基于虚拟仪器的远程测控系统设计及实现
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摘要
虚拟仪器(Virtual Instruments简称VI)是随着计算机软件技术发展起来的一项新型技术。它克服了传统仪器的弊端，利用计算机的强大计算能力和灵活的软件技术，在有限的硬件的基础上实现出符合需要的完全不同的各种仪器体系。本论文介绍了虚拟仪器的概念、特点、原理和组成。并论述了虚拟仪器的硬件结构和常用开发软件，较为详细地介绍了LabWindows／CVI开发环境的特点及其开放方式，重点阐述了一个二维精密伺服工作平台虚拟仪器网络测控系统的实现。
本论文的核心是描述在NI公司提供的PCI 7344运动控制卡的基础上，利用虚拟仪器技术建立一个对二维精密伺服工作平台的网络实时测控系统。通过PCI 7344运动控制卡同时控制一个步进电机驱动器和一个交流伺服电机驱动器，这两个驱动器分别驱动精密二维平台的X轴和Y轴运动，从而实现两轴的同步运动控制。该系统主要实现两大功能：一个是实现圆弧运动控制，另一个是实现两轴混合顺序向量运动控制。在圆弧运动功能模块里面，用户可以指定运动的半径、初始角度、运动角度、运动速度和加速度。在两轴混合向量运动功能模块里，用户除了可以指定运动的速度、加速度外，还可以定义每一段混合运动的起始位置。两大功能模块都可以通过位置监视器实时观察二维精密平台的运动轨迹。本系统利用DLL技术实现两大模块的功能，圆弧运动部分和向量运动部分都生成动态链接库，由主面板选择所需功能后再调入相应的动态链接库执行。这样大大提高了系统的性能，降低了系统占用，也使得系统易于扩展功能，同时生成的动态链接库也可以供其它程序使用。系统的网络部分使用网络通信中间件DataSocket技术实现，服务器程序不直接和客户机通信，而是单独地加载一个独立的DataSocket服务器，服务器程序将数据发送到这个独立的DataSocket服务器，客户端也从该服务器取数据。客户端可以将数据显示在二维平台运动位置监视器上，同时也可以将数据以文件的形式保存起来供日后分析使用。这样的结构使得服务器程序不必考虑负载问题，由单独的DataSocket服务器处理客户的访问，可以适应大用户量的要求。由于考虑到安全因素和网络速度现状，系统没有实现客户端对二维精密平台的直接控制。
Virtual Instruments is one of new technologies which is evolving with the development of computer technology. Utilizing the powerful computing capability of computer and flexible software techniques, it overcomes the limitations of traditional instruments and implements different kinds of instrument architectures demanded based on limited hardwares. In our thesis, firstly, we introduce the concepts, characteristics, principles and components of virtual instruments. Secondly, we detailedly discuss the hardware architecture and common development software of VI and then introduce the characteristics and development mode of LabWindows/CVI developing environment. At last, we implement a network measurement and control system for a two-dimension exact servant platform based on the LabWindows/CVI developing environment.
The main part of this thesis is the description of a real-time network measurement and control system of two-dimension exact server utilizing the VI technology based on PCI 7344 movement control card manufactured by NI company. Through PCI 7344 movement and control card's concurrent controlling a step driver and a AC servant driver, the two drivers can drive the movement along X-axis and Y-axis directions of two-dimension exact servant platform and finally realize concurrent movement along the tow axis. Our system implement tow main functions: curve movement control and two-axis mixed sequential vector movement control. In the curve movement control functional module, the user can define the radius, original angle, movement angle, speed and acceleration of movement. In the two-axis mixed sequential vector movement control functional module, in addition to defining the speed and acceleration of movement, the user can also define the original position of every section of mixed movement. The two functional modules both can timely observe the movement track of the two-dimension exact servant platform with
position monitor.
Utilizing Dynamic Link Library software technique, each of the two functional modules implemented in our system: curve movement and vector movement corresponds to a dynamic link library. And each DLL is loaded by selecting function demanded from the main control panel. Thus the system performance will be greatly improved and system workload will also be greatly decreased. At the same time, it is much convenient for the extension of system function and the generated DLLs can also be used by other programs. The system network component is implemented by DataSocket technology. That is, the program of server end will not directly communicate with that of client end, but solely load an independent DataSocket server. Server will send data to this independent DataSocket server and client will get the data from this DataSocket server. Client can show the data on a position monitor of the two-dimension movement platform and may also put the data into some files which will be used to analysis later. This kind of structure separate the workload from the server end and the independent DataSocket server is responsible for the accesses from clients to accommodate to great number of users' accesses. As considering the security factor and the current state of network communicating speed, our system doesn't implement the function of client's directly controlling the two-dimension exact servant platform.
本论文的核心是描述在NI公司提供的PCI 7344运动控制卡的基础上，利用虚拟仪器技术建立一个对二维精密伺服工作平台的网络实时测控系统。通过PCI 7344运动控制卡同时控制一个步进电机驱动器和一个交流伺服电机驱动器，这两个驱动器分别驱动精密二维平台的X轴和Y轴运动，从而实现两轴的同步运动控制。该系统主要实现两大功能：一个是实现圆弧运动控制，另一个是实现两轴混合顺序向量运动控制。在圆弧运动功能模块里面，用户可以指定运动的半径、初始角度、运动角度、运动速度和加速度。在两轴混合向量运动功能模块里，用户除了可以指定运动的速度、加速度外，还可以定义每一段混合运动的起始位置。两大功能模块都可以通过位置监视器实时观察二维精密平台的运动轨迹。本系统利用DLL技术实现两大模块的功能，圆弧运动部分和向量运动部分都生成动态链接库，由主面板选择所需功能后再调入相应的动态链接库执行。这样大大提高了系统的性能，降低了系统占用，也使得系统易于扩展功能，同时生成的动态链接库也可以供其它程序使用。系统的网络部分使用网络通信中间件DataSocket技术实现，服务器程序不直接和客户机通信，而是单独地加载一个独立的DataSocket服务器，服务器程序将数据发送到这个独立的DataSocket服务器，客户端也从该服务器取数据。客户端可以将数据显示在二维平台运动位置监视器上，同时也可以将数据以文件的形式保存起来供日后分析使用。这样的结构使得服务器程序不必考虑负载问题，由单独的DataSocket服务器处理客户的访问，可以适应大用户量的要求。由于考虑到安全因素和网络速度现状，系统没有实现客户端对二维精密平台的直接控制。
Virtual Instruments is one of new technologies which is evolving with the development of computer technology. Utilizing the powerful computing capability of computer and flexible software techniques, it overcomes the limitations of traditional instruments and implements different kinds of instrument architectures demanded based on limited hardwares. In our thesis, firstly, we introduce the concepts, characteristics, principles and components of virtual instruments. Secondly, we detailedly discuss the hardware architecture and common development software of VI and then introduce the characteristics and development mode of LabWindows/CVI developing environment. At last, we implement a network measurement and control system for a two-dimension exact servant platform based on the LabWindows/CVI developing environment.
The main part of this thesis is the description of a real-time network measurement and control system of two-dimension exact server utilizing the VI technology based on PCI 7344 movement control card manufactured by NI company. Through PCI 7344 movement and control card's concurrent controlling a step driver and a AC servant driver, the two drivers can drive the movement along X-axis and Y-axis directions of two-dimension exact servant platform and finally realize concurrent movement along the tow axis. Our system implement tow main functions: curve movement control and two-axis mixed sequential vector movement control. In the curve movement control functional module, the user can define the radius, original angle, movement angle, speed and acceleration of movement. In the two-axis mixed sequential vector movement control functional module, in addition to defining the speed and acceleration of movement, the user can also define the original position of every section of mixed movement. The two functional modules both can timely observe the movement track of the two-dimension exact servant platform with
position monitor.
Utilizing Dynamic Link Library software technique, each of the two functional modules implemented in our system: curve movement and vector movement corresponds to a dynamic link library. And each DLL is loaded by selecting function demanded from the main control panel. Thus the system performance will be greatly improved and system workload will also be greatly decreased. At the same time, it is much convenient for the extension of system function and the generated DLLs can also be used by other programs. The system network component is implemented by DataSocket technology. That is, the program of server end will not directly communicate with that of client end, but solely load an independent DataSocket server. Server will send data to this independent DataSocket server and client will get the data from this DataSocket server. Client can show the data on a position monitor of the two-dimension movement platform and may also put the data into some files which will be used to analysis later. This kind of structure separate the workload from the server end and the independent DataSocket server is responsible for the accesses from clients to accommodate to great number of users' accesses. As considering the security factor and the current state of network communicating speed, our system doesn't implement the function of client's directly controlling the two-dimension exact servant platform.
引文
(1) 《The Measurement and Automation Catalog 2000》National Instruments
(2) W. BLOKLAND, "Integrating the commercial software package LabVIEW with Fermilab's Accelerator Control NETwork".
(3) J. Zhao et al., "The BEPC Control System Upgrade", PAC'95, Dallas, May 1995
(4) Chung-Ping Young,Wei-Lun Juang,and Michael J.Devaney. Real-Time Intranet-Controlled Virtual Instrument Multiple-Circuit Power Monitoring. IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, VOL.49.NO.3.JUNE 2000
(5) ZOLTAN GINGL.VIRTUAL MEASUREMENT TECHNOLOGY IN THE EDUCATION OF PHYSICISTS AND COMMUNICATION ENGINEERS.IEEE
(6) J. Gary W. and G. W. Johnson: LabVIEW Graphical Programming: Practical Applications in Instrumentation and Control. McGraw Hill (1997)
(7) Abhay R. Samant, Mahesh L. Chugani and Michael Cerna: LabVIEW Signal Processing (Virtual Instrumentation Series). Prentice Hall (1998)
(8) Z. Gingl and Z. Kántor: "Intelligent general purpose data acquisition units for student labs." In this volume.
(9) H. N. Norton: Handbook of Transducers. Prentice Hall (1989)
(10) National Instruments Corporate, "PC-Based Industrial Automation", 1996
(11) L. Ma et al., "Using PCs in The BEPC Beam Diagnos-tic Instrumentation System", This Proceedings.
(12) 应怀樵．虚拟仪器与卡泰仪器技术的现状与发展趋势．国外电子测量技术，2000年第2期
(13) 刘君华．虚拟仪器编程语言LabWidnows/CVI教程．电子工业出版社，2001，8月第一版
(14) 胡生清．未来的仪器仪表—虚拟仪器国外电子测量技术．2000，(4)：19，20
(15) 陆申龙．开放教学实验室，提高学生创造能力[J]．实验室研究与探索，1999，(6)：8-10
(16) 王思华，叶文生，雷兆宜，陆尧胜．DataSocket技术及其在虚拟仪器远程测控系统中的应用．暨南大学电子工程系．暨南大学学报(自然科学版)，第21卷第3期2000年6月
(17) 李亚，王录，郝应光，唐祯安．基于Internet的远程虚拟实验室系统的开发．大连理工大学电子系．微型电脑应用，2001年第17卷第8期
(18) 刘民岷，杨平，吴浩文，基于虚拟仪器的实验室建设．实验技术与管理，2002年第2期
(19) 吴浩文，杨平，刘民岷．《基于Web多媒体远程教学环境的构建》．第十届通信设备结构工艺学术会议，2001年10月
(2) W. BLOKLAND, "Integrating the commercial software package LabVIEW with Fermilab's Accelerator Control NETwork".
(3) J. Zhao et al., "The BEPC Control System Upgrade", PAC'95, Dallas, May 1995
(4) Chung-Ping Young,Wei-Lun Juang,and Michael J.Devaney. Real-Time Intranet-Controlled Virtual Instrument Multiple-Circuit Power Monitoring. IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, VOL.49.NO.3.JUNE 2000
(5) ZOLTAN GINGL.VIRTUAL MEASUREMENT TECHNOLOGY IN THE EDUCATION OF PHYSICISTS AND COMMUNICATION ENGINEERS.IEEE
(6) J. Gary W. and G. W. Johnson: LabVIEW Graphical Programming: Practical Applications in Instrumentation and Control. McGraw Hill (1997)
(7) Abhay R. Samant, Mahesh L. Chugani and Michael Cerna: LabVIEW Signal Processing (Virtual Instrumentation Series). Prentice Hall (1998)
(8) Z. Gingl and Z. Kántor: "Intelligent general purpose data acquisition units for student labs." In this volume.
(9) H. N. Norton: Handbook of Transducers. Prentice Hall (1989)
(10) National Instruments Corporate, "PC-Based Industrial Automation", 1996
(11) L. Ma et al., "Using PCs in The BEPC Beam Diagnos-tic Instrumentation System", This Proceedings.
(12) 应怀樵．虚拟仪器与卡泰仪器技术的现状与发展趋势．国外电子测量技术，2000年第2期
(13) 刘君华．虚拟仪器编程语言LabWidnows/CVI教程．电子工业出版社，2001，8月第一版
(14) 胡生清．未来的仪器仪表—虚拟仪器国外电子测量技术．2000，(4)：19，20
(15) 陆申龙．开放教学实验室，提高学生创造能力[J]．实验室研究与探索，1999，(6)：8-10
(16) 王思华，叶文生，雷兆宜，陆尧胜．DataSocket技术及其在虚拟仪器远程测控系统中的应用．暨南大学电子工程系．暨南大学学报(自然科学版)，第21卷第3期2000年6月
(17) 李亚，王录，郝应光，唐祯安．基于Internet的远程虚拟实验室系统的开发．大连理工大学电子系．微型电脑应用，2001年第17卷第8期
(18) 刘民岷，杨平，吴浩文，基于虚拟仪器的实验室建设．实验技术与管理，2002年第2期
(19) 吴浩文，杨平，刘民岷．《基于Web多媒体远程教学环境的构建》．第十届通信设备结构工艺学术会议，2001年10月