基于PLC两轴运动控制的示教与再现

提出了一种基于西门子S7-200可编程控制器(PLC)实现两轴运动控制示教与再现功能的设计方法。利用PLC的高速计数器的正交计数模式实时记录编码器的运动位置信息,完成示教;通过其高速脉冲输出端输出高速脉冲,控制两轴电机运转,再现预定的运动轨迹。实验结果表明,该设计结构简洁,操作方便,抗干扰能力强,具有很高的系统再现精度。     

水火弯板运动控制系统的研究

通过分析水火弯板运动控制要求,设计基于嵌入式运动控制器MC206和艾默生PLC的运动控制系统,使用PLC通过MODBUS通信对运动轴和数字输入输出进行扩展,设计了PLC的MODBUS主站通信程序和伺服驱动程序,最后对主要控制参数进行了计算,设计的运动控制系统能够满足水火弯板工艺要求.     

基于PLC的玻璃磨边开孔工作站控制系统设计

为提高玻璃磨边开孔效率、降低人力劳动强度以及减少人为因素造成的孔位误差,设计基于PLC的玻璃自动定位磨边开孔控制系统。运用CTSC-226H运动控制型CPU为控制核心,通过在人机界面输入边角处理工艺、玻璃尺寸与开孔坐标参数,控制器输出高速脉冲控制三轴伺服模组的运动,实现对主轴电机的定位开孔与磨边动作。结果表明：该系统设计合理、运行稳定、人机交互性好、开孔定位精度高,满足生产要求。     

基于嵌入式软PLC技术的运动控制功能块的研究

嵌入式软PLC技术在以传统PLC技术、嵌入式系统及软PLC技术为基础发展而来。针对不同的运动控制器所需的编程语言不同的问题,深入研究了嵌入式软PLC技术和PLCopen准则,以广州创龙公司的omapl138开发板为硬件平台,移植基于Codesys SP为内核的操作系统,并以圆弧插补算法作为运动控制功能块的研究对象,实现了符合PLCopen规范的多轴运动控制功能块的开发。在Matlab软件中完成对功能块的仿真验证,并将功能块下载到不同运动平台上。结果表明,功能块执行正确,符合设计要求,具有良好的兼容性。     

自动焊接生产线上追加的单轴运动控制器的技术实现

以机器人为主体的自动生产线,都需要有足够的柔性,能加工多个对象.在已有机器人控制器配置的基础上,可通过追加一个或多个轴运动控制器来实现机器人自动生产线的柔性.文中介绍了追加的单轴运动控制器的技术实现,详细阐述了利用FPGA技术实现的可变频脉冲发生器.同时给出了仿真结果,表明该设计满足了机器人运动控制系统实时、高速的要求.     

超声波特征扫描成像系统的研制及应用

介绍了超声波特征扫描成像系统的研制,包括硬件和软件功能的设计及实现。系统硬件部分包含脉冲发射/接收器、高速同步数据采集模块、多轴运动平台和探头的夹持装置等;软件设计基于VC2008平台,包含数据采集、图像显示、运动控制、数据存储等功能模块。采用该系统对铁路钢轨轨头进行超声波扫描成像试验,给铁路钢轨在线超声波探伤提供技术支撑。     

基于TRIO和PLC双控制器的船舶焊接机器人运动控制系统设计

针对现阶段船舶制造业焊接工艺的自动化加工水平普遍不高、人工焊接成本较高、效率低下、质量参差不齐的现状,设计出一种基于嵌入式运动控制器TRIO和PLC的龙门架式八轴焊接机器人运动控制系统。通过控制器TRIO驱动机器人八轴联动,实现了大尺寸大曲率船体板材的自动化焊接,PLC保证了系统运行的正确逻辑、各种电气信号的控制和采集。两个控制器之间通过RS232自由口协议实现稳定双向串行通信。试验证明,该焊接运动控制系统大大提高了焊接效率和质量,降低了工人劳动强度,有较强的应用和推广价值。     

基于软PLC和EtherCAT总线的DELTA2机器人控制系统设计与实现

由于传统PLC需要依赖于特定的软硬件,其硬件、软件系统封闭,系统开放性和扩展性不足,并且现场数据传输实时性不高。针对这些问题,提出了一种利用实时以太网EtherCAT协议通讯,基于PC的软PLC运动控制方案。该方案通讯总线采用分布式时钟技术,使用标准以太网协议,无需专用网卡,便能够实现多轴精确同步控制,适合高速机器人的高精度伺服控制。通过在DELTA2高速并联机器人上的测试分析,结果表明:该控制方案使机器人的运动控制性能得到了很大的提升。     

基于前馈控制的数控机床进给运动轮廓误差分析

轮廓运动控制是运动控制领域研究的重要课题之一,其广泛应用于数控机床与其它自动化运动控制系统中。由于位置伺服系统跟随误差的存在,导致直线和圆弧运动时产生轮廓运动误差。前馈控制是一种有效减小跟随误差的方法,已广泛应用于数控机床进给运动控制。文章研究了两轴匹配时前馈控制增益和前馈控制滤波器带宽对两轴轮廓运动精度,特别是圆弧运动精度的影响。结论对合理选择前馈控制参数,提高轮廓运动精度具有实际应用价值。     

基于多轴运动的液晶面板检测的安全控制设计

针对液晶面板检测的多轴运动过程,进行了系统防碰撞安全控制技术研究。首先分析了检测过程多轴运动模式,设计了系统运动控制流程;然后应用坐标变换理论,将多轴运动控制映射到设备统一参考坐标系中;结合检测过程自动、手动与MDI工况下的模式差异分析,提出了基于位置预判和干涉区域实时侦测的运动安全综合控制方法,并集成开发了液晶面板检测多轴运动控制系统;最后依据检测工艺进行了三种工况模式下的多轴运动测试,验证了系统防碰撞安全控制技术的可行性。     

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.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

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.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.