Sistemas de controle precisam trabalhar com restrições temporais rigorosas para garantir seu correto funcionamento, sendo por isso considerados sistemas de tempo-real. Quando tais sistemas são distribuídos, as redes de sensores, atuadores e controladores estão interligados em geral, por redes de campo. Nesse contexto, as redes de campo desempenham um papel extremamente importante no comportamento global do sistema. O presente trabalho de pesquisa apresenta a descrição do processo de desenvolvimento de um system on-chip (SoC) para um sistema de controle. Diferentemente das abordagens clássicas, o trabalho está focado em implementar o sistema baseado em um paradigma diferenciado, baseado em lógica reprogramável. Apresenta-se o projeto e construção dos IP cores necessários para controlar um motor DC, utilizando o barramento control area network (CAN) para obter uma plataforma distribuída. A arquitetura on chip utilizada está baseada na especificação CoreConnect da IBM. São expostos, ainda, trabalhos de simulação tanto dos componentes isolados, como do sistema integrado, de forma a realizar uma comparação qualitativa do processo de desenvolvimento; Control systems require strict time constraints to work properly...

Empresas e instituições de pesquisa nacionais e internacionais tem concentrado esforços no sentido de desenvolver e promover a implementação do padrão internacional ISO 11783, baseado no protocolo de comunicação digital CAN (Contoller Network Area), para integração de dispositivos em máquinas e implementos agrícolas. Nesse contexto, é apresentado o desenvolvimento e a aplicação de um modelo baseado no formalismo das redes de Petri como uma ferramenta de suporte para a análise e implantação de uma rede CAN em aplicações com tempos-críticos. O modelo foi elaborado no ambiente para edição e simulação DesignCPN, sendo que a simulação é utilizada para a análise do desempenho e do comportamento de uma rede CAN com diferentes configurações que será embarcada em um veículo autônomo agrícola (VAA).; Intemational and national research institutions and companies have focused efforts to develop and promote the implementation of the international standard ISO 11783, based upon the digital communication protocol CAN (Controller Area Network), in order to integrate devices in machines and agricultural implements. Therefore, it is presented the development and the application of a model based on Petri nets' formalism as a tool for the support...

A utilização de eletrônica embarcada na agricultura tem crescido rapidamente, tornando necessária a utilização de diversos módulos a bordo da máquina (trator e implemento). Considerando-se os impactos relacionados a esta tendência, alternativas tecnológicas devem ser geradas e devidamente exploradas, especialmente sobre os sistemas de controle e o cabeamento requeridos. As arquiteturas eletro-eletrônicas devem garantir o mínimo de custo de implementação e tempo de manutenção. Os sistemas de controle devem operar maximizando a disponibilidade das informações, o que implica a necessidade de troca de dados entre estes diversos sistemas de controle e, portanto, a existência de um protocolo de comunicação serial internacionalmente padronizado. Neste contexto, este trabalho aborda os diversos protocolos de comunicação serial - como o RS232, o RS485 e o CAN (Controller Area Network) - e as suas normas específicas, voltadas às aplicações agrícolas, como a ISO11783 e a DIN 9684, comparando-as. Dessa análise resulta a indicação da ISO11783, norma baseada no protocolo CAN, como a mais interessante para as aplicações agrícolas. Essa norma é estudada em detalhes, o que permite a criação de um roteiro de estudo e implementação do referido protocolo. Finalmente...

Este trabalho é um modelo para controle de operação de frota de ônibus público urbano de baixa demanda, que objetiva o monitoramento (e intervenção, quando necessário), de forma que os ônibus monitorados cumpram a programação predeterminada pela grade-horária, evitando assim situações indesejáveis como atrasos ou congestionamentos nas estações de embarque e desembarque. A gestão do controle da movimentação dos ônibus se baseia em intervenções a serem realizadas na frota, considerando-se o sistema Bus Rapid Transit, que possui como grande diferencial as faixas segregadas para circulação dos ônibus. O objetivo é propor intervenções na frota (ações enviadas diretamente ao motorista como, por exemplo, diminuir a velocidade), e analisar os resultados, de forma a contribuir para diminuir dois grandes problemas em transporte público urbano: (1) o não cumprimento dos horários e (2) congestionamentos nas estações. Esses dois problemas geram reações em cadeia que acabam também afetando a regularidade de outros ônibus que compartilhar a mesma via e estações. Instituições públicas ou privadas de ônibus urbano podem obter benefícios utilizando um bom sistema de monitoramento e controle de frota, como por exemplo: mais segurança e previsibilidade nos horários...

O CAN (Controller Area Network) é um padrão no barramento de comunicação, amplamente difundido em aplicações industriais, particularmente em sistemas automotivos. Atualmente, um dos principais problemas no ramo automotivo é que esse barramento está com muitas mensagens no barramento, resultado da incorporação incremental de sistemas eletrônicos em automóveis, visto que há uma exigência maior de conectividade devido às exigências da sociedade e mercado. Como alternativa, vem sendo desenvolvida uma nova rede de comunicação, conhecida como CAN with Flexible Data-Rate (CAN-FD), que é um barramento com velocidade de transmissão de informação mais alta e maior capacidade de transporte de dados. Este projeto tem por objetivo principal explorar as funcionalidades da rede CAN-FD, através de simulações do trânsito de mensagens numa rede CAN-FD usando os dados de uma rede real CAN, e verificando a previsibilidade de ambas no âmbito de um protocolo que possa atender à demanda de sistemas complexos. A comparação é executada a partir de um conjunto de mensagens adicionadas na rede, para verificar os limites de transmissão de cada uma das redes, e os respectivos tempos de atraso das mensagens. Como um segundo estudo de caso...

Este documento trata da especificação de uma arquitetura aberta para controle de robôs manipuladores. A arquitetura é implementada utilizando o framework do projeto OROCOS, ambiente que já foi utilizado com sucesso em alguns sistemas de controle de robôs. Esta arquitetura é especificada para um robô manipulador genérico de N juntas, definindo componentes que abstraem o hardware dos robôs. A arquitetura é implementada com três tipos de controladores diferentes: PID independente por junta, controlador de torque calculado e controlador com feedforward. A sua validação é feita através da sua implementação em um robô real. Para isso é utilizada uma placa de acionamento, utilizando o barramento CAN devido ao seu determinismo e a sua taxa de comunicação. Também é necessário a utilização do modelo dinâmico do robô para as estratégias de controle de torque calculado e com feedforward. A obtenção de tal modelo é feita neste trabalho de forma analítica, e a seguir os parâmetros são identificados usando o sistema proposto.; This work deals with the specification of an open architecture for control of manipulator robots. The architecture is implemented by using the OROCOS framework. The architecture is specified for a generic manipulator robot with N joints...

Controller Area Network (CAN) is a popular and very well-known bus system, both in academia and in industry, initially targeted to automotive applications as a single digital bus to replace the wiring that were growing complexity, weight and cost with the advent of new automotive appliances. However, requirements have evolved and CAN’s dependability and bandwidth limitations led to the emergence of alternative networks such as FlexRay and TTP/C. Nevertheless, we believe that it is possible to improve CAN so it could fulfill contemporary requirements. This paper proposes the use of Flexible Time-Triggered CAN (FTT-CAN) to increase the available bandwidth while providing fault tolerance in CAN based systems with multiple buses. The architecture and flexibility of FTT based systems enables a tight yet flexible control of redundancy and bandwidth usage without increasing the complexity of the nodes. In this novel solution, a FTT-CAN Master controls the dispatching of messages among a set of independent buses. The Master can react online to bus failures switching the transmission of critical messages to a non-faulty bus, always keeping a predetermined redundancy level.; DETI

Public transportation users are constantly in search of regular service, fair cost, high safety, and physical and psychological comfort. Creating a system for bus route evaluation (BRE) can be considered to be among the basic requirements for public transportation management in cities. The need for a logical and scientific tool to support the decisions made by the policy makers of public transportation for the purpose of a higher quality of the services, specifically in a developing metropolitan such as Shiraz, Iran, proves the importance of such a system. In this study, firs, six routes among the 71 bus routes of metropolitan Shiraz were chosen. Subsequently, 16 criteria based on the theoretical literature and the data collected in a survey conducted by the Shiraz Public Bus Organization (SPBO) were produced. Then by using a two-stage multiple-criteria decision making (MCDM) model containing hierarchical Fuzzy Analytical Hierarchal Process (Fuzzy AHP) and TOPSIS methods the data was analyzed and the existing situation of the selected bus routes was evaluated. This study and the presented evaluation framework for the analysis of the current situation along with the comparison of the bus routes can help the managers and policy makers of bus transportation on their way to improving the services...

In this work, we present a hardware-software architecture for controlling the autonomous mobile robot Kapeck. The hardware of the robot is composed of a set of sensors and actuators organized in a CAN bus. Two embedded computers and eigth microcontroller based boards are used in the system. One of the computers hosts the vision system, due to the significant processing needs of this kind of system. The other computer is used to coordinate and access the CAN bus and to accomplish the other activities of the robot. The microcontroller-based boards are used with the sensors and actuators. The robot has this distributed configuration in order to exhibit a good real-time behavior, where the response time and the temporal predictability of the system is important. We adopted the hybrid deliberative-reactive paradigm in the proposed architecture to conciliate the reactive behavior of the sensors-actuators net and the deliberative activities required to accomplish more complex tasks; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior; Neste trabalho é apresentada uma arquitetura de hardware e software para controle do robô móvel autônomo Kapeck. O hardware do robô Kapeck é composto por um conjunto de sensores e atuadores organizados em um barramento de comunicação CAN. Dois computadores embarcados e oito placas microcontroladas foram utilizadas no sistema. Um dos computadores foi utilizado para o sistema de visão...

In recent years helpful guides have appeared in both English and Spanish to assist planners and officials to construct accessible buildings and pedestrian infrastructure which are usable by seniors, persons with disabilities, and all others who especially benefit from universal design. Less has been written about access to public transport systems. Very little guidance is available concerning specific issues which confront those planning Bus Rapid Transit (BRT) systems, mass transit systems which incorporate a spectrum of design and operational features on integrated trunk and feeder routes and which were initiated in Latin America and are now spreading throughout the region and beyond. The guidelines focus on the BRT environment and assume that interested parties can take advantage of existing guidelines to clarify general issues of access to public space, buildings, and pedestrian infrastructure. The guidelines generally follow the travel path of a passenger using a full-featured Bus Rapid Transit system. The accessible travel chain begins with sidewalks and pedestrian crossings and continues into a typical mid-island station served by buses with left-side doors (in countries where traffic drives on the right side). Buses pull up to an enclosed station with a ramped platform the height of the bus floor. The guidelines then focus on station features...

Bus stops are key links in the journeys of transit patrons with disabilities. Inaccessible bus stops prevent people with disabilities from using fixed-route bus services, thus limiting their mobility. The Americans with Disabilities Act (ADA) of 1990 prescribes the minimum requirements for bus stop accessibility by riders with disabilities. Due to limited budgets, transit agencies can only select a limited number of bus stop locations for ADA improvements annually. These locations should preferably be selected such that they maximize the overall benefits to patrons with disabilities. In addition, transit agencies may also choose to implement the universal design paradigm, which involves higher design standards than current ADA requirements and can provide amenities that are useful for all riders, like shelters and lighting. Many factors can affect the decision to improve a bus stop, including rider-based aspects like the number of riders with disabilities, total ridership, customer complaints, accidents, deployment costs, as well as locational aspects like the location of employment centers, schools, shopping areas, and so on. These interlacing factors make it difficult to identify optimum improvement locations without the aid of an optimization model. This dissertation proposes two integer programming models to help identify a priority list of bus stops for accessibility improvements. The first is a binary integer programming model designed to identify bus stops that need improvements to meet the minimum ADA requirements. The second involves a multi-objective nonlinear mixed integer programming model that attempts to achieve an optimal compromise among the two accessibility design standards. Geographic Information System (GIS) techniques were used extensively to both prepare the model input and examine the model output. An analytic hierarchy process (AHP) was applied to combine all of the factors affecting the benefits to patrons with disabilities. An extensive sensitivity analysis was performed to assess the reasonableness of the model outputs in response to changes in model constraints. Based on a case study using data from Broward County Transit (BCT) in Florida...

El Trabajo de Fin de Grado trata sobre el diseño e implementación de un paquete de funciones basadas en CAN bus. Dichas funciones se encargan de controlar el motor que va montado en el interior de la base que sustenta al robot ASIBOT. Este robot es desarrollado por el grupo de Robotics Lab del Departamento de Ingeniería de Sistemas y Automática de la Universidad Carlos III de Madrid. La arquitectura de control está implementada en C/C++. Para poder comunicarnos con el driver ISCM8005 debemos utilizar una placa que tiene las funciones básicas de un PC, dicha placa es la Roboard, en la que acoplaremos una placa miniPCI que es la HICO.CAN-miniPCI, con dicha placa comunicaremos vía CAN bus con el driver que controla el motor. El proyecto se ha desarrollado en el lenguaje de programación C/C++, la comunicación con los módulos ha sido por medio del protocolo de comunicación CANopen implementado sobre el bus de campo CAN. Este protocolo consigue una comunicación serie para el intercambio de información entre las unidades del sistema y soporta un eficiente control en tiempo real con un nivel de seguridad muy elevado. Las funciones implementadas que se encuentran desarrolladas dentro de la Roboard, son paquetes de CAN bus, que siguen el protocolo CANopen. Dichas funciones son llamadas remotamente utilizando una conexión en la que puede haber múltiples escritores para múltiples lectores (paradigma publicador/suscriptor)...

Bogota, the capital city of Colombia, is located near the geographic center of Colombia, 2,640 meters (8,661 ft) sea level. It is the largest and most populous city in the nation, with an estimated 8.2 million inhabitants in the metropolitan area in 2007 and a population density of 3,912 inhabitants per square kilometer. Its economy generates 25 percent of Colombia's total gross domestic product (GDP). The city's roads were highly congested with the significant growth in private car ownership and use. While private cars occupied 64 percent of the road space, they only represented 19 percent of the population, and the daily average commute time was 1 hour and 10 minutes each way. Other issues included high incidences of accidents and extremely high air pollution rates during peak travel hours. In 1999, after the new National Government rejected potential plans for a subway system, the Mayor of Bogota presented his plan for a Bus Rapid Transit (BRT) system, built upon the successful experience of Curitiba in Brazil. The transition to an effective BRT system would help realize the Mayor's four main goals by: (i) improving public transport system with respect to efficiency...

Buses are the most common form of urban transit but, in the developing world, are often seen as inefficient and polluting. It is well known that buses that are properly tuned and adjusted tend to be cleaner, safer and consume less fuel than poorly maintained buses. Fuel cost is a relatively large fraction of total cost especially when labor and bus costs are low, as in many developing countries. Hence, reducing fuel use through targeted maintenance of fuel inefficient buses can reduce significant expenditures especially in developing countries, freeing up resources for other improved city services. In addition, if city buses do not receive periodic maintenance that is adequate in quality and quantity, their emissions, both local and global, will suffer. In an effort to catalyze solutions for urban transport, the World Bank Group focused on development of a global Knowledge Product in the form of a 'Guidance Note' (GN) on bus maintenance procedures. The GN is directed towards city transit managers and their technical staff in developing countries to enhance the energy efficiency of city transit. The objective of this work effort is to prepare a Guidance Note (GN) on maintenance best practices that is a practical and useful tool to guide the implementation of a program that will enhance the fuel efficiency of buses. To address this objective...

In most large cities in developing countries, buses continue to be the public transport option of choice, carrying a large share of urban travelers. However, transit bus companies in these countries are often cash-strapped. In many cases, the operating cost per bus kilometer exceeds revenues and bus fares are often kept low irrespective of the cost of providing service. Many cities are dominated by old and fuel-intensive buses with high operating costs. Transit systems are also often plagued by overcrowded and undependable service, congested roadways and chaotic operating environments. Across the board, city officials in developing countries are under strong pressure to improve the efficiency and enhance the attractiveness of bus transportation. Fuel makes up a relatively large fraction of total bus operating costs, especially when labor costs are low, as in many developing countries. Fuel costs can be reduced by improving the driving style of bus drivers and through sound maintenance practices. A safe and economical driving style can reduce variable costs...

Bus Rapid Transit (BRT) is an alternative mode of public transportation that is often considered superior to the conventional bus system. This report offers a comparison of two BRT systems between a newly established one in York Region (York Region Transit’s VIVA) and a well-established one in Ottawa (OC Transpo’s Transitway). The purpose of this report is to examine the strengths of BRT, establish how BRT systems can learn from one another, and determine ways to improve various BRT systems in order to make them more attractive to potential riders. The two BRT systems were compared based on seven common criteria of BRT. It was found that both BRT systems have strengths and weaknesses and can each learn from one another. The most significant difference between the two is the fact that OC Transpo has over 30 km of its own running way, whereas VIVA currently has none; however, York Region Transit is in the process of constructing five running ways. Fortunately, despite its current lack of running ways, VIVA has managed to provide a superior bus service compared to York Region Transit’s conventional bus system. Ultimately, it has been found that BRT is an effective mode of transit that can provide efficient and sustainable transportation and has helped to increase public transit ridership.; A report submitted to the School of Urban and Regional Planning in conformity with the requirements for the degree of Master of Urban and Regional Planning

Very compact 70 MeV pulse race-track microtron is under construction now. To acquire outputs of beam-current transformers on every orbit and pulses of high voltage and RF field a distributed multi-channel beam diagnostic system was developed. Each acquisition controller consists of four fast differential amplifiers and one DSP-based micro-controller with on-chip ADC and CAN-bus controller. Each amplifier is coupled with beam-current transformer and has bandwidth of up to 150MHz and gain of up to 10. One of four channels is acquired during a measurement cycle. Another channel could be selected between two following pulses. All the controllers are connected via optically coupled CAN-bus with a host diskless PC running under Linux with the RTLinux extension. Dedicated software of the system consists of low level acquisition software for DSP, network software for controllers and host PC, application software for PC to present date for operator and control system. Standard CAN application layers were considered but refused because of the closed character of the whole system and centralised synchronisation of the whole system. Dedicated software of the system consists from low level acquisition software for DSP, network software for controllers and host PC...

With the feature of multi-master bus access, nondestructive contention-based arbitration and flexible configuration, Controller Area Network (CAN) bus is applied into the control system of Wire Harness Assembly Machine (WHAM). To accomplish desired goal, the specific features of the CAN bus is analyzed by compared with other field buses and the functional performances in the CAN bus system of WHAM is discussed. Then the application layer planning of CAN bus for dynamic priority is presented. The critical issue for the use of CAN bus system in WHAM is the data transfer rate between different nodes. So processing efficient model is introduced to assist analyzing data transfer procedure. Through the model, it is convenient to verify the real time feature of the CAN bus system in WHAM.; Comment: 6 pages, 2 figures, 4 tables

Ethernet is being considered as the backbone network protocol for next-generation automotive control networks. In such networks, Controller Area Network (CAN) messages related to automotive control can be sent from a CAN network to other sub-networks via the backbone Ethernet bus and, if the CAN messages have real-time constraints, these have to be guaranteed. This paper presents a simulation environment for CAN--Ethernet Audio Video Bridging (AVB) mixed networks based on OMNeT++. We use Ethernet AVB, which can guarantee network bandwidth, to improve the real-time property of CAN messages through the backbone Ethernet bus. To simulate the networks, we also developed a CAN--Ethernet AVB gateway (GW) model. To verify the efficacy of our model, we measured the latency of CAN messages sent from a CAN bus to an Ethernet AVB node via the backbone Ethernet AVB bus in both bandwidth-guaranteed and best-effort queue scenarios. The results indicate that the latency of Ethernet AVB frames containing CAN messages is minimized and limited by the bandwidth-guaranteed mechanism of Ethernet AVB.; Comment: Published in: A. F\"orster, C. Sommer, T. Steinbach, M. W\"ahlisch (Eds.), Proc. of 1st OMNeT++ Community Summit, Hamburg, Germany, September 2...

This paper describes the design and implementation of a new digital dimming electronic ballast with the capability of being remotely controlled in a digital way, this is achieved through a novel lighting network based on Controller Area Network (CAN) bus standard. The proposed ballast was designed to drive a T5, 28 Watts fluorescent lamp. The proposed functional performance was tested using an implemented lighting network system based on CAN 2.0A bus specification. The defined lighting network functions include dimming, turning on and off, and fault condition detection. The network control is made with a lighting system software in a personal computer (PC) through one specific CAN node, being able to address up to 2047 individually controllable ballasts. According to the obtained results the proposed digital dimming electronic ballast performed the established functions successfully, meeting C class of the International Electrotechnical Commission (IEC) standard. The resulting system consists of a novel fully functional CAN bus lighting network with a reliable two wire remote control. Applications for this CAN Bus lighting network include lighting systems focused on design issues like lamp dimming control for electrical energy consumption savings and efficient lamp maintenance. Such application areas cover building lighting management...