scholarly journals Thermal error of high speed feed system of NC machine tool

2018 ◽  
Author(s):  
Rong Li ◽  
Wei Lin ◽  
Yanan Wang ◽  
Yin Zhang ◽  
Juyong Zhang ◽  
...  
Keyword(s):  
Machine Tool ◽  
High Speed ◽  
Thermal Error ◽  
Feed System ◽  
Nc Machine Tool ◽  
Nc Machine

Fuzzy Evaluation and Modeling of Positioning Error of NC Machine Tool Feed System

2014 ◽  
Vol 536-537 ◽  
pp. 1607-1611
Author(s):  
Ming De Duan ◽  
Jia Jia Gu ◽  
Kang Hua Liu ◽  
Xiao Xiao Ji ◽  
Yu Ping Wang
Keyword(s):  
Mathematical Model ◽  
Machine Tool ◽  
High Speed ◽  
Evaluation Method ◽  
Fuzzy Comprehensive Evaluation ◽  
Fuzzy Evaluation ◽  
Positioning Error ◽  
Feed System ◽  
Nc Machine Tool ◽  
Nc Machine

With the experimental data of positioning precision of high-speed precision NC machine tool, a linear mathematical model of positioning error is established. Based on gray model and Cauchy problem formula, a nonlinear mathematical model is also established. The two models are evaluated by fuzzy comprehensive evaluation method to find the optimal prediction model. Compensated with a selection of positioning error compensation model, the confidence interval of 0.95 of positioning error is less than 3μm, meets the design requirements of the machine tool.

The Coupling Characteristic of HSK Tool-Holder/Spindle Interface for High-Speed NC Machine Tool

2014 ◽  
Vol 590 ◽  
pp. 121-125 ◽  
Author(s):  
Wen Kai Jie ◽  
Jian Chen ◽  
Deng Sheng Zheng ◽  
Gui Cheng Wang
Keyword(s):  
Machine Tool ◽  
Rotational Speed ◽  
High Speed ◽  
Nonlinear Finite Element Method ◽  
High Rotational Speed ◽  
Tool Holder ◽  
Nc Machine Tool ◽  
Machine Tool Accuracy ◽  
Nc Machine ◽  
Coupling Characteristic

The coupling characteristic of the tool-holder/spindle interface in high speed NC machine has significant influence on machine tool accuracy and process stability. With the example of HSK-E63, based on nonlinear finite element method (FEM), the coupling characteristic of the tool-holder/spindle interface under high rotational speed was investigated, the influence of interference, clamping force and rotational speed on the contact stress and the sectional area of clearance were discussed in detail. The results can be used as theoretical consideration to design and optimize the high speed tool-holder/spindle interface.

The Thermal Error Prediction of NC Machine Tool Based on LS-SVM and Grey Theory

2009 ◽  
Vol 16-19 ◽  
pp. 410-414 ◽  
Author(s):  
Chang Long Zhao ◽  
Yi Qiang Wang ◽  
Xue Song Guan
Keyword(s):  
Support Vector Machine ◽  
Correlation Analysis ◽  
Prediction Model ◽  
Machine Tool ◽  
Least Squares ◽  
Thermal Error ◽  
Support Vector ◽  
Error Prediction ◽  
Nc Machine Tool ◽  
Nc Machine

In this paper, a hybrid method of correlation analysis based on the gray theory and the least squares support vector machine is proposed to model the thermal error of spindle of NC machine tool and predict the thermal error. The gray correlation analysis is used to optimize the measuring points of spindle. The optimum measuring points and the measured thermal error of spindle are regarded as the data to be trained to build the thermal error prediction model based on the least squares support vector machine (LS-SVM). The results show that the thermal error prediction model based on LS-SVM of NC machine tool has advantages of high precision and good generalization performance. The prediction model can be used in real-time compensation of NC machine tool and can prove the process precision and reduce cost.

Numerical Control Machine Tool Motion Simulation and Analysis of Parts of the Crawling Phenomenon

2014 ◽  
Vol 971-973 ◽  
pp. 592-595 ◽  
Author(s):  
Ming Yin ◽  
Wen Tong Cheng ◽  
Li Juan Bai ◽  
Lan Lan Guo
Keyword(s):  
Machine Tool ◽  
Numerical Control ◽  
Mechanical Transmission ◽  
Feed System ◽  
Control Machine Tool ◽  
Nc Machine Tool ◽  
Dynamic Friction Coefficient ◽  
Damped Oscillations ◽  
Nc Machine ◽  
Tool Motion

NC machine creeping failure usually occurs in the mechanical part and feed servo system of NC machine tool feed system, because of low speed creeping phenomenon often depends on the characteristics of mechanical transmission parts. Crawling is generally due to transmission of machine tool stiffness is insufficient, friction and dynamic friction coefficient difference and friction damped oscillations caused by too small. This paper establishes the physical model and the mathematical model, through theoretical analysis and numerical simulation of machine movement components that crawl main reason, put forward to prevent the moving parts of the main measures of creeping.

The Influence and Suppression of Nonlinear Friction

2013 ◽  
Vol 753-755 ◽  
pp. 1760-1763
Author(s):  
Jian Jun Yang ◽  
Qin Wu ◽  
Chun Li Lei ◽  
Rui Cheng Feng
Keyword(s):  
Machine Tool ◽  
Control Method ◽  
Nonlinear Friction ◽  
Feed System ◽  
Positioning Accuracy ◽  
Nc Machine Tool ◽  
Nc Machine ◽  
Main Factors ◽  
And Control

Direct at NC machine tool feed system, the article analyzed the influence of the nonlinear friction at each motion joint, and points out that the nonlinear friction are the main factors that influence the positioning accuracy of the feed system. The article have discussed the methods for effectively compensation and controlling of the nonlinear friction respectively from two aspects of flutter compensation and predictly controlling the nonlinear friction, and proved the correctness of the compensation and control method that is proposed in this paper.

Research on Thermal Error Modeling of NC Machine Tool Based on BP Neural Networks

2009 ◽  
Vol 626-627 ◽  
pp. 135-140 ◽  
Author(s):  
Qian Jian Guo ◽  
X.N. Qi
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Machine Tool ◽  
Ant Colony Algorithm ◽  
Thermal Error ◽  
Error Modeling ◽  
Minimum Problem ◽  
Bp Neural Networks ◽  
Nc Machine Tool ◽  
Nc Machine

Through analysis of the thermal errors affected NC machine tool, a new prediction model based on BP neural networks is presented, and ant colony algorithm is applied to train the weights of neural network model. Finally, thermal error compensation experiment is implemented, and the thermal error is reduced from 35μm to 6μm. The result shows that the local minimum problem of BP neural network is overcome, and the model accuracy is improved.

Thermal Error Compensation on Boring & Milling Machining Center Feed System Based on PMAC

2014 ◽  
Vol 945-949 ◽  
pp. 1669-1672
Author(s):  
Jun Sun ◽  
Xing Liu ◽  
Zhi Xuan Li
Keyword(s):  
Real Time ◽  
Error Compensation ◽  
Tool Path ◽  
Thermal Error ◽  
Machining Accuracy ◽  
Feed System ◽  
Nc Machine Tool ◽  
Machining Center ◽  
Nc Machine ◽  
Processing Accuracy

Aiming to deal with thermal error of NC machine tool which can cause reduce of machining accuracy, this paper uses an external error compensation which interacts with NC controllers and PMAC multi-axis and then revises the tool path by adding the error tested in real-time by PMAC card. The processing accuracy is improved eventually. This method can compensate machine geometric errors and thermal errors in real-time. Comparing with other methods of error preventing, this method is more effective and affordable.

Machining error reduction by combining of feed-speed optimization and toolpath modification in high-speed machining for parts with rapidly varied geometric features

2017 ◽  
Vol 232 (4) ◽  
pp. 557-571
Author(s):  
Jian-wei Ma ◽  
Zhen-yuan Jia ◽  
De-ning Song ◽  
Fu-ji Wang ◽  
Li-kun Si
Keyword(s):  
Machine Tool ◽  
High Speed ◽  
Error Reduction ◽  
Feed Speed ◽  
Geometric Features ◽  
High Speed Machining ◽  
Machining Error ◽  
Nc Machine Tool ◽  
Speed Optimization ◽  
Nc Machine

Parts with rapidly varied geometric features are usually crucial parts in high-end equipment and widely applied in the fields of aerospace, energy and power, which are difficult or inefficient to process because of the more special structure and the higher requirement of machining precision. High-speed machining technology provides an effective method for parts with rapidly varied geometric features to solve the contradiction between high demand and low machining efficiency. However, as the existence of rapidly varied geometric features, the machining toolpath for such parts is always complex free-form curve and the actual moving speed of the workbench of the NC machine tool cannot reach the feed-speed set in the NC program timely due to the drive constraint of NC machine tool. Furthermore, the machine tool would vibrate violently when machining the rapidly varied geometric features. In this way, the big machining error will be formed. A machining error reduction method by combining of feed-speed optimization and toolpath modification in high-speed machining for such parts is proposed. First, considering that the actual feed-speed cannot reach the programmed value when the toolpath curvature is too large, the feed-speed is optimized with the constraints of jerk and acceleration limitations of the feed shafts, and a feed-rate smoothing algorithm is applied. Then, the compensated cutter locations are calculated via machining-error estimation. Finally, the modified NC codes are acquired according to the optimized feed-speed and the compensated toolpath. By combining the feed-speed optimization and toolpath modification, the high precision and high efficiency machining can be realized. The experimental results demonstrate the feasibility of the proposed approach. This study provides an effective approach to reduce the machining error in high-speed machining, and is significant for improving the processing precision and efficiency of parts with rapidly varied geometric features.

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