This Master thesis deals with the design of linear unit with hydraulic actuator for the robot with parallel kinematic structure. One of the objectives is to get an overview of the differences related to characteristics of design and construction between serial and parallel kinematic structure (PKS) of the industrial robots, as a new type of technical objects in robotics. In addition the aim is to create an original structural design of linear unit, as the basic constructional assembly and operational node of robot with PKS, according to the specified input values, such as power, pressure, speed and stroke, important for the design of linear hydraulic actuator.

Fatigue analysis is a critical stage in the design of any structural component. Typically fatigue is analysed during post-processing, but as the size of the analysed component increases, the amount of data stored for the analysis increases simultaneously. This increases the computational and memory requirements of the system, intensifying the work load on the engineer. A continuum mechanics approach namely ’Continuous time fatigue model’, for fatigue analysis is available in a prior study which reduces the computational requirements by simultaneously computing fatigue along with the stress. This model implements a moving endurance surface in the stress space along with the damage evolution equation to compute high-cycle fatigue. In this thesis the continuous time fatigue model is compared with conventional model (ie.Cycle counting) to study its feasibility. The thesis also aims to investigate the continuous time fatigue model and an evolved version of the model is developed for non-proportional load cases to identify its limitations and benefits.

Orientador: Gilberto Pechoto de Melo / Resumo: O uso da metodologia de observadores de estado para detecção de dano requer a análise da observabilidade do modelo físico-matemático do sistema e aponta para a necessidade de posicionar sensores de forma otimizada. Visto que plataformas veiculares podem se apresentar como sistemas com amortecimento não proporcional, é apresentada uma metodologia para o cálculo de índices de posicionamento H2 para este tipo de sistema. Para a plataforma veicular analisada com amortecimento proporcional, índices de posicionamento H2 são comparados com índices grammianos, sendo demonstrado que ambos resultam em uma mesma configuração ótima de sensores. A análise da observabilidade é conduzida a partir dos principais modos de vibrar , sendo utilizada a norma H2 para definição de quais modos devem ser retidos no modelo reduzido. Observadores robustos, atuando em paralelo com o sistema, são utilizados para localização e quantificação da severidade do dano. É mostrado que, para plataformas veiculares excitadas pela base com deslocamentos do tipo degrau, um índice de dano que compara as saídas medidas e estimadas permite alcançar este objetivo. / Abstract: The use of state observer's methodology for damage detection requires the observability analysis of the physical-mathematical model of the system and points to the need of positioning sensors optimally. Since vehicle platforms can be presented as systems with non-proportional damping, a methodology for calculating H2 positioning indices for this type of system is presented. For the vehicle platform analyzed with proportional damping, H2 positioning indices are compared with Grammian indices, showing that both result in the same optimal sensor con guration. The observability analysis is conducted from the main modes of vibration, using the H2 norm to define which modes should be retained in the reduced model. Robust observers acting in parallel with the system are used to locate and quantify the severity of the damage. It is shown that, for vehicle platforms stimulated by the base with step-type displacements, a damage index that compares the measured and estimated outputs reaches this goal. / Mestre

Cox proportional hazard model is often used to estimate the effect of covariates on hazard for censored event times. In this thesis we study the semiparametric models of additive risk for censored data. In this model the hazard is given as a sum of unknown baseline hazard function and a product of covariates and coefficients. Further the general additive-multiplicative model is assumed. In this model the effect of a covariate can be either multiplicative, additive or both at the same time. We focuse on determining the effect of a covariate in the general model. This model can be used to test for the multiplicative or addtive effect of a covariate on the hazard.

Over the last years, electrical roads have emerged as a cost effective and environmentally friendly solution towards a transportation system with less dependency on fossil fuels. This thesis presents the design of a search and locate system for road-bound conductive electrical roads with position control in two axes. The system is intended to find and follow the position of an electrified rail. The actuator system constitutes a firm groundwork for further research and development in this field. A laboratory test set up has been designed and both hardware and software parts have been constructed. The control of the system uses the CompactRIOTM technology from National Instruments. Results from the practical evaluation suggest that the non-linear characteristic of the system and the lack of direct position feedback from the motor rotation are the main causes of a non-accurate position control. Future development steps should focus on improving the mechanical design and include encoder feedback for the control loop as well as absolute automatic control with the incorporation of rail sensors.

Missile guidance and autopilot have been active fields of research since the second world war. There are lots of literature on the subjects, but the bulk of which are confined to overly simplified models, and therefore the publications of the methods applied to more realistic models are scarce. In this report a nonlinear 6 DOF simulation model of a tail-controlled air-to-air missile is considered. Through several assumptions and simplifications a linearized approximation of the plant is obtained, which then is used in the implementation of 5 guidance laws and 2 autopilots. The guidance laws are all based on a linearized collision geometry, and the autopilots are based on model predictive control (MPC). Both autopilots use linear quadratic MPC (LQMPC), and one is more robust to modelling errors than the conventional LQMPC. The guidance laws and autopilots are then evaluated with respect to performance in terms of miss distance in 4 interception scenarios with a moving target. The results show that the in this model the autopilots perform equally well, and that the guidance laws with more information about the target generally exhibit smaller miss distances, but at the cost of a considerably larger flight time for some scenarios. The conclusions are that the simplifying assumptions in the modelling are legitimate and that the challenges of missile control probably does not lie in the guidance or autopilot, but rather in the target tracking. Therefore it is suggested that future work include measurement noise and process disturbances in the model. / Det har forskats kring styrlagarna och styrautomaterna för robotar sedan an-dra världskrigets. Det finns mycket litteratur på områdena, men merparten av de publicerade resultaten behandlar enbart grovt förenklade modeller, och därför är tillgången på publikationer där metoderna applicerats i en mer realistisk modell begränsat. I denna rapport behandlas en olinjär simuleringsmodell av en jaktrobot som styrs med stjärtfenor och har sex frihetsgrader. Genom en rad antaganden och förenklingar erhålls en linjäriserad modell av missilen, vilket sedan används för implementering av fem styrlagar och två styrautomater. Styr-lagarna är alla baserade på en linjäriserad kollisionsgeometri och styrautomaterna är baserade på modellprediktiv styrning (MPC). Båda styrautomaterna använder linjärkvadratisk MPC, där den ena påstås vara mer robust gentemot modellfel. Styrlagarna och -automaterna utvärderas ur ett prestandaperspektiv med fokus på bomavstånd i fyra realistiska genskjutningsscenarier med ett rörligt mål. Resultaten visar att båda styrautomaterna presterar lika bra, och att de styrlagar med mer information om målets position/hastighet/acceleration generellt presterar bättre, men att de för vissa skjutfall får en väsentligt längre flygtid. Slutsatserna är att förenklingarna och antagandena i linjäriseringen är välgrundade, och att utmaningarna i missilstyrning inte ligger i utformning av styrlag/-automat, utan förmodligen i målsökningen. Därför föreslås det slutligen att framtida arbete bl. a. inkluderar mätbrus och störningar.

Proportional valves are widely used in fluid systems for controlling the volume flow rate or fluid pressure. The actuation of this valves is done by PWM-driven proportional solenoids, which enable self-sensing position determination abilities due to air gap-dependent electrical behaviour, e. g. for condition monitoring or position controlling tasks. However, the sensor properties of conventional proportional solenoids are poor due to ambiguities caused by hysteresis effects (magnetic hysteresis, eddy currents) and saturation effects. Thus, a sensor-designed actuator was developed with very low hysteresis effects and unique position determination by using electrical sheet and a particular air gap design. This paper deals with investigations of a novel self-sensing position determination approach on a demonstrator of the sensor-designed solenoid. The advantage of this method is an online consideration of transient effects such as mean current change and armature motion as well as temperature-dependent resistance. For this, a combined evaluation of the differential inductance and flux linkage during PWM periods is proposed.

The thesis focuses on influence of the AMS (Additional Member System) upon party systems of Scotland and Wales. This system is used for elections to Scottish parliament and Welsh national assembly. It was applied for the first election that was held in 1999 and it is still in use. This means AMS is used in both regions for the same time period, which allows us to compare the influence which the system has in different environment. The thesis analyzes results of all elections that were held in Scotland and Wales and defines their influence on particular parties and party systems it operates in. On the basis of these findings the general influence of AMS is formulated. Theoretical concepts by Maurice Duverger and Giovanni Sartori are used as a background for study of election systems and party systems. The position voter support and its changes are analyzed through valence theory, which uses opinion polls to explain election results. At the first sight the AMS seems to be the same one as another election system - MMP (Mixed Member Proportional). These systems are often confused or perceived as the same ones. So except the election results analysis this thesis explains also the difference between these systems and classifies them into right categories. It shows up that each of the systems belongs to...

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