Intelligent Error Compensation in CNC Machining through Synergistic Interactions Among Modeling, Sensing and Learning

2004 ◽  
Vol 471-472 ◽  
pp. 178-182 ◽  
Author(s):  
Zhan Qiang Liu ◽  
Jun Bo Zhang ◽  
Zhi Tao Tang
Keyword(s):  
Error Compensation ◽  
Operation Time ◽  
Cnc Machining ◽  
Sufficient Data ◽  
Cnc Machine ◽  
Cnc Turning ◽  
Synergistic Interactions ◽  
New Strategy ◽  
Turning Center ◽  
Workpiece Dimension

Industry is looking for practical means to improve the accuracy of the parts machined on CNC machines. Some artificial intelligence (AI) systems have been applied in modeling and compensating manufacturing process errors in CNC machining. However, these systems are not capable of predicting the results of a new operation if no sufficient data on a number of similar operations is available. A generalized AI approach named synergistic interactions amongst modeling, sensing and learning is proposed in this paper. Based on the AI approach, a new strategy of error compensation of workpiece dimension in CNC machining is developed and applied in a CNC turning center. Error compensation results are illustrated the effectiveness of the error compensation strategy. The learning curve shows that the error compensation confidence gradually progresses towards 100% confidence from zero along with the CNC machine operation time increasing.

Research on Modular Division Method of CNC Machine Tool

2012 ◽  
Vol 503-504 ◽  
pp. 78-81
Author(s):  
Zhong Qi Sheng ◽  
Zong Xiao Zhu ◽  
Xiang Dong Shi ◽  
Chao Biao Zhang
Keyword(s):  
Machine Tool ◽  
High Speed ◽  
Modular Design ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Cnc Turning ◽  
Modular Products ◽  
Turning Center ◽  
The Cost

Modular division is the first step of modular design, which also is the premise and basis of modular design. Whether modular division is reasonable can directly affect the systemic function performance and the cost of modular products. This paper introduces a new sort of modular division method, which divides the modules by calculating the correlations among sub-functions. At last, taking the high-speed CNC turning center as example, which is made by Shenyang Machine Tool Group, this paper proved the effectiveness and feasibility of the method.

An Integrated Modeling Approach for ANN-Based Real-Time Thermal Error Compensation on a CNC Turning Center

2013 ◽  
Vol 664 ◽  
pp. 907-915 ◽  
Author(s):  
Abderrazak El Ouafi ◽  
Michel Guillot ◽  
Noureddine Barka
Keyword(s):  
Real Time ◽  
Error Compensation ◽  
Thermal Error ◽  
Operating Conditions ◽  
Design Stage ◽  
Thermally Induced ◽  
Cnc Turning ◽  
Modeling Approach ◽  
Turning Center ◽  
Thermal Error Compensation

Thermally induced errors play a critical role in controlling the level of machining accuracy. They can represent a significant proportion of dimensional errors in produced parts. Since thermal errors cannot totally be eliminated at the design stage, active errors compensation appears to be the most economical and realistic solution. Accurate and efficient modeling of the thermally induced errors is an indispensable part of the error compensation process. This paper presents an integrated and comprehensive modeling approach for real-time thermal error compensation. The modeling process is based on multiple temperature measurements, Taguchi’s orthogonal arrays, artificial neural networks and various statistical tools to provide cost effective selection of appropriate temperature variables and modeling conditions as well as to achieve robust and accurate thermal error models. The experimental results on a CNC turning center confirm the feasibility and efficiency of the proposed approach and show that the resultant model can accurately predict the time-variant spindle thermal drift errors under various operating conditions. After compensation, the thermally induced spindle errors were reduced from 19m to less than 1 m. The proposed modeling optimization strategy can be effectively and advantageously used for real-time error compensation since it presents the benefit of straightforward application, reduced modeling time and uncertainty.

scholarly journals Geometric Measurements on a CNC Machining Device as an Element of Closed Door Technology

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4852
Author(s):  
Grzegorz Bomba ◽  
Artur Ornat ◽  
Piotr Gierlak
Keyword(s):  
Measurement System ◽  
Measurement Process ◽  
Cnc Machining ◽  
Measuring System ◽  
Cnc Machine ◽  
Statistical Process ◽  
Working Space ◽  
Closed Door ◽  
Accuracy And Repeatability

The article discusses the quality testing of a measuring system consisting of a CNC machine with measuring probes. The research was conducted in a broader context regarding the implementation of the closed door technology, i.e., production without human intervention, in an aviation plant manufacturing aircraft gearbox systems. This technology may involve automated measuring operations performed in machining centers, and not in measuring laboratories, provided that the quality of the measurements is appropriate. The aim of the study was to investigate whether the CNC machining device can be used to measure the geometric features of aircraft gearbox housing. For this purpose, measurement experiments were carried out with the use of three different probes. Measurements were carried out using four sequences of increasing complexity, so that, after error analysis, it was possible to find the causes of possible irregularities. A reference ring with known dimensions and position in the working space of the machine was used for the measurements performed as part of the assessment of the measurement system. The quality of the measurements was evaluated with the use of repeatability and reproducibility testing and statistical process control. The analysis results showed that the tested measurement system ensures adequate accuracy and repeatability, and the measurement process is characterized with adequate efficiency in relation to the manufacturing tolerance of the components produced using the machine. Thus, it was proven that the measurement process can be carried out on a machining device, which enables its integration into the closed door technology.

A Novel Method for Automated Tool Path Optimisation for CNC Machining Operations

2010 ◽  
Vol 166-167 ◽  
pp. 357-362
Author(s):  
Shahed Shojaeipour
Keyword(s):  
Tool Path ◽  
Target Location ◽  
Imaging System ◽  
Optimal Path ◽  
Digital Camera ◽  
Basic Program ◽  
Cnc Machining ◽  
Cnc Machine ◽  
Current Location ◽  
Tool Diameter

In this article, a new method for rapid tool movement in CNC machines is presented. Firstly, a single digital camera, installed on the Z-axis, captures the image of the workpiece on the work table. Image processing techniques, implemented using MATLAB, are then used to convert the image into a binary black and white image. This allows the locations of protruding edge sections on the workpiece, which could impede tool movement, to be identified. Quadtree decomposition is then performed on the binary image, and possible paths from the tool current location to its target location are found. These paths are then analysed based on the tool diameter clearance and the distance to the goal, and the shortest path with sufficient tool clearance is selected. A Visual Basic program then converts the selected path into G-code commands that provides instructions to the CNC machine tool such that this path is followed. With this method, the workpiece fixture location would not have to be precise as the imaging system would be able to automatically identify the target location with respect to the tool current location, along with the optimal path to reach it.

scholarly journals Rapid Measurement and Identification Method for the Geometric Errors of CNC Machine Tools

2019 ◽  
Vol 9 (13) ◽  
pp. 2701 ◽  
Author(s):  
Li ◽  
Yang ◽  
Gao ◽  
Su ◽  
Wei ◽  
...  
Keyword(s):  
Error Compensation ◽  
Machine Tools ◽  
Degrees Of Freedom ◽  
Cnc Machine Tools ◽  
Geometric Errors ◽  
Two Dimensional ◽  
Cnc Machine ◽  
Angle Sensor ◽  
Identification Method ◽  
Measuring Machine

Error compensation technology offers a significant means for improving the geometric accuracy of CNC machine tools (MTs) as well as extending their service life. Measurement and identification are important prerequisites for error compensation. In this study, a measurement system, mainly composed of a self-developed micro-angle sensor and an L-shape standard piece, is proposed. Meanwhile, a stepwise identification method, based on an integrated error model, is established. In one measurement, four degrees-of-freedom errors, including two-dimensional displacement and two-dimensional angle of a linear guideway, can be obtained. Furthermore, in accordance with the stepwise identification method, the L-shape standard piece is placed in three different planes, so that the measurement and identification of all 21 geometric errors can be implemented. An experiment is carried out on a coordinate measuring machine (CMM) to verify the system. The residual error of the angle error, translation error and squareness error are 1.5″, 2 μm and 3.37″, respectively, and these are compared to the values detected by a Renishaw laser interferometer.

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