Research on Modeling Flow of Volumetric Error for Five-Axis NC Machine Tools

2009 ◽  
Vol 626-627 ◽  
pp. 423-428
Author(s):  
Wei Sun ◽  
Hui Ma ◽  
Chao Feng Li ◽  
Bang Chun Wen
Keyword(s):  
Error Modeling ◽  
Characteristic Matrix ◽  
Volumetric Error ◽  
Machining Center ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Key Steps ◽  
Multi Body ◽  
Five Axis ◽  
Modeling Flow

Based on the achievements of early works, a volumetric error modeling flow which is based on multi-body system theory is put forward. The flow includes 4 key steps mainly: describing structure, setting up coordinate system, creating characteristic matrix and generating volumetric error model are respectively. The operating method of every step is discussed in detail and the solving formula is given. At last, taking the VMC650 machining center of milling and boring which is developed by a machine tool factory as example, the validity of modeling flow is verified. This study can be used as a reference for opening automatic modeling system.

Research on Error Compensation Techniques for NC Machine Tools

2013 ◽  
Vol 321-324 ◽  
pp. 833-837
Author(s):  
Gao Feng Zhu ◽  
Yan Lei Zhang
Keyword(s):  
Error Compensation ◽  
Machine Tools ◽  
Error Modeling ◽  
Machining Accuracy ◽  
Characteristic Matrix ◽  
Detection Model ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Multi Body ◽  
Error Parameter

Cause of machining error for NC Machine Tools is described, and principle of NC machinings error compensation on the basis of the existing in-line detection model of NC machine tools is analyzed in this paper. Regularity of error Modeling based on multi-body system is found,accordingly, we will find the corresponding characteristic matrix and transformation matrix if location features and sport features of the adjacent body are confirmed. Then, formula of error model is found, and we can get numerical solution and compensate error according to the identified error parameter. As a result, the machining accuracy of machine tools can be greatly improved.

Analysis on Geometry Error Software Compensation Technology Model of Gantry Five-Axis NC Machine Tool

2012 ◽  
Vol 241-244 ◽  
pp. 1470-1474 ◽  
Author(s):  
Hua Gang Han ◽  
Xiao Lin Hu ◽  
Ying Chun Li ◽  
Feng Shou Shang Guan
Keyword(s):  
Error Compensation ◽  
Machine Tools ◽  
Body System ◽  
Nc Machine Tool ◽  
Result Show ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Multi Body ◽  
Geometry Error ◽  
Five Axis

Based on multi-body system, the error model of gantry five-axis NC machine tools was discussed. The calculate method of precision process equation and NC instruction has been derived out. Based the above research works，make a emulate by using of geometry error compensation soft-ware. The result show machining precision can be improved through the error compensation method which is concluded in this paper.

Study of the Geometrical Error Modeling of NC Lathe Based on Multi-Body System Theory

2010 ◽  
Vol 139-141 ◽  
pp. 1093-1096
Author(s):  
Xiu Shan Wang ◽  
Yan Li ◽  
Yong Chang Yu
Keyword(s):  
System Theory ◽  
Error Compensation ◽  
Machine Tools ◽  
Error Modeling ◽  
Body System ◽  
Geometrical Error ◽  
Modeling Process ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Multi Body

The geometrical error modeling of the numerically controlled (NC) lathe is the key technique to kinematics design, precision analysis and error compensation. The study gives out the modeling process of the generally geometrical error model based on the multi-body system theory for the multi-axis NC machine tools. By the multi-system theory, using the low series body arrays to describe the complex mechanical system, the article has finished the geometrical error modeling of the numerically controlled lathe, analyzed the influence on the model of error of perpendicularity between the linear axes. The modeling method is highly-efficient and can not be affected by the structure of the NC machine tools. The error compensation and command correction can be implemented by the geometric errors model.

Error Modeling and Iterative Algorithm for Compensation Instructions of Five-Axes NC Machine Tools Based on the Multi-Body System Theory

2013 ◽  
Vol 658 ◽  
pp. 287-291
Author(s):  
Li Gang Cai ◽  
Huai Qing Lu ◽  
Rui Luo ◽  
Qiang Cheng ◽  
Pei Hua Gu
Keyword(s):  
Error Compensation ◽  
Translational Motion ◽  
Rigid Body Dynamics ◽  
Machining Accuracy ◽  
Characteristic Matrix ◽  
Body System ◽  
Nc Machine ◽  
Multi Body ◽  
Five Axis ◽  
Five Axes

The machining accuracy of NC machine can be improved significantly through the error compensation. The kernels of (multi-body system)MBS theories are that the number arrays of low-order body are used to describe the topological structures which are taken to generalize and refine MBS, and the characteristic matrix are employed to represent the relative positions and gestures between any two bodies in MBS. Based on the theory of rigid body dynamics and homogeneous coordinate transformation techniques, the space error model of five-axis gantry NC machine can be established, the modified NC instructions can be obtained and it prepares well ready for the software error compensation and the practical application. Gyratory motion of five-axis NC machine will generate the coupling of translational motion, so it is different from the three-axis NC machine in the process of error compensation and we need to decoupling.

Design of Motion Accuracy Measurement Device for NC Machine Tools with Three Displacement Sensors

2011 ◽  
Vol 5 (6) ◽  
pp. 847-854 ◽  
Author(s):  
Yukitoshi Ihara ◽  
◽  
Yuki Hiramatsu
Keyword(s):  
Measurement Device ◽  
Coordinate Measurement ◽  
Accuracy Measurement ◽  
Test Standards ◽  
Machining Center ◽  
Displacement Sensors ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Measurement Devices ◽  
Five Axis

To measure motion accuracy, including that of the rotary axis of five-axis machining center that have been widely introduced into production sites recently, a device with three displacement sensors combined to measure the center position of the master ball was invented and will be added to the International Standard. Such measurement devices are not difficult to produce in principle, but the commercially available products are expensive. This study discusses a threedimensional (3D) coordinate measurement device with multiple displacement sensors, discussing it in terms of the test standards of the machines to which the device has been applied and in relation to devices which have been studied, developed, and released. Our measurement device is then designed and produced, and its measurement accuracy is confirmed.

Volumetric error modeling and compensation considering thermal effect on five-axis machine tools

2012 ◽  
Vol 227 (5) ◽  
pp. 1102-1115 ◽  
Author(s):  
Yi Zhang ◽  
Jianguo Yang ◽  
Sitong Xiang ◽  
Huixiao Xiao
Keyword(s):  
Error Compensation ◽  
Machine Tools ◽  
Data Communication ◽  
Zero Point ◽  
Compensation System ◽  
Error Modeling ◽  
Volumetric Error ◽  
Position Errors ◽  
Homogeneous Transformation Matrix ◽  
Five Axis

This article intends to provide an error compensation system for five-axis machine tools. A volumetric error model is established with homogeneous transformation matrix method, from which compensation values of both orientation and position errors can be obtained. Thirty-seven errors on a five-axis machine tool are classified into three categories – functional, random, and negligible errors, among which the effect of the first one on volumetric accuracy is considered as great enough to be included in this model. Some typical modeling methods are discussed on positioning and straightness errors, considering both geometric and thermal effects. Then, we propose a compensation implementation technique based on the function of external machine zero point shift and Ethernet data communication protocol for machine tools. Finally, laser diagonal measurements have been conducted to validate the effectiveness of the proposed volumetric error compensation system.

scholarly journals Development of Motion Accuracy Measurement Method of Five Axis NC Machine Tools with ISO230-4

2006 ◽  
Vol 72 (7) ◽  
pp. 873-877
Author(s):  
Masaki USHIO ◽  
Norifumi KURMAE ◽  
Masahide KOUYA ◽  
Hiroyuki NARAHARA ◽  
Hiroyuki KORESAWA ◽  
...  
Keyword(s):  
Machine Tools ◽  
Measurement Method ◽  
Accuracy Measurement ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Five Axis

Enhancement of Motion Accuracy for Cone-Frustum Cutting Motion by Modified NC Program

2018 ◽  
Author(s):  
Kiichi Morishita ◽  
Ryuta Sato ◽  
Keiichi Shirase ◽  
Isamu Nishida
Keyword(s):  
Machine Tools ◽  
Opposite Sign ◽  
Accuracy Evaluation ◽  
Error Vector ◽  
Direction Error ◽  
Dynamic Motion ◽  
Machining Center ◽  
Nc Program ◽  
Nc Machine ◽  
Nc Machine Tools

Motion accuracy of NC machine tools is directory copied onto the machined shape. However, it is known that the motion accuracy is deteriorated by several error courses; geometric and dynamic motion errors of feed axes. In this study, in order to enhance the motion accuracy of NC machine tools, a method that modifies the NC program based on the normal direction error at each command point on the designed path is developed. In the method, the error vector between the commanded and estimated machined shape is obtained. The NC program for the motion is modified by adding the obtained error vector with the opposite sign. In order to confirm the effectiveness of the proposed method, 5-axis motion tests for cone-frustum cutting which is widely applied to the accuracy evaluation of 5-axis machining centers are carried out. At the first, it is confirmed that the proposed method can compensate the dynamic synchronous errors based on the feedback positions and angles of the axes. In addition, it is also confirmed that the proposed method can compensate both of dynamic and geometric errors based on the tool center point trajectory measured by a ball-bar system. As the results, it is clarified that the proposed method can effectively enhance the motion accuracy of the 5-axis machining center.

Geometric Error Modeling of a Vertical Machining Center

2013 ◽  
Vol 694-697 ◽  
pp. 1842-1845
Author(s):  
Gui Qiang Liang ◽  
Jun Xian Zhang ◽  
Fei Fei Zhao
Keyword(s):  
Coordinate Transformation ◽  
Transformation Method ◽  
Geometric Error ◽  
Error Modeling ◽  
Machining Accuracy ◽  
Geometric Errors ◽  
Lower Body ◽  
Body System ◽  
Machining Center ◽  
Multi Body

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.

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