【作者】 何干辉；

【导师】 谭定忠；

【作者基本信息】 哈尔滨工程大学 ， 机械电子工程， 2007， 硕士

【摘要】 虚拟仪器充分利用了计算机强大的软硬件资源，把计算机技术和测量技术紧密地结合起来。它通过上位电脑和下位仪器的结合，不仅具备传统仪器的功能，而且能够通过上位机软件实现硬件不具备的一些功能，还能降低仪器的整体成本。而基于USB总线接口的虚拟仪器有效地解决了传统总线形式(如RS232、PCI、并口、ISA等)传输速度低、安装过程繁琐、易受机箱内环境的干扰、受计算机系统资源限制等缺点，充分发挥了USB总线接口廉价、高速、支持即插即用、使用维护方便等优点，具有很强的实用性和研究价值。随着计算机技术和测试技术的飞速发展，基于USB接口的虚拟仪器将成为测试领域一种新的发展趋势，具有广阔的发展前景。本论文设计并研制了一个基于USB接口的虚拟示波器。论文内容主要包括硬件电路设计和软件编程；硬件电路设计了信号调理电路、A／D转换电路、数据缓存电路和USB通讯接口电路，信号调理电路将输入信号调整到A／D转换器的最佳分辨范围之内，A／D转换电路实现信号采集，采集结果通过USB通讯接口传给上位机。采用LabVIEW软件来编写上位机应用程序，编写了数据处理程序和人机交互界面，其中人机交互界面可以显示测量结果并接收控制指令。最后，还对系统抗干扰问题进行了研究。实际应用结果表明，本论文设计的基于USB接口的虚拟示波器，具有方便、易用、灵活等优点，而且成本低廉、功能强大，具有很高的精度和抗干扰能力。运用虚拟仪器技术，能够实现硬件和软件资源的共享，快速、方便地组建各种自动测试系统，利用计算机强大的功能，能够对信号进行采样、数字滤波、频谱分析和波形显示，还能够对采集的波形数据进行存储、回放和共享。更多还原

【Abstract】 The virtual instrument takes full advantage of the software and hardware resource of the computer, and combines the computer technology and the measurement technology tightly. With the combination of the computer and the measurement device, the virtual instrument not only has the functions of the traditional instrument, but also has many extra functions by using the computer software program; what’s more, it can reduce the cost of the whole equipment. Virtual instruments that based on the Universal Serial Bus interface effectively solved the problems with the traditional bus such as low speed, hard to install, easily be interfered, be limited by the resource of the computer, and they have large practicability and value to research because of their low cost, high speed, plug and play, easy to use and take cake. The virtual instrument that based on the USB interface is going to be the trend of development in the measurement area and has expansive improveing prospect.A virtual oscillograph which is based on the USB bus is designed and developed in this thesis. The principal content of this thesis includes the design of the hardwire connection and software programming. The signal conditioning circuitry, the analog-to-digital conversion circuitry, the data buffer circuitry and the USB interface circuitry are designed in the design of the hardwire connection. The signal conditioning circuitry adjusts the signal to the best differentiate range of the analog-to-digital converter, the analog-to-digital conversion circuitry converts analog signals to digital signals and the USB interface circuitry transmits the result of the analog-to-digital conversion to the PC. The application program that is programmed with the LabVIEW software has actualized the function of digital signal processing and the human-computer interaction, and the human-computer interaction can display the result of measurement and incept commands. In the end of the thesis, a study of the problem of antiinterference is made.The practical application indicates that this virtual oscillograph based on the USB has many merits such as facility, easy to use, agileness; in addition, it is low cost, powerfull and has high precision and stability. A great variety of automatic test systems will be constructed and the hardware and software resources can be shared. Signal sampling, digital filtering, spectral analysis and waveform display can be done by using the powerful function of the computer, and the data that has been acquired also can be stored, playback and partaken of.更多还原