基于LMI的时滞模糊大系统的分散镇定

讨论了具有时滞关联的模糊大系统的分散镇定问题，基于李亚普诺夫稳定性理论及大系统分散控制理论，给出了保证该时滞模糊大系统闭环渐近稳定的LMI形式的充分条件。满足这些充分条件的分散化并行分布补偿(DPDC)控制器参数可通过MATLAB的LMI工具箱有效地求取。因此本文提供了一个综合时滞关联模糊大系统DPDC模糊控制器的有效方法。     

非线性系统的自适应模糊控制器设计

针对非线性系统,为获得更好的控制控制效果,设计了模糊自适应控制器。在模糊控制器的基础上根据反馈控制和调整参数向量的自适应律的求解,综合李雅普诺夫稳定理论设计了模糊自适应控制器,以满足系统的稳定性和控制效果。为验证控制器的有效性,将该控制器应用到二级倒立摆系统的稳定控制,仿真结果表明该控制器的控制效果良好,并与传统的控制方法相比较,其控制效果更佳。     

An Adaptive Digital Pump Controller for Phase-Locked Servo Systems

A novel adaptive digital pump (phase/voltage) controller (ADPC) is presented for use in phase-locked servo systems without utilizing RC loop filters and high line-density encoders. The proposed ADPC is a multirate processor, of which the linear discrete-time model for the digital pump phase-locked servo system (DPPLS) is constructed. Simulation results that verify the theoretical work are also conducted.     

非线性奇异摄动系统的自适应模糊控制器设计

为解决模型未知情况下多输入多输出非线性奇异摄动系统的跟踪问题,提出一种新型的自适应模糊控制器。首先将被控系统分解为快慢子系统,对慢子系统,设计后件参数可调的直接型自适应模糊控制器,能保证系统的慢状态跟踪预定轨迹;对快子系统,则设计模糊控制器,能够保证快子系统的稳定,最终控制器为二者的合成。Lyapunov方法证明,只要摄动参数足够小,就能保证整个系统的稳定。仿真验证了所提方法的有效性。     

车载自组网中一种分布式自适应TDMA时隙分配策略

提出了一种适用于车载自组网的自适应TDMA时隙分配机制DATS,DATS利用节点的差异性优化TDMA时隙分配机制,并且能根据节点密度自适应地调节时隙分配比例。理论分析和实验结果表明,DATS时隙分配策略能提高节点竞争成功率,降低接入时延;与现有的几种协议相比能减少至少50%的节点冲突,且具有良好的可扩展性,能够适应局部节点密度的变化。     

An Adaptive Controller for Coupled Nonlinear Systems with Robotic Applications

An adaptive control algorithm is presented which is based on state derivative estimation and desired pole placement in a first-order discrete system model. The approach has the advantage that the system states are easily decoupled and that it works well on nonlinear systems. Several simulation studies for robotic systems are presented.     

模型参考自适应控制逆变器的研究

分析了模型参考自自就控制方法应用于逆变器控制的可行性,提出了一种控制方案。详细地分析了系统的工作原理,得出了仿真结果及相应的数字解释。结果表明,这是一种控制效果好的方案。     

Model Reference Adaptive Control Based on Adjustable Reference Model during Mode Transition for Hybrid Electric Vehicles

Hybrid elective vehicles (HEVs) operate in multiple driving modes, e.g., motor driving mode, engine driving mode, and combined driving mode, under various different scenarios. Therefore, mode transition between different driving modes is necessary to ensure high-efficiency operation of HEVs under various running conditions. This paper proposes adjustable reference model (ARM)-based model reference adaptive control (MRAC) to solve the problems of deviation from driver's intention and lack of adaptability to parameter changes. The driveline dynamics model during mode transition is built and validated. The dynamics in the mode before the mode transition is taken as the reference model whose parameters are estimated online. Thereafter, the adaptive law is derived. Simulation and hardware-in-loop experiments are carried out. The results show that the mode transition performance under varying driver's demand torque is satisfactory in terms of not only vehicle jerk, but also clutch slipping time and frictional loss. And, the controller has good adaptability to different vehicle masses and road slopes. The ability to deal with the disturbance in clutch torque with low frequency is also validated.     

Decentralized Inventory Control for Large-Scale Reverse Supply Chains: A Computationally Tractable Approach

In this paper, we consider a new inventory control technique for large-scale supply chains including repairs. The part flow is bidirectional with broken parts propagated upstream for repair. It is well known that available optimization techniques for inventory control for bidirectional stochastic supply chains are computationally intractable and also necessitate several simplifying assumptions. In contrast, the proposed approach is an adaptive scheme that scales well to practically interesting large-scale multi-item supply chains. Furthermore, practical issues such as stochastic transport delays, manufacturing times, and repair times and probabilistic characterization of part repair success are handled in a unified framework. The control scheme is based on a hierarchical two-level architecture that comprises an adaptive set point generator and a lower-level order-up-to policy. An application to aircraft supply chains involving multiple original equipment manufacturers (OEMs), depots, bases, squadrons, and planes is also investigated.     

Model Reference Adaptive Control Design for a Shunt Active-Power-Filter System

In this paper, model reference adaptive control (MRAC) is proposed for a single-phase shunt active power filter (APF) to improve line power factor and to reduce line current harmonics. The proposed APF controller forces the supply current to be sinusoidal, with low current harmonics, and to be in phase with the line voltage. The advantages of using MRAC over conventional proportional-integral control are its flexibility, adaptability, and robustness; moreover, MRAC can self-tune the controller gains to assure system stability. Since the APF is a bilinear system, it is hard to design the controller. This paper will solve the stability problem when a linearization method is used to solve the nonlinearity of the system. Moreover, by using Lyapunov's stability theory and Barbalat's lemma, an adaptive law is designed to guarantee an asymptotic output tracking of the system. To verify the proposed APF system, a digital signal controller (dsPIC30F4012) is adopted to implement the algorithm of MRAC, and a 1-kVA laboratory prototype is built to test feasibility. Experimental results are provided to verify the performance of the proposed APF system.     

基于跟踪微分器的模型参考自适应控制

为了处理二阶系统模型参数的大范围不确定性,提出了基于跟踪微分器的模型参考自适应控制,利用两个非线性跟踪微分器分别得到系统输出的微分信号和误差的微分信号,同时抑制了高频噪声放大效应。根据被控对象的数学模型,自适应调节律能自动实时调节控制律中的参数。实验结果表明,当雷达伺服系统被控对象模型的参数在较大范围内变化时,该新型控制器有效补偿了二阶系统参数的不确定性,提高了伺服系统稳态和动态跟踪精度,保证了系统的全局渐近稳定。     

Development and Specification of a Reference Model for Agent-Based Systems

Agent-based systems have been the object of intense research over the past decade. While great theoretical progress has been made, the software frameworks for creating agent-based systems offer considerable variability in their capabilities and functionality. This paper introduces a reference model for agent-based systems. The purpose of a reference model is to provide a common conceptual basis for comparing systems and driving the development of software architectures and other standards. The Foundation for Intelligent Physical Agents and other groups have advanced a number of agent standards, yet, to date, no comprehensive reference model has been presented for software systems composed of agents. This paper provides an overview of a reference model for agent-based systems. The agent systems reference model is the result of a multiyear effort studying software systems built with agents and software frameworks for implementing these systems. As part of this study, the team applied software reverse engineering techniques to perform static and dynamic analysis of operational agent-based systems. This analysis enabled identification of key common concepts across over one dozen different agent frameworks. To demonstrate its applicability, the reference model is then used to analyze a number of complete agent-based software systems. It is the belief of the authors that the reference model will be an essential prerequisite for future transition, deployment, and integration of agent-based systems.      

染整设备通用自适应控制器

主要结合目前各类国产染色机的特点，提出了一种通用智能自适应控制方法，基于该方法，研制成功了染整设备通用自适应控制器，可适用于种类常温常压和高温高压染整设备。应用表明，控制精度高，染色产品质量稳定，一等品率在９９％以上。     

Adaptive Meeting Scheduling for Large-Scale Distributed Groupware

This paper introduces a novel approach of collective scheduling among a community of distributed users. This approach, named Distributed Adaptive Scheduling (DAS), deploys flexible, lightweight agents to quickly find and suggest suitable solutions of scheduling for a large number of users. The DAS agents can move from one machine to another to co-ordinate mutually acceptable solutions for a proposed meeting. They also possess behavioural intelligence, by making adaptive decisions about next actions according to current environment and conditions. As a consequence, quick and efficient scheduling can be achieved for users located at different places. Experimental results have proved that DAS is especially suitable for large-scale distributed scheduling, and scheduling with complex calendars. The DAS approach has been successfully integrated with a personal assistant agent platform to provide completely automatic meeting scheduling for both stationary and mobile users. This revised version was published online in July 2006 with corrections to the Cover Date.     

Adaptive Decentralized Droop Controller to Preserve Power Sharing Stability of Paralleled Inverters in Distributed Generation Microgrids

This paper addresses the low-frequency relative stability problem in paralleled inverter-based distributed generation (DG) units in microgrids. In the sense of the small-signal dynamics of a microgrid, it can be shown that as the demanded power of each inverter changes, the low-frequency modes of the power sharing dynamics drift to new locations and the relative stability is remarkably affected, and eventually, instability can be yielded. To preserve the power sharing stability, an adaptive decentralized droop controller of paralleled inverter-based DG units is presented in this paper. The proposed power sharing strategy is based on the static droop characteristics combined with an adaptive transient droop function. Unlike conventional droop controllers, which yield 1-DOF tunable controller, the proposed droop controller yields 2-DOF tunable controller. Subsequently, the dynamic performance of the power sharing mechanism can be adjusted, without affecting the static droop gain, to damp the oscillatory modes of the power sharing controller. To account for the power modes immigration at different loading conditions, the transient droop gains are adaptively scheduled via small-signal analysis of the power sharing mechanism along the loading trajectory of each DG unit to yield the desired transient and steady-state response. The gain adaptation scheme utilizes the filtered active and reactive powers as indices; therefore, a stable and smooth power injection performance can be obtained at different loading conditions. The adaptive nature of the proposed controller ensures active damping of power oscillations at different operating conditions, and yields a stable and robust performance of the paralleled inverter system.      

自适应光学系统的自学习控制模型及其验证

在自适应光学系统中,传统比例-积分控制模型依赖于变形镜的响应矩阵,系统状态的改变会对变形镜响应矩阵造成影响,导致波前校正性能下降。通过重新定义BP(back-propagation)神经网络结构实现哈特曼斜率数据到控制信号的输出,并建立了控制模型。实验结果表明,所提模型摆脱了传统固定模型的限制,具有在线更新控制模型的特点,控制模型收敛性能良好,能适应系统状态变化,有较强的鲁棒性,同时提高了控制精度,一定程度上改善了控制性能。     

OFDM系统中的自适应信道估计

分析了现有的基于导频的OFDM信道估计技术,提出了一种低复杂度的自适应信道估计方法,并给出了最大时延扩展的实时估计方法,最后通过计算机仿真,给出了多径信道下MSE曲线,以及在DVB-T系统中的BER仿真曲线,验证了其可靠性和良好的性能。     

移动agent系统基准模型的研究

基于Internet的移动agent技术已经成为网络计算研究热点之一.针对目前移动agent研究中缺乏良好的移动agent环境基准模型的现状,本文给出了一个基于Internet的移动agent环境的基准模型ND-MATRM,该模型阐述了移动agent技术及其系统中涉及的公共术语及其解释、通用的体系结构、规范的服务及接口.该模型在指导系统研制、分析现有系统和标准化工作等方面均具有良好的应用前景.     

OSI Reference Model--The ISO Model of Architecture for Open Systems Interconnection

Considering the urgency of the need for standards which would allow constitution of heterogeneous computer networks, ISO created a new subcommittee for "Open Systems Interconnection" (ISO/ TC97/SC 16) in 1977. The first priority of subcommittee 16 was to develop an architecture for open systems interconnection which could serve as a framework for the definition of standard protocols. As a result of 18 months of studies and discussions, SC16 adopted a layered architecture comprising seven layers (Physical, Data Link, Network, Transport, Session, Presentation, and Application). In July 1979 the specifications of this architecture, established by SC16, were passed under the name of "OSI Reference Model" to Technical Committee 97 "Data Processing" along with recommendations to start officially, on this basis, a set of protocols standardization projects to cover the most urgent needs. These recommendations were adopted by T.C97 at the end of 1979 as the basis for the following development of standards for Open Systems Interconnectlon within ISO. The OSI Reference Model was also recognized by CCITT Rapporteur's Group on "Layered Model for Public Data Network Services." This paper presents the model of architecture for Open Systems Interconnection developed by SC16. Some indications are also given on the initial set of protocols which will-likely be developed in this OSI Reference Model.