Finite-time coordination in multiagent systems using sliding mode control approach

Finite-time stability in dynamical systems theory involves systems whose trajectories converge to an equilibrium state in finite time. In this paper, we use the notion of finite-time stability to apply it to the problem of coordinated motion in multiagent systems. Specifically, we consider a group of agents described by fully actuated Euler–Lagrange dynamics along with a leader agent with an objective to reach and maintain a desired formation characterized by steady-state distances between the neighboring agents in finite time. We use graph theoretic notions to characterize communication topology in the network determined by the information flow directions and captured by the graph Laplacian matrix. Furthermore, using sliding mode control approach, we design decentralized control inputs for individual agents that use only data from the neighboring agents which directly communicate their state information to the current agent in order to drive the current agent to the desired steady state. Sliding mode control is known to drive the system states to the sliding surface in finite time. The key feature of our approach is in the design of non-smooth sliding surfaces such that, while on the sliding surface, the error states converge to the origin in finite time, thus ensuring finite-time coordination among the agents in the network. In addition, we discuss the case of switching communication topologies in multiagent systems. Finally, we show the efficacy of our theoretical results using an example of a multiagent system involving planar double integrator agents.     

按平均收缩率计算注塑模成型尺寸的公式修正

讨论了现用计算公式的缺陷及原因,提出4个修正公式,并举例说明了修正后公式对确定合理的模具公差和保证注塑件顺利生产的重要经济意义。     

Speaker adaptive voice source modeling with applications to speech coding and processing

We discuss the use of low-dimensional physical models of the voice source for speech coding and processing applications. A class of waveform-adaptive dynamic glottal models and parameter identification procedures are illustrated. The model and the identification procedures are assessed by addressing signal transformations on recorded speech, achievable by fitting the model to the data, and then acting on the physically oriented parameters of the voice source. The class of models proposed provides in principle a tool for both the estimation of glottal source signals, and the encoding of the speech signal for transformation purposes. The application of this model to time stretching and to fundamental frequency control (pitch shifting) is also illustrated. The experiments show that copy synthesis is perceptually very similar to the target, and that time stretching and “pitch extrapolation” effects can be obtained by simple control strategies.     

射线探伤中环焊缝一次透照长度计算的探讨

通过对一次透照长度概念的分析以及对环焊缝内透偏心法(F相似文献   

基于全概率公式直接推求管运洪水

本文为保证防洪安全的前提下充分发挥水库的综合效益,提出了基于全概率公式推求管运洪水的方法,并详细阐述了其基本原理;提出了在资料较短或前、后汛期洪水特性大致相同的情况下运用全概率公式推求管运洪水的实际方法;以马边站的洪水资料进行实例研究,其结果表明基于全概率公式推算出来的管运洪水既能使水库工程达到防洪标准,又能充分发挥水库的综合效益。     

乳液聚合导致一种新的转相过程

借助电导率仪、光学显微镜和亚微粒子分析仪等测试手段。研究了乳液聚合导致一种新的转相过程,并用于八甲基环四硅氧烷的聚合中。研究表明:体系以 W/O 相态开始,单体由连续相向水相(分散相)内的胶束中扩散并发生聚合反应,形成 O/W/O 复合乳液。反应过程中连续相体积不断减小,分散相(O/W 复相)体积不断增大,当达到某一临界相比时,体系发生转相,转相后乳液为 O/W。对本实验物系,转相点临界相比主要由初始水油比和乳化剂浓度决定。同常规的乳液聚合相比,伴有转相现象的乳液聚合有其自身的特点,转相使得聚合速率、聚合物粒径及分布、乳液稳定性等发生变化。     

个人洗护用品配方原理及应用技术(Ⅱ)--护肤品配方原理及应用

从护肤品配方原理、各类配方成分(如乳化剂)介绍和其应用等方面讨论护肤品开发应用的相关注意要点，并给出了参考配方。     

模糊数学在橡胶配方优化设计中的应用

应用模糊数学设计理论，在建立橡胶配方设计多目标的隶属函数的基础上，对橡胶配方进行整体评价，得到最优配方。利用计算机数据库技术实现模糊法在橡胶配方设计中的应用 。     

高抗冲聚苯乙烯的研制 Ⅰ.预聚合反应动力学及相转变过程的研究

对HIPS预聚合反应阶段的动力学及相转变行为进行了研究,发现基础胶的种类、用量、搅拌速率及阻聚剂含量对苯乙烯预聚合反应动力学和相转变过程均有不同程度的影响。     

尼龙斜交载重轮胎早期损坏原因及解决方法探讨

针对尼龙余交载重轮胎使用过程中出现的早期损坏，分析了其使用因素和设计因素，从配方设计、结构设计等方面提出了相应的解决方法。同时认为加强工艺控制与结构、配方设计对轮胎性能的影响同等重要。