柳钢中板双机架轧机Level Ⅱ控制系统开发

针对柳钢2 800 mm 双机架中厚板轧机,自主设计开发了完整的Level Ⅱ计算机控制系统。Level Ⅱ系统由数据通讯模块、模型设定模块、模型自学习模块、轧件跟踪模块、数据管理模块等多个模块组成。数据通讯模块负责Level Ⅱ控制系统和其他系统之间的数据通讯;数据管理模块包括数据采集与数据记录,为模型计算查询模型参数,记录每块轧件的实际工艺过程参数等;轧件跟踪模块负责轧件从出炉到轧制结束全过程位置和数据的跟踪,并在不同的触发点调用其他功能模块,进行自动轧钢的轧件调度控制和轧制节奏控制;模型设定模块利用数学模型,计算轧制规程;模型自学习模块包括长期自学习和短期自学习。通过各功能模块的协作,可以实现轧机生产过程的模型自动设定和全自动轧钢控制。该系统已经成功应用于生产现场,且应用效果良好。     

皮带轮圆筒形凸台多道次拉深成形工艺研究

目的研究皮带轮圆筒形凸台多道次拉深成形工艺过程。方法根据拉深系数计算拉深道次,并采用有限元模拟软件模拟分析多道次拉深成形过程。结果根据计算,需采用八道次拉深成形筒形凸台,成形过程中最大等效应力、应变分布在凸模、凹模圆角位置处及筒壁外表。随着道次增多,坯料内累积的等效应力应变值增大。结论八道次拉深成形后,坯料内累积的应力应变值较大,筒形凸台尺寸符合要求,成形质量较好,根据模拟结果成功进行了生产试制。     

珠光体钢丝多道次拉拔成形过程中的应变路径分析

目的研究高强度珠光体钢丝冷拉大变形过程中应变路径的变化规律及其对力学性能的影响。方法运用网格重划分和场变量传递技术,建立钢丝多道次冷拉应变路径全纪录有限元模拟方法,预测钢丝由0.62 mm到0.09 mm的多道次冷拉过程应变路径的演变。结果 23道次冷拉变形后,钢丝的最大应变值可达到4.360。随着拉拔道次增加,最大与最小等效应变值之间的差值随之增大,由第1道次的0.028增大至第23道次的0.473。结论钢丝多道次拉拔过程中,各道次在心部到表层方向上的等效应变分布规律相同,均为先增大后减小;钢丝心部等效应变值最小,次表层处等效应变值最大。     

双筒形皮带轮多道次拉深成形工艺

目的 研究双筒型带轮多道次拉深成形过程。方法 根据冲压手册计算拉深道次与凸、凹模尺寸,并采用有限元模拟软件DEFORM,模拟分析多道次拉深成形过程。根据理论计算得出需要8道次拉深成形双筒形带轮。结果 随着成形道次的增加,内筒及外筒圆角处累积的应力应变值最大减薄最严重,从外筒至内筒壁厚持续减小,其中内筒底部圆角为厚度最小处。结论 通过8道次拉深的方法成形出所需的零件,零件壁厚达到所需要求,并成功试验出成形质量较好的样件。     

多台阶深筒形件成形工艺设计及仿真

根据塑性成形理论分析、计算确定某电器产品的阶梯圆筒件成形工艺,并建立有限元模型,实现多道次拉深过程的仿真.最后对仿真结果进行分析和试验验证.     

空调用过滤瓶数控旋压成形工艺研究

结合缩径成形和旋压过程,建立了薄壁管缩径旋压变形力的理论计算模型和旋压力的计算公式, 并对旋压方式、道次压下量Δ及旋轮进给比f等成形工艺参数对滚珠旋压成形的影响进行了试验研究.     

基于分区交错算法的高层建筑风振数值模拟平台及实例

基于分区交错算法,通过对商业流体软件Fluent和结构计算软件Ansys的二次开发,搭建了高层建筑风振数值模拟平台。耦合界面上非匹配网格的搜索配对和数据传递,以及流体域的网格更新均采用UDF(User Defined Functions)编程实现;流体计算采用大涡模拟方法配合使用流体并行计算技术,以兼顾计算效率和精度,通过UDF和Scheme语言编程实现流体域参数化求解,为确保流体和结构域时间步长一致,流体计算采用子迭代技术;结构计算采用APDL(Ansys Parametric Design Language)语言参数化编程;采用Visual C++语言编制数值模拟平台主进程实现模块间的相互调用。采用该方法,对大气紊流边界层风场内方形截面高层建筑的风振气弹响应进行了数值模拟,将计算结果与气弹模型风洞试验和文献数值模拟结果进行了对比;还通过有、无考虑气动弹性时结构位移响应的比较,分析了气动阻尼对结构风振响应的影响。结果表明,该数值模拟方法可以较精确地求解高层建筑结构的风振气弹响应问题。     

复合材料细观结构三维有限元网格模型的建立

提出了针对颗粒夹杂为椭球形状并呈随机分布的多相复合材料的三维有限元网格的建立方法,为复合材料细观结构研究提供了一种全自动的建模工具。引入了以体积为标度的任意两椭球骨料侵入的判别准则,实现了一种三维随机骨料的投放算法;在基于映射法的颗粒表面有限元网格生成算法中通过扫描线布点和局部连接技术较好地解决了网格极化现象;采用改进的三维AFT方法生成基体的四面体网格,并利用AFT特性一次生成所有颗粒夹杂的四面体网格;为进一步的复合材料细观结构与宏观力学性能的多尺度计算打下了基础。最后用几个算例验证了算法的有效性。     

轧钢过程仿真和跟踪系统的设计

文章针对目前热连轧带钢轧制领域的仿真和跟踪控制的现状开发出一套针对性强的轧钢过程仿真和跟踪系统,提供了应用程序、轧钢设备工作状况、模型计算设定的测试手段,有效提高了热连轧带钢生产的效率,方便了用户对热轧生产的维护和监控。文章着重分析了轧钢过程仿真和跟踪系统,将其分成了七个组成部分:仿真控制单元、轧件跟踪模块、步序器控制模块、粗轧道次控制模块、基础自动化模块、模型库、人机接口画面,并分析了每个模块的具体设计方法。     

气井参数测试新方案

介绍了一种基于PC开发环境的气井参数测试与计算系统的实现、构成和主要模块的功能。利用数据采集技术对井口及分离器的几个参数进行淮确测量，并据此计算出气井各个层位的压力、温度等参数。该系统可实现气井参数演示、动态监视、参数测量计算和数据处理，并自动生成和打印测试报告。     

A product-configuration-driven system for assembly planning within a product data management environment

This paper describes the results of a project sponsored by the Engineering and Physics Science Research Council (EPSRC) in collaboration with leading engineering and consultant companies, which is aimed at developing new methodologies for Computer-Aided Assembly Process Planning (CAAPP). The aims of this project were to investigate contemporary industrial requirements for CAAPP, study the feasibility of integrating CAAPP with data management tools via a product model and review current state-of-the-art systems and methodologies. The research has been focused on finding solutions to some of the limiting factors that have kept CAAPP an immature technology for many years. The deliverable of the research project is a novel assembly planning system, which has been developed in a Product Data Management (PDM) environment. The system takes the product configuration model derived from the PDM system as the input. This input is analysed by the system using intensive built-in knowledge to yield detailed assembly plans. The system achieves integration of CAAPP functionality with a PDM tool, providing a data control framework and a high-level data structure to form the basis of planning. The prototype system has an automatic planning module and an interactive planning sub-system that complements it. The interactive planning module also allows the user to capture the assembly knowledge and model it as a flowchart in the system. As fully automatic planning is a new field, comparison of automatically generated results with those of the semiautomatic system help to evaluate the system and build up user confidence.     

Design of a universal thermoelectric module test system for testing rat brain thermo electrichypothermia

A universal microcontroller test system, which aims to determine the parameters of thermoelectric modules under various thermal loads, has been designed and realised using a novel test method. The test system has been designed according to a more simplified form of the present formula set, which has been made to accept minimum variables as the input in order to obtain more precise results. It measures all the parameters of a working thermoelectric module by measuring only the hot-side temperature, module operation voltage, current and thermal voltage values of the module. The new test system has been used to measure a standard thermoelectric module (Melcor CP 1.4-127-10L) in order to verify its performance. It has also been used to test the operation of an experimental medical apparatus, which is used to induce hypothermia (low body temperature) in the brains of rats using a thermoelectric module     

A learning algorithm for self-calibration of a voltage calibrator

An algorithm either to extend the calibration period or to reduce the measurement uncertainty of a DC voltage reference module is presented. This module is used either as a transfer, independent, or working standard, or as a reference module incorporated into a larger measuring system. The basic idea is that the deviation history of measured voltage differences of reference elements of a group reference module during the calibration period can be used as a learning period for a neural network. This neural network, when created, can numerically correct particular reference elements later in the working period. Results were obtained by simulation and evaluated on the basis of empirical data and simulated input functions. Hardware solutions to model this algorithm are discussed     

列车垂向振动的半主动简谐隔振研究

依据拉格郎日方程,建立六自由度列车半主动隔振系统的垂向振动模型;应用MATLAB/SIMULINK仿真模块构造列车半主动隔振系统仿真模型,对列车进行时域分析。在轨道具有简谐输入的情况下对列车的隔振性能（如隔振位移、隔振传递率等）进行了计算分析,讨论了弹簧刚度、阻尼、车速、激励的波长等对隔振性能的影响。通过研究可得列车系统采用半主动开关阻尼器,确实能够改善系统的隔振性能。     

深度卷积神经网络在滑动轴承转子轴心轨迹识别中的应用

针对传统旋转机械智能识别方法需要人为提取特征及诊断精度低的问题,基于深度学习的强大学习能力,提出一种深度卷积神经网络故障诊断模型(Deep Convolutional Neural Network Fault Diagnosis Model,DCNN-FDM)用于轴心轨迹识别。该模型包括输入模块、特征提取模块及分类模块三部分。原始图像输入模型后,经过输入模块的二值化处理及最近邻插值,统一变为尺寸大小为32×32的单通道图像;经特征提取模块中两组交替的卷积层和池化层作用,得到图形特征;最后,这些特征经全连接层的扁平化处理而张成一维向量,输入到softmax分类器中进行分类。利用奇异值差分谱方法,对实测轴心轨迹进行提纯,得到4类轴心轨迹样本集用于DCNN-FDM的训练与预测。结果表明:所提模型较传统的浅层学习模型的识别效果好,可实现转子故障的精确诊断,识别率达到97.09%。最后通过全连接层的主成分可视化分析,验证了模型具备自适应特征学习能力。     

基于带阈值模块一维残差网络的刀具磨损监测方法

基于带阈值模块一维残差网络和双向长短期记忆网络,设计了刀具磨损监测模型和预测模型。将传感器信号经过小波分解后输入监测模型中,阈值模块自动选择阈值对信号降噪,残差模块提取信号特征,然后输出刀具磨损监测值,再将其输入到预测模型中获得刀具磨损预测值。实验证明:该监测模型与不带阈值模块的一维残差网络模型和卷积神经网络模型进行了对比,监测准确率分别提高了0.327%和1.697%;预测模型的预测效果较好,绝对误差仅为0.023。     

数字舰炮随动系统精度测试分析

对数字舰炮随动系统跟踪精度的角差量测试方法及全角量测试方法进行了分析,并用典型的SDC(Synchro-to-Digital Conversion,同步机数字转换器,1700/2系列)模块,对角差量测试方法在MATLAB平台上进行了仿真试验,发现传统的角差量测量方法用于采用SDC模块的舰炮随动系统存在不可忽略的测量误差.提出了采用全角量测量方法,利用误差相消原理对舰炮随动系统输入信号进行变换、测量的方案,仿真试验结果表明:该方法可大大减小数字舰炮随动系统精度测试误差.     

A vertically intersected dual-axis modularized reconfigurable actuator: design and application for a six-axis humanoid robot arm

A vertically intersected dual-axis modularized actuator system (DAMA) is developed and applied to a six-axis humanoid robot arm in this article. The DAMA consists of a two independent joint system, and the system structure is further refined using finite element analysis. It will be shown that the novel DAMA modular system can be used to easily construct a mechanism with any degrees of freedom. In other words, a modular or reconfigurable system can be achieved using the DAMA module. Based on simulations with ADAMS and MATLAB software packages, the system dynamic properties can be observed. In addition, the hardware and software systems of the DAMA are developed. The hardware architecture is composed of a microprocessor, an RS-232 to CAN bus module, and two independent-joint controller modules. The software control system is written in Visual C++. The system employs a simple but effective PID scheme to independently control the DAMA's two joints. The experimental results show that for an S-curve and circle trajectory input position command, the DAMA and the six-axis humanoid robot arm, which is formed by the DAMA module, can track the command well. Hence, the DAMA can be used as a generic module for multiple-degree-of-freedom systems.     

Impedance estimation of photovoltaic modules for inverter start-up analysis

Starting-up of photovoltaic (PV) inverters involves pre-charging of the input dc bus capacitance. Ideally, direct pre-charging of this capacitance from the PV modules is possible as the PV modules are current limited. Practically, the parasitic elements of the system such as the PV module capacitance, effective wire inductance and resistance determine the start-up transient. The start-up transient is also affected by the contactor connecting the PV modules to the inverter input dc bus. In this work, the start-up current and voltages are measured experimentally for different parallel and series connections of the PV modules. These measurements are used to estimate the stray elements, namely the PV module capacitance, effective inductance and resistance. The estimation is based on a linear small-signal model of the start-up conditions. The effect of different connections of the PV modules and the effect of varying irradiation on the scaling of the values of the stray elements are quantified. The System model is further refined by inclusion of connecting cable capacitance and contactor resistance. Dynamics of the resulting fifth-order model are seen to be consistent with those of the simplified third-order model. The analysis of this paper can be used to estimate the expected peak inrush current in PV inverters. It can also be used to arrive at a detailed modelling of PV modules to evaluate the transient behaviour.     

基于扫频技术的乐甫波器件测试系统

介绍了乐甫波器件的结构,设计制作了乐甫波器件,给出了乐甫器件的制作参数,搭建了基于扫频技术的测试系统,包括信号源模块、信号采集模块、微控制器模块等.通过DDS芯片AD9912在一定频率范围内,以一定频率间隔扫频输出高频正弦激励信号,利用AD8302芯片测量扫频范围内每一频率点的器件输入激励信号与输出响应信号幅值比,描绘出幅频特性曲线,并给出器件谐振频率.该测试系统的测量结果与网络分析仪基本一致,实现了网络分析仪的扫频功能.