CSP channels for CAN-bus connected embedded control systems

Closed loop control system typically contains multitude of sensors and actuators operated simultaneously. So they are parallel and distributed in its essence. But when mapping this parallelism to software, lot of obstacles concerning multithreading communication and synchronization issues arise. To overcome this problem, the CT kernel/library based on CSP algebra has been developed. This project (TES.5410) is about developing communication extension to the CT library to make it applicable in distributed systems. Since the library is tailored for control systems, properties and requirements of control systems are taken into special consideration. Applicability of existing middleware solutions is examined. A comparison of applicable fieldbus protocols is done in order to determine most suitable ones and CAN fieldbus is chosen to be first fieldbus used. Brief overview of CSP and existing CSP based libraries is given. Middleware architecture is proposed along with few novel ideas

An Approach to remote process monitoring and control

The purpose of this thesis is to present an approach to remote monitoring and operation of distributed real time process control systems. Conventional monitoring of process control systems currently requires a great deal of close supervision from trained personnel located on-site. In many cases, researchers, developers or maintenance personnel cannot be at every location where such a system is installed. Currently, a standardized architecture for remote access to such systems is not available. In addition, most of these systems are very expensive and under-utilized. Researchers would benefit by having access to different parts of a system concurrently The benefits of a layered architecture for remote process monitoring and control will be analyzed through the use of a demonstration system that was realized to examine the real time performance of the interconnection mechanisms between the process controller(s) and the system monitoring interfaces. Low level, real-time process control is achieved by using specialized networking schemes called fieldbusses to interconnect all control devices. In this system, fieldbus controllers will also assume the role of servers connected to the Internet, in order to make device information available to any local or remote clients. In the proposed architecture, remote clients are user interfaces, implemented as JAVA applets, which can be accessed with a web browser. The proposed system architecture allows for client interfaces to gain remote access to various types of fieldbusses transparently

Position paper on time and event-triggered communication services in the context of e-manufacturing

Modern factories are complex systems where advances in networking and information technologies are opening new ways towards higher efficiency. Such move is being driven by market rules with ever-increasing competition levels, in search for faster time-to-market, improved process yield, non-stop operations, flexible manufacturing and tighter supply-chain coupling. All these aims present a common requirement, i.e. a realtime flow of information, from the plant-floor up to the management, maintenance, suppliers and clients, to support accurate monitoring and control of the factory. This stresses the importance achieved by the communication infrastructure in modern manufacturing industry. This paper presents the authors view concerning the current trends in modern factory communication systems. It addresses the problems of seamlessly integrating different information flows with diverse requirements, mainly in terms of timeliness. In this aspect, the debate between event-triggered and time-triggered communication is revisited as well as the joint support for both types of traffic. Finally, a view of where factory communication systems are moving to is also presented, showing the impact of open and widely available technologies.FCT. Comissão Europeia(ARTIST,IST-2001-34820

Integration of sensor and actuator networks and the SCADA System to promote the migration of the legacy flexible manufacturing system towards the industry 4.0 concept

Se implementan redes de sensores y actuadores en los procesos de fabricación automatizados utilizando buses de campo industriales, donde las unidades de automatización y los sistemas de supervisión también están conectados a intercambiar información operacional. En el contexto de la cuarta revolución industrial entrante, llamada Industria 4.0, la gestión de las instalaciones de legado es una cuestión primordial a tratar. Este documento presenta una solución para mejorar la conectividad de un sistema de fabricación flexible heredado, que constituye el primer paso en la adopción del concepto de Industria 4.0. Tal sistema incluye el PROCESO de bus de campo FIELD BUS (PROFIBUS) alrededor del cual se interconectan los sensores, actuadores y controladores. En orden para establecer una comunicación efectiva entre la red de sensores y actuadores y una red de supervision se implementa un enfoque de hardware y software que incluye la conectividad Ethernet. Este se prevé que la labor contribuya a la migración de los sistemas heredados hacia la desafiante industria 4.0 marco. Los resultados experimentales prueban el correcto funcionamiento del FMS y la viabilidad de la propuesta.Networks of sensors and actuators in automated manufacturing processes are implemented using industrial fieldbuses, where automation units and supervisory systems are also connected to exchange operational information. In the context of the incoming fourth industrial revolution, called Industry 4.0, the management of legacy facilities is a paramount issue to deal with. This paper presents a solution to enhance the connectivity of a legacy Flexible Manufacturing System, which constitutes the first step in the adoption of the Industry 4.0 concept. Such a system includes the fieldbus PROcess FIeld BUS (PROFIBUS) around which sensors, actuators, and controllers are interconnected. In order to establish effective communication between the sensors and actuators network and a supervisory system, a hardware and software approach including Ethernet connectivity is implemented. This work is envisioned to contribute to the migration of legacy systems towards the challenging Industry 4.0 framework. The experimental results prove the proper operation of the FMS and the feasibility of the proposal.peerReviewe

Systems integration using Siemens\u27 PC based automation technology

Manufacturing Systems Integration is the progressive linking and combination of the various components of the system to merge their functional and technical characteristics into a comprehensive interoperable unit. It requires one to work with different hardware and software. There are a number of vendors providing a large number of products. Integrating these varieties of products provides a greater value than the sum of the value provided by the individual products. What hinders the effective integration of these components is the diversity in the design and the use of these products. Systems Integration is eased by well-established standards in data communication, programming languages, application development environments and computer operating systems. Many vendors have attempted to come up with standards that are relatively open. However, when one has to integrate data among multiple vendors\u27 architecture, a new set of challenges emerge. The Siemens\u27 PC-based automation technology is an emerging technology that appears to provide robust architecture for integrating all elements of the manufacturing environment. Applications ranging from simple control to distributed control and full-fledged Manufacturing Execution Systems can be developed using Siemens\u27 architecture. The primary focus of this applied research work is to develop a Manufacturing Execution System to control a flexible manufacturing system using Siemens PC-based automation technology. This technology is implemented in a Flexible Manufacturing cell named the CAMCELL. The CAMCELL consists of two CNC machining centers, assembly robots, and a vision system, all of which are interlinked by a material handling system. The software architecture of the CAMCELL is based on NIST\u27s five level hierarchy, discussed briefly in the report. Specifically it contains functional modules for order entry, scheduling and routing. In addition to these functional modules, there are various support modules such as order entry module, scheduler, router etc, two of which named the Inquire and the Pallet Controller that are implemented in this study. Siemens\u27 Step 7 and WTNCC software are used for the control and monitoring of the cell

Simulation and experimental evaluation of a flexible time triggered ethernet architecture applied in satellite nano/micro launchers

The success of small satellites has led to the study of new technologies for the realization of Nano and Micro Launch Vehicle (NMLV) in order to make competitive launch costs. The paper has the objective to define and experimentally investigate the performance of a communication system for NMLV interconnecting the End Systems as On-Board Computer (OBC), telemetry apparatus, Navigation Unit...we propose a low cost Ethernet-based solution able to provide the devices with high interconnection bandwidth. To guarantee hard delays to the Guide, Navigation and Control applications we propose some architectural changes of the traditional Ethernet network with the introduction of a layer implemented in the End Systems and allow for the lack of any contention on the network links. We show how the proposed solution has comparable performance to the one of TTEthernet standard that is a very expensive solution. An experimental test-bed equipped with Ethernet switches and Hercules boards by Texas Instruments is also provided to prove the feasibility of the proposed solution

Real-time communications over wired/wireless PROFIBUS networks supporting inter-cell mobility

PROFIBUS is an international standard (IEC 61158, EN 50170) for factory-floor communications, with several thousands of installations worldwide. Taking into account the increasing need for mobile devices in industrial environments, one obvious solution is to extend traditional wired PROFIBUS networks with wireless capabilities. In this paper, we outline the major aspects of a hybrid wired/wireless PROFIBUS-based architecture, where most of the design options were made in order to guarantee the real-time behaviour of the overall network. We also introduce the timing unpredictability problems resulting from the co-existence of heterogeneous physical media in the same network. However, the major focus of this paper is on how to guarantee real-time communications in such a hybrid network, where nodes (and whole segments) can move between different radio cells (inter-cell mobility). Assuming a simple mobility management mechanism based on mobile nodes performing periodic radio channel assessment and switching, we propose a methodology to compute values for specific parameters that enable an optimal (minimum) and bounded duration of the handoff procedure

Flexible time-triggered protocol for CAN: new scheduling and dispatching solutions

One of the possibilities to build robust communication systems with respect to their temporal behaviour is to use autonomous control based on the time-triggered paradigm. The FTT-CAN - flexible time-triggered protocol, relies on centralised scheduling but makes use of the CAN native distributed arbitration to reduce communication overhead. There, a planning scheduler is used within a master node to reduce the scheduling run-time overhead. On-line changes to the communication requirements can then be made under guaranteed timeliness. In addition FTT-CAN also allows an efficient combination of both time-triggered and event- triggered traffic with temporal isolation. In this paper, recent evolutions of the initial protocol definition concerning transmission of synchronous and asynchronous messages are presented. These consist in a time division of the elementary transmission window which optimises the available bandwidth for asynchronous messages, keeping the timeliness of synchronous messages without jeopardising their transmission jitter. A novel solution for the planning scheduler is also presented. It consists in an FPGA-based coprocessor which implements the planning scheduler technique without imposing overhead to the arbiter CPU. With it, it is possible to reduce strongly the plan duration thus allowing on-line admission demanded by system elements and, also, to extend the protocol application to high-speed networks

Current challenges and future trends in the field of communication architectures for microgrids

[EN] The concept of microgrid has emerged as a feasible answer to cope with the increasing number of distributed renewable energy sources which are being introduced into the electrical grid. The microgrid communication network should guarantee a complete and bidirectional connectivity among the microgrid resources, a high reliability and a feasible interoperability. This is in a contrast to the current electrical grid structure which is characterized by the lack of connectivity, being a centralized-unidirectional system. In this paper a review of the microgrids information and communication technologies (ICT) is shown. In addition, a guideline for the transition from the current communication systems to the future generation of microgrid communications is provided. This paper contains a systematic review of the most suitable communication network topologies, technologies and protocols for smart microgrids. It is concluded that a new generation of peer-to-peer communication systems is required towards a dynamic smart microgrid. Potential future research about communications of the next microgrid generation is also identified.This work is supported by the Spanish Ministry of Economy and Competitiveness (MINECO) and the European Regional Development Fund (ERDF) under Grant ENE2015-64087-C2-2. This work is supported by the Spanish Ministry of Economy and Competitiveness (MINECO) under grant BES-2013-064539.Marzal-Romeu, S.; Salas-Puente, RA.; González Medina, R.; Garcerá, G.; Figueres Amorós, E. (2018). Current challenges and future trends in the field of communication architectures for microgrids. Renewable and Sustainable Energy Reviews. 82(2):3610-3622. https://doi.org/10.1016/j.rser.2017.10.101S3610362282