基于PMAC快速PID整定与精度补偿研究

数控系统中动态性能与定位精度决定了加工质量及效率,为满足磨床数控系统控制要求及加工精度,研究快速整定PID方法及提高定位精度补偿方式,基于PMAC运动控制器搭建五轴数控工具磨床的全闭环伺服系统。针对伺服系统动态性能差、跟随误差较大等问题,阐述了基于PMAC的前馈-PID陷波滤波器伺服算法,提出了快速PID整定方法。针对定位精度差的问题,论述了定位补偿原理及方式,使用激光干涉仪进行目标点测量后制作螺距补偿和反向间隙补偿表。结果表明,PID整定方法得当,五轴磨床的动态响应性能良好,跟随误差大幅度减小;定位补偿措施合理,定位精度和重复定位精度大幅度提高,达到设计要求的3μm以内。     

基于Cortex-M4的环面蜗杆检测仪的全闭环控制系统（英文）

针对环面蜗杆检测仪系统控制及定位精度的需要,采用Cortex-M4作为主控制器,控制步进电机驱动载物台运动,步进电机采用闭环控制。光栅尺实时检测XYZ导轨的位置信息,并把光栅信号作为反馈信号,构成闭环运动控制系统,实现坐标系中XYZ轴的运动和时栅转台旋转的高精度定位。步进电机的驱动采用软硬件细分方法,克服了步进电机爬行和丢步现象。实验表明:该系统采用全闭环控制、步进电机软硬件细分方法,实现了三坐标轴±2μm的精密定位,保证了环面蜗杆检测仪的准确测量。     

基于Cortex-M4的环面蜗杆检测仪的全闭环控制系统

针对环面蜗杆检测仪系统控制及定位精度的需要,采用Cortex M4作为主控制器,控制步进电机驱动载物台运动,步进电机采用闭环控制。光栅尺实时检测XYZ导轨的位置信息,并把光栅信号作为反馈信号,构成闭环运动控制系统,实现坐标系中XYZ轴的运动和时栅转台旋转的高精度定位。步进电机的驱动采用软硬件细分方法,克服了步进电机爬行和丢步现象。实验表明：该系统采用全闭环控制、步进电机软硬件细分方法,实现了三坐标轴±2 μm 的精密定位,保证了环面蜗杆检测仪的准确测量。     

微电机轴球面成型加工方法的探讨

微电机轴端设计成R球面是减小电机振动和噪声的一种重要方法.为了提高微电机轴端R球面的加工效率,从微电机轴端R球面加工的相对运动关系入手,对微电机轴球面的磨削成型方法进行探讨,分析嵌件轮、工件和砂轮的运动关系,导出成型砂轮的砂轮形线的数学模型.为微电机轴球面的加工工艺建立和成型设备制造提供参考.     

面向芯片封装的冗余驱动T型XY运动系统的研制

面向芯片封装设备对高速高精度的需求,提出了一种多直线电机冗余驱动的T型XY运动系统.T型XY工作台以单直线电机作为Y轴动力源,双直线电机作为X轴动力源,并配以高分辨率、高精度的位置检测元件和控制系统,共同组成T型运动系统.叠加式的机械结构设计使得工作台尺寸小、质量轻、刚度高;多电机的冗余驱动为系统提供了更大推力以提高设备的加速度.通过扫频试验,建立了系统的实验模型,在实验模型基础上设计了控制器并进行了实验研究.该运动系统目前实现了最大速度0.65m/s,最大加速度9.25g,及微米级定位精度的性能指标,能够适应当前IC封装业发展对高速高精度的要求.     

基于PMAC运动控制卡的六自由度运动平台控制系统开发

通过研究典型Stewart运动平台相关理论,成功研发一台六自由度运动平台样机并进行了相关运动控制试验。该样机采用美国Delta Tau公司的PMAC运动控制卡控制6个步进电机带动的电动推杆实现对运动平台6个驱动杆的伸缩控制,从而达到控制运动平台姿态的目的。     

基于PMAC的数控铣齿机双电机消隙技术研究

螺旋锥齿轮铣齿机在数控加工过程中经常出现冲击和振荡等现象,严重影响齿轮加工精度。研究发现伺服传动系统中存在的齿隙非线性问题对铣齿机的加工精度、可靠性和稳定性有较大影响。通过比较消除齿隙方法,提出一种基于PMAC运动控制器的铣齿机传动系统双电机消隙方法。对双电机消隙的基本原理以及消除间隙的过程进行分析,并且根据双电机消隙原理设计试验流程;搭建基于“IPC+PMAC运动控制器”的双电机驱动应用系统,并在PMAC IDE中进行相关配置;最后基于上、下位机结构配置的数控系统试验装置,进行试验验证。试验结果表明：所提方法能够有效抑制齿隙非线性的干扰、提高系统的稳定性,证明所提双电机伺服消隙方案的可靠性。     

PMAC多轴运动控制器应用研究

本文通过对PMAC多轴运动控制器应用方案的论述，介绍了利用PMAC构建一个机电一体化实验装置所需要的软硬件结构，以及构建系统的方法、解决手段和需要注意的事项。     

基于IPC+PMAC的全自动汽车车牌压字机控制系统

针对国内车牌压字机存在自动化程度差、生产效率低和定位精度不高等问题,设计一种以IPC+PMAC为核心的汽车车牌自动压字机控制系统。采用IPC和PMAC控制字模库,实现对车牌字模的组合排序。利用PLC控制步进电机、气缸等完成车牌的上下料;由液压缸对车牌进行冲压,完成车牌的自动化压字。实验结果表明：该系统能够实现车牌的全自动化压字,提高车牌生产效率,降低生产成本,可为设计新型的汽车车牌压字机提供参考     

快走丝复杂曲面线切割伺服系统设计

采用工件运动的方式进行复杂曲面线切割加工是个很好的选择,而对工件的三维空间定位伺服机构的精确控制是进行零件加工的关键.以研制的三轴联动高精度数控转摆摆工作台为基础,提出了基于多轴运动控制器(PMAC)的五轴联动线切割机床伺服控制系统.介绍了机床的总体结构和PMAC卡的PID控制算法.控制环节采用底层开发的开放伺服PID控制策略,利用PMAC TURNING软件对转摆摆工作台各轴的PID参数进行了调节并获得了合理数据.试验表明工作台获得了较好的稳态特性和动态特性,实现了工作台的精确位置伺服控制.为实现高精度复杂曲面线切割加工提供了有力支持.也为研制复杂曲面电火花线切割智能制造系统奠定了基础.     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

The Mirror with Patterns of Auspicious Animals and Grapes——Exquisite cast mirror and the technology of surface tin-enrichment by rubbing-in and infiltration of tin-rich powder

<正>Bronze mirrors were used by the Chinese people before the introduction of the glass mirror.Only after it was replaced by the glass mirror did the bronze mirror gradually retreat from people's lives.Different styles of bronze mirrors were made in different historical periods,particularly in the Warring States Period,the Han and Tang Dynasties,which were the three peaks of the development of bronze mirror arts in ancient China.The casting techniques were exquisite.The surface of the bronze mirror was smooth and bright enough to reflect one's image,and there were scarcely any casting defects on the mirror surface.On the back of the bronze mirror,there were rich depictions of Arts and Humanities,and the ornamentations were also     

The 9th China International Diecasting Congress & Exhibition

The 9th China International Diecasting Congress ＆ Exhibition was held on July 22-24, 2014 at Shanghai New International Expc Centre. This exhibition was the most successful over the years, with over 6890 visitors and 155 exhibitors, and the exhibition area increased by 30% from 9,500 square meters in 2012 to 12340 square meters. Die casting enterprises from a total of 24 countries and regions, including China mainland, Chinese Taiwan and Hong Kong, South Korea, Japan, Germany, India, Thailand, Malaysia, the United States, Russia, Australia, Iran, Ukraine, Brazil, Colombia, Singapore, Austria, Canada, Croatia, France, Turkey, United Kingdom, Vietnam, attended the congress and exhibition.     

Introduction of the Fluid Control Engineering Institute of Kunming University of Science and Technology

正The Fluid Control Engineering Institute of Kunming University of Science and Technology was set up in 1996.The researches of institute concentrate on electro-hydraulic(pneumatic)servo/proportional control and hydromechatronics.The Institute is committed to research and development of electro-hydraulic control of high-end technical equipment in ferrous metallurgy refining produc-     

RARE METALS Volume Contents

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Antimony Induced Crystallization of Amorphous Silicon

Antimony induced crystallization of PVD (physics vapor deposition) amorphous silicon can be observed on sapphire substrates. Very large crystalline regions up to several tens of micrometers can be formed. The Si diffraction patterns of the area of crystallization can be observed with TEM (transmission electron microscopy). Only a few and much smaller crystals of the order of 1μm were formed when the antimony layer was deposited by MBE (molecular beam epitaxy) compared with a layer formed by thermal evaporation. The use of high vacuum is essential in order to observe any Sb induced crystallization at all. In addition it is necessary to take measures to limit the evaporation of the antimony.     

A CUMULATIVE FATIGUE DAMAGE RULE UNDER THE ALTERNATIVE OF CORROSION OR CYCLIC LOADING

Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic loading was proposed. The specimens of aluminum alloy LY12-CZ soaked in corrosive liquid for different times were tested under the constant amplitude cyclic loading to obtain S-N curves. The test was carried out to verify the proposed cumulative fatigue damage rule under the different combinations among corrosion time, loading level, and the cycle numbers. It was shown that the predicted residual fatigue lives showed a good agreement with the experimental results and the proposed rule was simple and can be easily adopted.