数控机床直线轴误差辨识与补偿

发布时间：2018-01-24 02:05

本文关键词： 数控机床几何误差误差综合模型误差补偿　出处：《哈尔滨工业大学》2016年硕士论文　论文类型：学位论文

【摘要】：目前,数控机床在装备制造业的不断发展中扮演着举足轻重的角色,它的精度通常代表着制造业的发展水平。组成数控机床的各运动部件在制造和装配过程中不可避免地产生几何误差,这严重影响了其最终的加工精度。因此本文将着重研究数控机床直线轴几何误差的建模、测量、辨识与补偿的方法,开发了一套基于MATLAB的直线轴误差辨识与补偿软件,并进行实验验证。本文对数控机床几何误差源进行分析,根据垂直度和直线度误差的定义,将数控机床直线轴通常认为的二十一项几何误差中的垂直度代入到直线度误差中,使其组成18项新的几何运动误差项。新的18项几何误差造成机床刀尖点与工件点相对位移的偏差值即为几何误差量。结合数控机床的运动传递关系,采用齐次坐标变换矩阵建立新的误差综合模型。在误差综合模型基础上,忽略高阶误差项,建立几何误差元素模型与误差量的简化函数关系。基于新的误差综合模型的简化式,本文改进分步辨识法辨识机床各直线轴位置误差和直线度误差。接着通过误差元素定义解算出垂直度和单向转角误差。推导几何误差元素与圆轨迹径向误差量映射关系检测辨识新误差项的合理性。本文使用Hedenhain KGM181平面光栅为数控机床误差量测量工具,结合辨识和测量原理,开发出集测量、辨识和补偿为一体的软件,并在XOY平面对数控机床进行新的分步辨识,成功辨识出主要误差元素模型,同时结合Renishaw XL-80激光干涉仪进行位置误差的验证。基于新的误差综合模型,本文提出了一种直线段分段补偿策略,开发了几何误差补偿模块。并在XOY平面内,使用平面光栅进行定位补偿验证和六边形路径补偿。实验结果表明,本文对直线轴的辨识与补偿所提出的策略提高了数控机床误差补偿的准确性和快速性。
[Abstract]:At present, NC machine tools play an important role in the continuous development of the equipment manufacturing industry. Its precision usually represents the level of development of the manufacturing industry. Geometric errors are inevitable in the manufacturing and assembly process of the moving parts of the NC machine tools. Therefore, this paper will focus on the modeling, measurement, identification and compensation of geometric errors of linear axis of NC machine tools. A set of linear axis error identification and compensation software based on MATLAB is developed and verified by experiments. The geometric error source of NC machine tool is analyzed and the definition of verticality and straightness error is given in this paper. The verticality of the 21 geometric errors commonly considered by the straight axis of NC machine tools is substituted into the straightness error. The new 18 items of geometric error result in the deviation between the point of cutting point and the point of workpiece is the geometric error, which is combined with the relation of motion transfer of NC machine tool. A new error synthesis model is established by using the homogeneous coordinate transformation matrix, and the higher-order error term is ignored on the basis of the error synthesis model. The simplified function relationship between geometric error element model and error error is established, and the simplified formula based on the new error synthesis model is established. In this paper, the linear axis position error and straightness error of machine tool are identified by improved stepwise identification method. Then the vertical and unidirectional rotation errors are calculated by the definition of error element, and the geometric error elements and radial error mapping of circular trajectory are deduced. The reasonableness of new error term for projective relation detection and identification. This paper uses Hedenhain. KGM181 plane grating is a tool for measuring error of NC machine tools. Combined with the principle of identification and measurement, the software of measurement, identification and compensation is developed, and the main error element model is successfully identified by a new step identification of NC machine tools in the XOY plane. At the same time, the position error of Renishaw XL-80 laser interferometer is verified. Based on the new error synthesis model, a piecewise compensation strategy for straight line segments is proposed. The geometric error compensation module is developed. In the XOY plane, the plane grating is used to verify the positioning compensation and the hexagonal path compensation. The experimental results show that. The strategy proposed in this paper improves the accuracy and rapidity of error compensation for NC machine tools.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG659

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