激光切割钢板效率研究

通过对二维激光切割钢板过程的分析,提出了激光切割钢板时间可分为有效切割时间与无效切割时间两部分,并指出激光切割效率的提高不仅在于提高切割速度,而且还在于缩短无效切割时间。认为二维空程最短路径研究仅是缩短无效切割时间提高效率的一个方面,缩短无效切割时间还可以从打孔、指令执行停顿、Z轴行程等方面进行。对切割路径前打孔的工艺过程进行了具体研究,提出了减少打孔的工艺处理方法,经SLCM-1225数控激光切割机切割试验,效率提高明显;同时也佐证了减少打孔能够缩短无效切割时间,进而提高切割效率。     

基于模糊控制的激光加工间隙控制设计分析

Z轴激光头的随动功能(焦位控制)是激光板材切割工艺的关键技术。为了满足激光板材加工适应复杂条件并具有快速性与稳定性的要求。针对Z轴随动功能,提出了基于模糊控制和前馈补偿相结合的控制方法,提高了激光切割头Z轴随动的动态响应性能与鲁棒性。以某数控激光切割随动系统为对象,进行仿真研究,并与普通PID控制器对比分析。结果表明:设计的模糊前馈控制器,响应特性优于普通PID控制器,具有更快的响应速度与更高的稳态精度,并能很好的消除扰动,为实际的系统优化设计提供了依据。     

基于欧拉回路的数控火焰切割路径优化研究与实现

数控火焰切割路径优化问题是尽量减少点火次数,保证每个零件的轮廓轨迹只切割一次的条件下尽可能的缩短火焰割嘴在轮廓间移动的空行程距离。在零件外轮廓切割问题上提出了一种基于欧拉回路的切割路径规划算法,先计算零件外轮廓的相邻关系,然后基于最小生成树算法思想利用空白废料区域通过搭"桥"法构造欧拉图,最后求解该欧拉图的欧拉回路,从而确定整个样板的切割路径。与现有文献的算法与工厂数控机床生产统计结果表明,使用该方法在外轮廓切割上能够保证一笔切割,解决了点火熄火打孔位置选取问题,空程比例大幅降低,明显提高了生产效率。     

激光切割路径的自适应飞行半径果蝇算法优化

为提高激光切割路径优化效果,同时针对果蝇算法(FOA)中果蝇个体的飞行半径的设置主要依靠经验的缺陷,提出了基于自适应飞行半径果蝇算法(AFRFOA)的激光切割路径优化方法.相比于FOA,AFR-FOA中的果蝇个体的飞行半径会随着迭代次数的增加而自适应的变化,克服了固定半径的缺陷,能够实现全局搜索和局部搜索的平衡.钣金激光切割路径优化实例表明,AFRFOA获得的切割路径中,空行程更短,切割耗时更少.     

高性能激光打标机软件体系结构

分析了加速度和空行程对激光打标机性能的影响,提出了一种基于流水线架构的高性能激光打标机软件体系结构,它以20μs的精细插补周期进行实时插补,并通过全局速度规划、空行程优化等方法在确保标刻质量的前提下显著提高了标刻速度。     

基于蚁群算法的矩形件切割路径优化

针对矩形件外轮廓切割问题,设计了基于蚁群算法的切割加工过程中空行程路径优化方法,开发了相应软件模块.该方法在矩形件外轮廓切割路线简化的基础上,结合旅行商问题的求解对切割起始点顺序进行优化,避免出现矩形件在切割过程中外轮廓被重复切割的问题.算例表明:该算法可显著减少空行程路径的总长度,有效缩短切割加工过程中的辅助时间,提...     

二维矩形件切割的路径优化

对二维矩形件切割的路径进行全局和局疗优化，全局优化是通过优化矩形块的切割顺序保证整体空行程最短，局部优化是通过共边切割和连续切割达到节约空行程和防止矩形件变形目的。     

基于DMC1856的五轴激光切割机控制系统研究

针对大功率、高精度、三维立体激光切割技术的控制问题,对多轴联动激光切割技术的轨迹插补和速度控制等问题进行了研究,提出了一种基于DMC1856运动控制器的五轴激光切割控制方案。激光切割主机采用了龙门倒挂式,其具有驱动激光头沿空间运动的X、Y、Z轴,以及激光头摆动的A、C轴共5个坐标轴。控制系统采用了NC嵌入PC的双CPU方式,在PC的Windows 7操作系统环境下,以.NET Framework为框架,开发了控制系统的后台管理程序、非均匀有理B样条曲线(NURBS)插补预处理算法等;NC部分以GALIL运动控制器DMC1856为核心,完成了NURBS插补的实时部分、位置控制、外围逻辑控制(PLC)等。在Matlab环境下对控制系统的NURBS插补算法与速度控制算法进行了仿真实验。研究结果表明,该控制系统适用于复杂自由空间曲面的激光切割,满足现代加工的高速、高精度要求。     

基于遗传算法的多主轴头加工空行程轨迹规划

针对多主轴头五轴机床加工时需手动规划空行程的问题,提出一种空行程轨迹自动规划方法。在机床运动学建模的基础上,针对刀位点轨迹和刀轴矢量,分别提出基于最短路径的刀位点轨迹规划和无碰撞刀轴矢量规划,将空行程规划问题转化为参数优化问题。为了简化碰撞检测,提出两级相交检测算法。通过加权系数法建立空行程规划的目标函数,并采用遗传算法求解,规划出一条无碰撞、运动时间最短、旋转轴角度变化量最小、末端轨迹最短的具有柔性的理想轨迹。在Vericut建立的仿真平台上,验证了该方法的可行性和有效性。所提方法具有拓展性,通过多次分解轨迹求取棱交点能够实现复杂工件的空行程规划。     

复杂轴类零件非圆轮廓接触式随动测量方法

非圆轮廓随动接触测量方法研究对实现曲轴、凸轮轴等复杂轴类零件高精度、高效率检测具有重要意义,针对复杂轴类零件非圆轮廓表面检测设计了一套接触式随动测量方案。借助头尾架环规建立工件坐标系,提出了回转中心与顶尖几何中心相对位置关系标定方法,建立了随动接触测量装置沿工件轴线方向运动时与回转轴线不平行引起的系统误差计算模型。利用凸轮基圆区域的转角与径向尺寸进行基圆最小二乘圆心位置寻优,以实现凸轮偏心修正,采用敏感点法与最小二乘法相结合的方式构建了凸轮升程误差评价模型。仿真分析了随动接触测量装置安装误差与顶尖几何中心标定误差对凸轮升程误差评定的影响。与ADCOLE 1200SH专用量仪的对比试验和重复性测量试验研究表明:SE13-J10型轴类零件随动接触测量机的凸轮尺寸、形位误差测量精度和重复精度满足轴类零件高精度测量需求,验证了接触式随动测量方案与凸轮误差评价模型的正确性。     

发动机缸体复杂平面加工路径优化策略

以缸体顶面和电机安装面的铣削加工为对象,提出了基于动态铣削弧长分析的平面加工路径优化理论与方法,利用UG建模与分析和高精度激光扫描成像技术,获得了不同走刀路径下的动态铣削弧长波动情况,最后以更优化的走刀路径提升了缸体顶面质量,改善了电机安装面加工振动和噪音的情况。     

关于缸盖座圈60°锥面宽度控制方法的研究

基于缸盖座圈锥面的加工品质对发动机功率、油耗与排放都有重要影响的认识,控制缸盖座圈锥面不同角度宽度尺寸可以提高缸盖进气气流的平顺性、稳定性,以保证发动机缸盖进气性能品质的一致性,为此探究了座圈底孔加工深度公差、座圈厚度公差、座圈加工深度公差三个因素和座圈底孔位置度公差,座圈内径公差,座圈同轴度,座圈锥面同轴度四个因素分别在Z轴和Y轴对60°锥面宽度的影响,得出可以通过改变加工起始位坐标获得所需要的60°锥面宽度的结论,实际加工结果验证了这一结论。     

3D激光切割机的MasterCAM后处理定制技术

在分析激光切割机床加工程序格式特点的基础上,以MasterCAM软件的3D数控铣削后置处理文档MPFAN.PST为参照,提出了两种后处理定制的方案及刀路定义要点,有效地解决了3D激光切割加工所需程序输出问题.     

A review of cutting path algorithms for laser cutters

This paper presents a review of the literature on generating cutting paths for laser cutting machines. Firstly, the cutting path problem is defined including all relevant technical side constraints which exist plentifully in laser cutting. Secondly, a former classification method is updated to include all types of cutting path problems. Thirdly, a comprehensive review of solution methods and related applications is presented. Throughout the literature review, trends in research in cutting path generation and interesting areas for future research are identified.     

Knowledge-based CNC torch path generation for laser cutting of planar shapes

In this paper, we propose a knowledge-based method for generating a CNC torch path for laser cutting of the outlines of planar shapes. The proposed method consists of two main phases: laser cutting knowledge construction and CNC torch path generation using the knowledge. In the first phase, laser cutting experiments are conducted on various operating parameters, and then empirical data are stored and analyzed to make up the knowledge of laser cutting. With this knowledge, we can inquire what a kerf width is for specific operating parameters. In the second phase, using the knowledge of laser cutting, the CNC torch path is generated for cutting the outlines of the given planar shapes. This phase is basically based on the offset generation of each outline by a sequence of arc splines, where the offset distance is the same as the half of the kerf width determined from the constructed knowledge. The proposed method based on laser cutting knowledge makes full use of arc interpolators in CNC torch path generation. The method can efficiently reduce the number of path segments while keeping the torch path within the desired accuracy.     

硬泡棉鞋垫斜边专用数控切削设备的研制

研究了硬泡棉鞋垫斜边专用数控切削设备的工作原理、机械结构和控制系统软硬件结构,介绍了用AutoCAD绘制硬泡棉鞋垫轮廓曲线并提取坐标点的方法,研究了用PLC控制二维数控平台实现鞋垫斜边平面曲线的方法,论文研究了用Z轴电机控制刀具切削方向以切削出硬泡棉鞋垫均匀光滑斜边的方法.     

Applying an On-line Crack Detection Technique For Laser Cutting by Controlled Fracture

A new laser cutting system, which uses a laser to induce controlled fracture and combines an image processing technique for crack detection and compensation of the laser path to control crack direction, is proposed in this study. The laser cutting is based on the controlled fracture technique, the laser beam strikes the surface of a thin brittle plate which results in a stable fracture. The cutting of the material results from crack propagation along the cutting path. Because the crack propagation at the crack tip is slower than the moving laser beam, the actual fracture trajectory will deviate from the desired trajectory, for example, when cutting a curve or a right angle, especially at high cutting speed. In order to eliminate the deviation, the actual position of the crack tip must be detected on-line and the path of the laser beam must be modified. The compensation is based on the lagging distance between the crack tip and the laser spot. The laser cutting system comprises a CO2 laser, a digital image-processing system, and an XYZ positioning table. The cutting of right angles for silicon wafers and the cutting of circular arcs for alumina ceramics are carried out to validate the system. The image processing speed of the crack detection system is 0.1 s per detection, which is fast enough for continuous on-line crack detection, so that the method can be applied for any complicated curve cutting.     

等离子熔积与激光切割复合直接制造CAM软件研究

针对等离子熔积制造易产生侧表面阶梯效应,导致精度和表面质量不高的问题,提出将等离子熔积和激光轮廓切割复合以改善熔积成形件表面质量的方法。开发了等离子熔积激光切割复合直接制造CAM软件,在软件中提出了一种带法向的分层切片方式,对等离子熔积、激光轮廓切割的轨迹分别进行了规划,产生相应的NC代码,并对2个单工序NC代码进行了复合,以达到等离子熔积和激光轮廓切割工艺上复合的目的。     

The effect of continuous and pulsed beam modes on cut path deviation in diode laser cutting of glass

During laser cleaving of brittle materials, with the controlled fracture technique, thermal stresses are generated which induce the crack and extend it along the cutting path, subsequently causing material separation. One of the problems in laser cutting of glass with this technique is the cut path deviation at the leading and the trailing edges of the glass sheet. Previous work with a continuous beam diode laser has shown the deviation to be partly due the high magnitudes of thermal stresses generated near the edges of the sheet. This paper reports on the effects of using a pulsed diode laser to cut soda lime glass. The effect of pulse parameters and cutting speed on the quality output variables such as cut deviation angle and surface finish are studied. Finite element modelling is also used to simulate the effects of the moving beam on stress generations to facilitate the understanding of the process mechanisms, and the results are compared with the experimental data. This work shows how to minimise the cut path deviation at the edges by reducing thermal stresses using optimum pulsed diode laser parameters and providing additional flexibility to the process.     

Strategies and Processes to Measure the Dimensional Geometry of Sheet Metal Parts for Exact Laser Cutting

This paper describes strategies and processes to measure the dimensional geometry and deformations of sheet metal parts, in order to improve accuracy in laser cutting. A robust circular triangulation laser probe was integrated into a CNC machining centre. For the development of the measuring system a non-contact laser sensor and a personal computer (PC) were integrated information-technically with the NC-controller of the machining centre, as introduced in this study. To meet the demands of the measuring tasks in laser machining, the meas-uring uncertainty of the selected laser probe with respect to different measuring procedures, such as the fixed height procedure, surface tracing procedure, and profile-orientated procedure for steel and plastic materials, was investigated in this study. When measuring uncertainty is considered, the profile-orientated procedure best meets the accuracy requirements. According to the experimental results, the uncertainty could be minimised to within ±20 μm in the middle measuring range. To shorten the measuring time, a twofold measuring strategy was developed. The first step checks for existing deviations quickly. If necessary, in the case of deviations of the actual machining path from the theoretical machining path, these can be quantified in the second step. A nine-point measuring strategy was proposed in this study in order to calculate the surface normal of the deformed sheet metal. An algorithm for calculating the path correction using these deviations and the calculated surface normal with respect to the coordinates and the surface normal of theoretical path position, was also presented. The algorithms were verified using the developed automatic measuring system on a 4-axis machining centre with satisfactory results. One specific characteristic of the strategy presented is that the machining path can be verified for the case of laser cutting for workpieces without edges or marks.