Torque Control of a DC Motor with a State Space Estimator and Kalman Filter Applied in Electrical Vehicles

This work presents a study over a torque-generated speed control of free wheel attached to a DC motor, for use on traction of mobile vehicles. Also, it presents the discrete state space model of a DC model and the Kalman filter’s equations and applications. This work presents a hardware-in-the-loop (HIL) system for design of a torque controller noticed that this process produces a faster design, coding, and parameter optimization of any embedded systems. The hardware used for the implementation of the system is discussed as the hardware-in-the-loop environment which makes possible the fast tuning and design of the system. In the absence of a torque sensor, this work uses the Kalman filter’s estimated states torque and speed as feedbacks of the system

Analysis of the Solar Tracking System for a Mobile Robot Prototype

Methods to detect the position of the sun and orientate a solar panel to its position are used in order to optimize the power generated. Two possible approaches are using light depending resistor (LDR) sensors, or using a GPS and equations that model the geometry between the Earth and the Sun. The main objective of this work is the proposal of a prototype system to optimize the harvesting of solar energy on photovoltaic panels. In this chapter, a mobile robot powered by a solar panel orientated by a LDR matrix and a GPS device was developed. The LDRs were used as the representation of vectors normal to a surface, where its sum resulted in the most lighted point. The GPS, in turn, provided location, date and time data, which were used in the calculations of the Sun?s azimuth and zenith, used to orientate the panel. The obtained results show that an orientated photovoltaic panel has a better performance when compared to a static panel. Possibilities and opportunities of research tend to grow for the next years with many possible works to be done in the future, both in mobile robotics and in other systems powered by photovoltaic panels

Desenvolvimento de sistema de simulação de tremores nas mãos causados pela Doença de Parkinson, visando a substituição de pacientes em testes com dispositivos vestíveis de supressão

A Doença de Parkinson (DP) é uma enfermidade que afeta milhares de pessoas em todo o mundo e caracterizada por ser neurodegenerativa progressiva que afeta o sistema nervoso central. Frequentemente, pessoas com DP sofrem com sintomas relacionados a apatia, depressão, constipação, desordem no sono, perda do olfato e problemas de cognição. No entanto, a doença é mais conhecida pelas implicações ao sistema motor, resultando em movimentos involuntários conhecidos como tremores. A existência destes tremores afeta profundamente os portadores da doença, causando dificuldades motoras e muitas vezes, até as inibem do convívio social. Buscando uma solução não intrusiva, existem trabalhos que realizam a aquisição de dados característicos dos tremores utilizando MEMS, câmeras de vídeo, tecnologias vestíveis, os quais se propõem a identificar padrões nos tremores ou ainda, desenvolver sistemas que façam a supressão dos movimentos involuntários por meio de atuadores posicionados em juntas específicas como o punho e o cotovelo. Assim, com base nos dados já existentes em artigos e na literatura, iniciou-se o desenvolvimento de um sistema mecatrônico baseado na plataforma Stewart, que simule de forma satisfatória os movimentos de tremor de repouso nas mãos causados pela doença de Parkinson. Neste trabalho, primeiramente foi implementado um simulador em ambiente computacional baseado no modelo cinemático e dinâmico da plataforma Stewart, para realizar testes e avaliar se o mecanismo robótico é capaz de replicar tais movimentos. A estrutura da plataforma foi desenhada em ambiente CAD no software Solidworks® e posteriormente, o modelo foi exportado para o software Matlab® utilizando o ambiente do Simulink e a Biblioteca Simscape Multibody, possibilitando estudos do espaço de trabalho, resposta dos motores ao estímulo em uma faixa de frequência de tremores, bem como o torque fornecido pelos motores. Este estudo antecede a construção de uma plataforma real, sendo importante avaliar como a cinemática e dinâmica dos movimentos funcionam durante a execução. O sistema tem como objetivo realizar testes preliminares com tremor sem a necessidade da presença do paciente, possibilitando a simulação da evolução da doença de Parkinson, variações nos movimentos do tremor, tanto em sua forma e amplitude, quanto no espectro da frequência. Durante a realização dos testes, considerando a configuração do simulador utilizada, a plataforma executou os tremores senoidais de 1Hz a 9Hz com coeficiente de correlação de Pearson acima de 0,9. Os resultados demonstram que a plataforma simulada possui capacidade de representação dos tremores de repouso da DP em todos os movimentos do punho. Essa implementação pode ajudar na comparação entre técnicas de supressão, substituir ou reduzir a participação de pacientes em testes de dispositivos supressores e auxiliar no desenvolvimento de novas tecnologias menos invasivas aos pacientes

Towards a Modular Pathological Tremor Simulation System Based on the Stewart Platform

Wearable technologies have aided in reducing pathological tremor symptoms through non-intrusive solutions that aim to identify patterns in involuntary movements and suppress them using actuators positioned at specific joints. However, during the development of these devices, tests were primarily conducted on patients due to the difficulty of faithfully simulating tremors using simulation equipment. Based on studies characterizing tremors in Parkinson’s disease, the development of a robotic manipulator based on the Stewart platform was initiated, with the goal of satisfactorily simulating resting tremor movements in the hands. In this work, a simulator was implemented in a computational environment using the multibody dynamics method. The platform structure was designed in a virtual environment using SOLIDWORKS® v2017 software and later exported to Matlab® R17a software using the Simulink environment and Simscape multibody library. The workspace was evaluated, and the Kalman filter was used to merge acceleration and angular velocity data and convert them into data related to the inclination and rotation of real patients’ wrists, which were subsequently executed in the simulator. The results show a high correlation and low dispersion between real and simulated signals, demonstrating that the simulated mechanism has the capacity to represent Parkinson’s disease resting tremors in all wrist movements. The system could contribute to conducting tremor tests in suppression devices without the need for the presence of the patient and aid in comparing suppression techniques, benefiting the development of new wearable devices

Operating Costs Reducing in MDF Manufacturing Industries

The sustained efforts by electric motors when subjected to cutting, trimming or finishing are directly related to the material being machined and the angle of attack of the tool. Choosing the right tool for this operation depends on an expected result. So the engines behave differently to each operation. The optimization between strength, speed, power, material and type of operation, can be found to reduce operational costs of production, besides determining the exact time to make the set-up of worn tool. The reduction in operating costs is an item of sustainability that outlines the strategic positioning on companies to become competitive in the global marketplace. With the great technological development present today, this issue goes away with the very latest products on the market for professionals who productivity will be dealt with in these modern maintenance equipment such as power quality analyzer, Imager, profile projector and microscope for research. The result of this work is the optimization of the cutting operation and energy consumption thereby demonstrating an optimum point of operation in a case study presented in this work

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

Mobile Robot navigation modelling, control and applications

This work presents and discusses the main topics involved on the design of a mobile robot system and focus on the control and navigation systems for autonomous mobile robots. Introduces the main aspects of the Robot design, which is a holistic vision about all the steps of the development process of an autonomous mobile robot; discusses the problems addressed to the conceptualization of the mobile robot physical structure and its relation to the world. Presents the dynamic and control analysis for navigation robots with kinematic and dynamic model and, for final, presents applications for a robotic platform of Automation, Simulation, Control and Supervision of Mobile Robots Navigation, with studies of dynamic and kinematic modelling, control algorithms, mechanisms for mapping and localization, trajectory planning and the platform simulator. © 2012 Praise Worthy Prize S.r.l. - All rights reserved

Virtual simulator for mobile robots navigation systems

This paper presents the virtual environment implementation for project simulation and conception of supervision and control systems for mobile robots, that are capable to operate and adapting in different environments and conditions. This virtual system has as purpose to facilitate the development of embedded architecture systems, emphasizing the implementation of tools that allow the simulation of the kinematic conditions, dynamic and control, with real time monitoring of all important system points. For this, an open control architecture is proposal, integrating the two main techniques of robotic control implementation in the hardware level: systems microprocessors and reconfigurable hardware devices. The implemented simulator system is composed of a trajectory generating module, a kinematic and dynamic simulator module and of a analysis module of results and errors. All the kinematic and dynamic results shown during the simulation can be evaluated and visualized in graphs and tables formats, in the results analysis module, allowing an improvement in the system, minimizing the errors with the necessary adjustments optimization. For controller implementation in the embedded system, it uses the rapid prototyping, that is the technology that allows, in set with the virtual simulation environment, the development of a controller project for mobile robots. The validation and tests had been accomplish with nonholonomics mobile robots models with diferencial transmission. © 2008 IEEE

Ferramenta de Ensino de Engenharia de Tráfego Telefônico a Distância Através da Web

Este trabalho pode enquadrar-se na modalidade de ensino a distância (EAD) através da Internet. Buscou-se aumentar a interatividade dos sistemas de EAD por meio do emprego de software de cálculo e simulações, neste trabalho pelo programa matemático Matlab. O emprego de pacotes matemáticos eficientes junto com tecnologias de hipermídia abre as portas de um novo paradigma de ensino e aprendizagem, a se consolidar na alvorada deste novo milênio. Hipertexto, gráficos, animações, áudio, vídeo, calculadores e simuladores eficientes incorporando técnicas de inteligência artificial e o avanço das redes de comunicações de banda larga pavimentarão o caminho a este novo horizonte. A contribuição deste trabalho, além da integração do Matlab em rede, foi o desenvolvimento de um curso introdutório à engenharia de tráfego, em formato hipertexto. Além disso, foram desenvolvidos calculadores das expressões mais importantes de tráfego telefônico para o ambiente do servidor Matlab. Através do programa calculador de tráfego telefônico, o usuário entra com os dados por seu navegador da Internet e os resultados calculados pelo sistema são retornados em forma numérica, de gráficos e de tabelas. O sistema também pode ser empregado em cálculos profissionais de engenharia de tráfego, substituindo com vantagens os métodos tradicionais que empregam tabelas e gráficos estáticos em papel

Machine learning hyperparameter selection for Contrast Limited Adaptive Histogram Equalization

Abstract Contrast enhancement algorithms have been evolved through last decades to meet the requirement of its objectives. Actually, there are two main objectives while enhancing the contrast of an image: (i) improve its appearance for visual interpretation and (ii) facilitate/increase the performance of subsequent tasks (e.g., image analysis, object detection, and image segmentation). Most of the contrast enhancement techniques are based on histogram modifications, which can be performed globally or locally. The Contrast Limited Adaptive Histogram Equalization (CLAHE) is a method which can overcome the limitations of global approaches by performing local contrast enhancement. However, this method relies on two essential hyperparameters: the number of tiles and the clip limit. An improper hyperparameter selection may heavily decrease the image quality toward its degradation. Considering the lack of methods to efficiently determine these hyperparameters, this article presents a learning-based hyperparameter selection method for the CLAHE technique. The proposed supervised method was built and evaluated using contrast distortions from well-known image quality assessment datasets. Also, we introduce a more challenging dataset containing over 6200 images with a large range of contrast and intensity variations. The results show the efficiency of the proposed approach in predicting CLAHE hyperparameters with up to 0.014 RMSE and 0.935 R 2 values. Also, our method overcomes both experimented baselines by enhancing image contrast while keeping its natural aspect