4-Axis Machine Tool Geometric Error Modeling and Measurement

2012 ◽  
Vol 152-154 ◽  
pp. 788-795 ◽  
Author(s):  
Fang Yu Pan ◽  
Ming Li ◽  
Chang Kai Xu

To improve the machining precision and reduce the geometric errors for 4-axis machine tool, multi-body system theory is introduced . Based on of the theory, ,through analysing the matrix of the position transformation and the displacement transformation, a model for the machine tool is put forth. By the laser Doppler displacement measurement, test is done and value of the errors is achieved which will benefit for later compensation.

2012 ◽  
Vol 271-272 ◽  
pp. 493-497
Author(s):  
Wei Qing Wang ◽  
Huan Qin Wu

Abstract: In order to determine that the effect of geometric error to the machining accuracy is an important premise for the error compensation, a sensitivity analysis method of geometric error is presented based on multi-body system theory in this paper. An accuracy model of five-axis machine tool is established based on multi-body system theory, and with 37 geometric errors obtained through experimental verification, key error sources affecting the machining accuracy are finally identified by sensitivity analysis. The analysis result shows that the presented method can identify the important geometric errors having large influence on volumetric error of machine tool and is of help to improve the accuracy of machine tool economically.


2011 ◽  
Vol 108 ◽  
pp. 61-66 ◽  
Author(s):  
Qiang Cheng ◽  
Dong Sheng Xuan ◽  
Jie Sun ◽  
Zhi Feng Liu

Parts of geometric error coupled into space error is the main reason that affects machining accuracy of machine tools; therefore, how to determine the effect of geometric error to the machining accuracy and then assigning geometry precision of parts economically is a difficult problem in machine tool designing process. Therefore, based on multi-body system theory, a sensitivity analysis method of geometric error is put forward in this paper. Let’s take precision vertical machining center for an example. Firstly, an accuracy model of machining center is established based on multi-body system theory, and with 21 geometric errors obtained through experimental verification, key error sources affecting the machining accuracy are finally identified by sensitivity analysis. The example analysis shows that the proposed method can effectively identify the main geometric errors of parts that have great influence on volumetric error of machine tool, and thus provides important theoretical basis to improve the accuracy of machine tool economically.


2014 ◽  
Vol 597 ◽  
pp. 454-457
Author(s):  
Li Ping Zhao ◽  
Hong Ren Chen ◽  
Yi Yong Yao ◽  
Hu Zhao ◽  
Peng Yan

Deformation error caused by cutting heart and external force is one of the key factors influencing machining precision in machining process. Aiming to identify the machine deformation which has the most important influence on machining precision, an identification method for sensitive error and deformation based on multi-body system theory has been proposed, which lay the basis of stiffness distribution of a machine tool and structure optimization of parts. At the end of this paper, the effective of this method is verified by using the machine tool for globoidal cam.


2013 ◽  
Vol 694-697 ◽  
pp. 1842-1845
Author(s):  
Gui Qiang Liang ◽  
Jun Xian Zhang ◽  
Fei Fei Zhao

The effect of geometric error on machining accuracy was researched by multi-body system theory, as well as homogeneous coordinate transformation method. Taking a vertical machining center as example, topological structure of the machine tool was described by lower body array. Lower body array of the machining center, motion freedom between adjacent bodies and geometric errors of the vertical machining center were analyzed. Geometric errors of the bodies in the multi-body system were expressed by homogeneous coordinate transformation. Error model for machining accuracy was deduced and geometric errors having influence on the machining accuracy were identified. The research results provide guidance for analyze of geometric errors on machining accuracy.


2013 ◽  
Vol 690-693 ◽  
pp. 3244-3248
Author(s):  
Gui Qiang Liang ◽  
Ai Rong Zhang ◽  
Ting Ting Guo

In order to improve machining accuracy of machining center, the effect of geometric error on machining accuracy was researched by multi-body system theory. Taking a vertical machining center as example, topological structure of the machining center was described by lower body array. Geometric errors of the bodies in the multi-body system were expressed by homogeneous coordinate transformation. Error model for machining accuracy was deduced and geometric errors having great influence on the machining accuracy were identified. The research results show that, straightness errors and linear displacement errors in three directions have direct influence on machining accuracy, and the effect on machining accuracy caused by angle errors are related to the dimensions of the machining center and travel distance of the three axes. The research results provide guidance for analysis on sensitivity of geometric errors.


2012 ◽  
Vol 229-231 ◽  
pp. 2474-2477 ◽  
Author(s):  
Lin Yang ◽  
Jin Yuan Wang ◽  
Rui Nan Wu ◽  
Wei Wu

This paper studies the influence of machine slideway precision on the overall accuracy of machine tools, and puts forward the root causes of the decline in accuracy of machine tool guide is rail wear, the decline of rail accuracy will impact on the adjacent unit cell, thus decline the accuracy of the machined parts; Finally takes floor-type milling & boring machine as research object, bases on geometric error models of the theory of multi-body system to describe the spindle box rail wear trends and establish relationship between the spindle box rail wear and the machine precision.


2013 ◽  
Vol 401-403 ◽  
pp. 135-138
Author(s):  
Zheng Lin Yu ◽  
Hao Tian Yang ◽  
Bo Yu ◽  
Li Dong Gu

Based on the theory of multi-body system, for thetangent method CNC aspheric machine tool, the paper shows out the topologicalstructure and the array of low-order body of the system, the modeling processis stated, a specific mathematical expression for the comprehensive error modelis established, and it will be a steppingstone to the error compensation forthe machine tool.


2014 ◽  
Vol 915-916 ◽  
pp. 313-317
Author(s):  
Xing Zu Ming ◽  
Wei Wang ◽  
Lei Zhao ◽  
Man De Li

Based on the multi-body system theories and used the homogeneous coordinate transform. Systematically analyzed the geometric error and thermal error of face gear NC grinding machine. Established the face gear NC grinding machine of grinding mathematical model of comprehensive error according with the mechanism grinding errors,To provide a theoretical basis of the error modeling analysis and the error compensation on NC grinding Machine Tool of face-gear.


Author(s):  
Qiang Cheng ◽  
Qiunan Feng ◽  
Zhifeng Liu ◽  
Peihua Gu ◽  
Ligang Cai

Geometric error has significant influence on the processing results and reduces machining accuracy. Machine tool geometric errors can be interpreted as a deterministic value with an uncertain fluctuation of probabilistic distribution. Although, the uncertain fluctuation can not be compensated, it has extremely profound significance on the precision and ultra-precision machining to reduce the fluctuation range of machining accuracy as far as possible. In this paper, a typical 3-axis machine tool with high precision is selected and the fluctuations in machining accuracy are studied. The volumetric error modeling of machine tool is established by multi-body system (MBS) theory, which describes the topological structure of MBS in a simple and convenient matrix form. Based on the volumetric error model, the equivalent components of the errors for the three axes are established by reducing error terms. Then, the fluctuations of equivalent errors and the machining accuracy in working planes are depicted and predicted using the theory of stochastic process, whose range should be controlled within a certain confidence interval. Furthermore, the critical geometric errors that have significant influence on the machining accuracy fluctuation are identified. Based on the analysis results, some improvement in the machine tool parts introduced and the results for the modified machine show that the prediction allow for reduction in errors for the precision and ultra-precision machining.


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