A Novel Approach Based on Knowledge Graph and XGBoost to Characterize and Predict Position- and Speed-Dependent Dynamics of Machine Tool Structure

2020 ◽  
Author(s):  
Chaochao Qiu ◽  
Xinyong Mao ◽  
Weiye Li
Keyword(s):  
Machine Tool ◽  
Knowledge Graph ◽  
Novel Approach ◽  
Machine Tool Structure

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.

Detektion von Bauteilfehlern aus Maschinendaten/Detection of workpiece flaws out of machine tool data – possibilities and limits

2019 ◽  
Vol 109 (11-12) ◽  
pp. 828-832
Author(s):  
M. Weigold ◽  
A. Fertig ◽  
C. Bauerdick
Keyword(s):  
Quality Assurance ◽  
Machine Tool ◽  
Machine Tools ◽  
Machining Time ◽  
Parallel Detection ◽  
High Data ◽  
Novel Approach ◽  
Data Rates ◽  
High Data Rates

Durch zunehmende Vernetzung und Digitalisierung von Werkzeugmaschinen und Automatisierungskomponenten ergibt sich die Möglichkeit, Signale mit hohen Datenraten und großer Vielfalt aufzuzeichnen. Der vorliegende Beitrag beschreibt erste Untersuchungen zur Realisierbarkeit einer prozessparallelen Detektion von Bauteilfehlern auf Basis interner Werkzeugmaschinendaten. Dabei werden Potenziale und Grenzen für diesen neuartigen Ansatz zur hauptzeitparallelen Qualitätssicherung aufgezeigt.   The increasing networking and digitization of machine tools and automation components provides the opportunity to record signals with high data rates and great diversity. This paper describes first investigations on the feasibility of a process-parallel detection of component defects on the basis of internal machine tool data. Potentials and limits for this novel approach to quality assurance parallel to machining time are presented.

Exakte posenabhängige Strukurmodelle*/Accurate virtual machine tool structures - Online-identification of the general model of a lightweight machine tool structure with pose-dependent dynamic behavior

2017 ◽  
Vol 107 (05) ◽  
pp. 323-328
Author(s):  
S. Apprich ◽  
F. Wulle ◽  
A. Prof. Pott ◽  
A. Prof. Verl
Keyword(s):  
Machine Tool ◽  
Least Squares ◽  
Dynamic Behavior ◽  
Natural Frequencies ◽  
Recursive Least Squares ◽  
Machine Model ◽  
Online Identification ◽  
Working Space ◽  
Machine Tool Structure ◽  
Machine Tool Structures

Serielle Werkzeugmaschinenstrukturen weisen ein posenabhängiges, dynamisches Verhalten auf, wobei die Eigenfrequenzen um mehrere Hertz im Arbeitsraum variieren können. Die genaue Kenntnis dieses Verhaltens gestattet eine verbesserte Regelung der Strukturen. Ein generelles parametrisches Maschinenmodell, dessen Parameter online durch einen Recursive-Least-Squares-Algorithmus an das reale Maschinenverhalten angepasst werden, stellt Informationen über dieses Maschinenverhalten bereit.   Serial machine tool structures feature a pose-dependent dynamic behavior with natural frequencies varying by serveral hertz within the working space. The accurate knowledge of this behavior allows an improved control of the structures. A general parametric machine model, whose parameters are adapted online to the actual machine tool behavior by a Recursive Least Squares algorithm, provides information about the pose-dependent dynamic behavior.

The Friction Effects for Contact Force Analysis of Three Axes CNC Machine Tool

2017 ◽  
Vol 739 ◽  
pp. 12-17
Author(s):  
Yunn Lin Hwang ◽  
Thi Na Ta ◽  
Jung Kuang Cheng
Keyword(s):  
Machine Tool ◽  
Contact Force ◽  
Dynamic Structure ◽  
Cnc Machine Tool ◽  
Force Analysis ◽  
Dynamic Effects ◽  
Cnc Machine ◽  
Efficient Simulation ◽  
Machine Tool Structure ◽  
Inertia Forces

In this paper, the influence of friction on static, dynamic characteristics, the strength and lifetime of a 3-axes flexible CNC machine tool are taken into account. The machine tool is first modelled by using finite element method (FEM) to perform static structural analysis. After that, the dynamic effects caused by the inertia forces and the displacement of moving part of the machine on contact stress are considered in this study. Then, the stress and contact force distributions on solid-flexible contact are also obtained. Finally, the influence of dynamic structure, cutting conditions and material properties on strength and lifetime of CNC machine tool are discussed by using fatigue analysis. Consequently, the proposed method can be used for efficient simulation of structural dynamics, lifetime assessment as well as interactions of the real CNC machine with the machine tool structure in a virtual environment.

scholarly journals Effects of Design Alterations on the Vibration Suppression of a Machine Tool Structure

2016 ◽  
Vol 15 (3) ◽  
pp. 122-129 ◽  
Author(s):  
Young Jo Kim ◽  
Seung Hoon Ro ◽  
Ho Beom Shin ◽  
Yun Ho Shin ◽  
Keun Sup Jung ◽  
...  
Keyword(s):  
Machine Tool ◽  
Vibration Suppression ◽  
Machine Tool Structure

Determination of Machine Tool Frequency Response Function During Cutting

2004 ◽  
Author(s):  
Emmanuil Kushnir
Keyword(s):  
Steady State ◽  
Machine Tool ◽  
Frequency Response ◽  
Response Function ◽  
Frequency Response Function ◽  
Dynamic Compliance ◽  
Cutting Conditions ◽  
Machine Tool Structure ◽  
Different Types ◽  
External Sources

The dynamic compliance (frequency response function - FRF) of a machine tool structure in the cutting zone under a cutting load is one of the major dynamic characteristics that define a machine’s cutting performance. The roundness and surface finish define the quality of the manufactured parts. These characteristics are developed during finishing and semi-finishing cuts. The kinowledge of machine tool dynamic compliance, defined in these steady-state cutting conditions, ensures parts quality and increase in machine tool productivity. The dynamic compliance is usually evaluated in tests, which are performed by means of hammers or vibrators (exciters). During these tests the machine does not cut and the machine components do not move relative to each other. The loads in the machine during cutting are defined by different internal and external sources that are acting in different points of the machine and in different directions. The real spectrum and frequency range of these forces is unknown. Experimental data acquired by different types of tests clearly show the difference in dynamic compliance for the same machine tool during cutting and idling. The machine tool dynamic tests performed by different types of external exciting devices do not take in consideration the real load conditions and interactions of moving components, including the cutting process itself and external sources of vibration. The existing methods of experimental evaluation of machine tool dynamic compliance during steady-state cutting condition require dynamometers to measure the cutting force and a special sensor to measure relative displacement between the cutting tool and workpiece. The FRF that is computed from these measurements represents a dynamic characteristic of the close loop system (machine structure and cutting process) and only under certain conditions may be considered as FRF of machine tool structure itself. The theory of stationary random processes allows defining the cutting conditions, under which the obtained data represent the FRF of machine tool structure, and provide estimations of random and bias errors of this evaluation. The simplified methodology of FRF estimation, based only on measurement of the spindle and tool vibration, is also presented in this paper. This methodology is used on an assembly line to obtain FRF for machine tools performance comparison and quality assurance.

Analysis of Chatter Vibration Through Step-Function Response

1972 ◽  
Vol 94 (4) ◽  
pp. 985-990
Author(s):  
H. Takeyama ◽  
O. Sakata
Keyword(s):  
Machine Tool ◽  
Step Function ◽  
Response Analysis ◽  
Chatter Vibration ◽  
First Approximation ◽  
Machine Tool Structure ◽  
On Line ◽  
Cutting Zone ◽  
Simple Evaluation ◽  
Cutting System

This paper deals with a challenge to apply the method of indicial response analysis for obtaining the frequency characteristics of total cutting system, tool system, and cutting zone. The feasibility of this method has been verified by simulation tests. Furthermore, linearity in cutting zone has been demonstrated to a first approximation by utilizing the proposed method. As examples of its application, on-line prediction or prevention of chatter vibration and simple evaluation of machine tool structure have been proposed.

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