摘要
随着现代工业和商业系统的持续发展，对控制系统中应用共享数据网络的需求也与日俱增。近些年，网络运动控制系统已越来越多的应用于基于因特网的远程操作中，并逐渐拓展到诸如高档数控系统和无轴印刷控制系统等领域中，其优势主要体现在：具有可扩展性好、可靠性高以及远程控制能力等优点；同时，它们能够解决接线复杂和传输距离限制等问题，以及显著减少安装、重新配置和维护的时间及其成本。但是，实时性和网络同步、网络调度和网络诱导延迟等网络影响因素给控制网络下的运动控制，尤其是高精度的多轴协调控制，带来了极大的挑战。
本学位论文以在高档数控系统和无轴印刷机中实现网络运动控制系统为应用背景，研究网络下多轴运动的同步问题。针对制造领域的传感器、执行器和运动控制器之间采用的现场设备网络，即实时以太网，将多轴运动控制的同步问题解耦为时钟同步和运动同步两个层面，着重解决如下三个问题：1.设计和开发实时以太网协议栈可重构的网络运动控制系统仿真和实验平台；2.建模时钟同步过程，设计时钟同步算法实现级联实时以太网系统中所有从节点的时钟同步精度量级为几十个纳秒，同时降低误差增长率，增加级联系统中可携带的从节点个数；3.设计基于实时以太网的多轴运动同步策略时，使算法分布运行于各节点中，同时还要考虑网络中诸如网络诱导延迟和网络调度策略等影响因素，并证明全局系统的渐近稳定性。本文的主要研究工作和创新性成果如下：
一、设计和开发了实时以太网下的开放式仿真和实验平台。通过这些平台，可以快速的实现基于各种实时以太网协议的多轴运动控制系统，为后面提出的时钟同步算法和多轴运动同步算法提供了很好的验证平台。尤其是设计的开放式实验平台，搭建时仅需要在相同的硬件设施上配置相关实时以太网协议栈，从而显著降低开发时间和成本。给出的两个应用实例说明了设计的开放式仿真和实验平台在研究中的可重构性和有效性。
二、针对实时以太网运动控制系统中实现多轴运动同步所需的关键基础技术――时钟同步，深入研究了基于IEEE1588的时钟同步策略。该策略基于频率补偿机制和点对点透明时钟机制，提出了一种实时同步协议来将这些时钟同步机制融入到实时以太网通信协议中。然后在对整体时钟同步过程进行建模和分析的基础上，设计了一种最优PI时钟伺服，以便能最小化时钟同步误差的积分平方误差。再者，通过分析长级联路径的实时以太网系统中时钟同步误差累积的原因，提出了一种基于卡尔曼滤波器的PI时钟伺服，以补偿由时间戳量化效应带来的误差累积现象，进而降低级联实时以太网中时钟同步误差的增长率。最后，在设计的开放式实验平台上对提出的各种时钟同步算法进行了实验验证。实验结果显示提出的时钟同步算法可以使从节点4测量到的峰到峰抖动仅为59.37ns，此性能可以与当下代表性研究成果相媲美，并且是在低成本晶振的基础上获得的。同时，算法还能够显著降低时钟同步误差的增长率，从而增加级联实时以太网系统中可携带的网络节点数目。
三、在实现的高精度时钟同步的基础上，针对实时以太网系统中的运动同步问题，提出了分布式位置同步控制器和分布式轨迹跟踪控制器。在控制器的设计过程中，不仅考虑了不同轴之间不同的负载惯量和干扰因素，更重要的是还考虑了实时以太网中消息调度策略和网络诱导延迟等主要影响因素。同时，提出在分布式位置同步控制器和轨迹跟踪控制器中采用运动消息估计器来估计当前时刻的位置误差，从而降低网络诱导延迟对运动同步精度的影响。并证明这些带延迟补偿的分布式位置同步控制器和轨迹跟踪控制器是渐近稳定的，最后从仿真和实验两个方面对提出的运动同步算法进行了验证。
本文所设计的高性能时钟同步算法和运动同步算法为实时以太网系统中实现多轴同步控制提供了理论和技术支撑。
Along with the continuous improvement in modern industrial and commercial systems, thereare increasing demands for applying a shared data network in control systems. For instance, in ap-plications with a large number of sensors and actuators, such as computer numerical control (CNC)machining centers, humanoid robots, printing machines, and automobiles, real-time control net-works can be used to perform information exchanges between a main controller and distributedaxes. Compared with traditional centralized control systems with directly wiring devices together,these network-based systems provide several advantages such as scalability, reliability, and remote-control capability. In addition, they reduce the problems of wiring connection and transmit-lengthlimitation, and decrease installation, reconfiguration and maintenance time and costs. However, thenetwork factors, such as real-time communication and network synchronization, message schedul-ing and network-induced delays, will be the big challenges for the motion control over controlnetworks, especially for the high-accuracy multi-axis coordinated control.
This dissertation focuses on the synchronization problems for multi-axis motions in net-worked motion control systems, which come from the applications of real-time Ethernet for ad-vanced CNC systems and shaftless-based printing machines. Considering the field device networksused for information exchanges among sensors, actuators and motion controllers in the manufac-turing field, the synchronization problems of the networked motion control systems can be dividedinto two aspects: time synchronization and motion synchronization. Time synchronization is usedto make all network nodes share a common sense of a time, while the motion synchronization isachieved by synchronizing the motion of each axis with those of others. And we focus on address-ing the following three problems: design and build open simulation and experimental platformsof the networked motion control systems for the algorithm verification; model the entire time syn-chronization process and design time synchronization algorithms to achieve the synchronizationaccuracy on the order of tens of nanoseconds for cascaded real-time Ethernet-based systems andreduce the growth rate of synchronization error, and thus, the maximum number of networkednodes can be correspondingly increased; design decentralized multi-axis synchronous controllerswith considering the message scheduling and the network-induced delays of real-time Ethernet,and prove the asymptotic stability of the global system. The main research work and the novel contributions are listed as follows:
First, we design and develop open simulation and experimental platforms to study the prob-lems of the decentralized control in the networked multi-axis motion control system. These plat-forms are designed as research tools, thus simplified the verification of new ideas about the timesynchronization and the decentralized coordinated control. Two case studies are then given toverify the effectiveness of the developed open platforms.
Second, in terms of the time synchronization, which is the essential technology for a net-worked motion control system to achieve multi-axis motion synchronization, we propose an IEEE1588-based synchronization strategy. The presented synchronization method adopts the frequencycompensation and peer-to-peer transparent clock mechanisms, and utilizes a real-time synchroniza-tion protocol to embed the time synchronization into the real-time communication cycle. An op-timal proportional-integral (PI) controller is then designed for the frequency compensation mech-anism based on the model and analysis of the time synchronization process. Besides, in real-timenetwork-based systems with long linear paths, the growth rate of time synchronization error is themajor barrier to the scalability of systems even if a transparent clock mechanism is used. In orderto reduce the growth rate of synchronization error due to the quantization error in timestamping, aKalman filter is designed based on a state-variable model, which is built for the PI controller-tunedslave clock. In addition, the quantization effect is analyzed and the variance of quantization error isquantitatively estimated for each slave node. Experiments are performed on the open experimen-tal platform to validate its effectiveness and demonstrate that the peak-to-peak jitter is measuredto be only59.37ns after four hops, which is comparable with the current state of the art of theresearch. And the growth rate of synchronization error can also be significantly reduced by thepresented synchronization method. This indicates that the maximum number of networked nodescan be correspondingly increased. It should be also noted that the experimental results are attrac-tive as the low-cost crystal oscillators (XOs) are used instead of temperature-compensated XOs oroven-controlled XOs.
Third, in real-time Ethernet-based systems, together with the different inertias and distur-bances in different axes, the message scheduling and the network-induced delays of real-time net-works are the main factors which cause synchronous problem. We thus design two decentralizedsynchronous controllers for such systems: one is the decentralized position synchronization con-troller, the other is the decentralized trajectory tracking controller. In the proposed controllers,position synchronization error is defined as a subset of all possible pairs of preceding axes due tothe limitations of message scheduling and network bandwidth. And, a motion message estimator isadopted in the synchronous controllers to reduce the effect of network-induced delays. It is proventhat the proposed controllers with the delay compensation can asymptotically stabilize both posi-tion and synchronization errors to zero. Simulations and experiments are performed to validate its effectiveness and demonstrate that it can achieve good position synchronization performance orgood contouring performance for the multi-axis motion over the real-time Ethernet.
The high performance time synchronization and motion synchronization algorithms proposedin this dissertation will provide theoretical and technical supports to achieve multi-axis synchro-nization control in real-time Ethernet-based systems.
引文
[1] Gupta R. and Chow M.,“Networked control system: Overview and research trends”, IEEETransactions on Industrial Electronics,2010,57(7),2527–2535.
[2]张向利,基于以太网的数控系统现场总线技术研究,华中科技大学博士学位论文,武汉,2008.
[3] Shi L.,“Kalman filtering over graphs: Theory and applications”, IEEE Transactions onAutomatic Control,2009,54(9),2230–2234.
[4]陈冰,基于时钟同步的网络化运动控制方法与实现,华中科技大学博士学位论文,武汉,2006.
[5]许万,基于实时以太网的多轴运动控制系统研究,华中科技大学博士学位论文,武汉,2009.
[6]任清荣,基于以太网的数控系统数字接口技术研究,华中科技大学博士学位论文,武汉,2008.
[7]李莉,“造纸业变频改造市场前景”,电器工业,2006,(6),28–34.
[8]王宝仁,网络化运动控制系统多轴协同关键技术研究,山东大学博士学位论文,济南,2008.
[9] Koninckx B. and Van Brussel H.,“Closed-loop, fieldbus-based clock synchronisation fordecentralised control systems”, Reconfigurable Manufacturing Systems and TransformableFactories,2006,213–234.
[10] Lian F., Yook J., Tilbury D., et al.,“Network architecture and communication modules forguaranteeing acceptable control and communication performance for networked multi-agentsystems”, IEEE Transactions on Industrial Informatics,2006,2(1),12–24.
[11]冯冬芹,金建祥,褚健,““工业以太网及其应用技术”讲座第3讲：以太网与现场总线”,自动化仪表,2003,24(6),65–70.
[12]金云飞,冯冬芹,金建祥等,“基金会现场总线令牌机制的研究”,工业仪表与自动化装置,2006,(3),16–18.
[13] Schill J.,“An overview of the CAN protocol”, Embedded Systems Programming,1997,10,46–63.
[14] Bender K., Profibus: the fieldbus for industrial automation, Prentice-Hall, Inc.,1993.
[15] Moss B.,“Real-time control on Ethernet”, Dedicated Systems Magazine,2000,53–60.
[16] Biegacki S. and VanGompel D.,“The application of DeviceNet in process control”, ISAtransactions,1996,35(2),169–176.
[17]冯冬芹,金建祥,“Ethernet与工业控制网络”,仪器仪表学报,2003,24(1),23–26.
[18] Flammini A., Ferrari P., Sisinni E., et al.,“Sensor interfaces: From field-bus to Ethernet andInternet”, Sensors and Actuators A: Physical,2002,101(1-2),194–202.
[19] Ding H., Zhang B., Ding Y., et al.,“On a novel low-cost web-based power sensor via theInternet”, Sensors and Actuators A: Physical,2007,136(1),456–466.
[20] Decotignie J.,“Ethernet-based real-time and industrial communications”, Proceedings ofthe IEEE,2005,93(6),1102–1117.
[21] Felser M.,“Real-time Ethernet-industry prospective”, Proceedings of the IEEE,2005,93(6),1118–1129.
[22] Ferrari P., Flammini A., Marioli D., et al.,“A distributed instrument for performance anal-ysis of real-time Ethernet networks”, IEEE Transactions on Industrial Informatics,2008,4(1),16–25.
[23] Jasperneite J., Imtiaz J., Schumacher M., et al.,“A proposal for a generic real-time Ethernetsystem”, IEEE Transactions on Industrial Informatics,2009,5(2),75–85.
[24] Imtiaz J., Jasperneite J., and Weber K.,“Redundant structures for a generic real-time Ether-net system”, Proceedings of the IEEE International Conference on Emerging Technologiesand Factory Automation, IEEE,2010,1–4.
[25] Automation S.,“Modbus messaging on TCP/IP implementation guide”,2002, http://www.modbus.org/.
[26] Schiffer V.,“The CIP family of fieldbus protocols and its newest member EtherNet/IP”, Pro-ceedings of the8th IEEE International Conference on Emerging Technologies and FactoryAutomation, IEEE,2001,377–384.
[27] Tovar E., Vasques F., and Burns A.,“Supporting real-time distributed computer-controlledsystems with multi-hop P-NET networks”, Control Engineering Practice,1999,7(8),1015–1025.
[28] Ethernet R.,“Vnet/IP: Proposal for a publicly available specification for real-time Ethernet”,2004.
[29] Ethernet R.,“EPL (Ethernet Powerlink): Proposal for a publicly available specification forreal-time Ethernet”,2004.
[30] Cena G., Seno L., Valenzano A., et al.,“Performance analysis of Ethernet Powerlink net-works for distributed control and automation systems”, Computer Standards&Interfaces,2009,31(3),566–572.
[31]冯冬芹,申屠久洪,王少勇等,“我国第一个拥有自主知识产权的EPA标准及其验证应用”,可编程控制器与工厂自动化,2004,(7),10–13.
[32] Feld J.,“PROFINET-scalable factory communication for all applications”, Proceedings ofthe IEEE International Workshop on Factory Communication Systems, IEEE,2004,33–38.
[33] Schemm E.,“SERCOS to link with Ethernet for its third generation”, Computing and Con-trol Engineering,2004,15(2),30–33.
[34]吕日昌,葛万成,“SERCOS-III在运动控制网络中实时与同步的实现”,信息技术,2009,(4),8–11.
[35] Jansen D. and Buttner H.,“Real-time Ethernet: The EtherCAT solution”, Computing andControl Engineering,2004,15(1),16–21.
[36] Prytz G.,“A performance analysis of EtherCAT and PROFINET IRT”, Proceedings of theIEEE International Conference on Emerging Technologies and Factory Automation, IEEE,2008,408–415.
[37] Kleines H., Detert S., Drochner M., et al.,“Performance aspects of PROFINET IO”, IEEETransactions on Nuclear Science,2008,55(1),290–294.
[38] Zhang X., Tang X., and Chen J.,“Time synchronization of hierarchical real-time networkedCNC system based on Ethernet/Internet”, The International Journal of Advanced Manufac-turing Technology,2008,36(11),1145–1156.
[39] Ren Q., Chen J., Tang X., et al.,“Internet/Ethernet-based computer numerical control sys-tem”, Proceedings of the IEEE International Conference on Automation and Logistics,IEEE,2007,2680–2685.
[40] Ren Q., Chen J., Tang X., et al.,“Study and implementation of digital interface protocolbased on Ethernet for NC system”, Proceedings of the3rd IEEE Conference on IndustrialElectronics and Applications, IEEE,2008,1720–1724.
[41] Ren Q., Chen J., Tang X., et al.,“Study of digital interface protocol based on Ethernet forNC system”, Proceedings of the International Conference on Information and Automation,IEEE,2008,1751–1756.
[42]刘明哲,徐皑冬,毕宇航,“确定性实时以太网通信协议研究”,仪器仪表学报,2005,26(8),505–507.
[43]冯冬芹,廖智军,金建祥等,“基于以太网的工业控制网络实时通信模型研究”,仪器仪表学报,2005,26(009),891–894.
[44]张承瑞,王金江,“基于标准以太网的实时同步网络及其工作方法”,2007.
[45]李洪波,吴凤鸽,孙增圻等,“网络控制系统仿真平台的设计与实现”,系统仿真学报,2006,18(006),1700–1704.
[46] Varga A.,“OMNeT++”, Modeling and Tools for Network Simulation,2010,35–59.
[47] McCanne S., Floyd S., Fall K., et al.,“Network simulator NS-2”,1997.
[48]张庆灵,张雪峰,“网络控制系统研究综述与前景展望”,信息与控制,2007,36(3),364–370.
[49] Henriksson D., Cervin A., andA rze′n K.,“TrueTime: Simulation of control loops undershared computer resources”, Proceedings of the15th IFAC World Congress on AutomaticControl, volume15,2002,973–973.
[50] Henriksson D., Cervin A., andA rze′n K.,“TrueTime: Real-time control system simula-tion with MATLAB/Simulink”, Proceedings of the Nordic MATLAB Conference, volume9,2003.
[51] Dai X., Long Z., Yang B., et al.,“Robust fault detection observer in wireless networked con-trol systems”, Proceedings of the Chinese Control and Decision Conference, IEEE,2011,2147–2152.
[52] Eyisi E., Bai J., Riley D., et al.,“NCSWT: An integrated modeling and simulation tool fornetworked control systems”, Simulation Modelling Practice and Theory,2012,27,90–111.
[53] Al-Hammouri A.,“A comprehensive co-simulation platform for cyber-physical systems”,Computer Communications,2012.
[54] Zhang Q., Tang Y., and Zhang W.,“Adaptive dynamic matrix control for network-basedcontrol systems with random delays”, Asian Journal of Control,2006,8(1),45–49.
[55] Lozoya C., Mart′P., Velasco M., et al.,“Analysis and design of networked control loopswith synchronization at the actuation instants”, Proceedings of the34th Annual Conferenceof IEEE Industrial Electronics, IEEE,2008,2899–2904.
[56]李雯,戴金海,“网络控制系统消息时延的仿真研究”,计算机仿真,2008,25(3),156–158.
[57]元亮,“针对时延和数据包丢失的网络控制系统分析与设计”,电力科学与工程,2009,25(7),42–45.
[58] Chow M. and Tipsuwan Y.,“Gain adaptation of networked DC motor controllers based onQoS variations”, IEEE Transactions on Industrial Electronics,2003,50(5),936–943.
[59] Tipsuwan Y. and Chow M.,“On the gain scheduling for networked PI controller over IPnetwork”, IEEE/ASME Transactions on Mechatronics,2004,9(3),491–498.
[60] Li H., Chow M., and Sun Z.,“EDA-based speed control of a networked DC motor systemwith time delays and packet losses”, IEEE Transactions on Industrial Electronics,2009,56(5),1727–1735.
[61] Li H., Chow M., and Sun Z.,“Optimal stabilizing gain selection for networked controlsystems with time delays and packet losses”, IEEE Transactions on Control Systems Tech-nology,2009,17(5),1154–1162.
[62] Li H., Sun Z., Chow M., et al.,“Gain-scheduling-based state feedback integral controlfor networked control systems”, IEEE Transactions on Industrial Electronics,2011,58(6),2465–2472.
[63] Li H., Sun Z., Liu H., et al.,“State feedback integral control of networked control systemswith external disturbance”, IET Control Theory&Applications,2011,5(2),283–290.
[64] Tipsuwan Y. and Chow M.,“Gain scheduler middleware: A methodology to enable existingcontrollers for networked control and teleoperation-part II: teleoperation”, IEEE Transac-tions on Industrial Electronics,2004,51(6),1228–1237.
[65] Hu W., Liu G., and Rees D.,“Networked predictive control over the Internet using round-trip delay measurement”, IEEE Transactions on Instrumentation and Measurement,2008,57(10),2231–2241.
[66] Zhao Y., Liu G., and Rees D.,“Design of a packet-based control framework for networkedcontrol systems”, IEEE Transactions on Control Systems Technology,2009,17(4),859–865.
[67] Wang R., Liu G., Wang W., et al.,“Guaranteed cost control for networked control systemsbased on an improved predictive control method”, IEEE Transactions on Control SystemsTechnology,2010,18(5),1226–1232.
[68] Hu W., Liu G., Rees D., et al.,“Design and implementation of web-based control laboratoryfor test rigs in geographically diverse locations”, IEEE Transactions on Industrial Electron-ics,2008,55(6),2343–2354.
[69] Lai C. and Hsu P.,“Design the remote control system with the time-delay estimator and theadaptive smith predictor”, IEEE Transactions on Industrial Informatics,2010,6(1),73–80.
[70] Lai C. and Hsu P.,“Realization of networked control systems on Ethernet with varied timedelay”, Proceedings of the IEEE International Conference on Systems Man and Cybernetics,IEEE,2010,66–73.
[71] Cheng C., Lai C., Wang B., et al.,“The time-delay effect of multiple-network systems inNCS”, Proceedings of the SICE Annual Conference, IEEE,2007,929–934.
[72] Chang C., Lai C., and Hsu P.,“The intelligent message estimator for wireless network con-trol systems”, Proceedings of the IEEE International Conference on Systems Man and Cy-bernetics, IEEE,2010,3821–3827.
[73] Natori K., Tsuji T., Ohnishi K., et al.,“Time-delay compensation by communication distur-bance observer for bilateral teleoperation under time-varying delay”, IEEE Transactions onIndustrial Electronics,2010,57(3),1050–1062.
[74]黄海,网络控制系统实验平台建设与算法设计,浙江大学博士学位论文,杭州,2007.
[75] Feng D., Huang W., Jin J., et al.,“EPA-based open network control system”, Proceedingsof the4th International Conference on Control and Automation, IEEE,2003,976–980.
[76] Wei G., Zongyu C., and Congxin L.,“Investigation on full distribution cnc system based onsercos bus”, Journal of systems engineering and electronics,2008,19(1),52–57.
[77] Mills D.,“Internet time synchronization: the network time protocol”, IEEE Transactions onCommunications,1991,39,1482–1493.
[78] Neagoe T., Cristea V., Banica L., et al.,“NTP versus PTP in computer networks clock syn-chronization”, Proceedings of the IEEE International Symposium on Industrial Electronics,2006,317–362.
[79] IEEE Std.1588-2002,“IEEE standard for a precision clock synchronization protocol fornetworked measurement and control systems”,2002.
[80] Eidson J., Measurement, control, and communication using IEEE1588, Springer-VerlagNew York Inc,2006.
[81] Vatanski N., Georges J., Aubrun C., et al.,“Networked control with delay measurement andestimation”, Control Engineering Practice,2009,17(2),231–244.
[82] Hong S.,“Bandwidth allocation scheme for cyclic-service fieldbus networks”, IEEE/ASMETransactions on Mechatronics,2001,6(2),197–204.
[83] Skaf J. and Boyd S.,“Analysis and synthesis of state-feedback controllers with timing jit-ter”, IEEE Transactions on Automatic Control,2009,54(3),652–657.
[84] Kobayashi Y., Kimura T., and Fujioka H.,“A servo motor control with sampling jitters”,Proceedings of the11th IEEE International Workshop on Advanced Motion Control, IEEE,2010,58–63.
[85] Smeds K. and Lu X.,“Effect of sampling jitter and control jitter on positioning error inmotion control systems”, Precision Engineering,2012,36(2),175–192.
[86] Harris K.,“An application of IEEE1588to industrial automation”, Proceedings of the IEEEInternational Symposium on Precision Clock Synchronization for Measurement, Control andCommunication, IEEE,2008,71–76.
[87] Ferrari P., Flammini A., Marioli D., et al.,“IEEE1588-based synchronization system fora displacement sensor network”, IEEE Transactions on Instrumentation and Measurement,2008,57(2),254–260.
[88] Subrahmanyan R.,“Timing recovery for IEEE1588applications in telecommunications”,IEEE Transactions on Instrumentation and Measurement,2009,58(6),1858–1868.
[89] Steinhauser F., Riesch C., and Rudigier M.,“IEEE1588for time synchronization of devicesin the electric power industry”, Proceedings of the IEEE International Symposium on Pre-cision Clock Synchronization for Measurement, Control and Communication, IEEE,2010,1–6.
[90] De Dominicis C., Ferrari P., Flammini A., et al.,“On the use of IEEE1588in existingIEC61850-based SASs: Current behavior and future challenges”, IEEE Transactions onInstrumentation and Measurement,2011,60(9),3070–3081.
[91] Neagoe T., Hamdi M., and Cristea V.,“Frequency compensated, hardware IEEE-1588im-plementation”,2006IEEE International Symposium on Industrial Electronics, volume1,2006,240–245.
[92] Correll K., Barendt N., and Branicky M.,“Design considerations for software only imple-mentations of the IEEE1588precision time protocol”, Proceedings of the IEEE Interna-tional Symposium on Precision Clock Synchronization for Measurement, Control and Com-munication,2005.
[93] Sourceforge,“The precision time protocol daemon (PTPd)”,2010, http://ptpd.sourceforge.net/.
[94] Ferrari P., Flammini A., Rinaldi S., et al.,“Improving robustness of the synchronizationquality of IEEE1588nodes”, Proceedings of the IEEE International Symposium on Pre-cision Clock Synchronization for Measurement, Control and Communication, IEEE,2010,36–41.
[95] Wang T., Chang F., and Lin S.,“Multidevice time measurement system via a PTPD net-work”, IEEE Transactions on Instrumentation and Measurement,2011,60(7),2304–2307.
[96] Benetazzo L., Narduzzi C., and Stellini M.,“Analysis of clock tracking performances for asoftware-only IEEE1588implementation”, Proceedings of the IEEE Instrumentation andMeasurement Technology Conference,2007,1–6.
[97] Meier S., Weibel H., and Weber K.,“IEEE1588syntonization and synchronization func-tions completely realized in hardware”, Proceedings of the IEEE International Symposiumon Precision Clock Synchronization for Measurement, Control and Communication,2008,1–4.
[98] Depari A., Ferrari P., Flammini A., et al.,“A new instrument for real-time Ethernet per-formance measurement”, IEEE Transactions on Instrumentation and Measurement,2008,57(1),121–127.
[99] Han J. and Jeong D.,“A practical implementation of IEEE1588-2008transparent clock fordistributed measurement and control systems”, IEEE Transactions on Instrumentation andMeasurement,2010,59(2),433–439.
[100] Cena G., Bertolotti I., Scanzio S., et al.,“On the accuracy of the distributed clock mecha-nism in EtherCAT”, Proceedings of the IEEE International Workshop on Factory Commu-nication Systems, IEEE,2010,43–52.
[101] Ferrari P., Flammini A., Rinaldi S., et al.,“Evaluation of clock synchronization accuracy ofcoexistent real-time Ethernet protocols”, Proceedings of the IEEE International Symposiumon Precision Clock Synchronization for Measurement, Control and Communication, IEEE,2008,87–91.
[102] Ferrari P., Flammini A., Rinaldi S., et al.,“On the seamless interconnection of IEEE1588-based devices using a PROFINET IO infrastructure”, IEEE Transactions on Industrial In-formatics,2010,6(3),381–392.
[103] Lian Y., Han Y., Huo M., et al.,“Design and FPGA verification of a novel reliable real-timedata transfer system”, Journal of Zhejiang University-Science A,2008,9(10),1406–1410.
[104] Balasubramanian S., Harris K., and Moldovansky A.,“A frequency compensated clock forprecision synchronization using IEEE1588protocol and its application to Ethernet”, Pro-ceedings of the Workshop on IEEE,2003,91–94.
[105] Abubakari H. and Sastry S.,“IEEE1588style synchronization over wireless link”, Proceed-ings of the IEEE International Symposium on Precision Clock Synchronization for Measure-ment, Control and Communication,2008,127–130.
[106] Macii D., Fontanelli D., and Petri D.,“A master-slave synchronization model for enhancedservo clock design”, Proceedings of the IEEE International Symposium on Precision ClockSynchronization for Measurement, Control and Communication,2009,1–6.
[107] Seong C., Lee S., and Choi W.,“A new network synchronizer using phase adjustment andfeedforward filtering based on low-cost crystal oscillators”, IEEE Transactions on Instru-mentation and Measurement,2010,59(7),1764–1774.
[108] Giorgi G. and Narduzzi C.,“Performance analysis of Kalman-filter-based clock synchro-nization in IEEE1588networks”, IEEE Transactions on Instrumentation and Measurement,2011,60(8),2902–2909.
[109] Jasperneite J., Shehab K., and Weber K.,“Enhancements to the time synchronization stan-dard IEEE-1588for a system of cascaded bridges”, Proceedings of the IEEE InternationalWorkshop on Factory Communication Systems, IEEE,2004,239–244.
[110] Cho J., Kim H., Wang S., et al.,“A novel method for providing precise time synchronizationin a distributed control system using boundary clock”, IEEE Transactions on Instrumenta-tion and Measurement,2009,58(8),2824–2829.
[111] IEEE Std.1588-2008,“IEEE standard for a precision clock synchronization protocol fornetworked measurement and control systems”,2008.
[112] Na C., Scheiterer R., Obradovic D., et al.,“Clock synchronization based on distributedhidden state estimation”, Proceedings of the IEEE International Symposium on PrecisionClock Synchronization for Measurement, Control and Communication,2009,1–6.
[113] Fontanelli D. and Macii D.,“Accurate time synchronization in PTP-based industrial net-works with long linear paths”, Proceedings of the IEEE International Symposium on Pre-cision Clock Synchronization for Measurement, Control and Communication, IEEE,2010,97–102.
[114] Wolfrum P., Scheiterer R., and Obradovic D.,“An optimal control approach to clock syn-chronization”, Proceedings of the IEEE International Symposium on Precision Clock Syn-chronization for Measurement, Control and Communication, IEEE,2010,122–128.
[115] De L V., Rapuano S., and Tomaciello L.,“One-way delay measurement: State of the art”,IEEE Transactions on Instrumentation and Measurement,2008,57(12),2742–2750.
[116]张向利,唐小琦,陈吉红等,“基于以太网的数控系统实时通信和时间同步”,计算机集成制造系统,2008,14(6),1148–1154.
[117] Bai Y.C., Tang X.Q., Wu G.P., et al.,“Research on multi-axis synchronous control in net-work CNC system”, Proceedings of the IEEE International Conference on Computationaland Information Sciences,2010,800–803.
[118] Jeong S. and You S.,“Precise position synchronous control of multi-axis servo system”,Mechatronics,2008,18(3),129–140.
[119] Koren Y.,“Cross-coupled biaxial computer control for manufacturing systems”, Journal ofDynamic Systems, Measurement, and Control,1980,102,265–272.
[120] Koren Y., Lo C., et al.,“Variable-gain cross-coupling controller for contouring”, CIRPAnnals-Manufacturing Technology,1991,40(1),371–374.
[121] Chiu G. and Tomizuka M.,“Contouring control of machine tool feed drive systems: Atask coordinate frame approach”, IEEE Transactions on Control Systems Technology,2001,9(1),130–139.
[122] Yeh S. and Hsu P.,“Estimation of the contouring error vector for the cross-coupled controldesign”, IEEE/ASME Transactions on Mechatronics,2002,7(1),44–51.
[123] Shih Y.T., Chen C.S., and Lee A.C.,“A novel cross-coupling control design for bi-axismotion”, International Journal of Machine Tools and Manufacture,2002,42(14),1539–1548.
[124] Sun D., Shao X., and Feng G.,“A model-free cross-coupled control for position synchro-nization of multi-axis motions: Theory and experiments”, IEEE Transactions on ControlSystems Technology,2007,15(2),306–314.
[125] Sun D. and Tong M.,“A synchronization approach for the minimization of contouring errorsof CNC machine tools”, IEEE Transactions on Automation Science and Engineering,2009,6(4),720–729.
[126] Hu C., Yao B., and Wang Q.,“Coordinated adaptive robust contouring controller design foran industrial biaxial precision gantry”, IEEE/ASME Transactions on Mechatronics,2010,15(5),728–735.
[127] Yang J. and Li Z.,“A novel contour error estimation for position loop-based cross-coupledcontrol”, IEEE/ASME Transactions on Mechatronics,2011,16(4),643–655.
[128] Yao B., Hu C., and Wang Q.,“An orthogonal global task coordinate frame for contouringcontrol of biaxial systems”, IEEE/ASME Transactions on Mechatronics,2012,17(4),622–634.
[129] Chen S., Liu H., and Ting S.,“Contouring control of biaxial systems based on polar coordi-nates”, IEEE/ASME Transactions on Mechatronics,2002,7(3),329–345.
[130] Chen S. and Wu K.,“Contouring control of smooth paths for multiaxis motion systemsbased on equivalent errors”, IEEE Transactions on Control Systems Technology,2007,15(6),1151–1158.
[131] Yeh S. and Hsu P.,“Analysis and design of integrated control for multi-axis motion sys-tems”, IEEE Transactions on Control Systems Technology,2003,11(3),375–382.
[132] Yan M., Lee M., and Yen P.,“Theory and application of a combined self-tuning adaptivecontrol and cross-coupling control in a retrofit milling machine”, Mechatronics,2005,15(2),193–211.
[133] Chen C. and Lin K.,“Observer-based contouring controller design of a biaxial stage systemsubject to friction”, IEEE Transactions on Control Systems Technology,2008,16(2),322–329.
[134] Sun D. and Ge S., Synchronization and control of multiagent systems, CRC Press,2010.
[135] Sun D., Wang C., Shang W., et al.,“A synchronization approach to trajectory tracking ofmultiple mobile robots while maintaining time-varying formations”, IEEE Transactions onRobotics,2009,25(5),1074–1086.
[136] Luck R. and Ray A.,“An observer-based compensator for distributed delays”, Automatica,1990,26(5),903–908.
[137] Montestruque L. and Antsaklis P.,“On the model-based control of networked systems”,Automatica,2003,39(10),1837–1843.
[138] Montestruque L. and Antsaklis P.,“Stability of model-based networked control systems withtime-varying transmission times”, IEEE Transactions on Automatic Control,2004,49(9),1562–1572.
[139] Natori K. and Ohnishi K.,“A design method of communication disturbance observer fortime-delay compensation, taking the dynamic property of network disturbance into ac-count”, IEEE Transactions on Industrial Electronics,2008,55(5),2152–2168.
[140] Natori K., Oboe R., and Ohnishi K.,“Stability analysis and practical design procedure oftime delayed control systems with communication disturbance observer”, IEEE Transac-tions on Industrial Informatics,2008,4(3),185–197.
[141] Lee K.C., Lee S., and Lee M.H.,“Remote fuzzy logic control of networked control systemvia Profibus-DP”, IEEE Transactions on Industrial Electronics,2003,50(4),784–792.
[142] Tipsuwan Y. and Chow M.,“Gain scheduler middleware: A methodology to enable exist-ing controllers for networked control and teleoperation-part I: Networked control”, IEEETransactions on Industrial Electronics,2004,51(6),1218–1227.
[143] Hsieh C. and Hsu P.,“The CAN-based synchronized structure for multi-axis motion controlsystems”, Proceedings of the IEEE International Conference on Systems, Man and Cyber-netics, volume2, IEEE,2005,1314–1319.
[144] Ren J., Li C., and Zhao D.,“CAN-based synchronized motion control for induction motors”,International Journal of Automation and Computing,2009,6(1),55–61.
[145] Wang Z., Yu D., Hu Y., et al.,“Design of distributed cross-coupled controller based onmotion control bus”, Proceedings of the Chinese Control and Decision Conference, IEEE,2009,1662–1667.
[146] Nun o E., Ortega R., Basan ez L., et al.,“Synchronization of networks of nonidentical Euler-Lagrange systems with uncertain parameters and communication delays”, IEEE Transac-tions on Automatic Control,2011,56(4),935–941.
[147] Fradkov A., Grigoriev G., and Selivanov A.,“Decentralized adaptive controller for synchro-nization of dynamical networks with delays and bounded disturbances”, Proceedings of the50th IEEE Conference on Decision and Control and European Control Conference, IEEE,2011,1110–1115.
[148] Cervin A., Henriksson D., and Ohlin M., TRUETIME2.0beta-Reference Manual, Depart-ment of Automatic Control, Lund University,2009.
[149]苏奎峰,吕强,耿庆锋等,“TMS320F2812原理与开发”,2005.
[150] IEC61784-2Ed.1,“Industrial Communication Networks-Profiles-Part2: Additional Field-bus Profiles for Real-Time Networks Based on ISO/IEC8802-3”, IEC,2007.
[151] Yook J., Tilbury D., and Soparkar N.,“A design methodology for distributed control systemsto optimize performance in the presence of time delays”, International Journal of Control,2001,74(1),58–76.
[152]邹彦,等,数字系统设计,航空工业出版社,2007.
[153] Xu X., Sheng X., Xiong Z., et al.,“Time-stamped cross-coupled control in networked CNCsystems”, Proceedings of the IEEE International Conference on Robotics and Automation,2011,4378–4383.
[154] Lian F.L., Moyne J., and Tilbury D.,“Control performance study of a networked machiningcell”, Proceedings of the American Control Conference, volume4,2000,2337–2341.
[155]“Industrial communication networks-Fieldbus specifications-Part3-12: Data-link layer ser-vice definition-Part4-12: Data-link layer protocol specification-Type12elements”, Interna-tional Electrotechnical Commission (IEC),2007.
[156] Ding M., Xu X., Yan Y., et al.,“An FPGA-based real-time solution for networked motioncontrol systems”, Proceedings of the International Conference on Intelligent Robotics andApplications,2012,581–591.
[157] Jasperneite J., Schumacher M., and Weber K.,“Limits of increasing the performance of in-dustrial Ethernet protocols”, Proceedings of the IEEE International Conference on Emerg-ing Technologies and Factory Automation, IEEE,2007,17–24.
[158] Vitturi S., Peretti L., Seno L., et al.,“Real-time Ethernet networks for motion control”,Computer Standards&Interfaces,2011,33(5),465–476.
[159] Lee J. and Edgar T.,“ISE tuning rule revisited”, Automatica,2004,40(8),1455–1458.
[160] Franklin G., Workman M., and Powell D., Digital control of dynamic systems, Addison-Wesley Longman Publishing Co., Inc. Boston, MA, USA,1997.
[161] Zucca C. and Tavella P.,“The clock model and its relationship with the Allan and relatedvariances”, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control,2005,52(2),289–296.
[162] Albert M.,“Open-architecture CNC close servo loop in software”, Modern Machine Shop,1997,7.
[163] Shi D., Wang B., and Wu H.,“A novel design of distributed servo system based on re-arranging functions between host controller and servo driver”, Proceedings of the IEEEInternational Conference on Automation and Logistics, IEEE,2007,480–484.
[164] Gu G., Zhu L., Xiong Z., et al.,“Design of a distributed multi-axis motion control sys-tem using the IEEE-1394bus”, IEEE Transactions on Industrial Electronics,2010,57(12),4209–4218.
[165] Liu G., Mu J., Rees D., et al.,“Design and stability analysis of networked control systemswith random communication time delay using the modified MPC”, International Journal ofControl,2006,79(4),288–297.
[166] Liu G., Xia Y., Chen J., et al.,“Networked predictive control of systems with random net-work delays in both forward and feedback channels”, IEEE Transactions on Industrial Elec-tronics,2007,54(3),1282–1297.
[167] Liu G.,“Predictive controller design of networked systems with communication delays anddata loss”, IEEE Transactions on Circuits and Systems II: Express Briefs,2010,57(6),481–485.
[168] Hsieh C.C. and Hsu P.L.,“Analysis and applications of the motion message estimator fornetwork control systems”, Asian Journal of Control,2008,10(1),45–54.
[169] Shang W., Cong S., Zhang Y., et al.,“Active joint synchronization control for a2-DOFredundantly actuated parallel manipulator”, IEEE Transactions on Control Systems Tech-nology,2009,17(2),416–423.