US Army Reliability Initiatives?In Concert with Air Force R&M 2000

This paper describes how the US Army is improving readiness through enhanced reliability, availability, and maintainability (RAM). The Army is serious about supplying its personnel with the kind of equipment that stays on line. The US Army Materiel Command is taking aggressive steps to ensure that systems achieve their RAM requirements. Too often the Army has been accused of settling for minimum performance. As is well known, industry is reactive; it responds to pressure to improve what the customer thinks is important. An important step to getting higher levels of reliability and maintainability is to stand together with the Air Force and Navy customers and demand that RAM design and manufacturing disciplines are carried out and contractual RAM requirements are achieved. The achievement of requirements must be accomplished during system development and fielding. Improved RAM results in improved productivity, user satisfaction, and lower operating and support (O&S) costs. Linking R&M initiatives with O&S cost is an important step in justifying the up-front design and manufacturing disciplines that improve field performance. Meeting RAM requirements is the beginning and not the end of Army reliability efforts. Continued efforts to improve RAM are the thrust. For each system, the Army strives for continued improvement. Increased reliability reduces O&S costs while improving fielded mission accomplishment. Contractors will continue their efforts to improve production quality and to eliminate systemic causes of field failures.     

Designing the CF-18 to be operationally ready

Primary Hornet program requirements include improved Operational Readiness (OR) and reduced Life Cycle Cost (LCC) compared to previous tactical aircraft. These requirements were translated into definitive and challenging reliability (R) and maintainability (M) design requirements. This paper describes the design and management techniques used to design superior R and M characteristics into the CF-18. A key to the Hornet's improved Operational Readiness is the firm R and M guarantees which will be demonstrated during the development program. Another important program management feature is the substantial R, M, LCC, and program management incentives (totalling $39M) which the contractor can earn. Principal CF-18 features designed to provide improved reliability include avionics equipment derating, improved cooling of the avionics, and reduced parts in the major subsystems such as radar, engine, and crew station. The Hornet's F404 engine also is designed for simplicity and reliability, being about four times as reliable as the J79. A major factor in achieving this improved CF-18 reliability is designing and testing to a realistic operational mission environment (OME). Most Hornet subsystems were required to complete reliability development testing utilizing this simulated OME. Maintainability features of the CF-18 design include improved equipment access, extensive built-in-test (BIT) and fault isolation, and an auxiliary power unit (APU) for ground maintenance. The Hornet's R and M performance during the flight test program demonstrates that the challenging reliability and maintainability design requirements are being met and often exceeded. The paper concludes with a summary of lessons learned during the Hornet program.     

航天测控设备状态配置和管理方法

针对我国航天测控网设备状态配置和管理方法现状,分析了测控设备任务准备和历史任务恢复节点的现实需要,提出了航天测控设备历史状态宏迁移、设备参数共享以及设备状态集中管理3种方法。通过分析比较,给出了设备状态集中管理和可扩展标记语言( XML)格式设备状态共享方法相结合的实现途径。该方法能够实现设备参数的快速设置和检查以及不同设备之间状态的共享,有利于提高整个测控网的自动化程度和运行效率。     

Reliability and Maintainability Parameters Evaluated with Simulation

In order to achieve a high probability of mission success (reliability), prolonged manned space missions require low failure rates for critical subsystems or components whose failure can be corrected before a mission abort or mission degradation, i.e., in-flight maintenance is one method of increasing mission success probability. In-flight repair or replacement of subsystems, subject to random times to failure, must be made before the maximum subsystem downtime is exceeded. Also, in-flight maintenance must take into account such factors as crew availability, time to repair, redundancy, failure rates, maximum allowable downtimes, and distributions of the preceding factors. The deterministic approach to obtain mission success probability is often too difficult to be applied within budget constraints. Therefore, a computer program was developed to estimate the reliability through simulation. Failures and repairs within a space vehicle were simulated, assuming a specific number of crewmen initially available for repair, constant failure rate, and lognormal repair times. Various parametric and sensitivity analyses of the important parameters were performed to determine their effects on mission success. For example, the effect of a subsystem's mean time between failures on mission success for selected crew sizes (keeping other variables constant) can be shown. An important realistic feature of the program is the associating of a repair priority with each subsystem. A higher priority subsystem can displace a lower priority subsystem already under repair and can be placed ahead of a lower priority subsystem in a waiting queue.     

基于改进粒子群算法的多UAV协同侦察任务规划

针对多无人机（UAV）协同侦察的任务规划问题,充分考虑侦察目标的侦察分辨率和时间窗约束,建立了数学模型;提出了一种改进的粒子群算法,使得粒子群能够较均匀地在问题空间内搜索,避免陷入局部极值,在保持传统PSO算法快速收敛的同时,加强了算法局部搜索能力。基于该模型和优化算法,制定了合理的多UAV协同侦察任务计划,使得多UAV协同侦察任务在满足任务要求、平台性能和战场约束的条件下具有最小代价和最优作战效能。     

Reliability Investment and Life-Cycle Cost

The reliability of avionic equipment profoundly influences life-cycle cost; the level of reliability attained largely depends upon the investment in reliability programs during development. As more investment is made in reliability improvement, some cost elements increase and others decrease. These opposing cost trends yield a unique minimum life-cycle cost (LCC). In order to find the level of investment in a reliability improvement program that minimizes LCC, the Reliability Investment Optimization (RIO) model has been developed. It identifies, for a particular avionic system, the level of reliability investment that minimizes the LCC of the equipment. This model employs a reliability-growth relationship based on the Duane model. The RIO model uses this reliability growth pattern to compute LCC as a function of MTBF (mean time between failures) where LCC comprises: 1) research, development, test and evaluation (RDT&E), 2) procurement, and, 3) operations and support (O&S). The RIO model uses summary level data that are appropriate for the timeframe of its most advantageous use, i.e., prior to detail design of the system. The degree of accuracy for the input parameters need not be high because results are not very sensitive to data accuracy. The model's results thus are quite stable. The RIO model was designed with avionic systems in mind. However, the model applies to a wider range of systems. Certain assumptions should be particularly scrutinized in extending usage beyond avionics, e.g., Poisson demand assumption versus a wearout failure pattern (failure rate increases over time), scheduled maintenance, and LCC element breakdown.     

C~4ISR系统效能层次化评估方法研究

分析了C4ISR系统效能层次化评估方法,以分系统各性能指标作战要求符合度的主客观加权和计算分系统的作战要求符合度,运用信息熵描述作战要求符合程度的不确定性实施各分系统性能评估;分系统性能评估结果作为输入,以C4ISR系统完成作战任务的成功率度量C4ISR系统效能,构造外界因素影响因子矩阵度量外界因素对各分系统信息熵的影响,以及各因素对C4ISR系统整体信息熵影响的权值,结合C4ISR系统信息流串、并联关系聚合各分系统信息熵,实施C4ISR系统效能评估.并基于定性分析构建了C4ISR系统对武器系统效能提升作用的定量函数.最后用实例验证该方法有效性.     

Redundancy optimization for multi-state system with fixedresource-requirements and unreliable sources

This paper considers a redundancy optimization problem for a multi-state system of: (1) elements that consume a fixed amount of resources to perform their task, and (2) a number of resource generating subsystems. The algorithm finds the optimal system-structure, subject to availability constraints, by choosing system elements from a list of available equipment. Each element is characterized by its productivity, availability, and cost. Elements of the main producing subsystem also have their specific resource consumption limitations. The objective is to minimize the sum of investment costs while satisfying demand, represented by a cumulative demand curve, with given probability. To solve the problem, a genetic algorithm is used for optimization. The procedure, based on the universal generating function, is used to evaluate the system-availability while assuming that the working elements of the main producing subsystem are chosen in such a way that the total system performance rate is maximal under given resource constraints. Examples demonstrate how to obtain the optimal structures of a simple 2-level system for various availability constraints     

Autonomic logistics

As was identified in the autonomic nervous system (ANS) analogy key points, an autonomic logistics (AL) approach must know what the optimal state of the system is and what constitutes an actionable deviation from that state. It must also know what to do to remedy that situation. The analysis approach presented will acquire the data to establish the optimal state. A mechanism to monitor and continuously refine the optimal state can then be developed. Like the ANS system, AL is ultimately a reactive system, the key is to strategically and systematically develop a suitable reaction management approach that minimizes system mission or performance risk. The analysis clearly defines the system limitation, expectations, and tolerance constraints. This results in implementation of supportable equipment, processes, and procedures that are better suited to achieve and sustain the desired level of mission success.     

SDXC设备控制系统的设计

基于光电混合交换模块的ＳＤＸＣ设备是为满足未来骨干通讯网络需要而研究的实验性系统，其控制部分需要满足多方面的要求。文章分析了这些要求，产邮控制系统硬件和软件的设计。     

A structured Solar System satellite relay constellation network topology design for Earth‐Mars deep space communications

The deep space exploration missions require high quality of communication performance between the Earth stations and various deep space explorers, such as Mars orbiters and rovers. Due to the difficulties on improving the point‐to‐point physical wireless link capacity, it is necessary to study the relay network communications under the structured idea. In this paper, the structured Solar System satellite relay constellation network is proposed for Earth‐Mars deep space communications, including the mission background, mathematic model, topology design, and performance analysis. The satellite relay constellation could be modelled as a 2‐dimensional structure with multiple concentric circle loops and multiple relate satellites on each loop. With the different optimal objectives as shortest path, minimum hops and minimum nodes required under the constraint threshold distance for each hop, both the Monte Carlo method and modified Shortest Path First algorithms are studied to work out the optimal network topology designs. Simulation results show that, our network topology design could satisfy the requirements on continuous dual‐directional end‐to‐end communications between the Earth and Mars over the whole mission life period and guarantee the performance of end‐to‐end multihop links above the lowest boundary.     

Maintainability Design Requirements for Future Space Systems

Design requirements which consider maintenance capability can be expected to be quite different for space system application when compared to those currently in use for today's weapon systems. Needs will vary, as will the base for the definition of quantized criteria. Maximum urgency is placed on crew safety, mission success, and meeting a launch window. The expressions for quantitative maintainability design criteria will shift from the familiar ``Meantime' base to one of ``Allowable Time,' ``Probability of Repair Within Time Limits,' and ``Expenditure of Human Energy.' This paper explores the operational requirements for maintainability in future space systems, discusses interface problems, and defines quantized maintainability objectives for the different applications of 1) spacecraft, 2) space stations, 3) boosters, and 4) support equipment.     

多无人机系统任务管理研究

针对多无人机系统多目标、多传感任务的复杂管理问题,构建了多无人机系统的任务管理框架.首先采用任务状态与目标相结合的方法生成任务元(目标任务状态),以任务元作为多无人机任务管理的研究对象,简化了系统的复杂性;然后创建了任务元生成与有效性判断方法;最后采用基于主客观偏好值离差最小化的多属性决策方法,解决了任务元优先权排序问...     

外场条件下机载通信系统原位性能测试研究

当前外场只对机载通信设备进行自检、功能检查,内场虽能进行性能测试,但是针对单个设备(子系统)的离位测试,不能反映通信系统的整体性能状态。也就是说,当前外场检查、内场测试均存在一定的局限性,必须寻求在外场条件下对通信系统进行原位性能测试的途径。以某型机载超短波通信系统为例,结合外场实际条件以及部队、厂所维修保障经验,提出了基于天线辐射和线缆连接两种原位性能检测方案。通过对方案设计、指标选取、测试原理及步骤的详细分析研究,结合实际的测试经历,实现了对机载通信系统的系统级性能的全面测试和验证,测试结果和数据对于部队掌握通信系统实际装机状态和更好地进行设备维护具有重要的指导意义。     

Design,Implementation, and Validation of KOMPSAT‐2 Software Simulator

In this paper, we present design features, implementation, and validation of a satellite simulator subsystem for the Korea Multi‐Purpose Satellite‐2 (KOMPSAT‐2). The satellite simulator subsystem is implemented on a personal computer to minimize costs and trouble on embedding onboard flight software into the simulator. An object‐oriented design methodology is employed to maximize software reusability. Also, instead of a high‐cost commercial database, XML is used for the manipulation of spacecraft characteristics data, telecommand, telemetry, and simulation data. The KOMPSAT‐2 satellite simulator subsystem is validated by various simulations for autonomous onboard launch and early orbit phase operations, anomaly operation, and science fine mode operation. It is also officially verified by successfully passing various tests such as the satellite simulator subsystem test, mission control element system integration test, interface test, site installation test, and acceptance test.     

红外车辆分离子系统的设计和性能分析

在机动车磁卡收费系统中,红外车辆分离子系统是一种重要设备,它是由平行等距红外线族构成的平面检测系统,其性能直接影响收费系统的正常运转。本文介绍该子系统的设计并对系统性能进行分析,得出:子系统采取相关检测技术后,不仅能有效地抑制外界干扰、噪声,还具有抗相邻红外信号干扰能力。     

智能烟草工厂底层物联设备远程检修系统设计

针对烟草工厂底层物联设备检修体系落后,设备检修效率低的问题,设计智能烟草工厂底层物联设备远程检修系统.采集现场设备运行数据,并将采集的数据存储至设备故障经验知识库,应用故障专家子系统调用设备故障经验知识库的数据信息,实时监控现场设备运行状态;利用故障树最小割集的故障诊断方法,诊断智能烟草工厂底层物联现场设备,依据诊断结...     

C^4 ISR系统效能层次化评估方法研究

分析了C^4ISR系统效能层次化评估方法,以分系统各性能指标作战要求符合度的主客观加权和计算分系统的作战要求符合度,运用信息熵描述作战要求符合程度的不确定性实施各分系统性能评估;分系统性能评估结果作为输入,以C^4ISR系统完成作战任务的成功率度量C^4ISR系统效能,构造外界因素影响因子矩阵度量外界因素对各分系统信息熵的影响,以及各因素对C^4ISR系统整体信息熵影响的权值,结合C^4ISR系统信息流串、并联关系聚合各分系统信息熵,实施C^4ISR系统效能评估。并基于定性分析构建了C^4ISR系统对武器系统效能提升作用的定量函数。最后用实例验证该方法有效性。