气动顺序逻辑控制系统设计的状态阵列法

本文提出气动顺序逻辑控制系统设计的状态阵列法。此方法对于相邻程序步为同一执行元件的不同动作的程序,可直接在动作程序中插入记忆元件;对于不属前述类型的程序,只要列出状态阵列并划分出逻辑矛盾区间,即可插入记忆元件。文中还提出了确定控制信号的步骤和技巧,以及用于判别控制信号正确与否的逻辑式正确性充要条件。本设计法直观、简便、易学。掌握这一方法能迅速和正确地设计出复杂的气动顺序逻辑控制系统。     

自动变速器液压控制系统FMEA

把自动变速器液压控制系统按功能分为供油调压和流量控制子系统、换档控制子系统、换档品质控制子系统和液力变矩器控制子系统4个部分,分别对其主要元件建立数学模型.对典型自动变速器液压控制系统的部分元件进行故障模式、影响分析.最后提出了基于风险顺序数的多故障模式分析方法.     

水辅成型系统的控制过程设计

通过对水辅成型工作过程的分析,确定了工作循环中水注射的各工序要求.设计了水辅成型水液压比例系统,在系统工作状态和时序参数分析计算的基础上,并综合考虑了水液压系统、注塑机的交互协调要求以及水辅成型工艺特性,提出了系统时序控制方法,并设计了相应的换向阀动作和顺序控制.     

液压教学综合实验台研制

针对液压传动课程的教学改革,研制一种液压教学综合实验台并进行详细说明。实验台包含组成常规液压系统的动力元件、控制元件、执行元件和辅助元件;能构成调压回路、节流调速回路、差动回路、双泵供油回路、顺序动作回路、减压回路、自锁保压回路、卸荷回路等液压基本回路。应用该实验台进行液压传动实验教学,能帮助学生理解和掌握液压元件的工作原理、系统的结构组成与基本布局、液压管线连接方式以及基本回路的控制设计方法等理论和应用知识,为工程应用打下了良好的基础。     

多执行元件液压系统节能研究

针对多执行元件液压系统中各执行元件所处工况不同而引起的流量利用率低和协调性不佳等问题,提出应用液压子系统模式,通过工况分析,合理调整液压系统执行元件动作时序,将液压系统分成两个子液压系统,由双联定量泵供油以降低液压系统的总功率,达到节能目的。     

液压系统自动循环的控制设计

1「攀鲈谑导噬?,很多设备工作过程包括若干工步 ,并按一定顺序自动完成且不断重复 ,此为自动工作循环过程。此过程可通过控制液压系统实现自动循环的控制。液压系统能提供较大的驱动力 ,且运动传递平稳、均匀、可靠、控制方便 ,因而被广泛应用于机床设备中。液压系统与ＰＬＣ控制结合起来 ,即可实现液压系统的自动化。本文以液压动力滑台工作自动循环控制为例进行分析设计。2　工作过程液压动力滑台是机床加工工件时完成进给运动的动力部件 ,由液压系统驱动 ,自动完成加工的自动循环。液压系统由电磁阀线圈的通断电来控制。电磁阀通断电…     

基于逻辑分析法的自动变速器液压系统设计

自动变速器液压控制系统的分析和设计比较繁琐和困难,主要原因在于不同类型的自动变速器在机械结构和控制方式上有较大差异,这就使得与其相匹配的液压控制系统也各有特点.在分析了解各种自动变速器液压控制系统的基础上,运用逻辑分析法推导和设计出一套较通用的液压控制系统,只需已知变速器执行元件表中各个执行元件在不同挡位时的工作状态,...     

液压回路的逻辑设计

液压传动系统中，存在着许多两种对立的工作状态，例如液压缸的前进与后退、液压马达的正转与反转、换向阀的接通与断开等。而逻辑代数中的每一逻辑变量也只有两种对立状态，因而液压回路中的逻辑关系完全可用逻辑代数来表示，所不同的是液压回路中的输入量对执行元件的控...     

液压逻辑元件及其在组成集成回路时的应用

近年来在生产设备中越来越多地采用液压传动。同时,不论在技术方面,还是在经济方面,对液压传动设备参数的要求愈来愈高。因此,在液压元件及液压回路的组成方面,不仅力求改善目前传统液压元件的品种,而且还要探讨新型的元件和系统,以满足不断增长的技术和经济上的要求。液压逻辑元件及集成回路就是其中的一种。 本文引述了各种类型的液压逻辑元件、它们的联接及在液压回路上的应用;详细叙述了组成液压集成回路时应用带有逻辑元件的通用组合块的可能性及其结构;最后指出了采用带逻辑元件的液压回路与采用带滑阀式换向阀的传统系统相比,在技术上和经济     

Non-contacting control of objects by pulse width modulated air-jet actuators and optical position feedback

In many areas of the food manufacturing industry use of contacting mechanical devices to manipulate the products frequently causes damage to the products and/or gives rise to system jamming particularly at higher feed flow rates. Techniques for manipulating objects by non-contacting means, namely by power air-jets, have been under development at Birmingham University. The advantage of non-contacting technology is the increase of flow rates of manufactured products beyond that currently sustainable by mechanical means without causing damage and system hold-ups. In the present paper, a technique for motion control of objects is presented which utilizes pulse width modulated fast acting power air-jets with piezotranslator drive stages, a transputer based digital image processor for position feedback and fuzzy logic techniques for the control algorithm.     

面向协同设计过程协调和优化的集成过程管理研究

在跨企业协同产品开发模式下,以项目为核心,分析了面向项目全产品开发周期任务流和过程流驱动的机制,根据协同设计过程链驱动的特点研究和开发了集成过程控制系统CDIPM,同时给出了过程综合控制和管理策略、过程活动对象建模、历史知识模板驱动任务划分和渐进迭代式任务分解和优化策略等关键技术的实现方法.     

基于Dueling Network与RRT的机械臂抓放控制

针对当前机械臂抓取与放置方式固定、指令单一、难以应对复杂未知情况的不足,提出一种基于深度强化学习与RRT的机械臂抓放控制方法。该方法将物件抓取与放置问题视为马尔科夫过程,通过物件视场要素描述以及改进的深度强化学习算法Dueling Network实现对未知物件的自主抓取,经过关键点选取以及RRT算法依据任务需要将物件准确放置于目标位置。实验结果表明:该方法简便有效,机械臂抓取与放置自主灵活,可进一步提升机械臂应对未知物件的自主操控能力,满足对不同物件抓取与放置任务的需求。     

Inhibiting Effect of Additives on Pressure Solution of Calcite

The task of protection of cultural heritage requires a better understanding of combined effects of mechanical and chemical factors involved in environmental deterioration of monuments. The present paper deals with extending some known physicochemical methods proposed for inhibiting the decay of unstressed materials to their study during water-assisted deformation. The tests have been carried out on natural limestone samples and calcite powders in CaCO₃ saturated aqueous solutions under static loads causing measurable pressure solution creep. In the solutions containing 1-hydroxyethylidene-1,1-diphosphonic acid, nitrilotriacetic acid, or ethylenediaminetetraacetic acid, the creep rate decreases considerably with increasing concentration of additives. The extent of creep deceleration has been found to be proportional to the independently estimated calcite surface area occupied by adsorbed species. This fact enables us to discriminate the adsorption-induced effect from other variables controlling the pressure solution rate and may be used in screening of compounds able to minimize the environmental impact on marble and limestone objects undergoing mechanical stresses.     

高速高精度数控机床恒温控制系统建模及仿真

依据制冷学原理,研制了一种适用于高速高精度数控机床的恒温控制系统,以PID控制恒温控制系统为研究对象,对系统中的各个主要被控对象进行建模,确定其系统的传递函数,并运用MAT-LAB/Simulink仿真软件对其进行系统仿真.采用了频域整定方法对PID控制参数进行整定,获得了较佳的PID控制参数,并通过仿真分析方法,验证了控制模型的可行性.     

FE Analysis of Nitinol Leaf Springs Used in a Compression Anastomosis Device

Reconstruction of the digestive system lumen patency (anastomosis creation) after its partial surgical removal is a common and crucial procedure. The conventional anastomosis methods use devices for mechanical suturing which are associated with high failure risk and can lead to major complications. The compression anastomosis as a sutureless method seems to be a promising alternative. However, attempts during the last two centuries have not been completely successful due to the complex character of the tissue-healing process. The specific mechanical behavior of Nitinol alloys was applied to the force element of the compression devices. These devices are becoming more widely adopted in surgery practice. The compression anastomosis device enables the anastomosis of colonic and intestinal tissue based on compression forces exerted by Nitinol leaf springs. By means of changing the strain distribution in the stressed leaves with varying moments of inertia, one can gain full control of the different stages in the force-deflection profile (i.e., linear elastic stage and the force plateau stage). The target of this study is the comparison of different Nitinol leaf geometries and evaluation of the finite elements analysis as a tool for preliminary design of such geometries. The results of this analysis allow us to establish regulation of the spring??s mechanical behavior, thus controlling the anastomosis creation in the compression anastomosis device.     

自由曲面激光仿型测量数据的光顺方法

数字化仿型控制系统已经成为仿型控制系统的发展趋势，而自由曲面几何特性的数字化是实现数字化仿型控制功能的难点和关键问题之一。本文讨论了曲面数字化过程中测量数据光顺问题，在分析了激光仿型测量数据特征和几种常见曲线光顺方法原理的基础上，确定了采用圆率法作为测量数据的光顺方法。文章给出了圆率法的基本原理和目标函数的优化方法，并通过实验验证了该方法是可行的。     

微焦点X射线分层成像无损检测方法

对薄层结构的复合材料及多层电路板进程密度分布情况有分层成像研究。提出一种新的成像方法，即在现有微焦点X辐射成像系统的基础上，采用一种特殊的摆动式扫描方式，非线性的层面合成可以仅仅从很少的投影中重建物体，该法具有扫描速度快、算法简单、时性好等特点，适于多层大面积复合材料以及多层电路板的快速成像检测。     

Auto-detection of strip area in 3D measurement

3D measurement is an important task for modern manufacturing, because 2D measurement cannot meet the increasing requirements for quality control in engineering. Among all, 3D recovery methods, by using structural lighting system are the most popular methods because of its non-destructive character. The acquiring of lighting strips, which have to be projected on the object is the most important work to ensure later matching work. In the former research, the position of the stripes in the image was very difficult to locate and must be drawn manually. Therefore, the aim of our research is to find a method to auto-detect the strip area. FFT (fast Fourier transform algorithm) are used to analyze the image character by row and by column. From the FFT result, in the power spectrum the strip area and non-strip area can be distinguished clearly. So the strip area can be marked exactly on the image, and image process algorithm can be used to pick up the strips only on this area. After the matching and 3D recovery algorithm, the 3D shape of the object can be plotted. The auto-detection strip algorithm can save a lot of time for the 3D measurement, automatically complete the 3D recovery procedure, and bring convenience to operators.     

Reconfigurable handling system

The demand for more versatile assembly and handling systems to facilitate customized production is gaining in importance, especially with regard to the constantly-increasing cost pressure, to expansion of the range of product versions and the shortening of innovation cycles. As a cost-effective approach for frequently changing assembly tasks, a novel manipulation concept has been developed by combining given robot technologies. This new handling system has a modular and adaptable layout, which consists of several mobile arms to manipulate the object in six-dimensional Cartesian space. After grasping, when the arms are attached to the object, the mechanical architecture is similar to parallel manipulators or cooperating robots. As the mounting and gripping points of the arms can easily be changed, the manipulator can be reconfigured so as to match the user’s preferences and needs. In addition to the kinematic adaption the regarding task, the hardware and new functions can be reconfigured as well. Contact elements, measurement and assembly devices as well as testing modules can easily be in integrated in the concept. A modular automatic control concept combined with a self-optimizing planning tool helps the user to find the optimal configuration and realize it in an economic way.