The Study of Compensation Method to Numerically-Controlled Machine Tool Geometrical Error

2014 ◽  
Vol 670-671 ◽  
pp. 1403-1405
Author(s):  
Lian Bing Wang

In this paper, the cause of nc machine tool geometric error made a more detailed analysis, the system error compensation methods are summarized, and on this basis this paper expounds the applications of all kinds of error compensation method, in order to further realize the accuracy of machine tool software upgrade to lay the foundation.

2012 ◽  
Vol 426 ◽  
pp. 239-242
Author(s):  
Xiao Jun Wang ◽  
Xiao Guang Fu

In this paper the characteristics of geometric errors is discussed in detail, error compensation methods used in productive practice and relevant examples are given. Finally, the application of error compensation in different situation is discussed according to the characteristics of machining center. The machine accuracy can be improved by error compensation. It has important practical reference value for reasonable use and maintaining of NC machine tool.


2012 ◽  
Vol 472-475 ◽  
pp. 2371-2376 ◽  
Author(s):  
Jin Dong Wang ◽  
Jun Jie Guo ◽  
Yu Fen Deng ◽  
Hai Tao Li

Error compensation is an effective method to improve the machining accuracy of NC machine tool. A laser tracker is used to rapidly and accurately detect the geometric error of NC machine tool in the paper. The machine tool is controlled to move on the preset path in the space, and a laser tracker is used to measure the motion trajectory of the machine tool. Each geometric error can be identified by error separation. Based on the error model of 3-axis machine tool, error compensation can be carried out by modifying the machining process (G code). Results of experiment show that, this measurement method is feasible, and modifying the G code for error compensation is also effective.


Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 748
Author(s):  
Qi Liu ◽  
Hong Lu ◽  
Xinbao Zhang ◽  
Yu Qiao ◽  
Qian Cheng ◽  
...  

The drive at the center of gravity (DCG) principle has been adopted in computer numerical control (CNC) machines and industrial robots that require heavy-duty and quick feeds. Using this principle requires accurate corrections of positioning errors. Conventional error compensation methods may cause vibrations and unstable control performances due to the delay between compensation and motor motion. This paper proposes a new method to reduce the positioning errors of the dual-driving gantry-type machine tool (DDGTMT), namely, a typical DCG-principle-based machine tool. An error prediction method is proposed to characterize errors online. An algorithm is proposed to quickly and accurately compensate the errors of the DDGTMT. Experiment results verify that the non-delay error compensation method proposed in this paper can effectively improve the accuracy of the DDGTMT.


Author(s):  
Jennifer Creamer ◽  
Patrick M. Sammons ◽  
Douglas A. Bristow ◽  
Robert G. Landers ◽  
Philip L. Freeman ◽  
...  

This paper presents a geometric error compensation method for large five-axis machine tools. Compared to smaller machine tools, the longer axis travels and bigger structures of a large machine tool make them more susceptible to complicated, position-dependent geometric errors. The compensation method presented in this paper uses tool tip measurements recorded throughout the axis space to construct an explicit model of a machine tool's geometric errors from which a corresponding set of compensation tables are constructed. The measurements are taken using a laser tracker, permitting rapid error data gathering at most locations in the axis space. Two position-dependent geometric error models are considered in this paper. The first model utilizes a six degree-of-freedom kinematic error description at each axis. The second model is motivated by the structure of table compensation solutions and describes geometric errors as small perturbations to the axis commands. The parameters of both models are identified from the measurement data using a maximum likelihood estimator. Compensation tables are generated by projecting the error model onto the compensation space created by the compensation tables available in the machine tool controller. The first model provides a more intuitive accounting of simple geometric errors than the second; however, it also increases the complexity of projecting the errors onto compensation tables. Experimental results on a commercial five-axis machine tool are presented and analyzed. Despite significant differences in the machine tool error descriptions, both methods produce similar results, within the repeatability of the machine tool. Reasons for this result are discussed. Analysis of the models and compensation tables reveals significant complicated, and unexpected kinematic behavior in the experimental machine tool. A particular strength of the proposed methodology is the simultaneous generation of a complete set of compensation tables that accurately captures complicated kinematic errors independent of whether they arise from expected and unexpected sources.


2011 ◽  
Vol 121-126 ◽  
pp. 1436-1442
Author(s):  
Huang Lin Zeng ◽  
Yong Sun ◽  
Xiao Hong Ren ◽  
Li Xin Liu

This paper is a study of the application of integrated intelligent computation to solve the problems of error compensation for high-precision a NC machining system. The primary focus is on the development of integrated intelligent computation approach to get an error compensation system which is a dynamic feedback neural network embedded in a NC machine tool. Optimization of error measurement points of a NC machine tool is realized by way of application of error variable attribute reduction on rough set theory. A principal component analysis is used for data compression and feature extraction to reduce the input dimension of a dynamic feedback neural network and reduce training time of the network. Taking advantage of ant colony algorithm on training of a dynamic feedback neural network does the global search so that network can converge to get a global optimum. Positioning error caused in thermal deformation compensation capabilities were tested using industry standard equipment and procedures. The results obtained shows that this approach can effectively improve compensation precision and real time of error compensation on machine tools.


2011 ◽  
Vol 314-316 ◽  
pp. 2082-2086 ◽  
Author(s):  
Yong Lu ◽  
Jian Guang Li ◽  
Dong Gao ◽  
Feng Zhou

Heavy-duty NC machine tool is difficult and costly to evidently improve their precision via manufacturing technology only. It is proved being an effective approach to improve machine tool manufacturing precision based on software error compensation. In this paper, an error compensation algorithm based on reconstructing NC program is discussed. Following comprehensive discussion on basic algorithm of positioning error compensation in detail, linear interpolation and circular interpolation movement error compensation algorithm are further sketched in brief. To decrease the machining error, NC program is reconstructed before actual machining. The experiment results show that error compensation methods based on reconstructing NC program can improve profile accuracy of heavy-duty NC machine tools obviously.


2011 ◽  
Vol 697-698 ◽  
pp. 249-252
Author(s):  
Yu Fen Deng ◽  
Jun Jie Guo ◽  
Jin Dong Wang ◽  
H. Wang

The paper presents the principle and algorithm of multi-point and time-sharing measurement method to detect the machine geometric accuracy.Its basic principle is based on laser tracker and the multilateral method,moreover,only one laser tracker is used in the measurement.Its cost is lower than multi-point and simultaneous measurement.Then the application of the method is introduced on a glass measuring instrument.The geometric error of the machine is separated in x and y direction.


2014 ◽  
Vol 926-930 ◽  
pp. 478-481
Author(s):  
Jun Liang Liu ◽  
Zi Lun Li ◽  
Luo Cheng Li ◽  
Zi Jie Song

Against to the problem of widely used of software error compensation, raises error compensation device to instead of PC to realize erro r compensation. And introduces multi-body system relating to error compensation, represents the feasibility and implementation techniques of software error compensation using SCM. This program will show great values in the field of CNC.


2012 ◽  
Vol 23 (4) ◽  
pp. 045003 ◽  
Author(s):  
Jindong Wang ◽  
Junjie Guo ◽  
Guoxiong Zhang ◽  
Bao'an Guo ◽  
Hongjian Wang

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