Control structure for a car-like robot using artificial neural networks and genetic algorithms

The idea of improving human’s life quality by making life more comfortable and easy is nowadays possible using current technologies and techniques to solve complex daily problems. The presented idea in this work proposes a control strategy for autonomous robotic systems, specifically car-like robots. The main objective of this work is the development of a reactive navigation controller by means of obstacles avoidance and position control to reach a desired position in an unknown environment. This research goal was achieved by the integration of potential fields and neuroevolution controllers. The neuro-evolutionary controller was designed using the (NEAT) algorithm “Neuroevolution of Augmented Topologies” and trained using a designed training environment. The methodology used allowed the vehicle to reach a certain level of autonomy, obtaining a stable controller that includes kinematic and dynamic considerations. The obtained results showed significant improvements compared to the comparison workCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQNão te

Aplicação de técnicas de controle preditivo em robô paralelo

This paper addresses the position tracking control application of a parallel robot using predictive control techniques. A Generalized Predictive Control strategy (GPC), which considers the linear dynamic model, is used to enhance the tracking position accuracy. The robustification of GPC against measurement noise and neglected dynamics using Youla parameterization is performed. A simulation of the orthoglide robot considering uncertainties related to geometrical and dynamic parameters, sensors noise and frictions is performed on two different trajectories. Finally, it is compared the ro-bustified GPC controller with the classical Computed Torque Control (CTC). The robustified GPC controller shows a better performance for high accelerations and it also reduces the effect of the noise in the control signal of the parallel robot.Este trabalho apresenta a aplicação de técnicas de controle preditivo para rastreamento de trajetórias de um robô paralelo. A estratégia de controle preditivo generalizado (GPC), que considera o modelo dinâmico linearizado, é usada para melhorar a precisão de rastreamento das trajetórias. O controlador preditivo generalizado é robustificado devido ao ruído de medição e dinâmicas não modeladas utilizando parametrização Youla. É realizada Uma simulação do robô Orthoglide considerando as incertezas dos parâmetros geométricos e dinâmicos, ruído nos sensores e atritos para duas trajetórias diferentes. Finalmente, o controlador GPC robus-tificado e a técnica de Controle de Torque Computado (CTC) são comparadas. Os resultados das simulações mostram que o controlador GPC robustificado apresenta um melhor desempenho para altas acelerações e também reduz o efeito do ruído no sinal de controle do robô paralelo.530540Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Intelligent maintenance of complex systems: a fractional order approach

Compete in the global market requires high quality of products with short time of manufacture, so it needs to minimize the time that the machinery is stopped, as well as a rapid quality control of manufactured products. These process are achieved by maintenance strategies that are strongly based on the subjective knowledge of an expert. In this work we use the proficiency of the fractional order calculus to approximate complex behavior with a few parameter, providing a new tool for quickly health evaluation.N/

Analise dinamica de um sistema com bifuração de potencia e controle de velocidade

Orientador: Douglas Eduardo ZampieriDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de CampinasResumo: Neste trabalho é desenvolvido a simulação digital simplificada de um veiculo híbrido, no intuito de se analisar a viabilidade de uma operação pré-programada por um perfil de percurso. O controle para o elemento principal do veiculo, sua transmissão, é analisada teórico e experimentalmente. Posteriormente são estudadas as instabilidades introduzidas pelo controle e também estabelecida uma rotina de cálculo baseada na generalização da técnica de matriz de transferência para determinação das freqüências naturais do sistema.Abstract: In this work a simplified digital simulation of an hybrid vehicle is developed, and the feasibility if the programmed operation of a driving cicle is investigated. The control of the transmission of the vehicle is analised theoretically and experimentally, and the instabilities introduced by the control are determined. A generalized technique based on transfer matrices is also developed and the natural frequencies of the transmission are obtained.MestradoMestre em Engenharia Mecânic

Control of a 6-DOF parallel manipulator through a mechatronic approach

This paper shows that a hierarchical architecture, distributing several control actions in growing levels of complexity and using resources of reconfigurable computing, enables one to take into account the ease of future modifications, updates and improvements in robotic applications. An experimental example of a Stewart—Gough platform control (a platform applied as the solution to countless practical problems) is presented using reconfigurable computing. The software and hardware developed are structured in independent blocks. This open architecture implementation allows easy expansion of the system and better adaptation of the platform to its related tasks

Fractional Order Calculus: Basic Concepts and Engineering Applications

The fractional order calculus (FOC) is as old as the integer one although up to recently its application was exclusively in mathematics. Many real systems are better described with FOC differential equations as it is a well-suited tool to analyze problems of fractal dimension, with long-term “memory” and chaotic behavior. Those characteristics have attracted the engineers' interest in the latter years, and now it is a tool used in almost every area of science. This paper introduces the fundamentals of the FOC and some applications in systems' identification, control, mechatronics, and robotics, where it is a promissory research field

Condition-Based Diagnosis of Mechatronic Systems Using a Fractional Calculus Approach

While fractional calculus (FC) is as old as integer calculus, its application has been mainly restricted to mathematics. However, many real systems are better described using FC equations than with integer models. FC is a suitable tool for describing systems characterised by their fractal nature, long-term memory and chaotic behaviour. It is a promising methodology for failure analysis and modelling, since the behaviour of a failing system depends on factors that increase the model’s complexity. This paper explores the proficiency of FC in modelling complex behaviour by tuning only a few parameters. This work proposes a novel two-step strategy for diagnosis, first modelling common failure conditions and, second, by comparing these models with real machine signals and using the difference to feed a computational classifier. Our proposal is validated using an electrical motor coupled with a mechanical gear reducer

Robust generalized predictive control of the Orthoglide robot

International audienceThe purpose of this paper is to address the synthesis and experimental application of a generalized predictive control (GPC) technique on an Orthoglide robot.Design/methodology/approach– The control strategy is composed of two control loops. The inner loop aims at linearizing the nonlinear robot dynamics using feedback linearization. The outer loop tracks the desired trajectory based on GPC strategy, which is robustified against measurement noise and neglected dynamics using Youla parameterization.Findings– The experimental results show the benefits of the robustified predictive control strategy on the dynamical performance of the Orthoglide robot in terms of tracking accuracy, disturbance rejection, attenuation of noise acting on the control signal and parameter variation without increasing the computational complexity.Originality/value– The paper shows the implementation of the robustified predictive control strategy in real time with low computational complexity on the Orthoglide robot

Environment for teaching and development of mobile robot systems

Using robots for teaching is one approach that has gathered good results on Middle-School, High-School and Universities. Robotics gives chance to experiment concepts of a broad range of disciplines, principally those from Engineering courses and Computer Science. However, there are not many kits that enables the use of robotics in classroom. This article describes the methodologies to implement tools which serves as test beds for the use of robotics to teach Computer Science and Engineering. Therefore, it proposes the development of a flexible, low cost hardware to integrate sensors and control actuators commonly found on mobile robots, the development of a mobile robot device whose sensors and actuators allows the experimentation of different concepts, and an environment for the implementation of control algorithms through a computer network. This paper describes each one of these tools and discusses the implementation issues and future works. © 2010 IEEE