http://www.ifac-papersonline.net/ en Copyright 09:04 AM Wednesday 08, 2012 IFAC-PapersOnline http://www.ifacpapersonline.com 09:04 AM Wednesday 08, 2012 09:04 AM Wednesday 08, 2012 ET webmaster@ifac-papersonline.net webmaster@ifac-papersonline.net http://www.ifac-papersonline.net/Detailed/31794.html 04:00 PM Wednesday 31, 1969 Contemporary industrial automation systems are using real-time Ethernet protocols, like PROFINET, for exchanging process and configuration data. In order to make automation systems more flexible and due to many other advantages, wireless technologies are introduced in certain application areas, e.g. the connection of sensors by the use of a wireless sensor network. In this typical scenario the integration of a newly deployed wireless sensor network into an existing system is required and of vital importance. This paper gives a short introduction to different wireless technologies that are being discussed at the moment for wireless sensor networks (WSNs) and to PROFINET IO. It also proposes a feasible integration approach regarding application layer object models and their corresponding mapping. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31781.html 04:00 PM Wednesday 31, 1969 Networked feedback control systems, which have been adopted across the wide range of industries, suffer from limitations in mobility and flexibility because of the network wires. A wireless communication network, such as ZigBee based on the IEEE 802.15.4 standard, may be considered as an effective alternative to overcoming this problem. However, a communication network for use in feedback control must satisfy strict requirements on the deterministic behavior in terms of message latency and jitter. The ZigBee protocol however may introduce significant delays, which are randomly varying with time, into the system. This paper presents a deterministic wireless network that can be used for feedback control systems. The proposed approach is based on a time-triggered mechanism implemented on top of the IEEE 802.15.4 standard. The effectiveness of the proposed method is investigated using a series of experiments on the control of DC motors. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31800.html 04:00 PM Wednesday 31, 1969 This paper describes a wireless based networked control system (NCS) and its diagnosis. The purpose is to show the specific characteristics of a wireless network compared to a classical wired network and their consequences on the diagnosis. A comparison of residuals generated to detect and isolate sensor faults in a control loop is made when two network protocols are used: a CAN network and a ZigBee wireless network. An additional residual is proposed to differentiate sensor faults from packet losses. A reconfiguration procedure is used to improve control performance in case of packet losses. A D.C motor control and diagnosis are simulated with Matlab/Simulink while the networks are simulated with TrueTime 1.5. A distributed diagnosis strategy is also proposed from overall system perspective. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31791.html 04:00 PM Wednesday 31, 1969 AFDX (Avionics Full Duplex Switched Ethernet, ARINC 664) used for modern aircraft such as Airbus A380 represents a major upgrade in both bandwidth and capability for aircraft data networks. Its reliance on Ethernet technology helps to lower some of the implementation costs, though the requirement for guaranteed service does present challenges to system designers. Thus, the problem is to prove that no frame will be lost by the network (no switch queue will overflow) and to evaluate the end-to-end transfer delay through the network. Several approaches have been proposed for this evaluation. Network calculus gives a guaranteed upper bound on end-to-end delays, while simulation produces more accurate results on a given set of scenarios. In this paper, the focus is on the end-to-end delays distribution. An important problem is the great number of different flows, since the evaluation has to be conducted on each flow. We use a simulation approach to show that different network architectures can lead to the same end-to-end delays distribution. Thus, we propose a generic simulation model for the evaluation of end-to-end delays distribution. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31820.html 04:00 PM Wednesday 31, 1969 this paper proposes a decentralized algorithm to organize an ad hoc sensor network into clusters by using Fuzzy Logic. Each sensor uses a Fuzzy decision making process to find the best Cluster Head. Simulation shows that this protocol is able to dynamically adapt to network mobility and also shows that with fuzzy logic we have stable clusters and so a cluster head have greater lifetime. Therefore respect to mobility, we have the minimum message exchange and so minimum energy consumption. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31807.html 04:00 PM Wednesday 31, 1969 Automatic surveillance systems as well as autonomous robots are technical systems which would profit from humanlike perceptive systems. We present a technical model for humanlike perception by multi-sensory fusion, symbolic information processing, and knowledge integration. The model is inspired by neuroscience. Information from diverse sensor sources is processed in parallel, transformed into symbolic representations, and further processed in a modular, hierarchical fashion. Higher-level symbolic information is gained by combination of lower-level symbols. Feedbacks from higher levels to lower levels are possible and symbol generation is also influenced by stored knowledge. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31784.html 04:00 PM Wednesday 31, 1969 This paper provides a runtime stability analysis of the Daisy-Chain clock synchronization algorithm running over CASCA - a time-triggered extension of CAN bus. The main objective is to show with practical results how to achieve global time base of high precision and how this precision is affected by the modification of the TDMA transmission schedule. That contributes by providing some basic guidelines for the task of designing time-triggered, TDMA-based distributed systems for embedded control applications. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31802.html 04:00 PM Wednesday 31, 1969 In most key industries, distributed real-time systems have found widespread use in order to ensure safety-critical functions. Design of such systems still represents a challenge because of many problems arisen by the combination of real-time, distribution, performance and safety. Fault-tolerant real-time networks have been a major research subject for these last years. OASIS provides a time-triggered multitasking and communication approach for designing safety-critical real-time systems. In order to fulfil the industrial needs, an extension to distributed architectures has been carried out which includes a TDMA-based deterministic and real-time protocol and its optimized version, called A-TDMA, presented here. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31811.html 04:00 PM Wednesday 31, 1969 Industrial Ethernet networks will increasingly be used in automation and control systems. In order to integrate existing solutions based on PLCs and fieldbus connected devices, appropriate migration strategies are required. The paper describes a proxy solution for integrating existing PLC-based solutions into PROFINET IO. The PLCs may be connected to the proxy using any communication protocol, including fieldbus and Ethernet. Besides runtime and engineering aspects of the proxy, security considerations are included to support and to enhance the security cell-concept. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31799.html 04:00 PM Wednesday 31, 1969 Recently, it has been suggested that the communication data exchanged by the IEEE 802.15.4 devices can be protected with the security services of confidentiality and integrity offered by the AES-CCM mode of operation. However, the typical type of devices implementing that standard present severe levels of computing constrains such as, computing power, memory space, and power drain, causing that the implementation of security services on such devices is frequently a challenge not easy to meet. In this paper we present a study of the hardware cost associated with the implementation of AES-CCM in reconfigurable hardware devices. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31803.html 04:00 PM Wednesday 31, 1969 Designing real-time embedded control systems follows usually a V-process and requires various languages and tools. Each language/tool provides a design methodology, and defines its own terminology and semantic. This lack of consistency leads usually to a disconnected design process where the transformation of models is usually performed manually. Thus, errors may be introduced in the models. Correcting these errors lengthens the design lifecycle and time to market. In this paper, we propose a new methodology which aims to fill the gaps due to the lack of consistency by unifying the terminologies and semantics used, and reduces the time spent in translation and debugging. This methodology does not propose a new global language which is far from each domain concerns and where the leaning curve is longer. The goal is rather to provide a multi-facet design using aspect and component approaches, and relying on an unified system metamodel in order to link the semantic differences between control and real-time computing languages and tools. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31798.html 04:00 PM Wednesday 31, 1969 Industrial process control architectures are generally composed of nodes organized in a cluster-tree. Today, wired communications between nodes enable guaranteeing the constraint respect attached to determinism. Innovations in wireless technology allow using these new technologies instead of wired systems. IEEE 802.15.4 standard meet industrial local network needs, but it does not propose any mechanisms to avoid beacon and GTS (Guaranteed Time Slot) collisions in meshed network. This communication proposes a new synchronization method for beacons and GTSs in meshed networks using IEEE 802.15.4. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31812.html 04:00 PM Wednesday 31, 1969 Teleoperation and supervision of robotic systems are usually made through field buses and wired links. In this paper we present the teleoperation and supervision of a biped robot - YABIRO1 - based on a wireless link. YABIRO uses two independent CAN networks for sensors and actuators control. With the development of specific devices we can monitor the state of the robot and, in addition, control its actions through a wireless link, applying the tunnelling technique for encapsulating CAN messages into a TCP/IP network with WiFi media. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31772.html 04:00 PM Wednesday 31, 1969 Wireless sensor networks are usually composed of autonomous nodes. Each networked node constructs its own neighbor table, routing table, and schedules internal tasks on its own. However, the inherently distributed control in a sensor network conflicts with the deterministic requirements when we develop real-time applications on top of wireless sensor networks. In this paper we argue for the case of centralized control in distributed wireless sensor networks. We first describe the characteristics of wireless sensor networks and real-time applications. Then we explain the gap between the demand and supply. We back our arguments with some tentative simulation results. The idea of running real-time applications over wireless sensor networks is motivated by WirelessHART, a standard to apply process control over wireless mesh networks. Not surprisingly, WirelessHART adopts centralized network management. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31789.html 04:00 PM Wednesday 31, 1969 A main step in evaluating reliability and safety properties of embedded communication systems consists in identifying potential failure modes. We present a classification of component and system level failure modes for time-triggered communication networks, such as TTP and FlexRay. Based on our experience in modeling and verifying industrial real-time systems, we propose a way to analyze the effect of these failure modes on a given system using the SAL framework. We discuss two modeling paradigms that are particularly suitable for time-triggered communication networks. These paradigms differ in the way time is represented, either as a discrete or a continuous variable. Moreover, we identify failure modes that can be represented by both modeling approaches, as well as failure modes that require a continuous representation. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31788.html 04:00 PM Wednesday 31, 1969 This paper introduces a mathematical model for analyzing the delay performance of time-critical and time-available data in the Foundation Fieldbus data link layer token-passing service. The mathematical model introduces the concept of virtual token rotation time to account for the dependency of the token rotation times on prioritized data in analyzing their data latency. The validity of the analytical model was verified using a simulation experiment. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31776.html 04:00 PM Wednesday 31, 1969 The revolution of communication is also in the AIRBUS Avionics. This presentation gives an outline of the embedded network technologies used in AIRBUS. It shall start by classic technologies of families A320, A330 and A340 and finish on the new technologies of networks which are and which will be our new bases in our new planes: A380, A400M, A350.....The various embedded technologies of network shall be presented, including ARINC 429 on the family A320, A330 & A340, AFDX backbone firstly implemented on A380, CAN as a system network on A380, and future field busses. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31824.html 04:00 PM Wednesday 31, 1969 This paper evaluates the error propagation and its effects in babbling idiot failure in a FlexRay-based network. The evaluation is based on about 35680 bit-flip fault injections inside different parts of the FlexRay communication controller. To do this, a FlexRay communication controller is modeled by Verilog HDL at the behavioral level. Then, this controller is exploited to setup a FlexRay-based network composed of four nodes. Nodes in this experiment are considered in two forms: 1) node without bus guardian, 2) node with bus guardian. The results of fault injection show that in first form about 4.57% of faults lead to the babbling idiot failures. Also in second form about 0.75% faults lead to babbling idiot failures. After this experiment and evaluation of the results, one improvement in the bus guardian is done. With this improvement, the results show that babbling idiot failures are eliminated completely. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31775.html 04:00 PM Wednesday 31, 1969 This paper deals with the embedded network dedicated to the entertainment system of passenger cabin in an aircraft. The work described in this paper focuses on a wireless solution to interconnect the main components of this system. The selected solution is UWB with smart antennas. This solution is proved to be able to provide the system with the needed bandwidth. The self-configuration capability of the system is also demonstrated. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31777.html 04:00 PM Wednesday 31, 1969 From embedded intersystem multiplex to wireless connectivity automotive drive High Value with High Tech Low Cost in transportation. The 60 millions new cars produced each year within earth are more and more demanding in robust, multi functional low cost embedded network. After the success of low and high speed CAR and LIN protocols for all vehicle purpose. FLEXRAY is starting a new carrier in the powertrain and chassis environment of new premium cars. At the same time, the mass volume market of interior bluetooth wireless connectivity is driving a new way to architecture the connected cockpit. We will fly over all those exiting challenges that could certainly generate synergies between automotive, aeronautics and space for our competitiveness. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31809.html 04:00 PM Wednesday 31, 1969 This abstract describes how the advantages of the two major device integration technologies EDDL and FDT are combined into one consistent future solution. The new concept concentrates especially on a clear structure and architecture to reduce dependencies and therefore the complexity of device integration. Based on this concept the ECT and the FDT Group jointly develop the unified future solution for device integration - Field Device Integration (FDI). http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31770.html 04:00 PM Wednesday 31, 1969 http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31785.html 04:00 PM Wednesday 31, 1969 This paper proposes a new real-time communication scheme for IEEE 802.11e HCCA networks. The proposed communication scheme is called Group Sequential Communication (GSC) and it aims the reduction of the polling overhead associated to the real-time message transmission when using the HCCA function. The GSC scheme partially eliminates the polling inefficiency, by means of a virtual token passing procedure among polled stations. Thus, it reduces the number of exchanged messages between the HCCA controller and the polled stations. The GSC uses a real-time group concept, where the real-time members of the group are granted a sequential access to the communication medium. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31771.html 04:00 PM Wednesday 31, 1969 A key challenge for wireless industrial networking is to successfully transmit a packet within a prescribed deadline despite the unfriendly properties of the wireless transmission medium. A very promising class of approaches exploits the concept of spatial diversity to improve the robustness of wireless transmission. The concept of relaying belongs to this class and in this paper we discuss how protocols for wireless industrial networks can be designed to include relaying approaches. An example protocol design is presented and the achievable probability for not missing a prescribed deadline is assessed in an example scenario, demonstrating the significant improvements possible with spatial diversity techniques. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/31793.html 04:00 PM Wednesday 31, 1969 The problem of providing a wireless communications for factory automation systems is still an open issue, notwithstanding the fact that there are a large number of solutions. A particularly import condition is for such systems to provide adequate behaviour in error-prone environments. In this paper, we compare, in error-prone conditions, the performance of two approaches that extend the PROFIBUS to support wireless communications. One of these approaches is based on repeaters and another is based on bridges. Additionally, we propose a set of enhancements to the bridge-based approach in order to detect and correct error situations. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif