【作者】 吴立力；

【导师】 孙景琪；

【作者基本信息】 北京工业大学 ， 电路与系统， 2001， 硕士

【摘要】 随着科学技术的进步，对测量技术的要求越来越高。电子测量技术在各个领域得到越来越广泛的应用，传统的电子测量仪器由于其功能单一，体积庞大，已经很难满足实际工作的需要。集成电路和计算机技术的迅猛发展使电子测量仪器逐渐向数字化、智能化方向发展，与传统仪器相比表现为：功能更强、处理速度更快、频带更宽、用途更广、操作更简单、体积更小、可扩充性更好。微型计算机的普及程度和性能不断提高，使得基于PC平台的虚拟仪器系统应运而生。虚拟仪器可以充分利用计算机的运算、存储和显示功能，因而在降低仪器成本的同时使仪器的灵活性和数据处理能力大大提高，可以很好地满足学校科研和教学改革的需要。 本文论述了基于虚拟仪器概念的信号采集系统的实现方案。使用自主开发的数据采集卡，最终实现了基于PC平台的，具有频率计和频谱分析仪功能的数字存储示波器系统。由于使用了LabVIEW进行系统的软件开发，使得本系统具有很好的通用性和灵活性。本文主要讨论在信号采集过程中的数据传输、显示和处理的方法以及实现过程中的关键技术。 数据传输是虚拟仪器系统中首先要解决的问题，本文使用基于动态链接库的LabVIEW驱动程序，实现了在LabVIWE中对仪器硬件的控制和对采样数据的传输。采样方式决定数字存储示波器的有效带宽，本文采用实时采样和等效采样相结合的方法，对高频周期性信号采用NT±△T等效采样法，有效地扩展了示波器的带宽。本文提出一种确定波形显示起始点的算法——最小均方误差法，解决了波形刷新时的同步问题。本文介绍了在软件面板中实现频谱仪的方法。最后，讨论了系统中可能出现的干扰和噪声并采取了相应的解决方法。更多还原

【Abstract】 With the advancement of science and technology, the development of measurement technique is getting more and more important. The application of electronic measurement technique has extended to more fields than ever. Due to limited functions and big size, traditional electronic measurement equipment is no longer suited for common purposes. Thanks to the rapid development of integrated circuit and computer technology, measurement instruments are becoming digitized and intelligentized. Compared with traditional equipment, the new instruments have more functions, higher processing speed, wider bandwidth, friendlier interface, smaller size and better expandability. The prevalence and rocketing development of personal computers give birth to a new kind of instrument, Virtual Instrument (VI). VI is based on PC platform, and can make use of the software and hardware resources of a PC. Compared with its ability of data processing and flexibility, VI has a low price, which means it is a good choice for research and teaching reform in universities. This dissertation discusses the implementation of a signal acquisition system, based on the concept of VI. With a self-developed data acquisition card connected to PC, a digital storage oscillograph (DSO) with the function of cymometer and spectrum analyzer is developed. The usage of LabVIEW, the specialized VI software platform, gives the system more flexibility and wider application. This dissertation focuses on key techniques in data transmission, display and processing. The main elements of this dissertation are as follows: developing LabVIEW instrument driver using Windows dynamic link library (DLL), combining real time and equivalent time (NT ?A T) sampling methods in signal acquisition, adoption of minimum mean square error (MMSE) method to synchronize signal displaying, realization of spectrum analyzer in LabVIEW and solutions to the noises possible to appear in the system.更多还原