【作者】 王玲飞；

【导师】 鲁昌华；

【作者基本信息】 合肥工业大学 ， 信号与信息处理， 2008， 硕士

【摘要】 数模混合电路广泛用于多媒体、无线网络和便携式数据系统。目前,数模混合电路的故障诊断中存在着数/模信号统一处理难、检测效率低、自动化程度不高的问题。因此,数模混合电路的故障诊断技术是近年来电路测试领域研究的热点。本文在用DES理论进行电路可测试性分析的基础上,将虚拟仪器技术应用到数模混合电路的测试中,所做的主要工作及成果如下:◆在深入研究自动测试技术和数模混合电路故障诊断方法的基础上,设计了将DES理论和虚拟仪器技术相结合的数模混合电路故障诊断的方案。◆选择了一个典型的数模混合电路,建立了该电路的DES模型。通过电路仿真软件对其进行故障仿真,建立了故障字典,用离散粒子群算法求取该电路的最小测试集。仿真和实验表明,该方法能够有效地约简故障诊断表。◆设计了数模混合电路虚拟测试系统的硬件方案,采用PC机+数据采集卡的结构搭建了实验平台。该方案有效地提高了检测速度,实现了故障测试的自动化。◆在虚拟仪器开发环境LabWindows/CVI中编程实现了对被测电路故障数据的采集,编写数据分析软件实现了被测电路故障点的准确定位。实验证明了DES理论和虚拟仪器技术结合应用于数模混合电路故障诊断的可行性。更多还原

【Abstract】 Mixed-signal(digital and analog)circuits are widely used in multimedia, the wireless network and the portable data system. There are some problems in present fault-diagnosis of mixed-signal circuits, such as difficulty in unifying the digital and analogue signal, poor efficiency, low automatization and so on. So the fault-diagnosis of mixed-signal circuits is a hotspot in the field of circuits testing.In this dissertation, the DES theory is used to analyse the testability of circuits, the virtual instrument technique is used in the fault diagnosis of mixed-signal circuits. The main work and contributions of the dissertation are summarized as follows:By deep research in Automatic Test System and fault-diagnosis of mixed-signal, a scheme was designed to realize the diagnosis by combining DES theory and the virtual instrument technique.A typical mixed-signal circuit was chosen, it’s fault model was built up. The software Multisim was used to simulate the circuit so as to build up the fault dictionary. The Discrete Particle Swarm Optimization Algorithm was used to get the minimum test set of the circuit, and then a reduced fault dictionary could be attained.The structure of the hardware was designed. The experiment circuit was built on SC-2075, PCI DAQ device was used to acquire data to the software system. In this way, the speed of test could be improved and automatization of the test could be realized.The program of acquiring data was completed in the VI environment LabWindows/CVI, the program of analysis was also completed according to the reduced fault dictionary. It can be certified that it is feasible to carry out the fault-diagnosis of mixed-signal circuits by combining with DES theory and the virtual instrument technique.更多还原