A Stochastic Approach to Characterization of Machine Tool System Dynamics Under Actual Working Conditions

1976 ◽  
Vol 98 (2) ◽  
pp. 614-619 ◽  
Author(s):  
F. A. Burney ◽  
S. M. Pandit ◽  
S. M. Wu
Keyword(s):  
Machine Tool ◽  
Working Conditions ◽  
Stochastic Approach ◽  
Relative Displacement ◽  
Process Dynamics ◽  
Actual Working ◽  
Machine Tool Structure ◽  
Vertical Milling ◽  
Vertical Milling Machine ◽  
Tool Dynamics

The machine tool dynamics is evaluated under actual working conditions by using a time series technique. This technique develops mathematical models from only one signal, viz., the relative displacement between the cutter and the workpiece. Analysis of the experimental data collected on a vertical milling machine indicates that the new methodology is capable of characterizing the machine tool structure and the cutting process dynamics separately. Furthermore, it can also detect and quantify the interaction between these two subsystems.

Mathematical Approach for Geometric Error Modeling of Three Axis CNC Vertical Milling Machine

2016 ◽  
Vol 842 ◽  
pp. 303-310 ◽  
Author(s):  
Widyanti Kwintarini ◽  
Agung Wibowo ◽  
Yatna Yuwana Martawirya
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Machining Process ◽  
Cnc Machine Tools ◽  
Milling Machine ◽  
Cnc Machine ◽  
Geometrical Errors ◽  
Vertical Milling ◽  
Vertical Milling Machine ◽  
Accuracy And Repeatability

The aim of this paper overviews about to find out the errors that come from three axis CNC vertical milling machine. The errors come from, the CNC milling machine can be modelled into mathematical models and later on these error models will be used to analyse the errors in the measured data. Many errors from CNC machine tools have given significant effects toward the accuracy and repeatability of manufacturing process. There are two error sources come from CNC machine tools such as tool deflection and thermal distortions of machine tool structure. These errors later on will contribute to result in the geometrical deviations of moving axis in CNC vertical milling machine. Geometrical deviations of moving axis such as linear positioning errors, roll, pitch and yaw can be designated as volumetric errors in three axis machine tool. Geometrical deviations of moving axises happen at every axis in three axis CNC vertical milling machine. Geometrical deviations of moving axises in linear and angular movement has the amount of errors up to twenty one errors. Moreover, this geometrical errors play the major role in the total amount of errors and for that particular reason extra attention towards the geometrical deviation errors will be needed along machining process. Each of geometrical error of three axes vertical machining center is modeled using a homogeneous transformation matrix (HTM). The developed mathematical model is used to calculate geometrical errors at each axis and to predict the resultant error vector at the interface of machine tool and workpiece for error compensation.

Sensorischer Spindelstock zur Thermo-Korrektur*/Sensory headstock for thermo compensation

2017 ◽  
Vol 107 (07-08) ◽  
pp. 500-506
Author(s):  
C. Prof. Brecher ◽  
M. Klatte
Keyword(s):  
Machine Tool ◽  
Strain Measurement ◽  
Milling Machine ◽  
Thermally Induced ◽  
Modeling Methods ◽  
Center Point ◽  
Vertical Milling ◽  
Vertical Milling Machine ◽  
Machine Tool Structures ◽  
Novel Methods

Vorgestellt wird ein Sensorkonzept zur integralen Dehnungsmessung für Werkzeugmaschinenstrukturen. Mithilfe dieser Sensoren ist die Implementierung traditioneller sowie neuartiger Methoden zur steuerungstechnischen Korrektur thermisch bedingter Tool-Center-Point-Verlagerungen möglich. Die Sensoren wurden im Spindelstock einer 3-achsigen Vertikalfräsmaschine umgesetzt sowie Korrekturkonzepte mit unterschiedlichen Modellierungsverfahren validiert.   In this paper, a sensor concept for integral strain measurement in machine tool structures is introduced. With the help of these sensors the implementation of both traditional and novel methods for the control-based compensation of thermally induced tool center point dislocations is possible. The sensors have been integrated in the headstock of a 3-axis vertical milling machine. Furthermore, correction concepts with different modeling methods have been validated.

Study on Thermal Deformation of Machine Tool under Different Environment Temperature

2013 ◽  
Vol 441 ◽  
pp. 576-579
Author(s):  
Fan Jie Luo ◽  
Dan Lu Song ◽  
Zhi Wei Li ◽  
Qing Yun Jian
Keyword(s):  
Machine Tool ◽  
Thermal Deformation ◽  
Field Analysis ◽  
Machining Accuracy ◽  
Milling Machine ◽  
Element Analysis ◽  
Front End ◽  
Vertical Milling ◽  
Environment Temperature ◽  
Vertical Milling Machine

Taking XK5034 vertical milling machine as the research object, its thermal characteristic's finite element analysis has been carried out through the ANSYS. The front-end of the spindle mainly affects the machining accuracy of machine tool, so on the basis of the temperature field analysis, its thermal deformation was analyzed under different environment temperature, and the change rules between environment temperature and thermal deformation of the front of the spindle was also acquired. The results show that the influence of machine tool thermal deformation under different temperature is obvious.

scholarly journals Mapping positional accuracy for milling machine table

2021 ◽  
pp. 21-25
Author(s):  
D. A. Blokhin ◽  
◽  
Yu. A. Blokhina ◽  
M. M. Lakman ◽  
◽  
...  
Keyword(s):  
Machine Tool ◽  
Forced Oscillations ◽  
Milling Machine ◽  
Positional Accuracy ◽  
Vibration Load ◽  
Laboratory Setup ◽  
Vertical Milling ◽  
Vertical Milling Machine

The article presents a technique for compiling a map of the positional accuracy of the table of a vertical milling machine when a vibration load of various frequencies is applied. A laboratory setup for creating forced oscillations of a cross table has been developed and manufactured. The reasons for the emergence of the highest deviations in specific areas of the working area of the machine tool are analyzed.

Cutting Process Dynamics Simulation for Machine Tool Structure Design

1986 ◽  
Vol 108 (2) ◽  
pp. 68-74 ◽  
Author(s):  
S. J. Lee ◽  
S. G. Kapoor
Keyword(s):  
Finite Element ◽  
Machine Tool ◽  
Structural Model ◽  
Face Milling ◽  
Cutting Process ◽  
Force Model ◽  
Milling Force ◽  
Process Dynamics ◽  
Machine Tool Structure ◽  
Milling Force Model

A methodology to simulate the real cutting process dynamics using a finite element structural model and a mechanistic face milling force model is proposed. While the finite element structural model provides an analytic way to assess structural dynamic characteristics, the mechanistic face milling force model calculates the time histories of cutting forces taking many cutting process parameters into consideration and acts as forcing functions to the structural model. The methodology is verified through experimentation. The effects of structural parameters and cutting process parameters on the dynamic behavior of the machine tool structure are also studied. The results indicate that the proposed methodology can greatly enhance the machine tool design process.

Analysis of the Coupled Vibration Between Feed Drive Systems and Machine Tool Structure

2015 ◽  
Vol 9 (6) ◽  
pp. 689-697 ◽  
Author(s):  
Ryuta Sato ◽  
◽  
Gen Tashiro ◽  
Keiichi Shirase ◽  
Keyword(s):  
Machine Tool ◽  
Degrees Of Freedom ◽  
Relative Displacement ◽  
Coupled Vibration ◽  
Motion Trajectories ◽  
Feed Drive ◽  
Proposed Model ◽  
Machine Tool Structure ◽  
Drive Systems ◽  
Feed Drive System

In this study, we have constructed a mathematical model that can analyze the coupled vibration of machine tool structure and feed drive systems. The model is proposed on the basis of the modal analysis of the actual machine tool structure. It consists of three translational and three rotational displacements of the bed, relative angular deformations between the bed and column, relative translational and angular deformations between the bed and saddle, and relative translational and angular deformations between the column and spindle head. In addition, each feed drive system is modeled using a vibration model, which has two degrees of freedom. The servo controllers of each axis are also modeled. To confirm the validity of the proposed model, frequency responses, motion trajectories of the feedback positions, linear scale positions, and the relative displacement between the table and head are measured and simulated. The effect of coupled vibrations on the tracking errors is examined with the help of both experiments and simulations. To investigate the effect of the servo systems on the vibration, both experiments and simulations are carried out by using feed drive systems in the following three conditions: mechanically clamped, servo-on, and servo-off. The results of experiments and the simulations show that the proposed model can express the mode of vibration and the influence of the condition of feed drive systems on the mode of vibration.

Identifying the Unit Area Dynamic Characteristic Parameters of Fixed Joint Based on Equivalent Single DOF System

2013 ◽  
Vol 483 ◽  
pp. 322-325 ◽  
Author(s):  
Yi Chuan Xiao ◽  
Liang Sheng Wu ◽  
Jian Feng Ma ◽  
Hao Hong
Keyword(s):  
Machine Tool ◽  
Dynamic Characteristic ◽  
Working Conditions ◽  
Frequency Response Function ◽  
Unit Area ◽  
Random Noise ◽  
Testing Device ◽  
Characteristic Parameters ◽  
Modal Test ◽  
Machine Tool Structure

A whole machine tool structure is a muti-DOF system, it is usually composed of many parts which are connected with joint interfaces. The structure is complicated that the accuracy of modal test is always in a low level. When doing modal test, equivalent single DOF method can not only improve the efficiency and decrease the difficulty, but also exclude interferences such as random noise. In this paper, the author simplified a two-DOF system into an equivalent single DOF system and derived its frequency response function, then analyzed a testing device for fixed joint by using the equivalent single DOF method, and measured several groups of unit area dynamic characteristic parameters of fixed joint interfaces in different materials and different working conditions. The dynamic characteristic parameters can be used in further study of machine tool joint interfaces.

A New Approach to the Analysis of Machine-Tool System Stability Under Working Conditions

1977 ◽  
Vol 99 (3) ◽  
pp. 585-590 ◽  
Author(s):  
F. A. Burney ◽  
S. M. Pandit ◽  
S. M. Wu
Keyword(s):  
Machine Tool ◽  
Working Conditions ◽  
Cutting Speed ◽  
Stochastic Approach ◽  
Static Stability ◽  
Face Milling ◽  
System Stability ◽  
New Approach ◽  
Characteristic Roots ◽  
The Stability

A new stochastic approach is developed in this paper for analyzing the machine-tool system stability under working conditions. Mathematical models are fitted to the relative longitudinal cutter-workpiece displacement data recorded under different cutting conditions during the face-milling operation on a milling machine. The stability of the system is judged from the characteristic roots of these models. The variation in stability is examined versus both the cutting speed and the feed, and good results are obtained. It is shown that not only the dynamic but also the static stability can be ascertained. Furthermore, the stability of subsystems can also be determined. The significance of these results is discussed with special reference to on-line chatter control. The analysis of vibration signals produced by similar but evenly and unevenly spaced face milling cutters is presented as a vindication of the new approach.

Dynamic Analysis of Milling Machine by Torque Signals

1981 ◽  
Vol 103 (2) ◽  
pp. 235-240 ◽  
Author(s):  
A. R. H. Shuaib ◽  
E. Garcia-Gardea ◽  
S. M. Wu
Keyword(s):  
Machine Tool ◽  
Milling Machine ◽  
Alternative Technique ◽  
Dynamic Data ◽  
Vertical Milling ◽  
Vertical Milling Machine ◽  
Mode Characteristics ◽  
The Stability ◽  
System Mode ◽  
Stability Limits

Cutting torque signals of a vertical milling machine are used for the analysis and identification of the machine tool system. The force signals are represented by stochastic differential equations obtained by the dynamic data system (DDS) modeling technique. The parameters of the models are used to identify the dynamic modes of the machine tool system. Changes in the dynamic behavior of the machine tool system with cutting conditions have been observed from the dynamic characteristics of the constituent dynamic modes. Stability of the system has been investigated using the most compliant machine tool system mode characteristics. This suggests an alternative technique for obtaining the stability limits of the system instead of the conventional lengthy chatter tests.

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