基于倍福CX控制器的AGV控制系统设计

对传统的人工叉车进行自动化改造可以大幅度提高车间物流自动化水平。以倍福控制器CX5130作为AGV控制核心,倍福控制器分别与激光导航传感器和无线终端通过TCP/IP协议通信,实现与AGV本体和调度系统的数据交换。激光导航传感器通过反光柱返回激光导航仪发射的激光束实现AGV的定位。倍福HMI界面作为人机界面方便操作和监控。实现AGV的自动运行之后,通过PID算法提高了AGV的定位精度。实验结果表明:所设计的控制系统能满足AGV系统使用要求,成本低,验证了其有效性和可行性。     

AGV控制系统研究

以固高科技有限公司的GE-40-SV运动控制器作为AGV运动控制核心,采用BG1Z型增量式编码器采集电机转速及方向,利用PC作为公共平台,以VC++6.0作为软件开发工具,建立了AGV的控制系统,从而实现AGV直行、转弯、自转及调速等基本运动功能。     

基于PMAC运动控制卡的AGV控制系统设计

介绍了一种基于PMAC运动控制器的AGV控制系统.建立了以PMAC为核心的AGV控制硬件结构,并采用Visual C++设计其控制软件.结果表明:使用PMAC作为AGV的控制器进行软硬件设计能够实现自动引导车的精确定位,并且能够降低系统的开发难度.     

一种基于标记码的AGV小车导航修正方法

在自动导航小车(Automated Guided Vehicle,AGV)系统中,二维码可以用来进行站点识别和位置修正。但是,常见的QR二维码存在解码时间长的问题,为此,设计了一种简易的标记二维码,来加快信息提取的速度。通过对采集的二维码图像进行预处理后,基于轮廓树算法提取图像中的二维码信息,通过与标准图像进行匹配获得AGV在定位块处的位置和姿态,从而实现AGV小车定位误差的消除和姿态调整,并获取与站点相关的信息。实验结果表明:所设计的标记二维码具有鲁棒性好、精度高和较好的实时性。     

基于ROS的工业机器人及AGV的视觉协同控制系统

当前自动化上下料的机器人之间仍各自独立运行，上下料位置固定缺乏柔性，智能化程度低。针对以上问题设计了基于ROS的工业机器人及AGV的视觉协同控制系统，用以实现智能化、柔性化的上下料工作。在ROS系统上，基于全局视觉与改进ArUco tag识别技术，开发了机械臂和AGV的识别与控制模块，实现了两种机器人在全局视觉下的识别与路径规划；并基于动态指令技术和ROS主从机通讯技术，实现了所开发ROS系统与机械臂和AGV的可靠通讯；最后，考虑不同机器人的协作规则和目标位姿计算方法，结合上述机器人识别与控制模块，提出了一种机械臂与AGV的视觉协同控制方法。实验测试表明，该系统能够实现多机器人的识别、控制与协同，工件托盘能够通过AGV按照要求实现任意指定位置的上下料接驳，具有良好的稳定性与柔性。     

物流搬运AGV的轨迹跟踪与控制

以物流搬运自动导向车AGV的轨迹跟踪为研究目标。建立了三轮式AGV的运动学模型,并对其运动特性进行了分析,提出了AGV的运动控制策略,获得了AGV轨迹跟踪的控制规律,并利用Lyapunov函数验证了控制系统的渐近稳定性。以具有任意初始误差的圆和直线为参考轨迹,应用Matlab／Simulink对控制系统进行了仿真研究。仿真结果验证了控制策略的有效性和正确性。     

AGV在冷轧磨辊间的应用

针对国内某钢厂冷轧磨辊间现阶段存在的轧辊运输效率低、员工负荷重、安全性低等问题,提出了使用现代化物流运输设备AGV,实现磨辊间轧辊的运输自动化和作业无人化。结合磨辊间实际情况,设计了AGV小车、AGV控制系统和周边输送系统。该方法有效地提升了作业效率、管理水平和安全性能,对AGV在磨辊间的使用有一定的参考意义。     

基于ROS与融合算法的AGV路径规划研究北大核心

针对传统A^(*)算法在AGV路径规划中存在搜索范围大、转折多、实时性差等缺点,以A^(*)算法为基础,通过建立栅格地图,改进启发函数,去除多余节点和提高避障安全性。针对AGV在复杂环境下的动态路径规划问题,将改进A^(*)算法与动态窗口算法进行融合,规划出一条具有实时性的最优路径。通过仿真实验,验证了改进算法的有效性与可行性,实现了路径优化。通过机器人操作系统进行实验,结果表明AGV运行时的路径规划合理,满足实际应用需求。     

便携式计算机电池保护器双面自动贴合机的研究与设计

针对便携式计算机电池保护器生产过程中存在的自动化程度低、麦拉片贴合良品率低等问题,设计了便携式计算机电池保护器双面自动贴合机及其控制系统。通过对便携式计算机电池保护器双面自动贴合机工艺要求及功能特点分析,确定设备整体设计方案,并对其关键部件进行了详细设计,包括麦拉片传送机构、麦拉片贴合机构等;采用PLC作为控制系统的主控制器,实现电池保护器双面自动贴合麦拉片;以触摸屏作为人机交互界面,实现设备调试及系统运行状态监测等功能。该设备已投入实际生产使用,应用效果表明:该设备运行稳定,操作简单,自动化程度高,提高了产品生产效率和良品率。     

双驱双向AGV控制系统设计

以工业平板电脑+可编程多轴控制器(PMAC)构成开放式控制器硬件系统,采用面向对象的C++程序设计语言进行上位机控制系统软件开发。根据技术要求进行系统功能需求分析,采用模块化的思想,设计系统软件总体结构;介绍了导航模块纠偏算法的实现。最后以双驱动双向AGV为机械本体进行停车定位测试。结果表明:该AGV的平均定位精度为5.144 mm,最大的定位精度为9.232 mm,其精度满足要求,该控制系统软件较好地完成了导航定位任务。     

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.     

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.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.     

电化学噪声数据处理方法概述

综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。