共查询到19条相似文献,搜索用时 125 毫秒
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分析了数控系统的伺服结构,根据数控伺服系统模型的传递函数,从数学上分析了直线轮廓和圆弧轮廓数控加工的轮廓误差.利用MATLAB的SIMULINK对数控伺服系统进行了建模,分别给出了直线轮廓加工、圆弧轮廓加工和螺旋线轮廓加工的轮廓误差仿真图形.该仿真结果与数学分析计算结果一致. 相似文献
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以HCNC-1HA(华中I型)数控铣床为例,由实际加工问题出发,提出了国内一些数控系统不能实现圆弧半径等于刀具半径的零件轮廓的加工问题,分析了导致这一问题的原因,给出了解决该问题的方案。 相似文献
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前馈控制可以提高交流伺服系统的跟踪性能,同时也是降低数控机床轮廓误差的一种有效手段.文章在速度前馈的基础上,研究了在电流闭环的给定信号上增加电流前馈作用的新型前馈控制结构,仿真结果显示该新型前馈控制结构很大幅度地提高了交流伺服系统在加减速段的位置跟踪性 能.将该控制结构应用到伺服割字机中,加工结果显示新控制结构下的轮廓误差有所减小,加工实物曲线更为平滑. 相似文献
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复杂曲面多轴数控加工非线性误差理论分析及控制 总被引:4,自引:0,他引:4
刘宏 《组合机床与自动化加工技术》2003,(12):66-68
针对复杂曲面通常采用的多轴数控加工方式,结合加工用刀具,建立了多轴数控加工的非线性误差的数学模型,分析其影响因素,并给出了有效减少非线性误差的控制方法。 相似文献
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Tracking and contour error control in CNC servo systems 总被引:13,自引:3,他引:10
R. Ramesh M.A. Mannan A.N. Poo 《International Journal of Machine Tools and Manufacture》2005,45(3):301-326
The dynamic response of a machine tool is a complex interaction of several factors that includes the basic design of the machine as well as the capability and performance of the corresponding axis servo system. In terms of the performance of the servo system, tracking and contour errors are two important aspects that significantly affect the machine tool. Extensive research has been conducted over the last several decades into the study of these error components. A number of different approaches have been proposed by various researchers that attempt to effectively address this problem. This paper attempts to study the work that has been carried out in minimising tracking and contour errors in CNC machine tools. 相似文献
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Virtual CNC system. Part II. High speed contouring application 总被引:4,自引:1,他引:3
Kaan Erkorkmaz Chi-Ho Yeung Yusuf Altintas 《International Journal of Machine Tools and Manufacture》2006,46(10):1124-1138
This paper presents a trajectory planning strategy for maintaining the tool positioning accuracy in high speed cornering applications. A 3D contour error estimation algorithm is presented for determining the geometric deviation from arbitrarily shaped toolpaths. Two spline fitting strategies are developed for smoothening sharp corners. The under-corner approach reduces the toolpath length, and therefore the cornering time. This technique yields successful results when used with a high bandwidth servo controller (such as sliding mode control), capable of accurately tracking the commanded toolpath. The over-corner approach is based on stretching out the sharp corner with a smooth curve, which counteracts the ‘undercut’ caused by the large phase lag in low bandwidth servo controllers (such as P–PI control). The cornering feedrate is adjusted in the Virtual CNC platform, developed in the first part of this article, to ensure that contour error violation does not occur. The achieved cornering accuracy is verified in experiments, which are in close agreement with predictions obtained with the Virtual CNC. 相似文献
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机床数控系统根据插补结果发出位置控制指令对各坐标轴进行独立的位置闭环控制,驱动相应的机械传动机构,最终实现精确的轮廓进给运动.本文研究了各轴位置闭环控制特性对轮廓误差的影响,分析了两坐标轴进给运动控制系统圆弧运动时因伺服系统有限带宽引起的半径误差和运动轴性能不匹配引起的椭圆误差,并进行了仿真验证. 相似文献
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数控机床中螺距误差补偿原理及测量方法研究 总被引:1,自引:0,他引:1
俞鸿斌 《组合机床与自动化加工技术》2008,(1):42-46
文章对数控机床反向间隙补偿和螺距误差软件补偿原理及测量方法进行深入的研究,提出一种高效、快速螺距误差测量和补偿值设定方法,并进行了具体实例应用。实践证明该检测方法操作简单方便,测量结果正确可靠,特别适合我国国情,可以满足生产企业数控机床定期螺距误差检测、及时校正反向间隙和机电联调的需要,能有效改善机床定位精度和加工精度,对数控机床的合理使用和维护具有重要的实用参考意义。 相似文献
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伺服系统的基本原则是闭环控制,跟踪误差必然存在.如果多轴联动设备上使用伺服系统驱动进给轴,跟踪误差会引起加工轮廓误差.高精度数控机床要求轮廓误差越小越好.文章在定位过程中的伺服系统位置跟踪误差曲线等效成梯形曲线的基础上,从插补控制器着手研究跟踪误差的预测补偿控制.试验结果证明该控制方法简单有效. 相似文献
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数控机床进给系统产生的轮廓误差对产品质量有着严重的影响。为了对轮廓误差进行补偿,设计一种迭代学习轮廓控制器,用以提高进给系统的轮廓跟随效果。对数控机床进给系统进行分析后,获取其跟踪误差以及轮廓误差的模型。在该模型的基础上,设计线性插值法和圆域插值法,用来计算轮廓误差的大小。接着对进给系统在s域的闭环传递函数进行分析,采用PID反馈补偿器,设计迭代学习轮廓控制器,利用该控制器对实际轮廓误差进行补偿。仿真结果显示:采用此方法跟踪期望轨迹时,产生的最大跟踪误差为6.57%,较PID方法减小了5.7%;在跟踪期望轮廓时,产生的最大轮廓误差为0.8 mm,较PID方法减小了0.7 mm。由此说明此方法对轮廓误差的补偿性能较好,能够对数控机床进给系统的轮廓跟随准确度进行较好的控制。 相似文献
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This paper presents an analytical prediction and compensation of contouring errors in five-axis machining of splined tool paths. The position commands are first fitted to piecewise quintic splines while respecting velocity, acceleration and jerk continuity at the spline joints. The transfer function of each servo drive is kept linear by compensating the disturbance effect of friction with a feed-forward block. Using the analytically represented five-axis, splined tool path, splined tracking errors and kinematic model of the five-axis machine tool, contouring errors are predicted ahead of axis control loops. The contouring errors are decoupled into three linear and two rotary drives, and the position commands are modified before they are sent to servo drives for execution. The proposed method has been experimentally demonstrated to show significant improvement in the accuracy of contouring five-axis tool paths. 相似文献