Dynamic Model Based on Genetic Algorithms of Prediction for the Thermal Deformation of Machine Tools

2006 ◽  
Vol 505-507 ◽  
pp. 163-168
Author(s):  
Chia Wei Chang ◽  
M. H. Chu ◽  
Yi Wei Chen ◽  
S.Y. Chien ◽  
Yuan Kang
Keyword(s):  
Genetic Algorithms ◽  
Machine Tool ◽  
Dynamic Model ◽  
Machine Tools ◽  
Prediction Accuracy ◽  
Thermal Deformation ◽  
Temperature Sensors ◽  
Model Order ◽  
Accuracy Of Prediction ◽  
Better Than

The compensation of thermal deformation is the most significant for the accuracy of a machine tool. This study proposes an approach based on genetic algorithms (GA) to build the dynamic model of the prediction for thermal deformation of a machine tool. GA is used to optimize the prediction accuracy by using appropriate number and locations of temperature sensors, the model order and the time delay between temperatures and thermal deformation. The compared results show that the proposed approach can improve the accuracy of prediction results and better than other methods.

scholarly journals Machining Tests to Evaluate Machine Tool Thermal Displacement in Z-Direction: Proposal to ISO 10791-10

2020 ◽  
Vol 14 (3) ◽  
pp. 380-385
Author(s):  
Soichi Ibaraki ◽  
◽  
Rin Okumura
Keyword(s):  
Machine Tool ◽  
Standardized Tests ◽  
Machine Tools ◽  
Thermal Deformation ◽  
Axial Direction ◽  
Technical Committee ◽  
Test Procedures ◽  
Thermal Displacement ◽  
Machining Test ◽  
Thermal Influence

Thermal deformation is one of the contributors of critical errors of machine tools. ISO 10791-10 describes standardized tests to evaluate a machine tool’s thermal deformation; however, they do not include cutting operations. By repeatedly performing the same machining feature, one can observe the change in geometric accuracy, which is typically caused by the thermal influence of the environment or the heat generated by the machine tool. This paper proposes a simple machining test to evaluate a machine tool’s thermal displacement in the tool’s axial direction (Z-direction). Together with a technical committee of the Japan Machine Tool Builders’ Association, the authors proposed the revision of ISO 10791-10 in ISO/TC39/SC2 to add the present machining tests. This paper presents the test procedures and case studies as well as a comparison with an alternative machining test.

Study on the Restraint Method of Thermal Deformation in the Machine Tools

2013 ◽  
Vol 797 ◽  
pp. 603-608
Author(s):  
Kyosuke Umezu ◽  
Kazuhito Ohashi ◽  
Shinya Tsukamoto
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Thermal Deformation ◽  
Estimation Accuracy ◽  
Machining Accuracy ◽  
Long Time ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Automatic Mass ◽  
Main Factor

In the NC machine tools for automatic mass production processing lines, it is demanded that high stable machining accuracy is maintained for a long time. The main factor of deterioration in machining accuracy depends on the thermal deformation of machine tool, and the measures are one of the most important issues in the machine tool design. The thermal deformation is practically estimated by the temperature changing state of machine tools based on obtained data of their thermal deformation chracteristics. The estimation accuracy of thermal deformation depends on the thermometry points of machine tool greatly. This study describes an approach to the most suitable thermometry points in machine tool to determine the effective thermal deformation measures experimentally. As a result, the existence of points where the temperature of components changed with relation to thermal deformation very closely was confirmed.

scholarly journals Dynamic Modeling and Experimental Research on Position-dependent Behavior of Twin Ball Screw Feed System

2021 ◽  
Author(s):  
Meng Duan ◽  
Hong Lu ◽  
Xinbao Zhang ◽  
Zhangjie Li ◽  
Yongquan Zhang ◽  
...  
Keyword(s):  
Machine Tool ◽  
Dynamic Model ◽  
Machine Tools ◽  
Experimental Tests ◽  
Ball Screw ◽  
Fe Model ◽  
Feed System ◽  
Dependent Behavior ◽  
Machine Tool Structure ◽  
Important Means

Abstract To establish the dynamic model of machine tool structure is an important means to assess the performance of the machine tool structure during the cutting process. It’s necessary to study the dynamics of the machine tools in different configurations for the sake of analyzing the dynamic behavior of the machine tools in the entire workspace. In this paper, a robust approach is presented to build an efficient and reliable dynamic model to evaluate the position-dependent dynamics of the twin ball screw (TBS) feed system. First, the TBS feed system is divided into several components and a finite element (FE) model is built for each component. Second, the Craig-Bampton method is proposed to reduce the order of the substructures. Third, a multipoint constraints (MPCs) method was introduced to model the mechanical joints substructures of the TBS system, and the spring-damper element (SDE) is employed to connect the condensation nodes. Finally, a series experimental tests and full order FE analysis are conducted on the self-designed TBS worktable in the four positions to validate the effectiveness of the proposed dynamic model. The results show that the proposed approach evaluates accurately the position-dependent behavior of the TBS system.

Simulation of Thermal Deformation for Spindle of Machine Tool

2010 ◽  
Vol 97-101 ◽  
pp. 2979-2982
Author(s):  
Chia Lung Chang ◽  
Yung Cheng Wang ◽  
Yi Chieh Wang ◽  
Bean Yin Lee
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Machine Tool ◽  
Machine Tools ◽  
Thermal Deformation ◽  
Experimental Measurements ◽  
Load Rating ◽  
Analysis Model ◽  
Bearing Load ◽  
Speed And Accuracy

In order to increase the efficiency of machine tools, the development of machine tools is toward higher speed and accuracy. The higher speed of spindle causes more thermal deformation, which reduces the accuracy of machine tools. In this study, finite element method is used to simulate the thermal deformation of spindle caused by the friction loads between spindle and bearings. The bearing load is estimated by the basic load rating from the bearing vendor and the required life of bearing. The simulated results are compared with experimental measurements to verify the analysis model. The result shows that the stabilized temperature of spindle increases as the speed increaser, while the stabilized displacement of spindle slightly increases as the speed increases.

FEM-Based Modeling to Simulate Thermal Deformation Process for High-Speed Ball Screw Drive Systems

2013 ◽  
Vol 481 ◽  
pp. 171-179 ◽  
Author(s):  
A.S. Yang ◽  
S.Z. Chai ◽  
H.H. Hsu ◽  
T.C. Kuo ◽  
W.T. Wu ◽  
...  
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Thermal Deformation ◽  
Drive System ◽  
Ball Screw ◽  
Frictional Heat ◽  
Thermal Dynamics ◽  
Screw Drive ◽  
Ball Screw Drive ◽  
Feed Drive System

Along with increasing speed and acceleration of numerically controlled machine tools, the influence of thermal dynamics characteristics on operating accuracy becomes more and more important. Improvement of thermal dynamics characteristics has turned out to be one of the crucial problems to develop machine tool of high performance. The positioning error of a feed drive system, mostly caused by the thermal deformation of a ball screw shaft, can directly affect the working accuracy of the machine tool. In this study, we applied the computational approach using the finite element method (FEM) to simulate the thermal expansion process for estimating the deformation of the ball screw system. In the numerical analysis, the deformation of the ball screw shaft and nut was modeled via a linear elasticity approach along with the assumption that the material was elastic, homogeneous, and isotropic. To model the reciprocating motions of the nut at a speed of 60m/min respecting to the screw shaft, we utilized the three-dimensional unsteady heat conduction equation with the frictional heat from the sources of the ball screw shaft, nut and bearings to calculate the temperature distributions for determining the temperature rises and axial thermal deformations in a ball screw shaft under operating situations. Simulations were conducted to explore the connection between the temperature increase of nut and the thermal deformation of the ball screw drive system, revealing the need of a compensation scheme for thermal error to improve the operating accuracy of machine tools.

scholarly journals Recurrent neural networks with long term temporal dependencies in machine tool wear diagnosis and prognosis

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Jianlei Zhang ◽  
Yukun Zeng ◽  
Binil Starly
Keyword(s):  
Neural Network ◽  
Tool Wear ◽  
Machine Tool ◽  
Recurrent Neural Network ◽  
Machine Tools ◽  
Prediction Performance ◽  
Sequential Data ◽  
Diagnosis And Prognosis ◽  
Proposed Model

AbstractData-driven approaches for machine tool wear diagnosis and prognosis are gaining attention in the past few years. The goal of our study is to advance the adaptability, flexibility, prediction performance, and prediction horizon for online monitoring and prediction. This paper proposes the use of a recent deep learning method, based on Gated Recurrent Neural Network architecture, including Long Short Term Memory (LSTM), which try to captures long-term dependencies than regular Recurrent Neural Network method for modeling sequential data, and also the mechanism to realize the online diagnosis and prognosis and remaining useful life (RUL) prediction with indirect measurement collected during the manufacturing process. Existing models are usually tool-specific and can hardly be generalized to other scenarios such as for different tools or operating environments. Different from current methods, the proposed model requires no prior knowledge about the system and thus can be generalized to different scenarios and machine tools. With inherent memory units, the proposed model can also capture long-term dependencies while learning from sequential data such as those collected by condition monitoring sensors, which means it can be accommodated to machine tools with varying life and increase the prediction performance. To prove the validity of the proposed approach, we conducted multiple experiments on a milling machine cutting tool and applied the model for online diagnosis and RUL prediction. Without loss of generality, we incorporate a system transition function and system observation function into the neural net and trained it with signal data from a minimally intrusive vibration sensor. The experiment results showed that our LSTM-based model achieved the best overall accuracy among other methods, with a minimal Mean Square Error (MSE) for tool wear prediction and RUL prediction respectively.

Application of Ubiquitous Sensor Network in Collection and Analysis of CNC Machine Tool Processing Status Information

2010 ◽  
Vol 455 ◽  
pp. 621-624
Author(s):  
X. Li ◽  
Y.Y. Yu
Keyword(s):  
Machine Tool ◽  
Sensor Network ◽  
Machine Tools ◽  
Thermal Error ◽  
Development Trend ◽  
Cnc Machine Tools ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Status Information ◽  
The Development Trend

Because of the practical requirement of real-time collection and analysis of CNC machine tool processing status information, we discuss the necessity and feasibility of applying ubiquitous sensor network(USN) in CNC machine tools by analyzing the characteristics of ubiquitous sensor network and the development trend of CNC machine tools, and application of machine tool thermal error compensation based on USN is presented.

Efficiency Improvement of Metal Lathing by Using of an Evaluation Technique of Assembly Machine Tools Quality

2016 ◽  
Vol 684 ◽  
pp. 421-428 ◽  
Author(s):  
D.S. Vasilega ◽  
M.S. Ostapenko
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Quality Evaluation ◽  
Composite Index ◽  
Production Operation ◽  
Evaluation Technique ◽  
Efficiency Improvement ◽  
Index Of Quality

They defined conditions of use, calculated a composite index of quality for different tools, chose a machine tool according to its quality evaluation, calculated efficiency of processing by tools with different parameters for a certain production operation.

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