Modelling and real-time compensation of cutting-force-induced error on a numerical control twin-spindle lathe

2009 â—½  
Vol 224 (4) â—½  
pp. 567-577 â—½  
Author(s):  
H Wu â—½  
H J Chen â—½  
P Meng â—½  
J G Yang
Keyword(s):  
Neural Network â—½  
Cutting Force â—½  
Real Time â—½  
Machine Tools â—½  
Error Model â—½  
Nc Machine â—½  

Cutting-force-induced errors are one of the major sources of error in numerical control (NC) machine tools. The error compensation technique is an effective way to improve the manufacturing accuracy of NC machine tools. Effective compensation relies on an accurate error model that can predict the errors exactly during the machining process. In the present paper a robust and accurate cutting-force-induced error model is built using a back-propagation (BP) neural network and a genetic algorithm (GA) for an NC twin-spindle lathe. The GA—BP neural network modelling technique not only enhances the prediction accuracy of the model but also reduces the training time of the BP neural network. A real-time compensation system of the cutting-force-induced error on the lathe is developed based on the cutting-force-induced error model. The errors were reduced by about 38 per cent after real-time compensation in a machining experiment.

2018 â—½  
Vol 32 (34n36) â—½  
pp. 1840109
Author(s):  
Jie Yuan â—½  
Zhicheng Ji â—½  
Yan Wang

The energy consumption of numerical control (NC) machine tools is mainly from the cutting process. Since the cutting process has multiple characteristics, such as nonlinear, multi-variable and time-varying characteristics, it is difficult to establish an accurate model of the cutting energy consumption by both the static modeling and the traditional mechanism modeling. In this paper, the unscented Kalman filter neural network (UKFNN) is proposed to model the cutting energy consumption of NC machine tools. In the resulting model, the unscented Kalman filter (UKF) is adopted to update weights and thresholds of the neural network in real time, improving the generalization ability and the accuracy of the model. Experimental results show that the proposed method is effective and reliable to model the cutting energy consumption of NC machine tools.


2012 â—½  
Vol 542-543 â—½  
pp. 1190-1195 â—½  
Author(s):  
Guo Zheng Zhang â—½  
Jiang Han â—½  
You Yu Liu

Setup datum of fixture design is an important factor of Numerical Control (NC) machining process planning. Using graph theory of FTG (Feature Tolerance relationship Graph) and DMG (Datum and Machining feature relationship Graph) technology, the feature relationship was proposed to construct a relational table of DMMT (Datum and Machining and Machine Tools) in NC machining setup process. The degree of graph as a discriminant evidence of the machining setup datum was given, so that the machining setup process planning was correctly designed. Combined with the capability of NC machine tools, the unit normal vector of feature facet between the feature datum and machining facet were multiplied to determine the fixture capability, which provide a reasonable proposal of machining setup process for multi-position rotation and multi-piece fixture design. Finally, a case study of machining setup process planning and multi-piece fixture equipment design from corporation was presented to verify the feasibility of the method that was based on the graph theory.


2013 â—½  
Vol 336-338 â—½  
pp. 1303-1308
Author(s):  
Jian Hong Zhou â—½  
Peng Shen â—½  
Zheng Weng

Chinese spinning technology has developed for more than 40 years. Especially in recent years, various kinds of spinning equipment have been developed and contributed a lot to Chinese equipment manufacturing industry, but it is blank in the light industry and civil industry. Due to the high cost and programming complexity of NC machine tools, we have no dedicated spinning machine and mostly rely on simple manual in the lampcover production. As to the above problems, we developed the lampcover NC spinning machines that can generate the track automatically and complete automatic control in the machining process.


2014 â—½  
Vol 26 (5) â—½  
pp. 529-539 â—½  
Author(s):  
Yoshimi Takeuchi â—½  
Keyword(s):  
Machine Tools â—½  
Current State â—½  
Machine Shops â—½  
Nc Machine â—½  
Unique Shape â—½  
Nc Data â—½  

<div class=""abs_img""><img src=""[disp_template_path]/JRM/abst-image/00260005/01.jpg"" width=""300"" />Asymmetric curved grooving</div> Multi-axis numerical control (NC) machine tools such as 5-axis control machining centers and 5-axis control multi-tasking machines are widely used in machine shops. NC data, which are prepared using computeraided manufacturing (CAM) systems, are used with multi-axis control NC machine tools that have a variety of advantages. This article describes the advantages ofmulti-axis control machining. The structure of CAM systems used for multi-axis control machining and the important role of collision avoidance in generating cutter location (CL) data are then explained. The transformation of CL data to NC data for use in machining, which is performed by a post-processor, is presented. Finally, an efficient machining method and unique shape creation via 6-axis control machining are explained. </span>


2018 â—½  
Vol 232 â—½  
pp. 01006
Author(s):  
Sanping Wang â—½  
Junwen Chen â—½  
Wei Yan

Energy consumption process is the basis for energy efficiency improvement of machine tools. Most of the existing researches focus on the static modelling of energy consumption of a machine tool; however, there are a few studies that paid attention to that how process parameters influence the energy consumption of machine tools during processing. It is noted that the process parameters can be selected to reduce energy consumption during machining processes without additional investment. In this paper, a characteristic energy consumption model for NC machine tool was proposed. Then, the mapping rule between process parameters and energy consumption of machine tool was studied, and the model was solved with the regular neural network (RNN). Finally, the result was verified with an experiment of milling the surface of aluminium block, which can effectively improve the energy efficiency of machine tool. The experiment results are shown that regular neural network is used to optimize the process parameters and process the same machining characteristics; we analyze the in machining process of machine tool based on the three cutting parameters, and then, a model of energy consumption. We employ to learn, and use this trained model to select optimal parameters.


2015 â—½  
Vol 741 â—½  
pp. 763-767
Author(s):  
Hui Liang Li

In this paper, a series of numerical control machine tool truncated failure data collect.The data are assumed to be two parameter weibull distribution and related parameters is obtained and relevant inspection and test of hypothesis, it is concluded that the mathematical model of batch of nc machine tool failure interval time distribution.Relevant indicators to determine the reliability of nc machine tools, machine tool's observations, Machine tool observations, point estimation and interval estimation index value provide a theoretical basis for the research on reliability of machine tool.


2012 â—½  
Vol 220-223 â—½  
pp. 395-401 â—½  
Author(s):  
Gen Bao Zhang â—½  
Jian Liu â—½  
Xiu Jun Fan

To eliminate the early failures and improve the reliability of numerical control (NC) machine tools, the comprehensive technology for these works is proposed in this paper. Firstly, model is established to describe the early failures of NC machine tools, then the formation of early failures and mechanism of early failures elimination are studied. Secondly, a comprehensive technical framework for eliminating early failures is introduced, with some detailed process and implementation. Finally, example of NC rotary table is shown to illustrate the applicability and validity of the technology for eliminating early failures of NC machine tools.


2014 â—½  
Vol 577 â—½  
pp. 421-424
Author(s):  
Le Ping Chu â—½  
De Ming Xiao â—½  
Zai Yu Chen â—½  
Cheng Rong Pian â—½  
Nan Wu â—½  
...  
Keyword(s):  
Machine Tool â—½  
Machine Tools â—½  
Nc System â—½  
Nc Machine â—½  
Plc Program â—½  

According to the communication principle of 840D numerical control (NC) system and internal data structure, the PLC program is developed to make 840D system state data transmit to the PC with the MPI channels; production status data real-time monitoring system based on 840D NC machine tools is developed, meanwhile, the monitoring and data management for NC machine tool production process status is realized.


2014 â—½  
Vol 1030-1032 â—½  
pp. 1305-1308
Author(s):  
Shi Chao Li â—½  
Song Lin Wu â—½  
Yan Kun Liang

It is a general processing technology that multi-axis NC machine tools is used for machining impeller at present. In order to improve the machining accuracy of the five-axis NC machine tools, the paper analyzes the computing interpolation error of the Multi-axis CNC system in detail. Some of the measures of tools selection have been proposed in purpose of diminishing the accumulative error of the system. The paper also establishes the optimized objective function to optimize the process parameters of the CNC machining based on the material removal rate. All these measures will improve the machining efficiency significantly and increase the stationary of the machining process.


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