Práca sa zaoberá objavujúcim sa nekonvenčným využitím moderných teodolitov, tiež známych ako Robotické Totálne Stanice (RTS), ako sledovací a navádzací systém, určením presnej pozície dynamicky sa pohybujúceho objektu. To sa týka najmä situácií, kde nie je možné využiť konvenčné polohovacie systémy akým je napríklad GNSS. Kinematicky určená poloha objektu kontinuálne sledujúcou RTS môže byť následne v reálnom čase využitá pre autonómnu navigáciu malých bezpilotných leteckých prostriedkov (UAV) poskytnutím referenčného súradnicového systému a okamžitej polohy v ňom. Podstatná časť práce je venovaná návrhu a realizácii vhodných experimentov, ktoré overia spoľahlivosť určovania presnej polohy objektu v presnom časovom okamžiku. Boli preverené stanice série S7 a S9 od spoločnosti Trimble a stanica S9 HP, ktorá disponuje frekvenciou kontinuálneho merania až do 10 Hz bola napokon využitá pre experimenty. Lokálny čas ovládacieho panelu TSC7, ktorý zabezpečuje komunikáciu so stanicou bol pomocou protokolu PTP synchronizovaný s lokálnym časom mini-počítača Raspberry Pi, ktorý následne poskytoval referenčné meranie skutočnej polohy objektu v čase. V závere sú zhrnuté výsledky experimentov.

Reducing energy consumption in pulp and paper refining requires a deep understanding of all the processes involved. This dissertation investigates fundamental mechanics of the low consistency mechanical refining process. Three studies investigate forces applied to wood fibers with the focus on how force profiles during bar passing events change with process variables such as fiber length and refiner load. In the first study a high resolution rotary encoder and a piezo ceramic force sensor are implemented in a 16-inch laboratory-scale low consistency refiner to explore the effect of plate gaps on bar-force profiles. The rotary encoder data is used to locate the rotor bars relative to the stator bar in which the sensor is located. Force profiles for bar passing events are registered to the position of rotor bars relative to the stator bar in which the sensor is located and mean force profiles are produced. These mean force profiles have potential to shed light on the fundamental mechanisms of mechanical refining. For large gaps, there is a late peak in the force profiles that occurs toward the end of the bar passing event. For gaps that are less than the critical gap, below which fiber cutting occurs, there is an early peak in the force profiles that occurs at the start of the bar passing event. It is hypothesized that the early peak represents the corner force and, therefore, that corner force is causal in the onset of fiber cutting. In the second study a set of piezo ceramic force sensors is implemented in a 52-inch mill-scale low consistency refiner to explore the effect of varying operating conditions on bar force profiles. Force profiles for individual bar passing events are identified based on key features in the time domain force data based on the knowledge acquired from the previous study in the pilot-scale refiner. The individual bar force profiles are classified as single peak events which feature one peak corresponding to the fiber compression force and as dual peak events corresponding to fiber compression force and the corner force. It is shown that dual peak events which are considered to represent the corner force, are present throughout the whole range of refining and increase with increased refining energy. After applying the dual peak analysis to the data from the previous study this behaviour was also found in the pilot-scale refiner data. Furthermore, it is found that different radial positions on the stator plate are subjected to different force profiles. This is thought to be due to the difference in tangential speed and a change in the fiber and floc material properties at different radial positions. In the third study the effect of refiner plate wear on bar force sensor measurements is explored by applying the dual peak analysis to long term data acquired from the mill-scale refiner. Bar passing events are analysed based on the dual peak ratio and the timing of the early peak in the dual peak events. Force measurements are evaluated over the full run time of a set of refiner plates. When comparing force profiles with refiner plate wear measurements and discharge fiber analysis, it is found that the decrease in the prevalence of the corner force correlates with the wear of the leading edge of the refiner bars, or bar rounding, for the run time of the refiner plate. This is accompanied by a decrease in plate performance which is represented by a decrease in fiber length and freeness reduction for the same refiner load. / Graduate

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: This thesis presents the design and implementation of all the subsystems required to perform precision autonomous helicopter landings within a low-cost framework. To obtain high-accuracy state estimates during the landing phase a vision-based approach, with a downwards facing camera on the helicopter and a known landing target, was used. An e cient monocular-view pose estimation algorithm was developed to determine the helicopter's relative position and attitude during the landing phase. This algorithm was analysed and compared to existing algorithms in terms of sensitivity, robustness and runtime. An augmented kinematic state estimator was developed to combine measurements from low-cost GPS and inertial measurement units with the high accuracy measurements from the camera system. High-level guidance algorithms, capable of performing waypoint navigation and autonomous landings, were developed. A visual position and attitude measurement (VPAM) node was designed and built to perform the pose estimation and execute the associated algorithms. To increase the node's throughput, a compression scheme is used between the image sensor and the processor to reduce the amount of data that needs to be processed. This reduces processing requirements and allows the entire system to remain on-board with no reliance on radio links. The functionality of the VPAM node was con rmed through a number of practical tests. The node is able to provide measurements of su cient accuracy for the subsequent systems in the autonomous landing system. The functionality of the full system was con rmed in a software environment, as well as through testing using a visually augmented hardware-in-the-loop environment. / AFRIKAANSE OPSOMMING: Hierdie tesis beskryf die ontwikkeling van die substelsels wat vir akkurate outonome helikopter landings benodig word. 'n Onderliggende doel was om al die ontwikkeling binne 'n lae-koste raamwerk te voltooi. Hoe-akkuraatheid toestande word benodig om akkurate landings te verseker. Hierdie metings is verkry deur middel van 'n optiese stelsel, bestaande uit 'n kamera gemonteer op die helikopter en 'n bekende landingsteiken, te ontwikkel. 'n Doeltreffende mono-visie posisie-en-orientasie algoritme is ontwikkel om die helikopter se posisie en orientasie, relatief tot die landingsteiken, te bepaal. Hierdie algoritme is deeglik ondersoek en vergelyk met bestaande algoritmes in terme van sensitiwiteit, robuustheid en uitvoertyd. 'n Optimale kinematiese toestandswaarnemer, wat metings van GPS en inersiele sensore kombineer met die metings van die optiese stelsel, is ontwikkel en deur simulasie bevestig. Hoe-vlak leidingsalgoritmes is ontwikkel wat die helikopter in staat stel om punt-tot-punt navigasie en die landingsprosedure uit te voer. 'n Visuele posisie-en-orientasie meetnodus is ontwikkel om die mono-visie posisie-en orientasie algoritmes uit te voer. Om die deurset te verhoog is 'n saampersingsalgoritme gebruik wat die hoeveelheid data wat verwerk moet word, te verminder. Dit het die benodigde verwerkingskrag verminder, wat verseker het dat alle verwerking op aanboord stelsels kan geskied. Die meetnodus en mono-visie algoritmes is deur middel van praktiese toetse bevestig en is in staat om metings van voldoende akkuraatheid aan die outonome landingstelsel te verskaf. Die werking van die volledige stelsel is, deur simulasies in 'n sagteware en hardeware-indie- lus omgewing, bevestig.

The objective of this diploma thesis is the design of a device that measures the vehicle’s centre of gravity height position. The first part defines individual methods of measurement using various measuring equipment. The next part deals with the definition of requirements for the device and the definition of the design. A stress-strain analysis was executed for selected components. This diploma thesis describes the preparation process of the vehicle and the device for the measurement. The next part is dedicated to the design of the measuring chain and to the evaluation of the results. The thesis concludes with a theoretic analysis of the measurement inaccuracy.

The aim of the thesis is to design a special purpose tool for sag measurement. Three possible solutions are proposed, for each the production cycle time is calculated and its approximate costs are estimated. The best solution in terms of a trade-off between both key quantities is suggested. Next part of the work deals with the selection of suitable drives for the manipulator as well as of the other components for the whole electrical device. Finally, a possible automated control of the complete machinery, including the electrical wiring diagram, is presented.

<p>У овој докторској дисертацији извршен је преглед постојећих метода мерења угаоног положаја и дат је предлог нове методе за мерење апсолутног угаоног положаја. Предложена мерна метода заснива се на примени трансформације боје објекта из Декартовог RGB простора боја у неки од цилиндричних, кориснички оријентисаних, простора боја (HSV, HSI, HLS). На бази предложене мерне методе конструисан је сензор апсолутног угаоног положаја који се састоји од три оптичка рефлексиона сензора и штампаног шаблона са сивом скалом. Тачност, поновљивост и резолуција мерења, постигнути приликом тестирања сензора су &plusmn;1 &deg;, &plusmn;0,3 &deg; и 0,1 &deg;.</p> / <p>U ovoj doktorskoj disertaciji izvršen je pregled postojećih metoda merenja ugaonog položaja i dat je predlog nove metode za merenje apsolutnog ugaonog položaja. Predložena merna metoda zasniva se na primeni transformacije boje objekta iz Dekartovog RGB prostora boja u neki od cilindričnih, korisnički orijentisanih, prostora boja (HSV, HSI, HLS). Na bazi predložene merne metode konstruisan je senzor apsolutnog ugaonog položaja koji se sastoji od tri optička refleksiona senzora i štampanog šablona sa sivom skalom. Tačnost, ponovljivost i rezolucija merenja, postignuti prilikom testiranja senzora su &plusmn;1 &deg;, &plusmn;0,3 &deg; i 0,1 &deg;.</p> / <p>In this doctoral thesis a review of existing methods for angular position<br />measurement is conducted and a new method for measuring absolute<br />angular position is proposed. The proposed measurement method is based<br />on the use of object color transformation from Cartesian RGB color space to<br />one of the user-oriented cylindrical color space (HSV, HSI, HLS). Оn the<br />basis of the proposed measurement method, absolute angular position<br />sensor consisting of three optical reflective sensors and a grayscale printed<br />pattern is constructed. Accuracy, repeatability and resolution of<br />measurement using proposed sensor were &plusmn; 1 &deg;, &plusmn; 0.3 &deg; and 0.1 &deg;.</p>

Trains are constrained to the railway tracks they operate on. This can be leveraged for absolute train positioning, where a train’s position can be mapped onto a digital track map (DTM). Extensive research has been dedicated to enhancing the accuracy of DTMs. However, certain practical applications necessitate compact DTMs that can be processed and transferred in real-time, thereby introducing a trade-off between accuracy and memory requirements. This study focuses on data reduction techniques for generating compact DTMs, presenting three distinct methods. Equidistantly sampled Cartesian coordinates are the input to all three methods as they employ different approaches: the linear method simplifies the polygonal chain that connects the coordinates, the spline method utilises smoothing B-splines for interpolation, and the geometric method interpolates the coordinates with a cubic spline and analyse the curvature to identify track segments and describe them geometrically. The performance of these methods is evaluated by their compactness in terms of the number of data fields needed, accuracy in representing track length, and the perpendicular distances between the ground truth track and the generated DTM. The compact DTM generation techniques are applied to three evaluation tracks specifically generated for this study, as well as two existing tracks in the Swedish railway network, each with distinct complexities and characteristics. On the evaluation tracks, the geometrical DTM excels when accuracy is prioritised. As greater perpendicular deviations are tolerated, the smoothed spline DTM method outperforms the other techniques in terms of compactness. The linear DTM method is superior when even greater perpendicular deviations are tolerated. On the existing tracks, the linear DTM method is outperforming the other methods in both accuracy and compactness, presumably because of limitations with the used data set. In conclusion, the choice of technique for generating compact DTMs depends on multiple factors, including the characteristics of the track and the desired level of accuracy. / Tåg är bundna till de järnvägsspår de trafikerar. Detta innebär att tågets digitala position kan förfinas genom att knyta tågets sensorinformation till en position på en digital spårkarta. Tidigare forskning har fokuserat på att förbättra precisionen i digitala spårkartor. Eftersom en del praktiska användningsområden av digitala spårkartor kräver att kartan är kompakt för att kunna bearbetas och överföras i realtid, uppstår en avvägning mellan precision och minneskrav. Denna studie fokuserar således på olika tekniker för datareduktion som kan användas för att generera kompakta spårkartor. Tre metoder tillämpas som alla använder samplade koordinater längs med järnvägsspåret som indata. Den linjära metoden förenklar det polygontåg som förbinder koordinaterna. I spline-metoden används utjämnande splines för att interpolera koordinaterna. Den geometriska metoden interpolerar koordinaterna med en kubisk spline och använder kurvaturen i splinen för att identifiera spårsegment och beskriva dessa geometriskt. De tre metoderna utvärderas och jämförs utifrån en analys avseende kompakthet, avvikelse från järnvägsspårets egentliga längd samt genom att mäta de vinkelräta avstånden mellan det riktiga spåret och spåret i den digitala spårkartan. Tre tågspår har skapats syntetiskt för att utvärdera de tre metoderna. Dessutom har två tågsträckor längs med Kinnekullebanan och Södra stambanan valts ut. Analysen visade att den geometriska spårkartan var mest kompakt på de syntetiska tågspåren när precision prioriterades högst. När kraven på precision minskades var spline-kartan mest kompakt på de syntetiska spåren. Däremot var den linjära metoden mest kompakt när kompakthet prioriterades över precision. Den linjära metoden var dominant med avseende på både precision och kompakthet på Kinnekullebanan och Södra stambanan, troligtvis på grund av begränsningar med den data över järnvägen som använts. Slutsatsen från denna studie är att valet av teknik för att generera kompakta spårkartor beror på flera faktorer, inklusive järnvägsspårets egenskaper och krav på precision.