Mission reliability of an automatic control system integrated with distributed intelligent built-in-test systems

This paper introduces distributed-centralized Built-in-Test (BIT) systems interfaced with an automatic control system with the purpose of improving mission reliability. By Using a block diagramming method, a complicated system is decomposed into mutually exclusive subsystems so that a distributed BIT is connected to each subsystem for multiple parallel processing of fault direction. The data produced by the distributed BITs is sent to a central control processor. We present a Markov process approach to analytically derive the mission reliability of an automatic control fault-tolerant system with distributed BITs. As diagnostic mistakes of the BIT, the false alarm and fault missing of BIT are considered with the malfunction of the BIT itself. Numerical examples are also prepared to evaluate the performance of distributed intelligent BITs, by comparing mission reliabilities corresponding to the variation of design parameters in a time domain.     

独立故障串并联控制系统可靠性的最优化研究

研究了独立故障的串并联复式控制系统在单个或多个约束条件下的可靠性最优化问题。从系统的物理概念出发,提出了一种混合方法。按照连续变量平衡提高各级串联环节的可靠性,分析得出了在约束条件下各个环节的并联个数的计算公式和简化计算思路。     

独立备用电源供电系统在航空器上的应用

介绍了独立备用电源供电系统在航空器上的应用与研究,包括独立备用电源的总体结构、工作原理、运行模式、系统BIT自检测以及RS232接口.独立备用电源供电系统在航空器发生电源故障断电时对于人员的疏散有着重要作用.     

新型防化发烟车RMST一体化设计与关键技术分析

针对我军装备可靠性维修性保障性测试性（RMST）设计中存在的问题,着眼防化发烟车任务特点和使用保障需求,提出将能执行任务率指标引入到新型发烟车RMST设计研制中,创建适用于防化发烟车的RMST设计流程、一体化设计定量指标体系和顶层参数数学模型,并对涉及到的系统工程设计、综合权衡优化、指标调整分配等关键技术进行分析。本文可为提高新型防化发烟车RMST设计水平提供一定的研究基础。     

Computer aided reliability for optimum maintenance planning

Computer aided Maintenance planning for mechanical equipment is presented in this work to implement the optimized extensive maintenance plan at a specific time horizon. The objective is to interchange the unscheduled corrective maintenance into scheduled preventive maintenance depending on historical data of equipment. This work is concerned with development of reliability analysis based on Weibull distribution. An optimization technique has been developed to provide the optimized preventive maintenance plan for the whole equipment during a required time horizon.     

基于Linux的双机热备系统设计

研究了双机热备技术,并创新性地运用双机热备技术设计了一个安全、实时的热备linux系统.通过双机热备技术在系统中的应用,提高了系统运行的安全性、稳定性,确保工作的正常运行.     

面向通信领域的主备倒换与数据同步技术

主备倒换是确保通信系统稳定、可靠运行的关键技术。提出了一种面向通信领域的主备倒换设计方案,并对其关键技术——主备数据同步进行了深入的研究。     

Application of reliability-based optimization to earth-moving machine: hydraulic cylinder components design process

Reliability-based design optimization (RBDO) incorporates probabilistic analysis into optimization process so that an optimum design has a great chance of staying in the feasible design space when the inevitable variability in design variables/parameters is considered. One of the biggest drawbacks of applying RBDO to practical problem is its high computational cost that is often impractical to industries. In search of the most suitable RBDO method for industrial applications, we first evaluated several existing RBDO approaches in details such as the double-loop RBDO, the sequential optimization and reliability assessment, and the response surface method. Then, based on industry needs, a platform incorporating/integrating the existing algorithm of optimization and reliability analysis is built for a practical RBDO problem. Effectiveness of the proposed RBDO approach is demonstrated using a simple cantilever beam problem and a more complicated industry problem.     

Reliability-driven deployment optimization for embedded systems

One of the crucial aspects that influence reliability of embedded systems is the deployment of software components to hardware nodes. If the hardware architecture is designed prior to the customized software architecture, which is often the case in product-line manufacturing (e.g. in the automotive domain), the system architect needs to resolve a nontrivial task of finding a (near-)optimal deployment balancing the reliabilities of individual services implemented on the software level.In this paper, we introduce an approach to automate this task. As distinct to related approaches, which typically stay with quantification of reliability for a specific deployment, we target multi-criteria optimization and provide the architect with near-optimal (non-dominated) deployment alternatives with respect to service reliabilities. Toward this goal, we annotate the software and hardware architecture with necessary reliability-relevant attributes, design a method to quantify the quality of individual deployment alternatives, and implement the approach employing an evolutionary algorithm.     

A bi-objective approach for shortest-path network interdiction

In the literature, solution approaches to the shortest-path network interdiction problem have been developed for optimizing a single figure-of-merit of the network configuration when considering limited amount of resources available to interdict network links. This paper presents a newly developed evolutionary algorithm that allows approximating the optimal Pareto set of network interdiction strategies when considering bi-objective shortest path problems. Thus, the paper considers the concurrent optimization of two objectives: (1) maximization of shortest-path length and (2) minimization of interdiction strategy cost. Also, the paper considers the transformation of the first objective into the minimization of the most reliable path reliability. To solve these multi-objective optimization problems, an evolutionary algorithm has been developed. This algorithm is based on Monte Carlo simulation, to generate potential network interdiction strategies, graph theory to analyze strategies’ shortest path or most reliable path and, an evolutionary search driven by the probability that a link will appear in the optimal Pareto set. Examples for different sizes of networks and network behavior are used throughout the paper to illustrate and validate the approach.     

A duality based framework for integrating reliability and precision for sensor network design

In sensor network design literature, requirements such as maximization of the network reliability [Y. Ali, S. Narasimhan, Sensor network design for maximizing reliability of linear processes, AIChE J. 39 (1993) 820–828; Y. Ali, S. Narasimhan, Redundant sensor network design for linear processes, AIChE J. 41 (1995) 2237–2249] and minimization of cost subject to precision constraints [M. Bagajewicz, Design and retrofit of sensor networks in process plants, AIChE J. 43 (1997) 2300–2306; M. Bagajewicz, E. Cabrera, New MILP formulation for instrumentation network design and upgrade, AIChE J. 48 (2002) 2271–2282] have been proposed as a criteria for optimally locating sensors. In this article, we show that the problems of maximizing reliability and maximizing precision (or minimizing variance) for linear processes are dual of each other. To achieve this duality, we propose transformations which can be used to convert sensor failure probabilities into equivalent sensor variances and vice versa. Thus, the duality enables working in a single framework with specified criteria on reliability as well as precision. As an application of this duality, we propose two formulations for the sensor network design problem viz., maximization of the network reliability subject to precision constraints and minimization of the network variance subject to reliability constraints. We also show the utility of these formulations to determine the pareto-front for the combinatorial sensor network design problem. Hydrodealkylation and steam-metering case studies are used to illustrate the proposed ideas.     

Enhancing rubber component reliability by response model

Product reliability, which is a dynamic quality characteristic, meaning that it is a function of time, is a determinant of manufacturer competitiveness. Multiple quality characteristics must be simultaneously considered in improving product reliability, because of these quality characteristics exhibiting a high correlation with product reliability. Therefore, enhancing the static quality characteristic of a product is essential for improving product reliability, particularly for formulating rubber components. For example, improving the reliability of oil seal components requires first simultaneously optimizing multiple quality characteristics, including hardness, tensile strength, and elongation, and so on. The subsequent reliability test is performed once these quality characteristics meet or exceed their specifications. This study primarily aims to improve the reliability of rubber components accounting for six-sigma quality level via the response model. The influences of noise factors are considered in experiment planning, and the effects of magnitude of process shift are involved in the optimization procedure to obtain a robust static quality characteristic and thus upgrade the reliability of rubber components. An experiment involving the formulation of oil seal demonstrates the effectiveness of this study.     

基于XML的无人机任务链模型

对无人机系统地面任务控制站与飞行器通信协议中的任务链进行了研究。根据功能将任务链分为航路计划、传感器计划、通信计划和控制权限交接计划4个部分,建立了能够支持复杂任务的任务链模型。采用XML语言对任务链进行表达,增强了任务链的标准性和通用性。最后实现了任务控制站通过任务链控制多架无人机协同执行任务的仿真。     

减小运行时优化开销的方法

运行时优化在程序运行期间,根据采集到的相关信息,确定程序的热点并进行优化,从而加速程序的执行。然而,运行时优化本身有一定的开销,有时候会抵消甚至超出优化得到的效果。该文设计和实现了一个基于SMP/IPF(英特尔安腾系列)/Linux架构的自适应二进制代码优化/编译框架,其中包含了运行时优化。分析了运行时优化的阶段和开销,并介绍了在设计和实现该框架的过程中,为减小这种开销所提出的思路和采用的方法。     

TCP／IP网络通信中TCP段大小的优化设计

讨论了在网络文件传输过程中ＴＣＰ段大小的最优化问题,给出了网络传输可靠因子的一般表达式,最后,得出了最优ＴＣＰ段大小与网络可靠因子的关系。     

非概率可靠性理论在机械臂架设计中的应用分析

以轮式起重机六边形箱形截面臂架为对象,对1 0 0吨汽车起重机椭圆截面臂架进行非概率可靠性优化,使其强度、刚度和稳定性满足非概率可靠度的条件下,重量最轻;并对椭圆截面中的大圆直径、顶边长度和圆心到顶边距离三者关系进行了分析,得出三者协同变化及独自变化时对臂架重量和可靠度的影响,为设计者提供了有力的参考依据。     

Optimizing a mail-order with discount and shipping costs

We address the problem of minimizing the total cost of a mail-order if a customer can choose among different companies. These companies may offer the items in his shopping list at different prices, and they add some charges or give discount, depending on the total value of ordered goods. While this optimization problem is hard in general, we show that it can be efficiently solved for some typical discount policies, either exactly or by invoking an approximation scheme for the Knapsack problem.     

弧焊焊机安全待机电源控制技术研究

针对弧焊焊机空载过程中存在的待机能耗和待机安全问题,提出了一种新颖的实现方案,给出了该方案的硬件结构图和软件流程图,从理论上分析了此方案产生的待机能耗,建立了能耗模型,从而彻底解决了弧焊焊机待机能耗和待机安全。