Development of an autonomous mobile robot with planning and location in a structured environment

Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do ParanáWith the advance of technology mobile robots have been increasingly applied in the industry, performing repetitive work with high performance, and in environments that pose risks to human health. The present work plans and develops a mobile robot platform for the micromouse competition. The micromouse consists of a small autonomous mobile robot that, when placed in an unknown labyrinth, is able to map it, search for the best path between the starting point and the goal and travel it in the shortest possible time. To accomplish these tasks, the robot must be able to self-locate, map the maze as it traverses it and plan paths based on the map obtained. The developed self-localization method is based on the odometry, the laser sensors present in the robot and on a previous knowledge of the start point and the configuration of the environment. Several methodologies of locomotion in unknown environment and route planning are analyzed in order to obtain the combination with the best performance. In order to verify the results, the present work is developed in real environment, in 3D simulation and also with a hardware in the loop capability. Labyrinths from previous competitions are used as basis for comparing methodologies and validating results. At the end it presents the algorithm capable of fulfilling all the requirements of the micromouse competition together with the results of its evaluation run.Com o avanço da tecnologia, os robôs móveis têm sido cada vez mais aplicados na indústria, realizando trabalhos repetitivos com alto desempenho e em ambientes que expõem riscos à saúde humana. O presente trabalho planeja e desenvolve um robô móvel para a competição micromouse. O micromouse consiste em um pequeno robô autônomo que, ao ser colocado em um labirinto desconhecido, é capaz de mapeá-lo, procurar o melhor caminho entre o ponto de partida e o objetivo, e percorrê-lo no menor tempo possível. Para realizar estas tarefas, o robô deve ser capaz de se auto-localizar, mapear o labirinto enquanto o percorre e planejar caminhos com base no mapa obtido. O método de auto-localização desenvolvido baseia-se na odometria, nos sensores a laser presentes no robô e em um prévio conhecimento do ponto de início e da configuração do ambiente. Diversas metodologias de locomoção em ambiente desconhecido e planejamento de rotas são analisadas buscando-se obter a combinação com o melhor desempenho. Para averiguação de resultados o presente trabalho desenvolve-se em ambiente real e em simulação 3D com hardware in the loop. Labirintos de competições anteriores são utilizados de base para o comparativo de metodologias e validação de resultados. Ao final apresenta-se o algoritmo capaz de cumprir todas as exigências da competição micromouse juntamente com os resultados em sua corrida de avaliação

Autonomous robot systems and competitions: proceedings of the 12th International Conference

This is the 2012’s edition of the scientific meeting of the Portuguese Robotics Open (ROBOTICA’ 2012). It aims to disseminate scientific contributions and to promote discussion of theories, methods and experiences in areas of relevance to Autonomous Robotics and Robotic Competitions. All accepted contributions are included in this proceedings book. The conference program has also included an invited talk by Dr.ir. Raymond H. Cuijpers, from the Department of Human Technology Interaction of Eindhoven University of Technology, Netherlands.The conference is kindly sponsored by the IEEE Portugal Section / IEEE RAS ChapterSPR-Sociedade Portuguesa de Robótic

Mobile Robotics

The book is a collection of ten scholarly articles and reports of experiences and perceptions concerning pedagogical practices with mobile robotics.“This work is funded by CIEd – Research Centre on Education, project UID/CED/01661/2019, Institute of Education, University of Minho, through national funds of FCT/MCTES-PT.

How the architecture of the CityCar enhances personal mobility and supporting industries

Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 121-124).Growing populations, increasing middle-class, and rapid urbanization - for today's urban dweller, all of these escalating factors continue to contribute to problems of excessive energy use, road congestion, pollution due to carbon emissions, and inefficient personal transit. Considering that the average vehicle in a city weighs thousands of pounds, usually caries only one person per trip, and expends significant proportions of its gasoline simply searching for resources such as parking, new efficient and intelligent modes of transportation are in need of exploration. This dissertation presents the design and development of an electric vehicle called the "CityCar" that confronts the aforementioned problems of urban mobility with a novel vehicle architecture. The assembly of the CityCar derives from a subset of "urban modular electric vehicle" (uMEV) components in which five core units are combined to create a variety of solutions for urban personal mobility. Drastically decreasing the granularity of the vehicle's subcomponents into larger interchangeable modules, the uMEV platform expands options for fleet customization while simultaneously addressing the complex rapport between automotive manufacturers and their suppliers through a responsibility shift among their respective subcomponents. Transforming its anatomy from complex mechanically-dominant entities to electrically-dominant modular components enables unique design features within the uMEV fleet. The CityCar for example exploits technologies such as a folding chassis to reduce its footprint by 40% and Robot Wheels that each are allotted between 72 to 120-degrees of rotation to together enable a seven-foot turning circle. Just over 1,000 pounds, its lightweight zero-emitting electric platform, comprised of significantly fewer parts, curbs negative externalities that today's automobiles create in city environments. Additionally, the vehicle platform developed from the assembly of several core units empowers a consortium of suppliers to self-coordinate through a unique modular business model. Lastly, the CityCar specific uMEV confronts problems within urban transit by providing a nimble folding mobility solution tailored specifically to crowded cities. Benefits, such as a 5:1 parking density and its reduced maintenance demands, are especially reinforced in the context of shared personal transportation services like Mobility-on-Demand.by William Lark, Jr.Ph.D

Modeling Robotic Systems with Activity Flow Graphs

Autonomous robotic systems are becoming increasingly common in our society, with research efforts towards automated goods transportation, service robots and autonomous cars. These complex systems have to solve many different problems in order to function robustly. Two especially important areas of interest are perception and high level control. Intelligent systems have to perceive their surroundings in order to facilitate autonomy. With an understanding of the environment, they then can make their own decisions based on high level control policies defined by the developers. Robotic systems differ drastically in their sensory capabilities, their computational power, and their designated tasks. When developing algorithms, however, we need to have a common modeling framework that enables us to generalize and re-use existing solutions. A modular approach, which is coherent across different platforms, also allows faster prototyping of new systems. In this dissertation we develop a modeling framework based on data flow that achieves this goal. We first extend the existing Synchronous Data Flow (SDF) model and combine it with reactive programming ideas and finite-state machines. Together, these existing frameworks enable us to model many aspects of complex robotic systems. We apply this model to a robot in a warehouse scenario to demonstrate the viability of the approach. Using three disjoint formalisms to model a robotic system has many downsides. In a first unification step we merge SDF and reactive programming into Hybrid Flow Graphs (HFGs), where we explicitly model synchronous and asynchronous data flow. We then apply the HFG model to the perception system of an autonomous transportation robot. In a last step, we eliminate the need for separate finite-state machines by introducing the concept of activity into the data flow. We therefore unify the different aspects into a single and coherent framework which we call Activity Flow Graphs (AFGs). The flow of activity enables us to model high level state directly in the data flow graph. The result is a single computation graph that can express both perception and high level control aspects of any robotic system. We then demonstrate this with multiple high level robotic system models. Finally, we make use of the uniform AFG model to provide a single graphical user interface that allows a developer to rapidly prototype complete robotic systems. Since all aspects of a robot can be implemented using the same theoretical framework, there is no need to switch between different paradigms. The user interface is designed to give immediate feedback, which speeds up prototyping, testing and evaluation, as well as debugging when working with real robots.Autonome Roboter werden zunehmend zu einem wichtigen Bestandteil unserer Gesellschaft, in Bereichen wie dem automatisierten Gütertransport, in der Servicerobotik und bei autonomen Automobilen. Diese komplexen Systeme müssen viele Problem lösen, um robust zu funktionieren. Zwei sehr wichtige Anwendungsfelder sind die Umgebungswahrnehmung und die Ablaufplanung. Intelligente Systeme müssen ihre Umgebung wahrnehmen, um autonom agieren zu können. Mit einem Verständnis der Umwelt können sie Entscheidungen treffen, welche auf abstrakten Richtlinien der Entwickler basieren. Verschiedene Roboter weichen stark in ihren sensorischen Fähigkeiten, in ihrer Rechenleistung und in ihren zu lösenden Aufgaben voneinander ab. Bei der Entwicklung von Algorithmen wird jedoch ein einheitliches Modellierungssystem benötigt, welches die Wiederverwendung von existierenden Lösungen erlaubt. Ein modulares System, welches über mehrere Plattformen hinweg genutzt werden kann, ermöglicht eine schnellere Entwicklung von neuen Systemen. In dieser Dissertation wird ein auf Datenfluss basierendes Modell entwickelt, welches diese Anforderungen erfüllt. Zuerst wird das existierende Synchronous Data Flow (SDF) Modell erweitert und mit Elementen von reaktiver Programmierung und endlichen Zustandsautomaten kombiniert. Zusammen können so viele Aspekte von Robotern modelliert werden. Das Modell wird auf einen Roboter in einem Warenhausszenario angewandt, um den Ansatz zu validieren. Drei verschiedene Formalismen zur Modellierung von Robotern zu verwenden hat viele Nachteile. In einem ersten Vereinigungsschritt werden SDF und reaktive Programmierung zu hybriden Flussgraphen (HFG) kombiniert, bei denen synchroner und asynchroner Datenfluss explizit modelliert werden. Dann wird das HFG-Modell auf die Wahrnehmungsmodule eines autonomen Transportsystems angewandt. Anschließend wird der Bedarf eines Zustandsautomaten beseitigt, indem das Konzept der Aktivität in den Datenfluss eingeführt wird. Dadurch werden alle Aspekte in einem einzigen, schlüssigen System vereinigt, welches Aktivitätsflussgraph (AFG) genannt wird. Der Aktivitätsfluss ermöglicht es, den höheren Systemzustand direkt im Datenflussgraphen zu modellieren. Als Ergebnis erhalten wir einen einzigen Berechnungsgraphen, der sowohl zur Beschreibung der Umgebungswahrnehmung als auch zur Kontrolle der höheren Abläufe benutzt werden kann. Dies wird anhand mehrerer Robotersysteme demonstriert. Eine graphische Benutzerschnittstelle wird bereitgestellt, welche von dem einheitlichen Modell Gebrauch macht, um ein schnelles Prototyping von Robotern zu ermöglichen. Da alle Aspekte mit demselben System modelliert werden, muss nicht zwischen verschiedenen Paradigmen gewechselt werden. Die Nutzerschnittstelle erleichtert Entwicklung, Test und Validierung von Algorithmen sowie das Auffinden von Fehlern bei echten Robotern

Authority-Sharing Control of Assistive Robotic Walkers

A recognized consequence of population aging is a reduced level of mobility, which undermines the life quality of several senior citizens. A promising solution is represented by assisitive robotic walkers, combining the benefits of standard walkers (improved stability and physical support) with sensing and computing ability to guarantee cognitive support. In this context, classical robot control strategies designed for fully autonomous systems (such as fully autonomous vehicles, where the user is excluded from the loop) are clearly not suitable, since the user’s residual abilities must be exploited and practiced. Conversely, to guarantee safety even in the presence of user’s cognitive deficits, the responsibility of controlling the vehicle motion cannot be entirely left to the assisted person. The authority-sharing paradigm, where the control authority, i.e., the capability of controlling the vehicle motion, is shared between the human user and the control system, is a promising solution to this problem. This research develops control strategies for assistive robotic walkers based on authority-sharing: this way, we ensure that the walker provides the user only the help he/she needs for safe navigation. For instance, if the user requires just physical support to reach the restrooms, the robot acts as a standard rollator; however, if the user’s cognitive abilities are limited (e.g., the user does not remember where the restrooms are, or he/she does not recognize obstacles on the path), the robot also drives the user towards the proper corridors, by planning and following a safe path to the restrooms. The authority is allocated on the basis of an error metric, quantifying the distance between the current vehicle heading and the desired movement direction to perform the task. If the user is safely performing the task, he/she is endowed with control authority, so that his/her residual abilities are exploited. Conversely, if the user is not capable of safely solving the task (for instance, he/is going to collide with an obstacle), the robot intervenes by partially or totally taking the control authority to help the user and ensure his/her safety (for instance, avoiding the collision). We provide detailed control design and theoretical and simulative analyses of the proposed strategies. Moreover, extensive experimental validation shows that authority-sharing is a successful approach to guide a senior citizen, providing both comfort and safety. The most promising solutions include the use of haptic systems to suggest the user a proper behavior, and the modification of the perceived physical interaction of the user with the robot to gradually share the control authority using a variable stiffness vehicle handling