数字电路的层次化测试生成新趋势

与传统的门级测试生成方法相比，数字电路的层次化测试生成方法采用层次化模块的方式，利用不同抽象级的电路信息，包括结构信息和功能信息，有利于加速测试生成，提高故障覆盖率，分析和综述了几类主要的层次化测试生成算法：预先生成低层模块测试法、模块在约束下直接生成全局测试法、高层模块动态展开法、高层软件测试与低层门级结构测试结合法等，并讨论今后有待解决的主要问题。     

测试图形生成的遗传算法研究

提出了一种用于组合电路测试图形生成的遗传算法。该算法把被测电路的测试生成问题转化为计算一种约束函数的最优解,可充分利用电路的结构信息。为故障节点生成测试时易于操作,且无需经过故障模拟,就可保证对所有可测的单固定型故障及多故障有较高的故障覆盖率。     

电路测试生成的一种并行处理方法

基于消息传递的多指令流多数据流多机并行系统，提出一种组合电路测试图形生成的新的并行处理方法。该方法首先定义基本门电路的特征函数，通过特征函数的迭加，得到与被测电路对应的一约束网络的特征函数ＣＡＴＰＧ，用遗传算法计算ＣＡＴＰＧ的零点获得故障的测试。     

组合电路伪穷举测试的一种生成算法

提出一种基于电路结构的伪穷举测试生成算法,通过对待测电路的逐步二块划分和对各个子电路的穷举测试,形成待测电路的伪穷举测试集.本算法从实际应用出发,基于电路结构进行选优划分,算法简单,运行速度快.通过这一算法,伪穷举测试能够实现机器自动生成,并充分发挥了伪穷举测试的各项优点,因此具有一定的实用价值.     

组合电路的主值、主值故障及其测试生成

对组合电路连线上的信号值提出用主值Z和辅值F表示,并提出用主值故障和辅值故障表示组合电路中的固定型故障模型.文中阐述了对主值故障进行测试生成的原理方法.该方法使各类基本门电路具有统一形式的功能描述,适用于由多种类型基本门电路构成的组合电路.     

基于神经网络的组合电路测试生成算法

介绍了一种基于神经网络的组合电路测试生成算法。该算法不同于传统的方法是它既不需要回退也不需要故障传播的过程。利用Hopfield神经网络模型将组合电路表示成双向的神经网络，通过故障注入，建立被测电路的约束网络，并构造网络的能量函数，将组合电路的测试矢量对应于神经网络能量函数的最小值点，从而运用遗传算法求解能量函数的最小值点来求得测试矢量。在一些基准电路上的实验结果表明本算法具有较高的故障覆盖率和较短的测试时间。     

一个基于神经网络的测试生成系统

介绍了一个基于组合电路的Hopfield神经网络模型的测试生成系统,系统中运用概率松驰搜索算法求解给定故障的测试矢量。实验结果表明了该系统的可行性。     

片上多处理器的层次化高速测试和验证技术

片上多处理器的体系结构具有高效、低功耗的特点,但由于整体逻辑规模较大,且存储系统有一致性的要求,因此其模拟器测试和验证的计算量大、复杂度高,整体采用传统的形式化测试方法测试速度慢.运用分隔测试技术可以在测试过程中降低整体计算的复杂度,将使用传统测试方法不能测试的复杂系统测试简单化;利用随机程序生成技术可以减少测试人员编写测试程序的时间并加速发现系统的错误,并行测试技术可以快速低功耗检验片上多处理器存储器系统的功能并具有良好的可扩充性.将上述测试方法集成在片上多处理器的测试中,能够对整体的计算量进行合理的分割和并行化,迅速定位整个系统的错误,大大缩减所需要的测试时间,降低了测试人员的工作量,提高测试结果的覆盖率和可信性.     

印制板测试码生成

根据我国自行研制的程控交换机 DS-2000印制板的特点,从工程实用的角度出发,提出了一个面向通路的测试码自动生成算法.该算法已用于实际印制板测试系统中.     

The structure-based multi-fault test generation algorithm for combinational circuit

Testgeneration of integrated circuitis a very activeresearch subject in CAD and digital system fault diag-nosis. With the improvement of the complexity and in-tegrated degree of circuit, the test of digital integratedcircuit becomes harder and harder. Although peoplehave studied this for several years, digital integratedcircuit test is still generally regarded as a difficult prob-lem in international areas at present.For the problem that test patterns are obtained bydetermined finite faults s…     

Research of the test generation algorithm based on search state dominance for combinational circuit

PODEM,FANandSOCRATESalgorithmsallpresentafewstrategiesacceleratingthetestpatterngenerationbasedoncircuitstructure.PODEMalgo rithm[1]introducesbacktrackingtechnology,anditre ferstestgenerationtoanimplicitenumerationprobleminn dimensionalspacesuchthatitbrea…     

Class hierarchical test case generation algorithm based on expanded EMDPN model

A new model of event and message driven Petri network（EMDPN） based on the characteristic of class interaction for messages passing between two objects was extended. Using EMDPN interaction graph, a class hierarchical test-case generation algorithm with cooperated paths （copaths） was proposed, which can be used to solve the problems resulting from the class inheritance mechanism encountered in object-oriented software testing such as oracle, message transfer errors, and unreachable statement. Finally, the testing sufficiency was analyzed with the ordered sequence testing criterion（OSC）. The results indicate that the test cases stemmed from newly proposed automatic algorithm of copaths generation satisfies synchronization message sequences testing criteria, therefore the proposed new algorithm of copaths generation has a good coverage rate.     

基于小波分析的数字电路动态电流测试技术

针对数字电路中常见的晶体管桥接故障,研究了数字电路动态电流测试及定位方法。利用小波包分析技术,提取小波系数中所包含的丰富的时频信息作为故障特征,建立故障字典。实验结果表明,该方法准确、高效,用于数字电路电流检测效果良好。     

Development of hydraulic power unit and accumulator charging circuit for electricity generation, storage and distribution

It is the purpose of the present paper to convert hydraulic energy to electric energy and saves both the pressure and electrical energy for re - use during the next system upstroke using two secondary units coupled to induction motor to drive cylinder loads. During upstroke operation, the variable pump/motor （P/M） driven by both electric motor and the second （P/M） works as hydraulic pump and output flow to the cylinders which drive the load. During load deceleration, the cylinders work as pump while the operation of the two secondary units are reversed, the variable （P/M） works as a motor generating a torque with the electric motor to drive the other （P/M） which transforms mechanical energy to hydraulic energy that is saved in the accumulator. When the energy storage capacity of the accumulator is attained as the operation continues, energy storage to the accumulator is thermostatically stopped while the induction motor begins to work as a generator and generates electricity that is stored in the power distribution unit. Simulations were performed using a limited PT2 Block, i.e. 2nd-order transfer function with limitation of slope and signal output to determine suitable velocity of the cylinder which will match high performance and system stability. A mathematical model suited to the simulation of the hydraulic accumulator both in an open-or close-loop system is presented. The quest for improvement of lower energy capacity storage, saving and re-utilization of the conventional accumulator resulting in the short cycle time usage of hydraulic accumulators both in domestic and industrial purposes necessitates this research. The outcome of the research appears to be very efficient for generating fluctuation free electricity, power quality and reliability, energy saving/reutilization and system noise reduction.     

A new approach to test generation for combinational circuits

Aimed at the generation of high-quality test set in the shortest possible time, the test generation for combinational circuits (CC) based on the chaotic particle swarm optimization (CPSO) algorithm is presented according to the analysis of existent problems of CC test generation, and an appropriate CPSO algorithm model has been constructed. With the help of fault simulator, the test set of ISCAS’85 benchmark CC is generated using the CPSO, and some techniques are introduced such as half-random generation, and simulation of undetected faults with original test vector and inverse test vector. Experimental results show that this algorithm can generate the same fault coverage and small-size test set in short time compared with other known similar methods, which proves that the proposed method is applicable and effective.     

开关短路试验对系统电压影响的仿真研究

分析了中国电科院大功率试验站进行10 kV,50 kA开关短路试验时,对系统清河变电站母线电压的影响。利用MATLAB/Simulink软件对开断试验过程中各母线电压波形的变化情况进行了仿真分析。根据仿真结果得到:在系统正常运行方式下,开关短路试验对系统清河变电站电压影响不大;在系统最小运行方式下,三相短路开关试验将对清河变电站的电压产生较大影响。     

高压断路器合成试验计算机测控系统

介绍了合成试验的基本原理,并重点论述了能够提高合成试验成功率的计算机测控系统。在该测控系统中讲述了采集电流和电压信号的传感元件、对测试系统的隔离保护、信号的放大、信号采集与数据处理、单片机与ＰＣ机的串行通讯,并论述了求取电流有效值的数据处理算法。