优化剪切控制在1580mm热轧线的实现

优化剪切控制系统在飞剪控制中的使用不仅降低了带钢切损,利于下游精轧咬钢,尤其在薄系列热轧带钢的生产中取得了良好的应用效果。     

飞剪计算机速度控制系统

斯罗曼飞剪机是实现带钢定尺剪切的重要设备,其运行速度与带钢的长度和厚度有关。本文介绍了它的速度模型软件实现方法和硬件构成原理。     

棒材生产线飞剪故障分析与处理

通过对棒材生产线飞剪控制过程的分析,找出剪切异常的原因,解决飞剪剪切异常的问题.     

在设计的同时进行仿真——Autodesk Inventor Professional在DANIELI冶金设备(北京)有限公司的应用

飞剪机的主要任务是将运行着的轧件按照工艺要求定尺剪断.随着轧机轧制速度和生产能力的不断提高,提高飞剪的速度和性能已成为人们致力研究的问题之一.飞剪机种类很多,根据其不同的剪切断面和速度快慢,被应用于不同的场合.目前较先进的机型为起停式曲柄飞剪,该飞剪一般处于静止状态,剪切时采用低惯量大扭矩直流电机,直接完成起动、剪切和制动等工艺过程.其实物模型如图1所示.     

高线飞剪控制原理及故障处理

本文着重介绍了高线飞剪的工作过程和控制原理。飞剪的起动和制动电流、恒速剪切速度及工作周期是飞剪控制的关键参数,只有控制好上述参数,才能确保飞剪正常运行。此外,还简要地介绍了飞剪的常见故障及其处理方法。     

飞剪的定位控制

针对飞剪剪切完后返回时的定位控制,提出分段直线控制与抛物线控制两种方法,使飞剪以最小的机械冲击力且不产生超调地返回原位。实践证明,用这两种方法进行定位控制,飞剪返回距原位不大于±15°,剪切棒材端面光滑,误差不大于2cm,剪切棒材的成材率大大提高。     

包米勒伺服系统在飞剪机上的应用

本文介绍了包米勒公司的伺服驱动系统以及飞剪控制的关键技术,通过针对飞剪应用开发的功能模块,实现对钢筋进行高速、高精度的定长剪切。     

高线飞剪控制系统

介绍高线飞剪控制系统,该系统采用主轧线S7-400PLC,配置FM458功能模块对飞剪进行逻辑控制、精确剪切、精准定位,从而实现系统的安全可靠运行。     

棒材倍尺飞剪T400控制方案优化

针对热轧棒材倍尺飞剪高速剪切时存在速度滞后并超调,影响产品质量,制约生产线运行速度的问题,对采用T400工艺板控制的热轧棒材倍尺飞剪,从原理上解析速度给定曲线对负载电流的影响,以参数化编程的方式实现控制方案优化。生产运行结果表明,采用优化控制方案,实现了倍尺飞剪高速精确剪切,达到了工艺要求的控制效果。     

起动式飞剪的微型机控制

用微机完成起动式飞剪对高速线材的剪切,可以提高剪切精度,降低废品率,具有很高的经济效益。本文讨论了飞剪微机控制系统的数学模型,提出自动校正砰-砰控制开关参数闭环位置系统的算法,并给出实现该系统的微机硬件和软件结构框图。     

经济实用的宽度定尺自动控制系统

介绍了一种利用数字电子技术改造传统产业的方法、利用PLC与变频器组成一位置随动系统，在钢板宽度定尺剪上完成了宽度定尺自动定尺与剪切。系统定尺精度高，剪切速度快，提高了钢板剪切质量和生产节奏，减轻了工人的劳动强度。     

小型材飞剪计算机双位置跟踪控制技术

通过对“万能式”飞剪机械传动系统的分析，提出了飞剪机组的剪刀与轧件位置、偏心轴与剪刀位置的计算机双位置跟踪控制技术和为保证剪切精度的在线轧辊测径技术，它完全达到了型材剪切的要求。通过一年的运行证明，设备达到了无维护、无故障运行的目标，仅提高成材率和降低备件、能源消耗等项费用，就为企业创效500多万元。这一技术和设备已达到国际同类产品的水平，在中小型材生产线上具有广泛的应用前景。     

Drill wear sensing and failure prediction for untended machining

Real-time control of drilling was carried out by measuring the thrust force and determining its gradient. Using a microcomputer-based feedback control system, experiments were carried out under different cutting conditions to test the effectiveness of the thrust force gradient in predicting failure. The system was able to predict failure due to excessive wear commonly encountered with 5 and 8 mm drills. With such drills, excessive weat at the outer corner led to an increase in the local temperature which in turn increased the wear. This led to very high temperatures (>600°C), causing local welding of the drill material to the peripheral surface of the hole being drilled. Furthermore, the high temperatures reduced the compressive yield strength of the drill material, causing sub-surface fracture to occur under the influence of the cutting loads. This cyclic phenomenon of “seizure” due to local welding and “release” due to shear fracture (i.e. “stick-slip”) caused sharp fluctuations in the thrust force under constant feed.

This paper discusses the effectiveness of the control system described above in predicting failure due to the excessive wear common to large drills. This system is also contrasted with another based on vibration measurements which has been successfully used to predict failure due to fracture common with small drills. This paper also presents other experimental sensor schemes in the literature. Finally, this paper proposes a framework for an “intelligent” machining process control system driven by multiple sensors, which would facilitate untended machining.     

掘进机恒功率自适应调速与记忆截割系统研究

由于掘进机在进给过程中截割头工作面负载变化存在随机性且幅度很大,设计并开发一套以可编程序控制器为数据采集和控制核心,上位机采用组态软件构建远程监控系统的掘进机自适应控制系统,采用多信息融合技术综合分析负载的变化,实现恒功率自适应调速,同时采用记忆截割与自适应调节相结合的控制方法,在记忆截割的基础上根据反馈信号进行局部调节,更新记忆曲线,保证掘进机的恒功率进给,延长掘进机截割头的使用寿命.     

基于嵌入式系统的切削颤振在线监测技术研究

针对机床切削过程中的颤振现象难于实时、精确监测和控制的问题,设计了一种基于"FPGA+ARM"结构的切削颤振在线监测系统。切削振动数据采集主控制逻辑用FPGA来实现,ARM则用来实现采集数据的处理及快速发出颤振警报。     

快速刀具伺服系统自抗扰控制的研究与实践

快速刀具伺服系统(fast tool servo, FTS)是实现非圆截面和非轴对称表面零件加工的关键部件. 加工过程中,FTS应克服时变切削力负载和自身参数的非线性, 驱动刀具完成高频高精度跟踪运动. 为了解决FTS的快速精密跟踪控制问题, 根据刀具运动参考轨迹已知的特点, 应用自抗扰控制原理和前馈控制策略, 针对基于剪应力和正应力电磁驱动的两种直线执行机构, 分别设计了采用线性和非线性扩张状态观测器的自抗扰控制器, 并利用传递函数和描述函数方法, 分析了线性控制器的跟踪精度和动态刚度特性, 探讨了非线性控制系统的极限环问题. 两种基于自抗扰控制的快速刀具伺服系统已应用于发动机椭圆截面活塞的精密车削和二维正弦微结构表面的超精密车削,满足了加工需求. 研究与应用结果表明: 自抗扰控制思想独特、算法易于工程实现, 具有很好的工程应用价值.     

Condition monitoring of CNC machining using adaptive control

In this work, an adaptive control constraint system has been developed for computer numerical control (CNC) turning based on the feedback control and adaptive control/self-tuning control. In an adaptive controlled system, the signals from the online measurement have to be processed and fed back to the machine tool controller to adjust the cutting parameters so that the machining can be stopped once a certain threshold is crossed. The main focus of the present work is to develop a reliable adaptive control system, and the objective of the control system is to control the cutting parameters and maintain the displacement and tool flank wear under constraint valves for a particular workpiece and tool combination as per ISO standard. Using Matlab Simulink, the digital adaption of the cutting parameters for experiment has confirmed the efficiency of the adaptively controlled condition monitoring system, which is reflected in different machining processes at varying machining conditions. This work describes the state of the art of the adaptive control constraint (ACC) machining systems for turning. AISI4140 steel of 150 BHN hardness is used as the workpiece material, and carbide inserts are used as cutting tool material throughout the experiment. With the developed approach, it is possible to predict the tool condition pretty accurately, if the feed and surface roughness are measured at identical conditions. As part of the present research work, the relationship between displacement due to vibration, cutting force, flank wear, and surface roughness has been examined.