Reactive motion planning and local navigation of robots remains a significant challenge in the motion control of robotic vehicles. This thesis presents new results on vision guided navigation using optical flow. By detecting key image features, calculating optical flow and leveraging time-to-transit (tau) as a feedback signal, control architectures can steer a vehicle so as to avoid obstacles while simultaneously using them as navigation beacons. Averaging and balancing tau over multiple image features successfully guides a vehicle along a corridor while avoiding looming objects in the periphery. In addition, the averaging strategy deemphasizes noise associated with rotationally induced flow fields, mitigating risks of positive feedback akin to the Larsen effect. A recently developed, biologically inspired, binary-key point description algorithm, FReaK, offers process speed-ups that make vision-based feedback signals achievable. A Parrot ARDrone2 has proven to be a reliable platform for testing the architecture and has demonstrated the control law's effectiveness in using time-to-transit calculations for real-time navigation.

This diploma thesis deals with complete designing and implementation of local navigation of a robot which travels according to set GPS. This work contains a study of contemporary used principles of the sensors which can be used as the components of the robot. There are sensors for measuring the surroundings of the robot and orientation of the robot in the environs. The equipment includes an instructing control unit with the ATmega8 microcontroller. This equipment collects data from the sensors and transfers them to the other systems of the robot. The following part of the thesis deals with the draft of the buses and communication protocols, which are necessary for connection between the sensors and the control unit. The I2C and RS232 buses were chosen as the most suitable. The communication protocol was borrowed from the semester project written by Bc. Michal Sitta. The main task of this control unit is reading out the data which have been measured from connected sensors. The realization of interface between the sensor bus and the major system is another core goal of the control unit. The system for a local navigation is designed with the approach which allows the widest range of extensibility. During the designing of the control unit the future possibility of insertion other sensors was taken into consideration.

The international communities of user interface, user experience and interaction designers are in an increasing need of considering Chinese users’ experiences when designing websites. China, along with other mandarin speaking populations, consists of a huge market. Almost one-fifth of global Internet users used Chinese as preferred language in 2020. Additionally, more and more companies worldwide are interested in doing business with the Chinese market.  Targeting the needs of internet users coming from a different cultural background requires a special approach as cultural characteristics may influence the users’ expectations. Even though there have been attempts to characterise user interface menus suitable for Chinese users, as of 2022, it is still challenging to access a study on explicitly navigation. The purpose of this qualitative study is to investigate how local navigation can be adapted to the needs of Chinese users. This study also aims to examine the differences between Chinese and European users’ local navigation preferences. During the study, 2 Chinese subjects and 2 European subjects tested three versions of a web prototype that been developed according to the already established research on designing user interface (UI) for Chinese users. Each prototype alternative presented one of the three local navigation alternatives: inverted L, horizontal and embedded vertical. The data has been collected through conducting contextual inquiry in the form of semi-structured interviews and observations. The gathered information was then analysed through thematic analysis. The two themes: Accessibility of content and Interpreting functionality emerged from the coded data. This study acknowledged that differences between local navigation for Chinese and European users arise in cognitive traits. The Chinese users tend to categorise based on interdependence and relationship (thematic cognitive style) rather than to classify by functions, analyse components and infer common features (functional cognitive style). Furthermore, it has been recognised that Chinese population performs better with horizontal menu layouts with English interfaces. Results from this study show that the horizontal local navigation gained the biggest amount of positive feedback from Chinese interviewees, whereas vertical one the least. Even though, the findings illustrate that both Chinese and European subjects considered horizontal local navigation to be the most effective solution, interviewed Chinese users represented the least homogeneity in preferences. This study suggests that in order to develop guidelines for a fully functioning navigation system with English interfaces suitable for Chinese users, more studies on not solely local but also global and contextual navigation should be carried out. / Interaktionsdesigners samt UI/UX-designers över hela världen världen är i ett ökande behov av att ta hänsyn till kinesiska användares erfarenheter när de designar webbplatser. Kineserna, tillsammans med andra mandarintalande befolkningar, består av en enorm marknad. Nästan en femtedel av de globala internetanvändarna använde kinesiska som sitt föredragna språk i 2020. Dessutom, fler och fler företag globalt blir mer intresserade av att göra affärer med den kinesiska marknaden. För att se till att behoven hos internationella internetanvändare tillgodoses, krävs det ofta ett speciellt tillvägagångssätt. Detta eftersom kulturella egenskaper möjligtvis kan påverka användarnas förväntningar. Syftet med denna kvalitativa studie är att undersöka hur lokal navigering kan anpassas till kinesiska användarnas behov. Även om det redan finns några studier som satsar på att känneteckna användargränssnittsmenyer lämpliga för kinesiska användare, saknas det fortfarande studier som undersöker möjliga anpassningar av just navigering. Denna studie syftar vidare till att undersöka skillnaderna mellan kinesiska och europeiska användarnas lokala navigeringspreferenser. Under studien testade 2 kinesiska och 2 europeiska deltagare, tre versioner av en webbprototyp. Prototypen utvecklades enligt den redan etablerade forskningen kring design av användargränssnitt (UI) för kinesiska användare. Varje version av prototypen innehöll ett av de tre lokala navigeringsalternativen: inverted L, horizontal och embedded vertical. Data samlades in genom kontextuella undersökningar i form av semistrukturerade intervjuer och observationer. Den insamlade informationen analyserades sedan genom en tematisk analys. De två teman som framkom ur den kodade datan var: Tillgänglighet av innehåll och Tolkning av funktionalitet. Denna studie erkände att skillnader mellan lokal navigering för kinesiska och europeiska användare uppstår i kognitiva egenskaper. De kinesiska användarna tenderar att kategorisera baserat på ömsesidigt beroende och relation (tematisk kognitiv stil) snarare än att klassificera efter funktioner, analyskomponenter och härleda gemensamma drag (funktionell kognitiv stil). Dessutom har det insetts att den kinesiska befolkningen presterar bättre med horisontella menylayouter med engelska gränssnitt. Resultat från denna studie visar att den horisontella lokala navigeringen fick den största mängden positiv feedback från kinesiska intervjupersoner, medan den vertikala minst. Även om resultaten illustrerar att både kinesiska och europeiska ämnen ansåg horisontell lokal navigering vara den mest effektiva lösningen, representerade intervjuade kinesiska användare minst homogenitet i preferenser. Denna studie föreslår att för att utveckla riktlinjer för ett fullt fungerande navigationssystem med engelska gränssnitt lämpliga för kinesiska användare, bör fler studier om inte bara lokal utan även global och kontextuell navigering genomföras.

Aquesta tesi està inspirada en els agents naturals per tal de planificar de manera dinàmica la navegació d'un robot diferencial de dues rodes. Les dades dels sistemes de percepció són integrades dins una graella d'ocupació de l'entorn local del robot. La planificació de les trajectòries es fa considerant la configuració desitjada del robot, així com els vértexs més significatius dels obstacles més propers. En el seguiment de les trajectòries s'utilitzen tècniques locals de control predictiu basades en el model, amb horitzons de predicció inferiors a un segon. La metodologia emprada és validada mitjançant nombrosos experiments. / In this thesis are used natural agents for dinamic navigation of a differential driven wheeled mobile robot. The perception data are integrated on a local occupancy grid framework where planar floor model is assumed. The path-planning is done by considering the local desired configuration, as well as the meaningful local obstacle vertexes. The trajectory-tracking is implemented by using LMPC (local model predictive control) techniques, with prediction horizons of less than one second. Many experiments are tested in order to report the validity of the prosed methodology.

When we look at the eld of robotics we nd that exist a lot of types of robots. Some of tham use location navigation and global navigation for their work. This work aims to map options of location navigation and description of basic technique which used. Especially, we will deal with algorithms which work with optical sensors, for example camera, stereocamera or laser which scan medium. Practise section this work is focused on the proposal and implementacion algorithm which working with local navigation for robot's return to the starting position. All this work is connecting with tracked robot which formed in the framework one of project realization at Faculty of information technology.