基于STM32+FPGA的多轴运动控制器的设计

运动控制器是数控机床、高端机器人等自动化设备控制系统的核心。为保证控制器的实用性、实时性和稳定性,提出一种以STM32为主控制器、FPGA为辅助控制器的多轴运动控制器设计方案。给出了运动控制器的硬件电路设计,将S形加减速算法融入运动控制器,提高了控制精度,可有效避免过冲、振荡等现象的发生。在三维点胶机平台上对运动控制器的性能进行了测试,结果表明：点胶机各轴能按照设定的轨迹运动,运行平稳且实时性高,具备良好的应用前景。     

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.     

基于ARM+DSP+FPGA的机器人运动控制器研究

为了满足机器人运动控制器实时性的要求,研究一种基于ARM+ DSP+ FPGA的机器人运动控制器,分析该机器人运动控制器的体系结构特点、硬件电路设计和各主要模块.所研究的控制器能够实现机器人可靠的运动控制.     

基于FPGA和NiosⅡ的运动控制器研究

采用现场可编程门阵列( FPGA)+ NiosⅡ的硬件设计方案,设计一款三轴运动控制器。在FP-GA内部嵌入NiosⅡ软核CPU,并利用这个CPU实现速度控制和粗插补算法,同时利用FPGA硬件逻辑实现串口控制、I/O处理及精插补算法,软硬件协同完成高速、高精度运动控制。测试结果表明：该运动控制卡具有电路紧凑、性价比高、实时性强等优点。     

级联式运动控制网络高精度同步策略

在级联式运动控制系统中,为了解决各运动轴不同步的问题,提出了高精度的多轴同步补偿策略。简单介绍了主控制器与伺服节点之间的通信过程,探究了通信延时的主要影响因素,并在FPGA硬件平台上设计了同步补偿定时器,然后根据节点间的通信延时情况配置定时器的补偿时间,以实现多轴运动同步启动的功能。最后通过硬件实验,搭建起五轴同步运动控制系统,验证了该同步补偿策略的有效性,且性能稳定,具有一定的实用价值。     

基于串口通信的六轴运动控制器的研发及应用

文章针对数控系统研发中运动控制这一重点问题,提出了采用基于PC机串口开发六轴运动控制器的观念和方法.利用PC机的串口资源,研制开发基于串口通信的六轴运动控制器.采用C51系列单片机设计了该运动控制器的硬件结构,详细介绍了通信协议,系统设计了六轴运动控制器的软件结构.并把该运动控制器用于数控焊接机和数控校直机,取得了较好的经济和社会效益.     

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。     

基于μC/OS-Ⅱ的多轴运动控制器的设计

介绍了以DSP和FPGA为核心的多轴运动控制器的硬件组成,详细说明了基于μC/OS-Ⅱ的运动控制器内部各任务的建立,阐述了如何利用消息队列实现插补算法和走步控制,最后给出了运动控制器的应用实例。     

一种通用嵌入式多轴运动控制器及其应用

提出了ARM微控器LPC2214与4轴3联动DSP运动控制芯片MCX314A相结合的通用运动控制器方案。阐述了该运动控制器在X、Y两轴数控伺服工作台中的应用原理。该控制器具有高速度、高精度、高可靠性、成本低等特点,它在数控机床的控制中有重要的应用价值。     

基于ARM-MCX514的机器人-数控协同系统运动控制器设计

由于机器人工作的复杂性日益增加,单个机器人的工作能力愈发显得不足,针对当前问题,提出将ARM微控制器与MCX514运动控制芯片相结合用于机器人-数控系统的协同运动控制。在硬件设计层面,以ARM微控制器与MCX514运动控制芯片为核心硬件,设计了芯片间的通信线路以及外围电路和接口。在软件设计层面,依托FreeRTOS嵌入式操作系统,采用多线程编程模式,由MCX514控制四自由度数控系统,ARM控制三轴的机械臂部分,利用握手式基坐标系标定方法实现机器人与数控系统的协同运动,并设计了配套的上位机程序。通过与ACR9000运动控制器的对比分析,证明所设计开发的控制器精度达到预期效果,具有一定的市场价值和应用前景。     

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.