Factory Automation Part 3 pdf

FactoryAutomation72 Fig. 17. Percentage of lost and recovered packets. 8. Conclusions This chapter has analyzed the feasibility of a 802.11 based wireless real-time communication system. For that purpose a wireless communication architecture that properly integrates the leading IEEE 802.11 technology, the RTnet framework, and the Xenomay nano-kernel has been implemented. This architecture has been experimentally tested for various transmission data rates, baseband processor sensitivities, and sampling intervals, with and without interfering traffic. Experiments have demonstrated that by properly setting protocol parameters a robust real-time service can be provided. 9. References Andersson M.; Henriksson D.; Cervin A. & Arzen K. E. (2005). Simulation of wireless networked control systems, Proceedings of the 44th IEEE Conference on Decision and Control, and the European Control Conference, Seville, Spain, Dec. 2005. ANSI (1994). Portable Operating Sytem Interface (Posix). ANSI, IEEE, 1994. Baillieul J. & Antsaklis P. J. (2007). Control and Communication Challenges in Networked Real-time Systems. Proceedings of the IEEE, Vol. 95, No. 1, (Jan. 2007) 9-28. Baliga G. & Kumar P. R. (2005). A middleware for control over networks, Proceedings of the 44th IEEE Conference on Decision and Control, and the European Control Conference, Seville, Spain, Dec. 2005. Barr M. (2003). Choosing an RTOS. Tech. Rep. Embedded Systems Programming, Jan. 2003. Benvenuti C. (2006). Understanding Linux Network Internals. O’Reilly, 2006. Biasi M. D.; Snickars C.; Landernas K. & Isaksson A. J. (2008). Simulation of process control with wirelesshart networks subject to packet losses, Proceedings of 4th IEEE Conference on Automation Science and Engineering, Washington DC, USA, Aug. 2008. Boggia G.; Camarda P.; Grieco L. A. & Zacheo G. (2008a). Toward wireless networked control systems: an experimental study on real-time communications in 802.11 wlans, Proceedings of 7th IEEE International Workshop on Factory Communication Systems, WFCS, Dresden, Germany, May 2008. Boggia G.; Camarda P.; Grieco L. A. & Zacheo G. (2008b). An experimental evaluation on using TDMA over 802.11 MAC for wireless networked control, Proceedings of Emerging Technologies and Factory Automation, ETFA, Hamburg, Germany, Sep. 2008. Boughanmi N.; Song Y. & Rondeau E. (2008). Wireless networked control system using IEEE 802.15.4 with GTS, Proceedings of 2nd Junior Researcher Workshop on Real-Time Computing, JRWRTC, Rennes, Brittany, Oct. 2008. Burda R. & Wietfeld C. (2007). Multimedia over 802.15.4 and ZigBee Networks for Ambient Environmental Control, Proceedings of the IEEE VTC Spring, Dublin, Ireland, Apr. 2007. Buttazzo G.; Velasco M. & Martì P. (2007). Quality-of-Control Management in Overloaded Real-time Systems. IEEE Trans. on Computers, Vol. 56, No. 2, (Feb. 2007) 253–266. Cena G.; Bertolotti I. C.; Valenzano A. & Zunino C. (2007). Evaluation of response times in industrial WLANs. IEEE Trans. on Industrial Informatics, Vol. 3, No. 3, (Aug. 2007) 191–201. Cervin A.; Ohlin M. & Henriksson D. (2007). Simulation of networked control systems using truetime, Proceedings of the 3rd International Workshop on Networked Control Systems: Tolerant to Faults, Nancy, France, Jun. 2007. Chen J.; McKernan A.; Irwin G. W. & Scanlon W. G. (2008). Experimental characterisation and analysis of wireless network control systems, Proceedings of the IET Irish Signals and Systems Conference, ISSC, Galway, Ireland, Jun. 2008. Choi D. H.; Lee J. I.; Kim D. S. & Park W. C. (2006). Design and implementation of wireless eldbus for networked control systems, Proceedings of SICE-ICASE International Joint Conference, Bexco, Busan, Korea, Oct. 2006. DIAPM (2008), Real-time application interface (RTAI) for Linux. Tech Rep. Politecnico di Milano, 2008, available online: http://www.rtai.org. Flammini A.; Marioli D.; Sisinni E. & Taroni A. (2009). Design and implementation of a wireless eldbus for plastic machineries. IEEE Trans. on Industrial Electronics, Vol. 56, No. 3, (Mar. 2009) 747–755. Floroiu J.; Ionescu T. C.; Ruppelt R.; Henckel B. & Mateescu M. (2001). Using NDIS intermediate drivers for extending the protocol stack. a case-study. Computer Communications, Vol. 24, No. 7-8, (Apr. 2001) 703–715. Gerum P. (2004). Xenomai – implementing a RTOS emulation framework on GNU/Linux. Available online : http://www.xenomai.org/documentation. Hasan M. S.; Yu H.; Griffiths A.& Yang T. C. (2007). Simulation of distributed wireless networked control systems over MANET using OPNET, Proceedings of the IEEE International Conference on Networking, Sensing and Control, London, UK, Apr. 2007. Hespanha J. P.; Naghshtabrizi P. & Xu Y. (2007). A Survey of Recent Results in Networked Control Systems. Proceedings of the IEEE, Vol. 95, No. 1, (Jan. 2007) 138–162. AReal-timeWirelessCommunicationSystembasedon802.11MAC 73 Fig. 17. Percentage of lost and recovered packets. 8. Conclusions This chapter has analyzed the feasibility of a 802.11 based wireless real-time communication system. For that purpose a wireless communication architecture that properly integrates the leading IEEE 802.11 technology, the RTnet framework, and the Xenomay nano-kernel has been implemented. This architecture has been experimentally tested for various transmission data rates, baseband processor sensitivities, and sampling intervals, with and without interfering traffic. Experiments have demonstrated that by properly setting protocol parameters a robust real-time service can be provided. 9. References Andersson M.; Henriksson D.; Cervin A. & Arzen K. E. (2005). Simulation of wireless networked control systems, Proceedings of the 44th IEEE Conference on Decision and Control, and the European Control Conference, Seville, Spain, Dec. 2005. ANSI (1994). Portable Operating Sytem Interface (Posix). ANSI, IEEE, 1994. Baillieul J. & Antsaklis P. J. (2007). Control and Communication Challenges in Networked Real-time Systems. Proceedings of the IEEE, Vol. 95, No. 1, (Jan. 2007) 9-28. Baliga G. & Kumar P. R. (2005). A middleware for control over networks, Proceedings of the 44th IEEE Conference on Decision and Control, and the European Control Conference, Seville, Spain, Dec. 2005. Barr M. (2003). Choosing an RTOS. Tech. Rep. Embedded Systems Programming, Jan. 2003. Benvenuti C. (2006). Understanding Linux Network Internals. O’Reilly, 2006. Biasi M. D.; Snickars C.; Landernas K. & Isaksson A. J. (2008). Simulation of process control with wirelesshart networks subject to packet losses, Proceedings of 4th IEEE Conference on Automation Science and Engineering, Washington DC, USA, Aug. 2008. Boggia G.; Camarda P.; Grieco L. A. & Zacheo G. (2008a). Toward wireless networked control systems: an experimental study on real-time communications in 802.11 wlans, Proceedings of 7th IEEE International Workshop on Factory Communication Systems, WFCS, Dresden, Germany, May 2008. Boggia G.; Camarda P.; Grieco L. A. & Zacheo G. (2008b). An experimental evaluation on using TDMA over 802.11 MAC for wireless networked control, Proceedings of Emerging Technologies and Factory Automation, ETFA, Hamburg, Germany, Sep. 2008. Boughanmi N.; Song Y. & Rondeau E. (2008). Wireless networked control system using IEEE 802.15.4 with GTS, Proceedings of 2nd Junior Researcher Workshop on Real-Time Computing, JRWRTC, Rennes, Brittany, Oct. 2008. Burda R. & Wietfeld C. (2007). Multimedia over 802.15.4 and ZigBee Networks for Ambient Environmental Control, Proceedings of the IEEE VTC Spring, Dublin, Ireland, Apr. 2007. Buttazzo G.; Velasco M. & Martì P. (2007). Quality-of-Control Management in Overloaded Real-time Systems. IEEE Trans. on Computers, Vol. 56, No. 2, (Feb. 2007) 253–266. Cena G.; Bertolotti I. C.; Valenzano A. & Zunino C. (2007). Evaluation of response times in industrial WLANs. IEEE Trans. on Industrial Informatics, Vol. 3, No. 3, (Aug. 2007) 191–201. Cervin A.; Ohlin M. & Henriksson D. (2007). Simulation of networked control systems using truetime, Proceedings of the 3rd International Workshop on Networked Control Systems: Tolerant to Faults, Nancy, France, Jun. 2007. Chen J.; McKernan A.; Irwin G. W. & Scanlon W. G. (2008). Experimental characterisation and analysis of wireless network control systems, Proceedings of the IET Irish Signals and Systems Conference, ISSC, Galway, Ireland, Jun. 2008. Choi D. H.; Lee J. I.; Kim D. S. & Park W. C. (2006). Design and implementation of wireless eldbus for networked control systems, Proceedings of SICE-ICASE International Joint Conference, Bexco, Busan, Korea, Oct. 2006. DIAPM (2008), Real-time application interface (RTAI) for Linux. Tech Rep. Politecnico di Milano, 2008, available online: http://www.rtai.org. Flammini A.; Marioli D.; Sisinni E. & Taroni A. (2009). Design and implementation of a wireless eldbus for plastic machineries. IEEE Trans. on Industrial Electronics, Vol. 56, No. 3, (Mar. 2009) 747–755. Floroiu J.; Ionescu T. C.; Ruppelt R.; Henckel B. & Mateescu M. (2001). Using NDIS intermediate drivers for extending the protocol stack. a case-study. Computer Communications, Vol. 24, No. 7-8, (Apr. 2001) 703–715. Gerum P. (2004). Xenomai – implementing a RTOS emulation framework on GNU/Linux. Available online : http://www.xenomai.org/documentation. Hasan M. S.; Yu H.; Griffiths A.& Yang T. C. (2007). Simulation of distributed wireless networked control systems over MANET using OPNET, Proceedings of the IEEE International Conference on Networking, Sensing and Control, London, UK, Apr. 2007. Hespanha J. P.; Naghshtabrizi P. & Xu Y. (2007). A Survey of Recent Results in Networked Control Systems. Proceedings of the IEEE, Vol. 95, No. 1, (Jan. 2007) 138–162. FactoryAutomation74 Heynicke R.; Kruger D.; Wattar H. & Scholl G. (2008). Modular wireless eldbus gateway for fast and reliable sensor/actuator communication, Proceedings of Emerging Technologies and Factory Automation, ETFA, Hamburg, Germany, Sep. 2008. IEEE (1999a). IEEE 802.11, Information Technology -Telecommunications and Information Exchange between Systems. Local and Metropolitan Area Networks. Specic Requirements. Part 11: Wireless LAN MAC and PHY Specications, 1st ed., ANSI/IEEE Std. 802.11, ISO/IEC 8802-11. IEEE standard for Information Technology, 1999. IEEE (1999b). IEEE 802.11, Supplement to IEEE Standard for Information Technology. Local and Metropolitan Area Networks. Specic Requirements. Part 11: Wireless LAN MAC and PHY Specications: Higher-Speed Physical Layer Extension in the 5 GHz Band, IEEE Std 802.11a, ISO/IEC 8802-11:1999/Amd 1:2000(E). IEEE standard for Information Technology, 1999. IEEE (1999c). Supplement to IEEE Standard for Information Technology. Local and Metropolitan Area Networks. Specic Requirements. Part 11: Wireless LAN MAC and PHY Specications: Higher-Speed Physical Layer Extension in the 2.4 GHz Band, IEEE Std 802.11b). IEEE standard for Information Technology, 1999. IEEE (2003). Supplement to IEEE Standard for Telecommunications and Information Exchange Between Systems-LAN/MAN Specic Requirements-Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specications: Further Higher-Speed Physical Layer Extension in the 2.4 GHz Band, IEEE Std 802.11g. IEEE standard for Information Technology, 2003. IEEE (2005). Amendment to Standard for Information Technology. LAN/MAN Specic Requirements -Part 11: Wireless MAC and PHY Specications: MAC Quality of Service (QoS) Enhancements, IEEE 802.11e/D13.0. IEEE standard for Information Technology, 2005. IEEE (2006). Std. 802.15.4, Part. 15.4: Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specications for Low-Rate Wireless Personal Area Networks (LR-WPANs). IEEE standard for Information Technology, Sept. 2006. Kim W.; Ji K. & Ambike A. (2006). Real-time Operating Environment for Networked Control Systems. IEEE Trans. on Automation Science and Engineering, Vol. 3, No. 3, (Jul. 2006) 287–296. Kiszka J. (2005b). The real-time driver model and rst applications. Tech. Rep. Xenomai, available online: http://www.xenomai.org/documentation/ Kiszka J.; Wagner B.; Zhang Y. & Broenink J. (2005a). RTnet – a exible hard real-time networking framework, Proceedings of the 10th IEEE International Conference on Emerging Technologies and Factory Automation, Catania, Italy, Sep. 2005. Krber H. J.; Wattar H. & Scholl G. (2007). Modular wireless real-time sensor/actuator network for factory automation applications. IEEE Trans. on Industrial Informatics, Vol. 3, No. 2, (May 2007) 111–119. Lee S.; Park J. H.; Ha K. N. & Lee K. C. (2008). Wireless networked control system using NDIS-based four-layer architecture for IEEE 802.11b, Proceedings of IEEE Int. Workshop on Factory Communication Systems, WFCS), Dresden, Germany, May 2008. Liu G. P.; Xia Y.; Chen J.; Rees D. & Hu W. (2007). Networked Predictive Control of Systems with Random Network Delays in both Forward and Feedback Channels. IEEE Trans. on Industrial Electronics, Vol. 54, No. 3, (Jun. 2007) 1282–1297. Massa A. (2002). Embedded Software Development with ECos. Prentice Hall PTR, 2002. McKenney P. (2005). A realtime preemption overview. LWN.net, available online: http://lwn.net/Articles/146861. Moyne J. R. & Tilbury D. M. (2007). The Emergence of Industrial Control Networks for Manufactoring Control, Diagnostics, and Safety Data. Proceedings of the IEEE, Vol. 95, No. 1, (Jan. 2007) 29–47. Nair G. N.; Fagnani F.; Zampieri S. & Evans R. J. (2007). Feedback Control Under Data Rate Constraints: An Overview. Proceedings of the IEEE, Vol. 95, No. 1, (Jan. 2007) 108– 137. Nethi S. ; Pohjola M.; Eriksson L. & Jntti R. (2007). Platform for emulating networked control systems in laboratory environments, Proceedings of IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks, WoWMoM), Helsinki, Finland, Jun. 2007. Neumann P. (2007). Communication in industrial automation what is going on?. Control Engineering Practice, Vol. 15, No. 11 (Nov. 2007) 1332-1347. Pellegrini F. D.; Miorandi D.; Vitturi S. & A. Zanella (2006). On the use of wireless networks at low level of factory automation systems. IEEE Trans. on Industrial Informatics, Vol. 2, No. 2, (May 2006) 129–143. Ralink (2006) Technologies. Ralink rt2500 chipset overview. Tech Rep. Ralink Technologies, available online: http://www.ralinktech.com Rauchhaupt l. (2002). System and device architecture of a radio based eldbusthe reldbus system, Proceedings of the 4th IEEE International Workshop on Factory Communication Systems, Vasteras, Sweden, Aug. 2002. Robinson C. L. & Kumar P. R. (2007). Sending the most recent observation is not optimal in networked control: Linear temporal coding and towards the design of a control specic transport protocol, Proceedings of the 46th IEEE Conference on Decision and Control, New Orleans, Louisiana, USA, Dec. 2007. Schenato L.; Sinopoli B.; Franceschetti M.; Poolla K. & Sastry S. S. (2007). Foundations of Control and Estimation over Lossy Networks. Proceedings of the IEEE, Vol. 95, No. 1, (Jan. 2007) 163–187. Silberschatz A.; Galvin P. B. & Gagne G. Operating System Concepts (7th Edition). Wiley, 2004. Song J.; Han S.; Mok A. K.; Chen D.; Lucas M.; Nixon M. & Pratt W. (2008). Wirelesshart: Applying wireless technology in real-time industrial process control, Proceedings of IEEE Real-Time and Embedded Technology and Applications Symposium, St. Louis, MO, USA, Apr. 2008. Straumann T. (2001). Open source real time operating systems overview, Proceedings of the 8th International Conference on Accelerator and Large Experimental Physics Control Systems, San Jose, CA, USA, 2001. Tabbara M.; Nesic D. & Teel A. R. (2007). Stability of Wireless and Wireline Networked Control Systems. IEEE Trans. on Automatic Control, Vol. 52, No. 9, (Sep. 2007) 1615– 1630. Varshney U. (2003). The Status and Future of 802.11-Based WLANs. IEEE Computer, Vol. 36, No. 6, (Jun. 2003) 102–105. Walke B. H.; Mangold S. & Berlemann L. (2006). IEEE 802 Wireless Systems, John Wiley and Sons, 2006. Willig A.; Matheus K. & Wolisz A. (2005). Wireless technologies in industrial networks. Proceedings of IEEE, Vol. 93, No. 6, (Jun. 2005) 1130–1150. AReal-timeWirelessCommunicationSystembasedon802.11MAC 75 Heynicke R.; Kruger D.; Wattar H. & Scholl G. (2008). Modular wireless eldbus gateway for fast and reliable sensor/actuator communication, Proceedings of Emerging Technologies and Factory Automation, ETFA, Hamburg, Germany, Sep. 2008. IEEE (1999a). IEEE 802.11, Information Technology -Telecommunications and Information Exchange between Systems. Local and Metropolitan Area Networks. Specic Requirements. Part 11: Wireless LAN MAC and PHY Specications, 1st ed., ANSI/IEEE Std. 802.11, ISO/IEC 8802-11. IEEE standard for Information Technology, 1999. IEEE (1999b). IEEE 802.11, Supplement to IEEE Standard for Information Technology. Local and Metropolitan Area Networks. Specic Requirements. Part 11: Wireless LAN MAC and PHY Specications: Higher-Speed Physical Layer Extension in the 5 GHz Band, IEEE Std 802.11a, ISO/IEC 8802-11:1999/Amd 1:2000(E). IEEE standard for Information Technology, 1999. IEEE (1999c). Supplement to IEEE Standard for Information Technology. Local and Metropolitan Area Networks. Specic Requirements. Part 11: Wireless LAN MAC and PHY Specications: Higher-Speed Physical Layer Extension in the 2.4 GHz Band, IEEE Std 802.11b). IEEE standard for Information Technology, 1999. IEEE (2003). Supplement to IEEE Standard for Telecommunications and Information Exchange Between Systems-LAN/MAN Specic Requirements-Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specications: Further Higher-Speed Physical Layer Extension in the 2.4 GHz Band, IEEE Std 802.11g. IEEE standard for Information Technology, 2003. IEEE (2005). Amendment to Standard for Information Technology. LAN/MAN Specic Requirements -Part 11: Wireless MAC and PHY Specications: MAC Quality of Service (QoS) Enhancements, IEEE 802.11e/D13.0. IEEE standard for Information Technology, 2005. IEEE (2006). Std. 802.15.4, Part. 15.4: Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specications for Low-Rate Wireless Personal Area Networks (LR-WPANs). IEEE standard for Information Technology, Sept. 2006. Kim W.; Ji K. & Ambike A. (2006). Real-time Operating Environment for Networked Control Systems. IEEE Trans. on Automation Science and Engineering, Vol. 3, No. 3, (Jul. 2006) 287–296. Kiszka J. (2005b). The real-time driver model and rst applications. Tech. Rep. Xenomai, available online: http://www.xenomai.org/documentation/ Kiszka J.; Wagner B.; Zhang Y. & Broenink J. (2005a). RTnet – a exible hard real-time networking framework, Proceedings of the 10th IEEE International Conference on Emerging Technologies and Factory Automation, Catania, Italy, Sep. 2005. Krber H. J.; Wattar H. & Scholl G. (2007). Modular wireless real-time sensor/actuator network for factory automation applications. IEEE Trans. on Industrial Informatics, Vol. 3, No. 2, (May 2007) 111–119. Lee S.; Park J. H.; Ha K. N. & Lee K. C. (2008). Wireless networked control system using NDIS-based four-layer architecture for IEEE 802.11b, Proceedings of IEEE Int. Workshop on Factory Communication Systems, WFCS), Dresden, Germany, May 2008. Liu G. P.; Xia Y.; Chen J.; Rees D. & Hu W. (2007). Networked Predictive Control of Systems with Random Network Delays in both Forward and Feedback Channels. IEEE Trans. on Industrial Electronics, Vol. 54, No. 3, (Jun. 2007) 1282–1297. Massa A. (2002). Embedded Software Development with ECos. Prentice Hall PTR, 2002. McKenney P. (2005). A realtime preemption overview. LWN.net, available online: http://lwn.net/Articles/146861. Moyne J. R. & Tilbury D. M. (2007). The Emergence of Industrial Control Networks for Manufactoring Control, Diagnostics, and Safety Data. Proceedings of the IEEE, Vol. 95, No. 1, (Jan. 2007) 29–47. Nair G. N.; Fagnani F.; Zampieri S. & Evans R. J. (2007). Feedback Control Under Data Rate Constraints: An Overview. Proceedings of the IEEE, Vol. 95, No. 1, (Jan. 2007) 108– 137. Nethi S. ; Pohjola M.; Eriksson L. & Jntti R. (2007). Platform for emulating networked control systems in laboratory environments, Proceedings of IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks, WoWMoM), Helsinki, Finland, Jun. 2007. Neumann P. (2007). Communication in industrial automation what is going on?. Control Engineering Practice, Vol. 15, No. 11 (Nov. 2007) 1332-1347. Pellegrini F. D.; Miorandi D.; Vitturi S. & A. Zanella (2006). On the use of wireless networks at low level of factory automation systems. IEEE Trans. on Industrial Informatics, Vol. 2, No. 2, (May 2006) 129–143. Ralink (2006) Technologies. Ralink rt2500 chipset overview. Tech Rep. Ralink Technologies, available online: http://www.ralinktech.com Rauchhaupt l. (2002). System and device architecture of a radio based eldbusthe reldbus system, Proceedings of the 4th IEEE International Workshop on Factory Communication Systems, Vasteras, Sweden, Aug. 2002. Robinson C. L. & Kumar P. R. (2007). Sending the most recent observation is not optimal in networked control: Linear temporal coding and towards the design of a control specic transport protocol, Proceedings of the 46th IEEE Conference on Decision and Control, New Orleans, Louisiana, USA, Dec. 2007. Schenato L.; Sinopoli B.; Franceschetti M.; Poolla K. & Sastry S. S. (2007). Foundations of Control and Estimation over Lossy Networks. Proceedings of the IEEE, Vol. 95, No. 1, (Jan. 2007) 163–187. Silberschatz A.; Galvin P. B. & Gagne G. Operating System Concepts (7th Edition). Wiley, 2004. Song J.; Han S.; Mok A. K.; Chen D.; Lucas M.; Nixon M. & Pratt W. (2008). Wirelesshart: Applying wireless technology in real-time industrial process control, Proceedings of IEEE Real-Time and Embedded Technology and Applications Symposium, St. Louis, MO, USA, Apr. 2008. Straumann T. (2001). Open source real time operating systems overview, Proceedings of the 8th International Conference on Accelerator and Large Experimental Physics Control Systems, San Jose, CA, USA, 2001. Tabbara M.; Nesic D. & Teel A. R. (2007). Stability of Wireless and Wireline Networked Control Systems. IEEE Trans. on Automatic Control, Vol. 52, No. 9, (Sep. 2007) 1615– 1630. Varshney U. (2003). The Status and Future of 802.11-Based WLANs. IEEE Computer, Vol. 36, No. 6, (Jun. 2003) 102–105. Walke B. H.; Mangold S. & Berlemann L. (2006). IEEE 802 Wireless Systems, John Wiley and Sons, 2006. Willig A.; Matheus K. & Wolisz A. (2005). Wireless technologies in industrial networks. Proceedings of IEEE, Vol. 93, No. 6, (Jun. 2005) 1130–1150. FactoryAutomation76 Wu J. & Chen T. (2007). Design of Networked Control Systems with Packet Dropouts,” IEEE Trans. on Automatic Control, Vol. 52, No. 7, (Jul. 2007) 1314–1319. Yaghmour K. (2001). Adaptive domain environment for operating systems. Tech. Report Adeos, available online: http://www.opersys.com/ftp/pub/Adeos/adeos.pdf. WhentheIndustryGoesWireless:Drivers,Requirements,TechnologyandFutureTrends 77 WhentheIndustryGoesWireless:Drivers,Requirements,Technology andFutureTrends SimonCarlsenandStigPetersen x When the Industry Goes Wireless: Drivers, Requirements, Technology and Future Trends Simon Carlsen 1 and Stig Petersen 2 1 StatoilHydro ASA, Harstad, 2 SINTEF ICT, Trondheim 1,2 Norway 1. Introduction Through the last ten to fifteen years wireless communication technology has become a natural and fully integrated part of our everyday lives. The two most exposed applications, digital mobile telephony and wireless computer networks, are so common that it is hard to imagine a world without these technologies. In addition, a number of different everyday devices in the home, in the car or in the office communicate with each other over short range wireless links, utilizing technologies like Bluetooth or similar. Even though what is said above may seem obvious to most people in the industrialized world, the situation is somewhat different when it comes to applications of wireless technology in the industry itself. Compared to the numerous applications of wireless communication that we all are so familiar with and have learned to consider as indispensable from a consumers’ point of view, the benefits of wireless solutions in industrial applications have until the last few years not been so obvious. Of course, different industries and companies are at different stages regarding the implementation and adoption of wireless technology, but in general we see a conservative approach, and the reasons for such a progression are many. This chapter will deal with some important aspects as the industry slowly evolves from a wired world into the wireless domain. It is organized as follows; section 2 examines the motivations and drivers for introducing wireless technology within the industry, section 3 presents the industrial requirements which the wireless technology must fulfil in order to be a viable option to today’s wired solutions, section 4 gives an overview of the most relevant international standards for industrial wireless communications, and section 5 concludes the chapter by identifying the current trends and important future research areas for industrial wireless technology. 2. Applications, drivers and motivation To enable the introduction of any new technology in the enterprise, a major driver and motivational factor is the potential financial gains, i.e. reduced costs and/or increased 4 FactoryAutomation78 revenue. Secondly, if new technology has the potential to benefit other important aspects such as health, safety or the environment (HSE), they would also be considered interesting for the industry. Potential areas in which wireless technology can be beneficial to the industry can be divided into three distinct applications; mobile ICT (information and communication technology), wireless instrumentation, and asset and personnel tracking. 2.1 Mobile ICT The development and rapid deployment of systems adhering to the IEEE Std 802.11 for wireless local area networks (WLANs) have enabled Internet access to mobile devices such as laptops, personal digital assistants (PDAs) and high-end mobile phones, from nearly anywhere at any time. WLAN access points are deployed in office buildings, public spaces, airports, cafeterias and in private homes, providing either free or purchasable Internet access to everybody in the vicinity. While wireless access in the home, office or public spaces mainly has focused on internet access and access to enterprise systems on the office network, the focus is somewhat different for industrial applications. Some relevant application areas involving the use of mobile ICT in the industry includes:  Simplification of work processes  Simplify or automate routine test procedures  ‘Bringing the control room to the field’  Online field access to status, maintenance logs etc for instruments and components as a part of fault diagnostics procedures  Inspection and maintenance tasks by means of WLAN enabled mobile cameras, where the field operator communicates in real-time over video and audio with remote expert centres Commonly, mobile ICT applications in the industry are associated with local on-site WLAN networks, which to date has more or less followed the same implementation strategy as for WLANs’ in office environments. The benefits for deploying local network infrastructure are many. For example, it ensures sufficient bandwidth for demanding applications, and the security and data integrity aspects are locally controlled. In some industries, however, the costs for deploying local infrastructure for enabling wireless coverage in the process areas can be significant. This is particular relevant in industries which comprise explosive atmospheres, such as Oil & Gas and mining. In such areas, very strict restrictions apply regarding requirements for all electrical apparatus intended for use inside specific zones. In Europe, the ATEX directive (European Parliament and the Council, 1994) contains the governing rules, regulations and requirements for the use of electrical equipment in hazardous environments. Other countries have similar directives, for example in North America and Canada the North American Hazardous Locations Installation Codes (National Electric Code for the US and the Canadian Electrical Code for Canada) define rules and regulations on equipment and area classifications requirements for hazardous locations. Network equipment planned for use in such areas must be certified to conform to these regulations. In practise, this involves either regular equipment built into specially designed enclosures, or it demands for complete redesigns of the equipment itself. The certification is a comprehensive process that can only be carried out by selected certification agencies. This leads to significant increases in equipment cost. As an example, a WLAN access point manufactured for corporate use has a cost of approximately 800 – 1,000 USD in its ordinary version. The ATEX-certified version (the same access point built into an enclosure, and the unit certified as a whole), has a cost in the order of 8,000 – 10,000 USD, e.g. the price has increased by a factor of ten. In addition, strict installation procedures for equipment in process plants are further cost-driving parameters. The above facts, combined with a general lack of pre-certified WLAN equipment in the market designed for use in explosive atmospheres, has been a showstopper for the rapid deployment of large-scale mobile ICT in industries like the Oil & Gas. For these reasons, these industries have started looking at public networks such as GPRS and UMTS as alternative access channels. We end this section by giving an example on the use of mobile ICT to simplify a work process in the process industry. The example is taken from (Petersen et al., 2008). 2.1.1 Example – Simplifying maintenance routine jobs Traditionally, work processes in process industries involve a number of manual operations. A typical workflow for operation and maintenance tasks is presented in Fig. 1. The flowchart illustrates how several activities have to be performed in a given order. If we consider a maintenance operation where notifications and work orders are required, typically the whole process has the following (simplified) progression from a field operators’ point-of-view: 1. Initiate operation 2. Create a notification. This is commonly done with the corporate Enterprise Resource Planning (ERP) system 3. Await confirmation from ERP system 4. Create work order through ERP 5. Await signed work permit 6. Prepare operation 7. Plan operation 8. Execute maintenance operation 9. Close operation 10. Verify technical condition restored 11. Update documentation, both in technical documentation systems and ERP Wireless network access in the field can help simplify this process. Consider a Personal Digital Assistant (PDA) with wireless access to the company’s backbone systems. The PDA is equipped with an RFID or barcode reader for reading information from tagged plant equipment. When the field operator detects a faulty component that is subjective to maintenance, the tag of the component is read or scanned with the PDA. A notification describing the upcoming maintenance operation is created on the PDA. This information is then transmitted via the wireless network into the ERP system. As soon as the necessary confirmation is received, a work order is created. During the maintenance operation, the field operator can update the technical documentation online from his mobile device. As a finishing activity, a verification of the technical condition of the component has to be performed, commonly requiring that the operator is physically present in the field. When the verification is passed, the operator is able to remotely flag the status of the work order as finished using the PDA. WhentheIndustryGoesWireless:Drivers,Requirements,TechnologyandFutureTrends 79 revenue. Secondly, if new technology has the potential to benefit other important aspects such as health, safety or the environment (HSE), they would also be considered interesting for the industry. Potential areas in which wireless technology can be beneficial to the industry can be divided into three distinct applications; mobile ICT (information and communication technology), wireless instrumentation, and asset and personnel tracking. 2.1 Mobile ICT The development and rapid deployment of systems adhering to the IEEE Std 802.11 for wireless local area networks (WLANs) have enabled Internet access to mobile devices such as laptops, personal digital assistants (PDAs) and high-end mobile phones, from nearly anywhere at any time. WLAN access points are deployed in office buildings, public spaces, airports, cafeterias and in private homes, providing either free or purchasable Internet access to everybody in the vicinity. While wireless access in the home, office or public spaces mainly has focused on internet access and access to enterprise systems on the office network, the focus is somewhat different for industrial applications. Some relevant application areas involving the use of mobile ICT in the industry includes:  Simplification of work processes  Simplify or automate routine test procedures  ‘Bringing the control room to the field’  Online field access to status, maintenance logs etc for instruments and components as a part of fault diagnostics procedures  Inspection and maintenance tasks by means of WLAN enabled mobile cameras, where the field operator communicates in real-time over video and audio with remote expert centres Commonly, mobile ICT applications in the industry are associated with local on-site WLAN networks, which to date has more or less followed the same implementation strategy as for WLANs’ in office environments. The benefits for deploying local network infrastructure are many. For example, it ensures sufficient bandwidth for demanding applications, and the security and data integrity aspects are locally controlled. In some industries, however, the costs for deploying local infrastructure for enabling wireless coverage in the process areas can be significant. This is particular relevant in industries which comprise explosive atmospheres, such as Oil & Gas and mining. In such areas, very strict restrictions apply regarding requirements for all electrical apparatus intended for use inside specific zones. In Europe, the ATEX directive (European Parliament and the Council, 1994) contains the governing rules, regulations and requirements for the use of electrical equipment in hazardous environments. Other countries have similar directives, for example in North America and Canada the North American Hazardous Locations Installation Codes (National Electric Code for the US and the Canadian Electrical Code for Canada) define rules and regulations on equipment and area classifications requirements for hazardous locations. Network equipment planned for use in such areas must be certified to conform to these regulations. In practise, this involves either regular equipment built into specially designed enclosures, or it demands for complete redesigns of the equipment itself. The certification is a comprehensive process that can only be carried out by selected certification agencies. This leads to significant increases in equipment cost. As an example, a WLAN access point manufactured for corporate use has a cost of approximately 800 – 1,000 USD in its ordinary version. The ATEX-certified version (the same access point built into an enclosure, and the unit certified as a whole), has a cost in the order of 8,000 – 10,000 USD, e.g. the price has increased by a factor of ten. In addition, strict installation procedures for equipment in process plants are further cost-driving parameters. The above facts, combined with a general lack of pre-certified WLAN equipment in the market designed for use in explosive atmospheres, has been a showstopper for the rapid deployment of large-scale mobile ICT in industries like the Oil & Gas. For these reasons, these industries have started looking at public networks such as GPRS and UMTS as alternative access channels. We end this section by giving an example on the use of mobile ICT to simplify a work process in the process industry. The example is taken from (Petersen et al., 2008). 2.1.1 Example – Simplifying maintenance routine jobs Traditionally, work processes in process industries involve a number of manual operations. A typical workflow for operation and maintenance tasks is presented in Fig. 1. The flowchart illustrates how several activities have to be performed in a given order. If we consider a maintenance operation where notifications and work orders are required, typically the whole process has the following (simplified) progression from a field operators’ point-of-view: 1. Initiate operation 2. Create a notification. This is commonly done with the corporate Enterprise Resource Planning (ERP) system 3. Await confirmation from ERP system 4. Create work order through ERP 5. Await signed work permit 6. Prepare operation 7. Plan operation 8. Execute maintenance operation 9. Close operation 10. Verify technical condition restored 11. Update documentation, both in technical documentation systems and ERP Wireless network access in the field can help simplify this process. Consider a Personal Digital Assistant (PDA) with wireless access to the company’s backbone systems. The PDA is equipped with an RFID or barcode reader for reading information from tagged plant equipment. When the field operator detects a faulty component that is subjective to maintenance, the tag of the component is read or scanned with the PDA. A notification describing the upcoming maintenance operation is created on the PDA. This information is then transmitted via the wireless network into the ERP system. As soon as the necessary confirmation is received, a work order is created. During the maintenance operation, the field operator can update the technical documentation online from his mobile device. As a finishing activity, a verification of the technical condition of the component has to be performed, commonly requiring that the operator is physically present in the field. When the verification is passed, the operator is able to remotely flag the status of the work order as finished using the PDA. FactoryAutomation80 Start task Notification necessary? Create Notification Work Order required? Prepare operation Simplified Execution Close task Execute planned operation Operation planning required? Operation planning YES YES YES NO NO NO Fig. 1. Typical workflow for mainteance operation 2.2 Wireless instrumentation Recent advances in wireless technology have enabled the development of low-cost, low power wireless sensors capable of robust and reliable communication (Akyildiz et al., 2002). The IEEE Std 802.15.4 (IEEE 802.15.4, 2006) defines the physical layer (PHY) and the medium access control sublayer (MAC) for low-rate wireless personal area networks. Inherent features such as ultra-low complexity, cost and power makes it a very suitable standard for wireless sensor network (WSN) solutions (Yu, Q et al., 2006). With a growing number of both standardized and proprietary solutions based the IEEE Std 802.15.4 PHY and MAC appearing on the market, it has quickly become the de facto standard for WSNs. Using sensors to monitor both the performance and the operational environment of industrial plants and facilities allows for greater insight into operational requirements and potential safety problems. The sensors are used to monitor a wide range of parameters, e.g. pipeline pressure, flow, temperature, vibration, humidity, gas leaks, fire outbreaks and equipment condition. The collected sensor data is then used to make informed just-in-time decisions on plant performance and operational conditions. It is expected that the continuing advances in WSN technologies will enable wireless sensing, monitoring and control applications within the following industrial areas (Petersen et al., 2007):  Condition and performance maintenance monitoring  Area and property surveillance and monitoring  Environmental monitoring  Emergency management  Process control In addition, eliminating the need for cables will contribute to reduced installation costs, and extend coverage into areas previously either too remote or too hostile to be viable for wired instrumentation. Furthermore, using wireless sensors provides the possibility of doing temporary installations and mobile installations, for example in conjunction with turnarounds and shutdowns. So, flexibility and installation time are major beneficial factors making the use of wireless sensors very cost-effective compared to traditional instrumentation. As an example on a real-world application, a wireless sensor network was installed at an oil production platform in the North Sea. The complete scenario is extensively described in (Carlsen et al., 2008) 2.2.1 Example – Using Wireless Sensor Networks to Enable Increased Oil Recovery The actual oil field is in its tail-end lifecycle, and, combined with the geological structure consisting of many small oil accumulations, occasional loss of flow from the wells was not readily detected, which lead to unplanned stops in the production. During the construction stage back in the 1980’s, no flow metering devices were installed inside the flow lines. Calculations performed by staff personnel at the actual license show that unpredicted stops in production due to unexpected loss of well pressure counts for annual financial losses in the order of 40 million USD. Based on these calculations, it is clear that a reliable, easy to install detection system for alerting upcoming pressure losses is very attractive for gaining increased revenue. The installation and maintenance of a traditional detection system (flow meters inside the pipes) is complex and requires a complete production shutdown, and was not considered an alternative. Another showstopper for introducing wired sensor equipment in a live production environment is the need for cables. As these units need both wired power and a wired communication link, the complexity and cost factors are high. A simple approach to determine loss of flow in a well is to measure the temperature of the well flow line, some distance downstream of the wellhead. This is based on the principle that loss of flow causes a reduction in surface temperature of the pipe as heat is lost to the surroundings. The typical well fluid temperature is approximately 60ºC, thus the temperature measurement can be performed on the pipe’s surface. This eliminates the need for an invasive installation, which greatly simplifies installation. Until recently, loss of flow from individual wells was detected by plant operators manually probing the surface temperature of the flow lines during inspection rounds one or two times each 12 hour shift. By introducing battery-operated wireless temperature sensors clamped on to the outer surface of the pipes, the installation of the sensor unit is simpler and wires can be eliminated. The installation is not time-consuming and can be performed during normal operation of the facility. [...]... market, of which some are proprietary while others are based on open standards The most commonly used standards are listed in Table 2 Frequency 125- 135 kHz 13. 56 MHz Technology Inductive coupling Standards ISO 11784 ISO 11785 ISO 142 23 ISO 144 43 ISO 156 93 ISO 18000-6 Inductive coupling 860-960 Radio MHz backscatter Table 2 Overview of RFID standards Range < 50 cm Applications Animal identification . Technologies and Factory Automation, Catania, Italy, Sep. 2005. Krber H. J.; Wattar H. & Scholl G. (2007). Modular wireless real-time sensor/actuator network for factory automation applications Neumann P. (2007). Communication in industrial automation what is going on?. Control Engineering Practice, Vol. 15, No. 11 (Nov. 2007) 133 2- 134 7. Pellegrini F. D.; Miorandi D.; Vitturi S Control, Vol. 52, No. 9, (Sep. 2007) 1615– 1 630 . Varshney U. (20 03) . The Status and Future of 802.11-Based WLANs. IEEE Computer, Vol. 36 , No. 6, (Jun. 20 03) 102–105. Walke B. H.; Mangold S. &