scholarly journals Enhancing machining accuracy reliability of multi-axis CNC machine tools using an advanced importance sampling method

2021 ◽  
Vol 23 (3) ◽  
pp. 559-568
Author(s):  
Zhiming Wang ◽  
Hao Yuan
Keyword(s):  
Importance Sampling ◽  
Machine Tools ◽  
Sampling Method ◽  
Great Influence ◽  
Error Model ◽  
Cnc Machine Tools ◽  
Machining Accuracy ◽  
Cnc Machine ◽  
Importance Sampling Method ◽  
Comprehensive Error Model

The purpose of this paper is to propose a general precision allocation method to improve machining performance of CNC machine tools based on certain design requirements. A comprehensive error model of machine tools is established by using the differential motion relation of coordinate frames. Based on the comprehensive error model, a reliability model is established by updating the primary reliability with an advanced importance sampling method, which is used to predict the machining accuracy reliability of machine tools. Besides, to identify and optimize geometric error parameters which have a great influence on machining accuracy reliability of machine tools, the sensitivity analysis of machining accuracy is carried out by improved first-order second-moment method. Taking a large CNC gantry guide rail grinder as an example, the optimization results show that the method is effective and can realize reliability optimization of machining accuracy.

Reliability Analysis about A/C-Axis of Woodworking Five-Axis Milling Head

2014 ◽  
Vol 635-637 ◽  
pp. 407-410
Author(s):  
Shuang Yong Wang ◽  
Wei Zhang ◽  
Qian Wei Zhang ◽  
Jian Hua Yang ◽  
Peng Fei Zhang
Keyword(s):  
Theoretical Analysis ◽  
Reliability Analysis ◽  
Machine Tools ◽  
Theoretical Basis ◽  
Cnc Machine Tools ◽  
Machining Accuracy ◽  
Cnc Machine ◽  
Core Feature ◽  
Drive Motor ◽  
Five Axis

As a core feature of high-end CNC machine tools, the torque carrying performance of five-axis milling head directly affects the machining accuracy and reliability. Through theoretical analysis and derivation, combining experimental prototype, the A/C-axis cutting torque formula of five-axis milling head on woodworking is obtained. The reliability analysis provides a theoretical basis for drive motor selection and five-axis milling head structural optimization and improvement.

scholarly journals Analysis of Nonlinear Error Caused by Motions of Rotation Axes for Five-Axis Machine Tools with Orthogonal Configuration

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Cong Geng ◽  
Yuhou Wu ◽  
Jian Qiu
Keyword(s):  
Machine Tools ◽  
Cnc Machine Tools ◽  
Reference Plane ◽  
Maximum Deviation ◽  
Machining Accuracy ◽  
Cnc Machine ◽  
Nonlinear Error ◽  
Rotation Axes ◽  
Five Axis ◽  
The Relationship

Since a nonlinear relationship exists between the position coordinates of the rotation axes and components of the tool orientation, the tool will deviate from the required plane, resulting in nonlinear errors and deterioration of machining accuracy. Few attempts have been made to obtain a general formula and common rules for nonlinear error because of the existence of various kinematic structures of machine tools with orthogonal configuration. This paper analyzes the relationship between the deviation of cutter location points and motion of tool orientations. Five-axis CNC machine tools are divided into two groups according to the configuration of the two rotational joints and the home position. Motions of the tool are regarded as a combination of translation and rotation. A model for error calculation is then built. The maximum deviation of the tool with respect to the reference plane generated by the initial and the final orientation is used to quantify the magnitude of the errors. General formulas are derived and common change rules are analyzed. Finally, machining experiment is conducted to validate the theoretical analysis. The research has important implications on the selection of a particular kinematic configuration that may achieve higher accuracy for a specific machining task.

Research of On-Line Monitoring Technology of Machining Accuracy of CNC Machine Tools

2013 ◽  
Vol 846-847 ◽  
pp. 268-273
Author(s):  
Rong Bo Shi ◽  
Zhi Ping Guo ◽  
Zhi Yong Song
Keyword(s):  
Neural Network ◽  
Machine Tools ◽  
Cnc Machine Tools ◽  
Frequency Domain Method ◽  
Machining Accuracy ◽  
Cnc Machine ◽  
Monitoring Technology ◽  
The Neural Network ◽  
Network Identification ◽  
On Line

This paper analyzes CNC machine tools machining error sources, put forward a kind of on-line monitoring technology of CNC machine tools machining accuracy based on online neural network. Through the establishment of CNC machine tools condition monitoring platform, collection sensor signal of the key components of CNC machine tools, using time domain and frequency domain method of the original signal processing, extract the characteristic related to machining accuracy change, input to the neural network, identification the changes of machining accuracy. The experimental results show that, the on-line monitoring technology based on neural network, can identify the changes of machining accuracy.

scholarly journals The Use of Response Surface Methodology to Optimize Parameter Adjustments in CNC Machine Tools

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Shao-Hsien Chen ◽  
Wern-Dare Jehng ◽  
Yen-Sheng Chen
Keyword(s):  
Regression Analysis ◽  
Response Surface ◽  
Machine Tools ◽  
Cnc Machine Tools ◽  
Contour Plot ◽  
Machining Accuracy ◽  
Analysis Method ◽  
Cnc Machine ◽  
Acceleration And Deceleration ◽  
Feed Axis

This paper mainly covers a research intended to improve the circular accuracy of CNC machine tools and the adjustment and analysis of the main controller parameters applied to improve accuracy. In this study, controller analysis software was used to detect the adjustment status of the servo parameters of the feed axis. According to the FANUC parameter manual, the parameter address, frequency, response measurements, and the one-fourth corner acceleration and deceleration measurements of the machine tools were adjusted. The experimental design (DOE) was adopted in this study for taking circular measurements and engaging in the planning and selection of important parameter data. The Minitab R15 software was adopted to predict the experimental data analysis, while the seminormal probability map, Plato, and analysis of variance (ANOVA) were adopted to determine the impacts of the significant parameter factors and the interactions among them. Additionally, based on the response surface map and contour plot, the optimal values were obtained. In addition, comparison and verification were conducted through the Taguchi method, regression analysis to improved machining accuracy and efficiency. The unadjusted error was 7.8 μm; through the regression analysis method, the error was 5.8 μm and through the Taguchi analysis method, the error was 6.4 μm.

The Vibration Detection System of CNC Machine Tools and the Application of Spindle Test

2011 ◽  
Vol 487 ◽  
pp. 473-477
Author(s):  
Yu Hou Wu ◽  
Liang Wu Rao ◽  
De Hong Zhao ◽  
K. Zhang
Keyword(s):  
Machine Tools ◽  
Detection System ◽  
Cnc Machining ◽  
Cnc Machine Tools ◽  
Machining Accuracy ◽  
Vibration Source ◽  
Cnc Machine ◽  
Structural Dynamic ◽  
Machining Center ◽  
Vibration Detection

This paper introduces the composition of CNC machine tools and the classification of vibration. Based on the method of vibration diagnosis and the sensors, data acquisition instrument and signal analysis software produced by China Orient Institute, self-designed a high precise and portable vibration detection system. By this system, we can detect the engraving spindle of the shaped stone CNC machining center which own school developed, and analyze the possible causes of vibration. Figures out that the detection system is an effective testing equipment for quickly identifying the vibration source of machine tools. It plays an important role in providing the basis for structural dynamic design, guaranteeing the machining accuracy and improving the machine’s service life.

Error Source Identification of Machining Accuracy of Five-Axis Linkage CNC Machine Tools

2013 ◽  
Vol 846-847 ◽  
pp. 34-39 ◽  
Author(s):  
Zhi Ping Guo ◽  
Zhi Yong Song ◽  
Rong Bo Shi
Keyword(s):  
Machine Tools ◽  
Thermal Error ◽  
Geometric Error ◽  
Cnc Machine Tools ◽  
Machining Accuracy ◽  
Error Source ◽  
Cnc Machine ◽  
Test Part ◽  
Part Surface ◽  
Five Axis

The error sources of machining accuracy of CNC machine tools including geometric error, thermal error, system error and error of load control etc. The error source affect the relative position of the cutting tool and the workpiece by the dynamic motion, and then affect the machining accuracy of the workpiece. By trial cutting method, "S" test part is a new test part for detecting machining accuracy of five-axis linkage machine tools. Through experiment and simulation, identification of the error source of the machining accuracy and the regular of "S" test part surface errors, surface quality, results show that "S" test part can reflect the machining accuracy of CNC machine tool.

scholarly journals Reliability Evaluation of CNC Machine Tools Considering Competing Failures of Fault Failure Data and Machining Accuracy Degradation Data

2021 ◽  
Author(s):  
Cong Feng ◽  
Zhaojun Yang ◽  
Chuanhai Chen ◽  
Jinyan Guo ◽  
Jiangong Leng ◽  
...  
Keyword(s):  
Machine Tools ◽  
Failure Modes ◽  
Reliability Evaluation ◽  
Cnc Machine Tools ◽  
Machining Accuracy ◽  
Failure Model ◽  
Cnc Machine ◽  
Failure Data ◽  
Degradation Data ◽  
Degradation Failure

Abstract Traditional reliability evaluation of CNC machine tools usually considers a single failure mode of fault failure or degradation failure, or considers fault failure and degradation failure to be independent of each other. However, in the actual working conditions, fault failure and degradation failure are mutually affected, and the reliability evaluation of the competing failure models of CNC machine tools by considering the two failure modes comprehensively can get more accurate evaluation results. Therefore, this paper proposes a reliability evaluation method for CNC machine tools considering fault failure data competing with machining accuracy degradation data. A fault failure model of CNC machine tools is established based on a non-homogeneous Poisson process. The fault failure model is updated according to the different effects of each maintenance result of the failure on machining accuracy. By integrating multiple geometric errors of CNC machine tools through multi-body system theory, the amount of machining accuracy degradation is extracted. A machining accuracy degradation failure model is established using the Wiener process. Considering the correlation between fault failure and degradation failure, a competing failure model based on the Coupla function is developed for evaluating the reliability of CNC machine tools. Finally, the effectiveness of the proposed method is verified by example analysis.

Sign in / Sign up

Export Citation Format

Share Document