Air traffic management design considerations

An air traffic management system (ATMS) is a network-centric system being used to manage another network-centric system, namely, an air transportation system. We are developing a design language for network-centric systems and design guidelines for the development system of engineers and domain specialists involved in designing and integrating systems. Note: this development system with today's technology is also a network-centric system. An outline of the design language under construction and the design guidelines being studied is provided. Specifically we discuss ATMS mission objectives (e.g., average yearly throughput of people and freight for a high demand scenario); ATMS sample usage scenarios (e.g., ATMS reroutes air traffic in time and space in reaction to major weather deviation along the northeast coast); and system objectives for an ATMS (e.g., timelines of a specific high volume of messages from aircraft, weather sensors, and airports). We lay out some key design decisions associated with both the development system of engineers and domain specialists and the operational ATMS. Examples of key design decisions for the engineering system are: 1) appropriate partitioning of functional/physical architectures of the engineering system; 2) appropriate degree to telecollaboration and collaboration among design/integration groups; 3) appropriate incremental delivery packages for an incremental delivery schedule of ATMS elements; and 4) appropriate levels and thrusts of the risk management program. Examples of key design decisions for the operational ATMS are: 1) throughput and security trades of the ATMS and 2) throughput and resiliency to weather changes. Finally, we relate network-centric architecture issues to both of the above sets of design decisions.     

一种空间超大型可展开柔性聚光器

面向空间太阳能电站（SSPS）对大口径太阳能聚光器的应用需求,提出一种超大型、轻量化、高精度的空间可展开柔性聚光器的新构型。采取理论建模、计算仿真、优化设计相结合的方法对其抛物面构型原理、展开机构折展原理、展开态结构稳定性、动态聚焦精度等问题进行研究,并完成大口径可展开柔性聚光器的设计。提出了基于多层弹性花瓣镜体复合结构的大口径柔性聚光器优化创新设计方法。由于采用薄板柔索结构,本聚光器具有精度高、展收体积比大、质量轻、在线控制简单等优点,为空间太阳能电站千米级聚光器提供一种创新设计方法。     

Algorithm of calculating the light airplane flight performance and rational design airscrew parameters at the preliminary design stage

A technique is proposed of calculating the characteristic flight velocities for an airplane with taking into account the nominal performance of a piston engine. We consider an algorithm of design calculation for the airscrew blade geometry (twist angle, chord and optimal angle of attack along blade). Feasible rational versions of design parameters are discussed.     

Active phased array design for high reliability

We discuss strategies for designing: active phased array antennas with high reliability. We show how to consider fault-tolerance in the design of the antenna architecture, so that replacement of failed components can be avoided for an extended period of time. First, we address the dependence of antenna life cycle cost on component failure rates. Then we discuss the design of active phased array architecture for maximizing antenna mean-time-between-failures (MTBF). The antenna MTBF is defined in terms of a specified degradation in peak sidelobe level. We present simulated data showing the effect of random, single, and clustered element failures on the peak sidelobe level of a low sidelobe antenna aperture. We use these data as a basis for analyzing various phased array architectures in terms of their antenna MTBF     

Alternative statements of optimal load-bearing structure design problems

We analyze the well-known statements of optimal design problems for load-bearing maximum rigidity structures in which a principle of the minimum of total potential energy of structure deformation is used. A version of the generalized statement of optimization problems for processes described by linear equations with a symmetric operator is proposed. On the basis of the version outlined, we present a mathematical algorithm for obtaining beam structures of maximum rigidity, in which the finite element method is used to solve an analytical problem. We give the numerical results of solving two problems of optimal design of maximum rigidity structures that are simulated by cantilever and statically indeterminate beams.     

Waveform Design for Multistatic Radar Detection

We derive the optimal Neyman-Pearson (NP) detector and its performance, and then present a methodology for the design of the transmit signal for a multistatic radar receiver. The detector assumes a Swerling I extended target model as well as signal-dependent noise, i.e., clutter. It is shown that the NP detection performance does not immediately lead to an obvious signal design criterion so that as an alternative, a divergence criterion is proposed for signal design. A simple method for maximizing the divergence, termed the maximum marginal allocation algorithm, is presented and is guaranteed to find the global maximum. The overall approach is a generalization of previous work that determined the optimal detector and transmit signal for a monostatic radar.     

混料线性对数比模型的D-最优试验设计

混料问题我们可以在医药、化工、农业等诸多领域中经常遇到。对于该问题在1984年由Aitcison和Bacon-Shone提出了线性对数比模型。针对设计空间为的线性对数比模型，已有D-最优设计的分析形式的解并由关颖男教授给出了A-最优设计。作者针对另一个设计空间的混料线性对数比模型，给出了D-最优设计以及最优配置件。并利用D-最优准则讨论了该线性对数比模型的最优解是在Z集合的顶点处取得。     

Design and integration of a solar AMTEC power system with anadvanced global positioning satellite

A 1,200-W solar AMTEC (alkali metal thermal-to-electric conversion) power system concept was developed and integrated with an advanced global positioning system (GPS) satellite. The critical integration issues for the SAMTEC with the GPS subsystems included: (1) packaging within the Delta II launch vehicle envelope; (2) deployment and start-up operations for the SAMTEC; (3) SAMTEC operation during all mission phases; (4) satellite field of view restrictions with satellite operations; and (5) effect of the SAMTEC requirements on other satellite subsystems. The SAMTEC power system was compared with a conventional planar solar array/battery power system to assess the differences in system weight, size, and operations, Features of the design include the use of an advanced multitube, vapor anode AMTEC cell design with 24% conversion efficiency, and a direct solar insolation receiver design with integral LiF salt canisters for energy storage to generate power during the maximum solar eclipse cycle, The modular generator design consists of an array of multitube AMTEC cells arranged into a parallel/series electrical network with built-in cell redundancy. Our preliminary assessment indicates that the solar generator design is scaleable over a 500 to 2,500-W range. No battery power is required during the operational phase of the GPS mission. SAMTEC specific power levels greater than 5 We/kg and 160 We/m² are anticipated for a mission duration of 10 to 12 years in orbits with high natural radiation backgrounds     

Reconfiguration of flight control systems for actuator failures

We consider the problem of designing fault tolerant control for transient failures in the flight control system caused by harsh electromagnetic environments. We examine principles of fault tolerant design and discuss integrated local supervisory control of these systems. As an example, we present a sample design of a control mixer to achieve fault tolerance in the event of failures in the actuators     

Asynchronous router specification

We describe the application of three formal design tools to a case study in the design of a distributed system. The case study in question involves the specification of an asynchronous message router; the three design tools are process algebra (specifically Milner's Calculus of Communicating Systems CCS), the modal μ-calculus and the Edinburgh Concurrency Workbench (CWB). We demonstrate how an informally-presented specification can be formalised within the language of the modal μ-calculus, allowing for a rigorous mathematical analysis of the correctness of our proposed implementation. For modest-sized versions of the router, this correctness proof has been carried out using the CWB     

基于遗传算法的起落架布局设计技术

起落架布局是飞机概念设计阶段十分重要的一环。本文基于遗传算法原理进行起落架布局设计,利用设计中的限制条件和设计经验,确定起落架布局参数的设计空间,通过遗传算法的并行计算,依据目标函数快速高效地确定起落架布局设计的最优方案。     

复杂组合曲线的设计与拟合——重节点B样条法

本文在非均匀B样条的基础上,采用重节点方法设计和拟合复杂组合曲线。对于各种不同的重节点情况,解决了反求特征多边形顶点时线性方程组的降秩问题,并建立了统一表达式。由于考虑到使用中可能遇到的各种情况,程序通用性强,使用方便,能快速地拟合、设计、修改复杂组合曲线,为计算机辅助几何设计与绘图中应用B样条提供了一种具有较大灵活性的方法。     

好设计（GOOD DESIGN）的思索

面对新世纪的挑战,科技的飞速发展,竞争的日益激烈,中国的工业设计不应该停留在对西方的渴望和激情上,应该有所反省并从理论、观念上有所突破。“入世”的迫在眉睫,更应该使我们增加冷静、理性的思考和分析,在进行功能、形式创新的同志,还要增加我们的预测、创造、审美综合能力,时刻抓住市场对“好设计” 的企盼,做出让消费者感到惊喜和喜爱的设计来。     

Predictive information design for the novel generation of display for the highly-augmented aircraft

We consider the task of predictive information design allowed for improvement of flying qualities in precise tracking tasks, in particular for the landing of an aircraft, the dynamics of which is characterized by the transportation time delay.     

Decentralized detection over multiple-access channels

We study the decentralized detection problem in a general framework where arbitrary number of quantization levels at the local sensors are allowed, and transmission from the sensors to the fusion center is subject to both noise and interchannel interference. We treat both Bayesian and Neyman-Pearson approaches to the problem, and develop an iterative descent algorithm to design the optimal quantizers and fusion rule. Some numerical examples for both approaches are also presented     

关于新一代飞机的设计载荷

设计载荷是确定飞机结构重量和保证安全的重要因素。常规操纵系统飞机的设计载荷都是由现行的强度规范规定的。但是对于采用主动控制技术和复合材料的高机动飞机,现行的规范已不合适。在过去10年中,飞机界的专家对此问题进行了大量研究。本文根据北约公开的材料介绍这些研究工作。本文首先评述了现有规范并指出其不足,然后讨论了安全系数。为确定主动控制的新飞机的设计载荷,介绍了3种方法,即概率法、作战飞行参数法和飞行参数包线法及其在EF2000飞机设计中的应用;还介绍了飞机设计的各种动载荷;最后提出了确定我国新一代飞机设计载荷的建议。     

Optimal motion planning for dual-spacecraft interferometry

We address the question of design and optimal control of a class of dual-spacecraft interferometric imaging formations. The first main contribution is that we combine two ideas introduced separately in the literature and propose a maneuver that offers improved imaging performance. We then formulate an optimal control problem to minimize fuel consumption and maximize image quality by minimizing the relative speed, which is proportional to the signal-to-noise ratio (SNR) of the reconstructed image. We show that the necessary conditions are also sufficient and that the resulting optimal control is unique. Finally, we apply a continuation method to solve for the unique optimal trajectory.     

The LDA ? An Integrated Diagnostics Tool

In this paper we describe the Logic Designer's Apprentice (LDA). The LDA is a knowledge-based computer program (an ``expert system') that designs digital electronic circuits. The LDA extends existing CAD/CAE capabilities by providing a computer aid to the design process, supplementing those that assist the drafting, layout, and simulation processes. It seeks to ensure that appropriate testability (and in the future, other ``ility') features are incorporated during the earliest stages of design in accord with the guidelines defined for Integrated Diagnostics. We discuss issues relevant to the engineering development of other knowledge-based tools needed for Integrated Diagnostics including tool selection and choice of knowledge representation.     

巡航导弹航向规避弹道的优化设计

航向规避弹道的设计可视为一个多约束的优化问题。对此，通过选择导弹到达每个航路点的时间，用两点约束问题代替多点约束问题，得出了控制能量最优解，并分析了弹道特性。计算结果表明，弹道曲线在不超出导弹可用过载的前提下，通过所有航路点，并满足落点要求。该方法可用于航迹规划研究。     

Optimal Data Fusion in Multiple Sensor Detection Systems

There is an increasing interest in employing multiple sensors for surveillance and communications. Some of the motivating factors are reliability, survivability, increase in the number of targets under consideration, and increase in required coverage. Tenney and Sandell have recently treated the Bayesian detection problem with distributed sensors. They did not consider the design of data fusion algorithms. We present an optimum data fusion structure given the detectors. Individual decisions are weighted according to the reliability of the detector and then a threshold comparison is performed to obtain the global decision.