Set invariance in control

The properties of positively invariant sets are involved in many different problems in control theory, such as constrained control, robustness analysis, synthesis and optimization. In this paper we provide an overview of the literature concerning positively invariant sets and their application to the analysis and synthesis of control systems.

中国东部上第三系硬粘土的工程地质特性及边坡开挖工程环境效应研究

The engineering geological properties of Neogene hard clays and related engineering problems are frontiers in the fields of Engineering Geology, Soil Mechanics and Rock Mechanics. Recently, it has been recognized that Neogene hard clay is the intermediate type of material between the soil and the rock. Many aspects of them, such as sampling, testing, calculating and engineering process, are special, which could not be researched by means of theories and methods of traditional Soil Mechanics of Rock Mechanics. In order to get real knowledge and instruct the engineering practice, intersect studying of multiple disciplines, including Engineering Geology, Soil Mechanics and Rock Mechanics, etc., is necessary. Neogene hard clay is one of the important study objects of regional problem rocks & soils in our country, which extensively distributed in China, especially in Eastern China. Taking the related areas along the middle line of the Project of Transferring Water from the South to the North (e.g. Nanyang basin, Fangcheng-Baofeng area and Handan-Yongnian area), South-west of Shandong, Xu-Huai area and Beijing area, etc. as main study areas, the paper divided Neogene hard clays into reduction environment dominated origin and oxidation environment dominated origin, which distributed on areas western and eastern to Mount Taihangshan respectively. Intermediate types are also existed in some areas, which mainly distribute near the edges of depositional basins; they are usually of transitions between diluvial and lacustrine deposits. As to Neogene hard clays from Eastern China, the clay particle content is high, and montmorillonite or illite/montmorillonite turbostratic mineral is the dominating clay mineral. The content of effective montmorillonite is very high in each area, which is the basis for the undesirable engineering properties of Neogene hard clays. For hard clays from the same area, the content of effective montmorillonite in gray-greenish hard clay is much higher than that in purple-brownish or brown-yellowish hard clay, which is the reason why the gray-greenish hard clay usually has outstanding expansive property. On the other hand, purple-brownish or brown-yellowish hard clay has relatively less montmorillonite, so its property is better. All of these prove that the composition (clay mineral) of Neogene hard clay is the control factor for the engineering properties. Neogene hard clays have obvious properties such as fissured, overconsolidated and expansive, which are the main reasons that many engineering problems and geological harzards usually occur in Neogene hard clays. The paper systematically elaborates the engineering properties of Neogene hard clays from Eastern China, analyses the relationships between engineering properties and basic indexes. The author introduces the ANN method into the prediction of engineering property indexes of hard clays, which provides a new way for quantitatively assessment and prediction of engineering property indexes. During investigation in the field, the author found that there exists obvious seam-sheared zone between different hard clays in Miocene Xiacaowan formation in Xu-Huai area. Similar phenomenon also exists near the borderline between Neogene hard clays and underlying coal measures in the Southwest of Shandong province, which could be observed in the cores. The discovery of seam-sheard zone has important theoretical and practical significance for engineering stability analysis and revealing the origin of fissures in Neogene hard clays. The macrostructure, medium structure and microstructure together control the engineering properties of hard clays. The author analyses and summarizes the structural effects on hard clays in detail. The complex of the strength property of hard clays is mostly related to the characteristics of fissures, which is one of the main factors that affect the choice of shear strength parameters. So structure-control theory must be inseparably combined with composition-control theory during the engineering geological and rock/soil mechanics research of hard clays. The engineering properties, such as fissured, overconsolidated and expansive, control the instability of engineering behaviors of Neogene hard clays under the condition of excavation, i.e. very sensitive to the change of existence environment. Based on test data analysis, the author elaborates the effects of engineering environment change on the engineering properties. Taking Nanyang basin as example, the author utilizes FEM to study the effects of various factors on stability of cutting canal slopes, than sets forth the characteristics, development laws and formation mechanism of the deformation and failure of hard clay canal slopes, summarizes the protection and reinforcement principles, as well as the protection and remedy steps. On the basis of comparison of engineering properties of domestic and foreign Neogene muddy deposits, in the view of whole globe and associated with the geological characteristics of China, the paper demonstrates that the intermediate type of the material between the soil and the rock, named "hard clay/soft rock", which can not be separated abruptly, really exists in China. The author has given a preliminary classification based on its geological origin and distribution law, which is very significant for promoting the mixture of Engineering Geology, Soil Mechanics and Rock Mechanics. In the course of large scales engineering construction in China, many engineering experiences and testing data are gained, summarizing these testing results and automatically managing them with computer technology are very necessary. The author develops a software named "Hard Clay-Soft Rock Engineering Geological Information Management and Analysis System (HRGIMS)", realizes the automatic and visual management of geo-engineering information, on the basis of information management, the functions of test data analysis and engineering property prediction are strengthened. This system has well merits for practice and popularization.

双足爬壁机器人壁面凹过渡步态规划研究

针对腿足式爬壁机器人在壁面过渡时的步态规划问题,以一种真空吸附式双足爬壁机器人为研究对象,在步态分析的基础上,基于有限状态机建立了机器人的步态模型,进而提出了基于加权插值和BP神经网络的双足爬壁机器人壁面凹过渡在线步态规划算法,为提高机器人壁面过渡的自主控制能力奠定了基础.仿真分析和实验结果表明,该步态规划算法对于实际的机器人系统是有效的和可行的.

基于视觉和超声信息的机器人行为控制

随着机器人应用范围的不断扩展,机器人所面临的工作环境也越来越复杂,多数是未知的、动态的和非结构化的。通过对基于行为的机器人控制技术的研究,设计了一种用于完成多目标任务的移动机器人行为控制系统。将基于行为的控制技术融合进模糊控制的思想中,使移动机器人的行为通过运用模糊控制和基于优先度的行为决策来实现,并且通过视觉信息使机器人能够完成面向目标的任务。

蠕动爬行攻泥机构转向工作特性的有限元分析

针对用于沉船打捞的水下攻泥机器人蠕动爬行攻泥机构的结构与工作机理 ,建立了适当的有限元计算模型 ,进而通过弹塑性有限元计算 ,模拟了攻泥机构处于土中不同深度的工作情况 ,建立了攻泥机构前进位移V和转向角θ之间关系的通用公式。通过它可以实现对攻泥机构前进路线的规划与自动控制

大型过程工业自动化全过程体系结构

本文首先论述了体系结构对大型自动化系统开发的重要意义，接着从生命周期的观点、递阶控制的观点、自控系统组成三要素的观点对体系结构进行了竖向、纵向、横向的分析。并讨论了各类参考模型对支持平台的要求，最后提出了大型过程工业自动化全过程体系结构，该体系结构对“八·五”攻关课题“大型过程工业综合自动化总体技术”具有指导作用。

双机器人协调控制系统

本文描述了基于集散控制原理,采用分层递阶结构建立的一个3级结构双机器人协调控制系统.该系统共分3层,最高层为任务规划级.它对双机器人作业进行离线编程及仿真,并负责对整个系统的监控和管理.第2层为协调级,它实现机器人作业的协调控制.并通过传感器信息对机器人轨迹进行实时修正.该层既可接收来自上层的命令或指令.对机器人进行控制,亦可在该层上独立编程.实现对机器人的控制.第3层为执行级,它实现高精度伺服控制.此外,该系统还提供了灵活的编程环境及良好的人机界面.用户可根据需要选择离线编程环境或实时编程环境,并且可在其相应的界面下工作,运行结果表明,系统性能稳定可靠,结构合理,编程环境灵活.我们在该系统上,成功地进行了PUMA562机器人和PUMA760机器人的点位协调和轨迹协调以及复杂的联合作业.

滑动控制理论在海洋机器人动态定位系统中的应用

本文论述了一种新的鲁棒性控制方法——滑动控制理论.并将该方法应用于海洋机器人的动态定位系统设计.仿真结果表明该方法是相当成功和有效的,对系统的参数变化有强鲁棒性.

自动生产线和柔性制造系统的建模、分析与控制

自动生产线和柔性制造系统是典型的离散事件动态系统,近几年在控制理论界受到极大重视。本文首先对自动生产线的建模与分析的研究概况做了综述,重点放在排队网络模型。然后介绍了柔性制造系统的管理与控制问题。

金属粉末激光成形系统的研究

为了实现功能零件金属粉末激光快速成形的制备,研究开发了一套金属粉末激光成形系统。系统基于模块化设计思想,主要包括5个组成部分。每个模块既具备各自的特定功能,又相互协调来统一完成功能零件快速成形制备,而且系统具备高度柔性和自动控制的特点,使得操作与运转简单易行。

An ambient proof and wide tuning range LC VCO with automatic amplitude control for tuner applications

This paper represents a LC VCO with AAC (Auto Amplitude Control), in which PMOS FETs are used as active components, and the varactors are directly connected to ground to widen Kvco linear range. The AAC circuitry adds little noise to the VCO and provides it with robust performance over a wide temperature and carrier frequency range. The VCO is fabricated in 50-GHz 0.35-mu m SiGe BiCMOS process. The measurement results show that it has -127.27-dBc/Hz phase noise at 1-MHz offset and a linear gain of 32.4-MHz/V between 990-MHz and 1.14-GHz. The whole circuit draws 6.6-mA current from 5.0-V supply.

A 1.1GHz LC VCO with Automatic Amplitude Control for Tuner Applications

This paper presents an LC VCO with auto-amplitude control （AAC）, in which pMOS FETs are used,and the varactors are directly connected to ground to widen the linear range of Kvco. The AAC circuitry adds little noise to the VCO but provides it with robust performance over a wide temperature and carrier frequency range.The VCO is fabricated in a chartered 50GHz 0.35μm SiGe BiCMOS process. The measurements show that it has - 127. 27dBc/Hz phase noise at 1MHz offset and a linear gain of 32.4MHz/V between 990MHz and 1.14GHz.The whole circuit draws 6. 6mA current from 5V supply.