Towards AGV Optimization using ROS and Stage Simulator

Autonomous Guided Vehicles (AGV) are currently being used in industry to move materials efficiently. Simulators may be used to help calculate the right number of AGVs needed for a particular task and also which types better suit the necessity of a company. This paper analyzes the characteristics of many of the most used simulators and focus on evaluating an environment using Stage and Robot Operating System (ROS), to find experimentally if one AGV may complete a specific task taking into account eventual path blockages by random events.info:eu-repo/semantics/publishedVersio

High level coordination and decision making of a simulated robotic soccer team

Tese de mestrado integrado. Engenharia Informática e Computação. Faculdade de Engenharia. Universidade do Porto. 201

Simulador de conductas humanas en situaciones de emergencia ocasionadas en lugares cerrados basado en sistemas multiagentes

Las evacuaciones en situaciones de emergencia se han convertido en un tema de gran interés para el ser humano, debido a que en algunos casos por no estar prevenido, suceden catástrofes las cuales se hubieran podido evitar, es por esto que un simulador de personas bajo el paradigma de sistemas multiagentes ayudara a proporcionar información para el personal de planeación en situaciones de emergencia mucho más real que un simulacro. El prototipo del simulador se ha desarrollado bajo un ambiente distribuido ayudando para que la eficiencia del sistema soporte gran número de personas.Ingeniero (a) de SistemasPregrad

Immune systems inspired multi-robot cooperative shepherding

Certain tasks require multiple robots to cooperate in order to solve them. The main problem with multi-robot systems is that they are inherently complex and usually situated in a dynamic environment. Now, biological immune systems possess a natural distributed control and exhibit real-time adaptivity, properties that are required to solve problems in multi-robot systems. In this thesis, biological immune systems and their response to external elements to maintain an organism's health state are researched. The objective of this research is to propose immune-inspired approaches to cooperation, to establish an adaptive cooperation algorithm, and to determine the refinements that can be applied in relation to cooperation. Two immune-inspired models that are based on the immune network theory are proposed, namely the Immune Network T-cell-regulated---with Memory (INT-M) and the Immune Network T-cell-regulated---Cross-Reactive (INT-X) models. The INT-M model is further studied where the results have suggested that the model is feasible and suitable to be used, especially in the multi-robot cooperative shepherding domain. The Collecting task in the RoboShepherd scenario and the application of the INT-M algorithm for multi-robot cooperation are discussed. This scenario provides a highly dynamic and complex situation that has wide applicability in real-world problems. The underlying 'mechanism of cooperation' in the immune inspired model (INT-M) is verified to be adaptive in this chosen scenario. Several multi-robot cooperative shepherding factors are studied and refinements proposed, notably methods used for Shepherds' Approach, Shepherds' Formation and Steering Points' Distance. This study also recognises the importance of flock identification in relation to cooperative shepherding, and the Connected Components Labelling method to overcome the related problem is presented. Further work is suggested on the proposed INT-X model that was not implemented in this study, since it builds on top of the INT-M algorithm and its refinements. This study can also be extended to include other shepherding behaviours, further investigation of other useful features of biological immune systems, and the application of the proposed models to other cooperative tasks

Optimizing simulated humanoid robot skills

Tese de mestrado integrado. Engenharia Informática e Computação. Faculdade de Engenharia. Universidade do Porto. 201

Development of behaviors for a simulated humanoid robot

Mestrado em Engenharia de Computadores e TelemáticaControlar um robô bípede com vários graus de liberdade é um desafio que recebe a atenção de vários investigadores nas áreas da biologia, física, electrotecnia, ciências de computadores e mecânica. Para que um humanóide possa agir em ambientes complexos, são necessários comportamentos rápidos, estáveis e adaptáveis. Esta dissertação está centrada no desenvolvimento de comportamentos robustos para um robô humanóide simulado, no contexto das competições de futebol robótico simulado 3D do RoboCup, para a equipa FCPortugal3D. Desenvolver tais comportamentos exige o desenvolvimento de métodos de planeamento de trajectórias de juntas e controlo de baixo nível. Controladores PID foram implementados para o controlo de baixo nível. Para o planeamento de trajectórias, quatro métodos foram estudados. O primeiro método apresentado foi implementado antes desta dissertação e consiste numa sequência de funções degrau que definem o ângulo desejado para cada junta durante o movimento. Um novo método baseado na interpolação de um seno foi desenvolvido e consiste em gerar uma trajectória sinusoidal durante um determinado tempo, o que resulta em transições suaves entre o ângulo efectivo e o ângulo desejado para cada junta. Um outro método que foi desenvolvido, baseado em séries parciais de Fourier, gera um padrão cíclico para cada junta, podendo ter múltiplas frequências. Com base no trabalho desenvolvido por Sven Behnke, um CPG para locomoção omnidireccional foi estudado em detalhe e implementado. Uma linguagem de definição de comportamentos é também parte deste estudo e tem como objectivo simplificar a definição de comportamentos utilizando os vários métodos propostos. Integrando o controlo de baixo nível e os métodos de planeamento de trajectórias, vários comportamentos foram criados para permitir a uma versão simulada do humanóide NAO andar em diferentes direcções, rodar, chutar a bola, apanhar a bola (guarda-redes) e levantar do chão. Adicionalmente, a optimização e geração automática de comportamentos foi também estudada, utilizado algoritmos de optimização como o Hill Climbing e Algoritmos Genéticos. No final, os resultados são comparados com as equipas de simulação 3D que reflectem o estado da arte. Os resultados obtidos são bons e foram capazes de ultrapassar uma das três melhores equipas simuladas do RoboCup em diversos aspectos como a velocidade a andar, a velocidade de rotação, a distância da bola depois de chutada, o tempo para apanhar a bola e o tempo para levantar do chão. ABSTRACT: Controlling a biped robot with several degrees of freedom is a challenging task that takes the attention of several researchers in the fields of biology, physics, electronics, computer science and mechanics. For a humanoid robot to perform in complex environments, fast, stable and adaptable behaviors are required. This thesis is concerned with the development of robust behaviors for a simulated humanoid robot, in the scope of the RoboCup 3D Simulated Soccer Competitions, for FCPortugal3D team. Developing such robust behaviors requires the development of methods for joint trajectory planning and low-level control. PID control were implemented to achieve low-level joint control. For trajectory planning, four methods were studied. The first presented method was implemented before this thesis and consists of a sequence of step functions that define the target angle of each joint during the movement. A new method based on the interpolation of a sine function was developed and consists of generating a sinusoidal shape during some amount of time, leading to smooth transitions between the current angle and the target angle of each joint. Another method developed, based on partial Fourier Series, generates a multi-frequency cyclic pattern for each joint. This method is very flexible and allows to completely control the angular positions and velocities of the joints. Based on the work of developed by Sven Behnke, a CPG for omnidirectional locomotion was studied in detail and implemented. A behavior definition language is also part of this study and aims at simplifying the definition of behaviors using the several proposed methods. By integrating the low-level control and the trajectory planning methods, several behaviors were created to allow a simulated version of the humanoid NAO to walk in different directions, turn, kick the ball, catch the ball (goal keeper) and get up from the ground. Furthermore, the automatic generation of gaits, through the use of optimization algorithms such as hill climbing and genetic algorithms, was also studied and tested. In the end, the results are compared with the state of the art teams of the RoboCup 3D simulation league. The achieved results are good and were able to overcome one of the state of the art simulated teams of RoboCup in several aspects such as walking velocity, turning velocity, distance of the ball when kicked, time to catch the ball and the time to get up from the ground

Ambiente de simulação para agentes em futebol robótico

Mestrado em Engenharia de Computadores e TelemáticaO teste de algoritmos na área da robótica pode ser uma tarefa difícil, especialmente se o teste envolver múltipos robots. Neste contexto o uso de um simulador torna-se uma ferramenta importante no teste de algoritmos pois permite ultrapassar algumas limitações e oferece várias vantagens. CAMBADA é a equipa de futebol robótico da liga de tamanho médio da Universidade de Aveiro, Portugal. A equipa está familiarizada com as limitações do uso de robots reais para o teste de algoritmos. Devido a isso o simulador criado pela equipa Brainstormers Tribots foi adaptado para prover um ambiente de simulação ao software CAMBADA e estava em uso aquando do início desta dissertação. O simulador oferecia pouca flexibilidade na modelação dos robots que resultava em comportamentos imprecisos, oferecia também reduzida interacção com a simulação. O objectivo desta dissertação é criar um ambiente de simulação para agentes em futebol robótico com a intenção de melhorar o ambiente de simulação da equipa CAMBADA. O simulador deve ser capaz de simular dinâmica de objectos a três dimensões, sensores e actuadores ao mesmo tempo que oferece visualização do mundo e a possibilidade de interagir com a simulação. Da pesquisa realizada sobre simuladores robóticos o simulador Gazebo respeitava os nossos requisitos e foi escolhido para código base do nosso simulador. Para criar um ambiente simulado adequado à equipa CAMBADA alguns componentes do Gazebo foram alterados e novos sensores e actuadores virtuais foram desenvolvidos. Vários componentes do software CAMBADA tiveram que sofrer alterações de modo a suportar um ambiente simulado. O robot virtual foi modelado de modo a assemelhar-se com o robot real com o objectivo de obter comportamentos mais precisos. O simulador desenvolvido substituiu a solução anteriormente criada pela equipa CAMBADA e foi usado nos testes de preparação para a participação da equipa no RoboCup 2010 em Singapura onde deu o seu contributo na obtenção do terceiro lugar.In the field of robotics, testing algorithms with the real robots can be a di cult task, specially if the test involves more than one robot. In this context a simulator is an important tool for testing algorithms because it helps overcome some limitation and o ers several advantages. CAMBADA is the RoboCup MSL soccer team of the University of Aveiro, Portugal. The team is familiar with the limitations of using the real robots for testing algorithms. Therefore, a simulator created by the Brainstormers Tribots team was adapted to provide a simulated environment for their software and was used for testing at the time of the beginning of this thesis. The simulator offered low flexibility on the modeling of the robots from which resulted inaccurate behaviors, it also o ered reduced interaction with the simulation. The purpose of this thesis is to create a simulation environment for robotic soccer agents with the intention of improving the simulated environment for the CAMBADA team. The simulation must provide three-dimensional dynamics of objects, be capable of simulating sensors and actuators, allow the visualization of the simulation and provide interaction with the simulation. From the conducted survey about robotic simulators, the simulator Gazebo complied with our requirements and was chosen to provide the code base for our simulator. To create an adequate simulation environment for the CAMBADA team some components of Gazebo were modi ed and new sensors and actuator were developed. Several components of the CAMBADA software had to be modified to support the simulated environment. The virtual robot was modeled to resemble the real robot to provide more accurate behaviors. The developed simulator substituted the previous solution created by CAMBADA team and was used in the preparation tests for the participation in the RoboCup 2010 in Singapore where it contributed to obtain of the third-place

Spark -- A Generic Simulator for Physical Multi-agent Simulations

In this paper we describe a new multi-agent simulation system, called Spark, for physical agents in three-dimensional environments. Our goal in creating Spark was to provide a great amount of flexibility for creating new types of agents and simulations. To achieve this, we implemented a flexible application framework and exhausted the idea of replaceable components in the resulting system. In comparison to specialized simulators, users can effortless create new simulations by using a scene description language. Spark is a powerful and flexible tool to state different multi-agent research questions. It is used as official simulator for the first three-dimensional RoboCup Simulation League competition. We present the concepts we used to achieve the flexibility in our system and show how we seamlessly integrated the different subsystems into one user-friendly framework