenteras. Skapandet av verktyget krävde ett grafiskt användargränssnitt så olika ramverk för denna uppgift presenteras och diskuteras i detalj. Resultatet av projektet är ett verktyg som med vidare utveckling kan vara till stor användning för utvecklare och servicetekniker som arbetar med RCS.

For the transport of their spacecraft from the vehicle assembly building to the launch pads at Kennedy Space Centre, Florida, the National Aeronautics and Space Administration (NASA) is using two special crawler transporters since 1965. First developed for the Saturn V rocket the crawler transporters have been sufficient for all following generations of space ships so far. But for the new generation of Orionspacecraft which is under development now, a load capacity increase for the crawler transporter of plus 50% was necessary. For this task Hunger Hydraulik did develop new jacking, equalizing and levelling (JEL) cylinders with sufficient load capacity but also with some new features to improve the availability, reliability and safety of this system. After design approval and manufacture of the cylinders they have been tested in a special developed one-to-one scale dynamic test rig and after passing this the cylinders had to prove their performance in the crawler transporter itself. This article describes the general application and introduces the technical requirements of this project as well as the realized solution.

An interest in developing the intelligent machine system that works in conjunction with human has been growing rapidly in recent years. A number of studies were conducted to shed light on how to design an interactive, adaptive and assistive machine system to serve a wide range of purposes including commonly seen ones like training, manufacturing and rehabilitation. In the year 2003, Human Adaptive Mechatronics (HAM) was proposed to resolve these issues. According to past research, the focus is predominantly on evaluation of human skill rather than human performance and that is the reason why intensive training and selection of suitable human subjects for those experiments were required. As a result, the pattern and state of control motion are of critical concern for these works. In this research, a focus on human skill is shifted to human performance instead due to its proneness to negligence and lack of reflection on actual work quality. Human performance or Human Performance Index (HPI) is defined to consist of speed and accuracy characteristics according to a well-renowned speed-accuracy trade-off or Fitts' Law. Speed and accuracy characteristics are collectively referred to as speed and accuracy criteria with corresponding contributors referred to as speed and accuracy variables respectively. This research aims at proving a validity of the HPI concept for the systems with different architecture or the one with and without hardware elements. A direct use of system output logged from the operating field is considered the main method of HPI computation, which is referred to as a non-model approach in this thesis. To ensure the validity of these results, they are compared against a model-based approach based on System Identification theory. Its name is due to being involved with a derivation of mathematical equation for human operator and extraction of performance variables. Certain steps are required to match the processing outlined in that of non-model approach. Some human operators with complicated output patterns are inaccurately derived and explained by the ARX models.