Measurement of Finishing Errors for Evaluation of Dynamic Characteristics of NC Machine Tools

2005 ◽  
Vol 295-296 ◽  
pp. 625-630
Author(s):  
S.C. Kim ◽  
C.H. Lee ◽  
B.H. Lee
Keyword(s):  
Machine Tools ◽  
Dynamic Error ◽  
Geometric Error ◽  
Point Of View ◽  
Experimental Result ◽  
Accuracy Evaluation ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Precision Machine Tools ◽  
Circular Interpolation

Efficient development of method for performance evaluation of machine tools has been regarded as the most important issue to enhance accuracy and quality for users and manufacturers. Recently, a method of accuracy evaluation for machine tools has been studied as interests on precision machine tools have rapidly increased. From this point of view, the circular interpolation test of machine tools is recognized as the most useful method to identify the dynamic accuracy of NC machine tools by ISO, ANSI/ASME and others. In this paper, we studied and developed a formal measurement system with a grid encoder to analyze the final accuracy of NC machine tools. We analyzed the servo system error and the geometric error of NC machine tools through measuring the dynamic error signals by using this system. We verified the experimental result and enhanced the reliability by means of comparing the characteristics of the developed system with the kinematical ball-bar system.

Measurement point selection and compensation of geometric error of NC machine tools

2020 ◽  
Vol 108 (11-12) ◽  
pp. 3537-3546
Author(s):  
Hongwei Liu ◽  
Rui Yang ◽  
Pingjiang Wang ◽  
Jihong Chen ◽  
Hua Xiang ◽  
...  
Keyword(s):  
Machine Tools ◽  
Geometric Error ◽  
Measurement Point ◽  
Point Selection ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Measurement Point Selection

scholarly journals Theoretical Analysis of Circular Interpolation Contouring Error at Quadrant Changing Position in NC Machine Tools.

2001 ◽  
Vol 67 (1) ◽  
pp. 152-156 ◽  
Author(s):  
Jun FUJITA ◽  
Sadaji HAYAMA ◽  
Minoru HAMAMURA ◽  
Kazuhiro SHIBA ◽  
Yoshiaki KAKINO ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Machine Tools ◽  
Contouring Error ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Circular Interpolation

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.

A novel approach to calculating the dynamic error reflected on an S-shaped test piece

2020 ◽  
pp. 095440622096215
Author(s):  
Weiwei He ◽  
Liping Wang ◽  
Liwen Guan
Keyword(s):  
Test Piece ◽  
Machine Tools ◽  
Dynamic Error ◽  
Dynamic Performance ◽  
Error Distribution ◽  
Feed System ◽  
Test Pieces ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Five Axis

This paper proposes a novel approach to calculating the dynamic error distribution reflected on an S-shaped test piece. First, a numerical model of an S-shaped test piece is established, and the distribution characteristics for the twist angle and curvature are analysed. Second, a delay continuous method (DCM), which can transform the discrete input into a delayed step input, is presented to express the single-axis dynamic error affected by the input quantitatively in the form of a mathematical expression. Based on the sinusoidal input, the feasibility of the DCM is verified by comparing the experimental results of a Simulink simulation model and a mathematical expression derived by the DCM. Third, according to a new three-point tangential (NTPT) positioning algorithm and the DCM, this article makes the first attempt to investigate the quantitative calculation method of the influence of the dynamic performance of a servo feed system for five-axis numerical control (NC) machine tools on the dynamic error distribution for S-shaped test pieces after processing. Parameter p, representing the dynamic characteristic of the servo feed system, is varied to compare the difference of the dynamic error distribution law on S-shaped test pieces. The calculation results show that the parameter p can be adjusted to reduce the dynamic error of the final machined test pieces. It is important to improve the dynamic performance of servo feed systems for five-axis NC machine tools and enhance the machining quality of test pieces. In addition, compared with the calculation results of the dynamic error distribution for an NAS979 test piece, the S-shaped test piece can reflect the dynamic performance of the servo feed system for five-axis NC machine tools more accurately and effectively. Finally, the effectiveness of the proposed calculation method is verified through processing experiments on a five-axis NC machine tool.

Research on Distributed Remote Monitoring System for NC Machine Tools

2012 ◽  
Vol 190-191 ◽  
pp. 786-789
Author(s):  
Xing Guo Han ◽  
Bin Wu Wang
Keyword(s):  
Monitoring System ◽  
Remote Monitoring ◽  
Machine Tools ◽  
Middle Layer ◽  
Linear Interpolation ◽  
Remote Monitoring System ◽  
Middleware Technology ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Circular Interpolation

A whole design scheme of distributed remote monitoring system of NC machine tools is put forward and the middleware technology of combination of CORBA and web service is importantly discussed in this paper.This system is divided into three layers—field layer,middle layer and user layer. Finally, in this system platform, the errors of circular interpolation and linear interpolation are measured.

Error Modeling and Identification Technology for Circular Path of NC Machine Tools

2013 ◽  
Vol 278-280 ◽  
pp. 345-349
Author(s):  
Zhen Ya He ◽  
Jian Zhong Fu ◽  
Xin Hua Yao
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Measurement Method ◽  
Geometric Error ◽  
Error Modeling ◽  
Circular Path ◽  
Rate Condition ◽  
Nc Machine ◽  
High Feed ◽  
Nc Machine Tools

An error mapping modeling and identification technology for the circular path test of NC machine tools is proposed. First, geometric error modeling of the NC machine tool was established and the theory of the laser measurement method was introduced. Then through further analyzing the influence of the geometric errors to circular path deviations, the error items were identified, such as the displacement errors, backlashes and squareness errors. Finally measurement and compensation experiment of circular path was conducted. The experimental results show that the geometric error modeling is feasible, and the measurement method can be set up easily and rapidly, even can be used to measure smaller radius circular path under a high feed rate condition. After compensation, the accuracy of the circular path of the machine tool is improved by 50.88%.

scholarly journals The Influence of Guide Mechanism to the Circular Interpolation Contouring Error at Quadrant Changing Position in NC Machine Tools.

2002 ◽  
Vol 68 (3) ◽  
pp. 435-440 ◽  
Author(s):  
Jun FUJITA ◽  
Minoru HAMAMURA ◽  
Kazuhiro SHIBA ◽  
Yoshiaki KAKINO ◽  
Atsushi MATSUBARA ◽  
...  
Keyword(s):  
Machine Tools ◽  
Contouring Error ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Circular Interpolation
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