地下变电站辅机控制仿真系统的研究

地下变电站辅机系统具有设备类型繁多、控制类型繁杂、关联复杂等问题.为此,采用XML语言对整个仿真系统进行建模,使用分层设计的方式实现人机交互,利用标准数据库进行外部数据接口设计,对各个子系统之间的数据交互进行模块化设计.根据地下变电站辅机系统特点,设计和实现了辅控后台仿真以及日常巡视、操作和事故处理等子系统.应用结果表明,该系统具有较好的可扩展性和可维护性.     

On the design of emergent systems: an investigation of integration and interoperability issues

Many useful manmade systems in this world are extremely complex; a typical example is a large infrastructure. No design team ever invents these artifacts because they are too complex. These artifacts are made by combining existing elements (legacy) and by building new subsystems without explicit and comprehensive up-front coordination. To a large extent, these complex systems emerge and evolve. Experience shows that designers frequently fail to develop artifacts that, when combined, facilitate the emergence of effective and efficient systems. This paper formally elaborates the mechanism behind this phenomenon, and proposes principles for the design of components for emergent systems. The above insights were gained during the development of research prototypes for multi-agent manufacturing control; manufacturing systems are notorious for experiencing integration and interoperability problems as described above. Consequently, the design principles are discussed and illustrated on the design of multi-agent manufacturing control systems but also on work by others. Finally, although this paper mainly discusses the above in a generic fashion, and although the generic statements hold in an application-independent manner, it is important to appreciate that the applicability of the above insights and principles has significant limitations, which are discussed in the paper.     

A Novel Approach to Motion Control Design for Functionally Related Systems

When a complex task has to be performed by multiple systems, it imposes functional dependencies between the states and/or outputs of the systems. These functional dependencies create a system of’ virtually’ interconnected subsystems, even though they may be physically separated. The component subsystems within the overall system we call ‘functionally related systems’. This paper deals with motion control design for functionally related systems. The design is based on identifying functions. The control design is then performed by projecting the system dynamics into the function space. The main goal is to obtain unit control distribution matrix in the function space and enforce a desired dynamics for each of the identified functions.     

Modeling high assurance agent-based Earthquake Management System using formal techniques

Disaster management systems are complex applications due to their distributed and decentralized nature. Various components execute in parallel with high need of coordination with each other. In such applications, interaction and communication issues are difficult to model and implement. In this paper, we have proposed agent-based Earthquake Management System (EMS) which is modeled and analyzed using formal approach. Traditionally, such systems undergo through various transformations starting from requirement models and specification to analysis, design and implementation. A variety of formal approaches are available to specify systems for analyzing their structure and behavior; however, there are certain limitations in using these techniques due to their expressiveness and behavior requirements. We have adopted combination of Pi-calculus and Pi-ADL formal languages to model EMS from analysis to design. The formal approach helps to enhance reliability and flexibility of the system by reducing the redundant information. It reduces chances of errors by explicitly mentioning working flow of information. Additionally, a prototype application is presented as proof of concept in EMS context. We have also evaluated our formal specification by using ArchWare and ABC tools; also, comparison of prototype application with major existing techniques is highlighted.     

A C++ Simulator Generator from Graphical Specifications

Many languages for computer systems simulation (like GPSS and CSim) use a stochastic model of systems with the provision of adding procedural code for those aspects of the system that cannot be captured easily by a stochastic model. However, they do not support the hierachical simulation of complex systems well. Complex computer systems may have to be simulated at various levels of abstraction in the interests of tractability: the flexibility of being able to freely move between the different levels of abstraction is very desirable. For example, in the area of computer architecture, one might have analytical models, detailed simulation models and trace-driven models. In addition, these languages do not have user-friendly interfaces for specification of the simulated system. In this paper, we discuss the design and implementation of a simulation package for hierachical simulation of non-real-time computer systems: a Simulator Generator from a Graphical System Specification (SIGGSYS}). A new language for system specification has been designed. In addition, the package has the following components: • A graphical user interface to aid specification of the system to be simulated. • A rear end that generates C++ code that implements a simulator for the specified system. • A complete object library along with the header files that implement a functionally complete set of C++ base classes which can be built upon. C++ has been chosen as the intermediate language so that the modeller can use its support for object oriented programming. © 1997 John Wiley & Sons, Ltd.     

Multi-layered interactive energy space modeling for near-optimal electrification of terrestrial,shipboard and aircraft systems

In this paper, we introduce a basic multi-layered modeling framework for posing the problem of safe, robust and efficient design and control that may lend itself to ripping potential benefits from electrification. The proposed framework establishes dynamic relations between physical concepts such as stored energy, useful work, and wasted energy, on one hand; and modeling, simulation, and control of interactive modular complex dynamical systems, on the other. In particular, our recently introduced energy state-space modeling approach for electric energy systems is further interpreted using fundamental laws of physics in multi-physical systems, such as terrestrial energy-systems, aircrafts and ships. The interconnected systems are modeled as dynamically interacting modules. This approach is shown to be particularly well-suited for scalable optimization of large-scale complex systems. Instead of having to use simpler models, the proposed multi-layered modeling of system dynamics in energy space offers a promising basic method for modeling and controlling inter-dependencies across multi-physics subsystems for both ensuring feasible and near-optimal operation. It is illustrated how this approach can be used for understanding fundamental physical causes of inefficiencies created either at the component level or are a result of poor matching of their interactions.     

A component-based simulation environment for statistical process control systems analysis

This paper describes a simulation environment, called Prosim, which permits a user to define components, subsystems, and their interconnections to analyse a statistical process control (SPC) system. The components and systems are defined and analysed interactively. A library of standard SPC objects containing models for the Xbar, range, exponential weighted moving average, p-chart and other SPC techniques have been created which help define the control application. The PC-based tool is tested on theoretical, and real data, and is useful for the design and trouble shooting of a manufacturing system. It is also an effective teaching and research tool.     

一种基于PMBus协议的总线控制器的设计

现今电力电子技术中的子系统已被集成到整个系统中,数字电源技术有助于降低开关损耗并管理系统复杂的功耗来源。为了优化数字电源系统,必须在电源子系统之间建立标准化的通信方式。在英特尔公司基于I2C总线的系统管理总线规范SMBus以及其改进版本PMBus中,对传统电源系统中的功耗、裕度等相关功率测试均需手动改变无源组件和每个测试用例的额外设置,使得系统级电源管理的设计非常麻烦,基于此,利用PMBus总线规范设计一种总线从控制器,并通过主机与之通信验证其功能,最终实现数字集成电路的物理版图,为数字电源简化设计提供了一种经济有效的方法。     

The integrated system for design,analysis, system simulation and evaluation of the small satellite

This paper aimed at the design methods of modern small satellites, integrated design and modularization assembling, put forward the design idea of the integrated system for design, analysis, system simulation and evaluation of the small satellite (ISDASE). Advanced simulation software and the real-time simulator (AC104) have been selected to set up the integrated system that includes two parts: mathematical simulation system and hardware-in-loop simulation system for developing and testing both software and hardware on board. It is used to optimize, simulate and evaluate the system scheme during the conception design stage, to demonstrate and verify the performance and specification of the components and subsystems during the development stage, and to deal with the fault diagnosis and procession during the test and operation stage.     

LabVIEW在快堆控制系统仿真的应用

快中子增殖反应堆作为一种新型的核能系统将成为未来核电领域的主要发展方向。在实验快堆的设计过程中,利用计算机仿真技术参与其控制系统设计有助于缩短设计周期、降低设计费用和提高设计质量。本文结合国外典型钠冷快堆的有关文件及数据,研究了反应堆系统的建模和仿真技术,并利用LabVIEW平台上对该系统进行了仿真程序的开发与计算。并对钠冷快堆的各种工况,在各种扰动时的瞬态进行了仿真运行和分析。本论文建立的控制仿真系统的方法及所编写的各子程序也具有较强的可移植性,为快堆控制系统的设计提供了研究方向和基本数据。     

Resilience in supply networks: Definition,dimensions, and levels

Oftentimes, seemingly robust systems fail, almost inexplicably, due to unforeseen events leading to disruption. Exploration and research of the mechanisms behind the failure of such systems have revealed that those capable of surviving are not robust, but resilient. This has spawned a stream of research on the resilience of different complex systems, from ecosystems, to the human body, to supply chains and communication networks. Supply networks are complex adaptive systems in which a subset of agents create flow and are required to deliver such flow to sink agents located at the other end of the network. Delivery of flow under pre-defined service conditions requires resilient design and operation protocols.In this article, a supply network formalism is introduced, and the concept and dimensions of resilience in supply networks, explored. Five core components of resilience are derived from reviewed definitions; two resilience dimensions, structure and control protocols, and two resilience levels, agent and network level, are characterized based on insights from articles in literature. Finally, emerging trends in resilience research as well as current research gaps are presented and future work directions outlined.     

Reflections on the computer in management of production systems

The production system is an economic system managed by man and composed of man. The subsystems of the production system can be divided into reactive responsive and purposeful ones. On the basis of a multitude of components constituting purposeful systems (people) the productions systems as economic systems can be divided into elementary, simple and complex ones. The computer is an artificial system, capable of data storing and processing, or respectively capable of directly causing changes in states of other systems. One can distinguish two computer functions, namely an information function which consists of the intellectual preparation of human actions, and an interference function consisting of the technical causing of changes in states of other systems. So in speaking of the computer-aided management of production systems one implies such a human interference in the behaviour of production systems and their subsystems which is made by the aid of the computer. This interference may refer to reactive and responsive systems (subsystems) as well as to purposeful systems, i.e. people. It implies various applications of the computer in both functions.     

卫星光通信精确跟踪控制系统的参数化综合优化设计

精确跟踪对准控制系统在卫星光通信中起着至关重要的作用.我国已完成的墨子号量子科学实验卫星,是基于经典随动系统理论设计的跟踪与瞄准系统,并在实践中取得了圆满效果.面向未来更远距离的空间通信应用,对跟踪与瞄准系统提出了更高的精度要求,传统的控制方法很难满足.为此本文提出了精确瞄准系统的一种参数化设计方法,抛弃了传统方法的精、粗系统分别设计的思想,对两级子系统进行整体设计,充分地利用了系统中的设计自由度.通过综合优化这些设计自由度,实现了系统对阶跃干扰的解耦和复杂干扰的抑制、不敏感极点配置和控制增益极小化等各项设计要求,从而显著地提高了对准精度.仿真结果表明,对准精度由原来的微弧度量级提高到了纳弧度量级.     

Probability Collectives: A multi-agent approach for solving combinatorial optimization problems

Complex systems generally have many components. It is not possible to understand such complex systems only by knowing the individual components and their behavior. This is because any move by a component affects the further decisions/moves by other components and so on. In a complex system, as the number of components grows, complexity also grows exponentially, making the entire system to be seen as a collection of subsystems or a Multi-Agent System (MAS). The major challenge is to make these agents work in a coordinated way, optimizing their local utilities and contributing the maximum towards optimization of the global objective. This paper discusses the theory of Collective Intelligence (COIN) using the modified version of Probability Collectives (PC) to achieve the global goal. The paper successfully demonstrated this approach by optimizing the Rosenbrock function in which the coupled variables are seen as autonomous agents working collectively to achieve the function optimum. To demonstrate the PC approach on combinatorial optimization problems, two test cases of the Multi-Depot Multiple Traveling Salesmen Problem (MDMTSP) with 3 depots, 3 vehicles and 15 nodes are solved. In these cases, the vehicles are considered as autonomous agents collectively searching the minimum cost path. PC is successfully accompanied with insertion, elimination and swapping heuristic techniques. The optimum results to the Rosenbrock function and both the MDMTSP test cases are obtained at reasonable computational costs.     

双层多态加权$k/n$系统可用性模型与冗余设计优化

鉴于当前多态系统可用性模型刻画分层性能要求的不足,定义一种更加通用的双层多态加权$k/n$系统,提出新的分层运算符结合通用生成函数的方法解决权重的跨层次依赖问题,建立系统可用度模型;针对多态系统冗余设计面临的“子系统和部件综合选择问题”,构建可用度约束下的系统总成本优化模型,利用遗传算法编程获取各子系统和部件的经济数量;以某供电系统为例验证所提出模型及方法的正确性和有效性,并对比说明双层性能要求对系统可用性和经济性的影响. 研究成果可为复杂系统在不同性能要求下的设计优化提供决策支持.     

DEVS methodology for evaluating time-constrained message routing policies

Due to its ability to support temporal issues of systems, discrete event simulation is widely applicable to real-time system design. This paper presents a methodology for the modeling and simulation of time-constrained message routing policies for hypercube interconnected real-time systems. The methodology is based on a framework called the DEVS (discrete event systems specification) formalism which supports modular and hierarchical specification of discrete event models. Within the methodology, we first develop DEVS specification for models for hypercube computers and experimental frames to measure the performance of alternative message routing policies. We then implement such specification in DEVSIM++, a C++-based modeling/simulation environment that implements the DEVS formalism. Simulations of various message routing policies are performed, and the performances of such policies are compared.     

The design and testing of a force feedback dental simulator

The Iowa Dental Surgical Simulator is a haptic simulator to train dental students in the haptic skills of dentistry. The initial design emphasizes the detection of carious lesions. This work describes the software and implementation of the prototype system, the design tradeoffs' and the technical issues associated with haptic and graphics subsystems. The work also describes the current system performance, including a formal evaluation by practicing dentists and performance measures. A discussion of the limitations of the current system is followed by an analysis of opportunities to improve the quality of the simulator. The results should be of interest to designers of medical haptic simulation systems and other simulation designers.     

Specifying transaction-based information systems with regularexpressions

The work is about the formal specification of transaction-based, interactive information systems. A transaction is a task that the user can execute independently, and the system can be defined as a partially ordered set of transactions. The general framework is the transformational paradigm, based on the classical Waterfall development model (W.W. Royce, 1970). The stages are systems analysis, software specification, design, and implementation. The systems analysis and software specification stages are covered. An informal, transaction-oriented method for systems analysis is proposed. The resulting system specification involves two parts: a high-level specification of each transaction and a formal specification of the system's control flow, i.e., the order of execution of the transactions. The system's control flow is expressed in a formal language describing concurrent regular expressions built on transaction names. At the software specification stage, some operational requirements, such as connect/disconnect transactions and the application of the all-or-nothing principle, are added to the system specification. Then a serial product automaton (SPA) is used to transform the concurrent expression into a single regular expression. This result is proven to be consistent with the system specification     

大型高空台进排气控制半物理仿真系统设计

为构建大型复杂高空模拟试车台进排气控制半物理仿真系统,提出了仿真模型和实物部件相结合的系统设计方法。依据系统结构组成及工作机理统筹规划系统仿真模型和实物部件,利用理论建模、系统辨识方法建立仿真模型,并基于PLC完成系统设计和软件开发,最终将仿真模型和实物部件高效统一形成半物理仿真试验台。通过仿真平台实现了系统一体化虚拟仿真,结果表明系统运行可靠稳定,能够准确模拟真实发动机试车过程。