基于FPGA的故障修复演化技术研究

演化硬件的自修复特性能够有效解决电路系统的可修复性故障,但演化硬件存在电路演化速度慢、演化成功率不高的缺陷,如何在修复约束期限内完成电路演化成为关键难点。提出一种基于演化硬件的实时系统容错架构,通过建立故障树实时监测电路故障,利用故障补偿机制维持系统正常运行,并采用演化硬件技术修复电路故障,实现故障的在线实时修复。采用FPGA构建容错系统测试环境,通过随机故障注入对比验证不同演化算法的自修复能力,实验结果表明,在实时性约束下故障电路的修复率达到95%,有效提升了系统的稳定性和可靠性。     

可重构系统的演化修复机制

利用演化算法实现系统自修复是一种新的容错设计思路,但是演化是一个非常耗时的过程.已有的演化容错系统多属于静态演化,演化过程仅发生在系统设计阶段,系统在运行过程中不具有演化修复的能力.这类演化容错系统虽然可以避免演化耗时,但是只能修复已知错误,无法修复未知错误.针对上述问题,文中提出一种基于动态演化的修复机制,容错系统采用可重构系统和被检测系统的耦合设计方案.当被检测系统出现故障时,可重构系统通过系统演化实现在线自修复.为了减少演化耗时,系统根据错误类型采取不同措施:如果出现已知错误,系统直接在预置配置库中搜索修复配置;如果出现未知错误,则通过动态演化在线生成修复配置,并更新预置配置库.最后,将该容错设计方案用于典型电路的故障模式.实验结果表明,文中提出的演化修复机制提高了系统运行的实时可靠性,预置配置库设计减少了演化耗时.     

基于硬件演化的电子电路故障自修复研究综述

阐述了硬件演化的基本原理, 对基于硬件演化的故障自修复国内外现状作了详细的介绍, 对故障自修复中重要的步骤作了说明, 并指出了目前存在的问题和改进的方向。基于硬件演化的故障自修复必将具有广阔的前景和重大的工程应用价值。     

基于独立演化系统的演化硬件实验

演化硬件是指能利用进化算法实现自修复和自适应的硬件。融合了电路自动设计、可重构硬件、人工智能和自治系统等相关内容它不仅是一种具有自适应与自修复特性的仿生物态硬件电路,是新兴的仿生电子学的主要研究内吝之一,而且是一种新颖的硬件设计思想与方法。该文设计了一种基于FPTA的DSP独立演化系统,并对外部演化结果进行下载测试,实现了对外部演化结果的检验通过测试证明该演化系统适用于FPTA单细胞或多细胞演化实验。     

基于独立演化系统的演化硬件实验

演化硬件是指能利用进化算法实现自修复和自适应的硬件。融合了电路自动设计、可重构硬件、人工智能和自治系统等相关内容。它不仅是一种具有自适应与自修复特性的仿生物态硬件电路,是新兴的仿生电子学的主要研究内容之一,而且是一种新颖的硬件设计思想与方法。该文设计了一种基于FPTA的DSP独立演化系统,并对外部演化结果进行下载测试,实现了对外部演化结果的检验。通过测试证明该演化系统适用于FPTA单细胞或多细胞演化实验。     

基于演化硬件的容错电路设计与实现

在讨论了电磁仿生和演化硬件内进化运行机制的基础上,引进虚拟可重构电路技术,完成了演化平台的设计和容错电路的实现;在传统CGP模型上改进加入(1+λ)演化策略,采用内进化方式,在注入部分虚拟固定故障的条件下,实现了2位乘法器容错电路的演化生成,多次实验得出的平均演化代数约在11000代左右;从而为研究电路的在线演化和自修复工作提供有效的技术支持,为提高电子系统在复杂电磁环境下的抗扰和防护能力提供了新的途径。     

基于EHW和RBT的不同类型故障快速修复策略

由于常规的基于EHW的故障自修复策略存在故障修复类型单一、面对大规模电路修复速度慢、不能实时快速自适应的修复故障等问题,在前期工作中提出了基于EHW和RBT的故障自修复策略。基于此,本文对不同故障类型下的故障快速修复策略进行了研究。由于不可能预知实时检测到的故障类型,在本文的自适应修复策略中,统一将检测到的故障作为固定型故障进行修复。演化算法根据故障信息演化矫正电路,MUX根据实时检测到的故障信息进行开断,从而保证UUT的正常运行。通过实例仿真证明,本文提出的快速修复策略的可行性和有效性得到了验证。     

基于TMR-EHW的高可靠性电机控制系统

为提高恶劣环境中控制系统的可靠性,将三模块冗余（TMR）容错与演化硬件（EHW）自修复相结合,实现基于TMR—EHW结构的现场可编程门阵列电机控制系统。该系统利用TMR快速发现和定位故障,屏蔽出错模块并保持容错运行,利用EHW进行自修复,使出错模块恢复正常工作,系统可靠性得到提高。     

基于虚拟可重构电路的演化平台设计

在讨论了电磁仿生和演化硬件内进化运行机制的基础上,针对复杂电磁环境下电子系统的可靠性问题进行研究.为实现系统功能自修复,引进虚拟可重构电路技术,设计并实现了演化平台.在传统CGP模型上改进加入(1+λ)演化策略,采用内进化方式,完成了2位乘法器的演化,实验得出的平均演化代数约在550代左右,证明了此平台的可行性和快速性.从而为研究电路的演化生成和自修复工作提供有效的实验环境,为提高电子系统在复杂电磁环境下的抗扰和防护能力验证了新的途径.     

基于多维属性的构件化软件演化相似性度量方法研究

对不同软件进行演化相似性度量和比较能帮助软件维护人员理解软件演化及预测其演化趋势。然而,传统的研究大多度量单一软件演化属性的变化,虽然有些也涉及到多维演化属性,但并没有与软件的演化相似性相联系;同时亦缺乏在较高抽象层次度量软件演化相似性的有效途径。为此,以构件为基本单位,提出了一种基于多维演化属性的构件化软件演化相似性度量模型。即通过在原子构件层和系统(复合构件)层定义演化属性,进而度量原子构件之间以及系统(复合构件)之间的演化相似性。初步的实验表明,在原型工具的支持下该方法能辅助软件维护人员进行软件演化相似性的判断。     

Evolutionary design and adaptation of high performance digital filters within an embedded reconfigurable fault tolerant hardware platform

Finite impulse response filters (FIRs) are crucial devices for robust data communication and manipulation. Multiplierless filters have been shown to produce high performance systems with fast signal processing and reduced area. Furthermore, the distributed architecture inherent in multiplierless filters makes it a suitable candidate for fault tolerant design. Alternative approaches to the design of fault tolerant systems have been proposed using evolutionary algorithms (EAs) and the concept of evolvable hardware (EHW). This paper presents an evolvable hardware platform for the automated design and adaptation of multiplierless digital filters. Filters are realised within a dedicated programmable logic array (PLA) based on the Primitive Operator Filter design principle. The platform employs a genetic algorithm to autonomously configure the PLA for a given set of coefficients. The ability of the platform to adapt to increasing numbers of faults was investigated through the evolution of a 31-tap low-pass FIR filter. Results show that the functionality of filters evolved on the PLA was maintained despite an increasing number of faults covering up to 25% of the PLA area. Additionally, three PLA initialisation methods were investigated to ascertain which produced the fastest fault recovery times. It was shown that seeding a population of random configuration-strings with the best configuration currently obtained resulted in a 6 fold increase in fault recovery speed over other methods investigated.     

基于MATLAB的自修复飞控系统仿真

可靠性和可维护性是当代飞控系统面临的首要问题,自修复飞控系统在解决这两方面问题的同时,提高了飞机的生存能力。采用ＭＡＴＬＡＢ仿真语言,开发出自修复飞控系统仿真平台,实现了收音机的全面运动仿真。同时,根据自修复飞控系统的需要,可进行了收音机故障的加载,以及对故障进行检测、隔离和估计,然后完成飞行重构,具备了完整的自修复飞控系统信息功能。     

基于进化硬件的自修复TMR系统设计及其可靠性分析

将进化硬件与传统TMR容错设计思想相结合,提出了一种具有在线自修复功能的自修复TMR系统设计方法。该系统具有多重容错和修复机制:总体采用TMR,可自动检测到故障模块;系统中每个模块均采用组件备份法,可通过组件切换法快速修复模块故障;而模块中每个组件也可通过进化进行修复。因而具有更强的容错能力和更高的可靠性。以具有片内三模冗余的2 bit乘法器为例进行了验证。最后,给出了该系统的可靠性模型,推出了可靠性计算公式,从理论上对该系统的可靠性进行了分析。结果表明:该系统能有效修复stuck-at故障,具有更长的使用寿命和更高的可靠性。     

一种用于白盒测试评估的错误播种方法

软件错误播种方法不仅可以用来评价软件的性能和研究软件错误的特性，而且还可通过播种错误为软件测试方法的评估提供必要的条件。考虑到白盒测试所针对的错误类型是程序代码级错误，为了方便错误播种，将程序代码错误分为计算型错误、域错误和程序接口错误，并针对这3类错误提供了一种改进的基于程序变异的软件错误播种方法。     

结构残差在基于SDG故障分离中的应用

符号有向图（SDG）是大规模复杂系统中故障传播关系的描述模型,但它仅能通过在相容通路上的定性推理进行故障分离,因此有着明显的局限性。而结构残差是定量故障分离的成熟方法,将其引入基于SDG的故障分离中,用以提高系统故障分离的能力,弥补SDG方法的不足。具体的做法是将SDG转化为结构残差的描述形式,再利用结构残差的基本思想,分别就变量是否完全可检测的情况给出了具体的故障分离方法。这样做可以提高系统故障分离的鲁棒性和准确性。应用实例表明,该方法可通过残差计算,准确判断故障源,实现故障分离。     

The customizable fault/error model for dependable distributed systems

Dependability is a qualitative term referring to a system's ability to meet its service requirements in the presence of faults. The types and number of faults covered by a system play a primary role in determining the level of dependability which that system can potentially provide. Given the variety and multiplicity of fault types, to simplify the design process, the system algorithm design often focuses on specific fault types, resulting in either over-optimistic (all fault permanent) or over-pessimistic (all faults malicious) dependable system designs.A more practical and realistic approach is to recognize that faults of varied severity levels and of differing occurrence probabilities may appear as combinations rather than the assumed single fault type occurrences. The ability to allow the user to select/customize a particular combination of fault types of varied severity characterizes the proposed customizable fault/error model (CFEM). The CFEM organizes diverse fault categories into a cohesive framework by classifying faults according to the effect they have on the required system services rather than by targeting the source of the fault condition. In this paper, we develop (a) the complete framework for the CFEM fault classification, (b) the voting functions applicable under the CFEM, and (c) the fundamental distributed services of consensus and convergence under the CFEM on which dependable distributed functionality can be supported.     

模糊聚类与SVM诊断模拟电路单软故障的方法

针对低可测性模拟电路中存在的模糊组问题,提出一种模拟电路单个软故障诊断的方法．该方法对被测电路的故障进行模糊聚类,根据聚类的有效性指标自适应确定聚类数,并利用聚类的信息来确定可测元件集,引入支持向量机对故障进行分类识别．支持向量机结构简单、泛化能力强．最后,以模拟和混合信号测试标准电路证实了文中方法的有效性．     

On the Use of Functional Test Generation in Diagnostic Test Generation for Synchronous Sequential Circuits

We study the relationship between diagnostic test generation for a gate-level fault model, which is used for generating diagnostic test sets for manufacturing defects, and functional test generation for a high-level fault model. In general, a functional fault may partially represent some of the effects of one gate-level fault but not another. Generating a test sequence for the functional fault is then likely to detect one gate-level fault but not the other, thus distinguishing the two faults. This relationship points to the ability to use a functional test generation procedure (that targets functional fault detection) as a way of generating diagnostic test sequences for gate-level faults. We use this observation in two ways. The more direct way is to define functional faults that correspond to the differences between pairs of gate-level faults. The second way is to use functional test sequences as diagnostic test sequences without explicitly considering gate-level faults. We support the use of the resulting procedures with experimental results.     

A Novel Robust Attitude Control for Quadrotor Aircraft Subject to Actuator Faults and Wind Gusts

A novel robust fault tolerant controller is developed for the problem of attitude control of a quadrotor aircraft in the presence of actuator faults and wind gusts in this paper. Firstly, a dynamical system of the quadrotor taking into account aerodynamical effects induced by lateral wind and actuator faults is considered using the Newton-Euler approach. Then, based on active disturbance rejection control (ADRC), the fault tolerant controller is proposed to recover faulty system and reject perturbations. The developed controller takes wind gusts, actuator faults and measurement noises as total perturbations which are estimated by improved extended state observer (ESO) and compensated by nonlinear feedback control law. So, the developed robust fault tolerant controller can successfully accomplish the tracking of the desired output values. Finally, some simulation studies are given to illustrate the effectiveness of fault recovery of the proposed scheme and also its ability to attenuate external disturbances that are introduced from environmental causes such as wind gusts and measurement noises.