scholarly journals Experimental derivation of a condition monitoring test cycle for machine tool feed drives

2021 ◽  
Author(s):  
Maximilian Benker ◽  
Sebastian Junker ◽  
Johannes Ellinger ◽  
Thomas Semm ◽  
Michael F. Zaeh
Keyword(s):  
Machine Tool ◽  
Condition Monitoring ◽  
Machine Tools ◽  
Test Bench ◽  
Economic Benefits ◽  
Ball Screw ◽  
Test Cycle ◽  
Feed Drives ◽  
Monitoring Test ◽  
Sensor Signals

AbstractDue to their critical influence on manufacturing accuracy, machine tool feed drives and the monitoring of their condition has been a research field of increasing interest for several years already. Accurate and reliable estimates of the current condition of the machine tool feed drive’s components ball screw drive (BSD) and linear guide shoes (LGSs) are expected to significantly enhance the maintainability of machine tools, which finally leads to economic benefits and smoother production. Therefore, many authors performed extensive experiments with different sensor signals, features and components. Most of those experiments were performed on simplified test benches in order to gain genuine and distinct insights into the correlations between the recorded sensor signals and the investigated fault modes. However, in order to build the bridge between real use cases and scientific findings, those investigations have to be transferred and performed on a more complex test bench, which is close to machine tools in operation. In this paper, a condition monitoring test cycle is developed for such a test bench. The developed test cycle enables the recording of a re-producible data basis, on which models for the condition monitoring of BSDs and LGSs can be based upon.

High-Precision Tracking Control of Machine Tool Feed Drives Based on ADRC

2016 ◽  
Author(s):  
Chengyong Zhang ◽  
Yaolong Chen
Keyword(s):  
Machine Tool ◽  
High Precision ◽  
Tracking Control ◽  
Position Control ◽  
Feedback System ◽  
Pi Controller ◽  
Ball Screw ◽  
Feed Drives ◽  
Precision Tracking ◽  
Precision Tracking Control

In this paper, the active-disturbance-rejection control (ADRC) is applied to realize the high-precision tracking control of CNC machine tool feed drives. First, according to the number of the feedback channel, the feed systems are divided into two types: signal-feedback system, e.g., linear motor and rotary table, and double-feedback system, e.g., ball screw feed drive with a load/table position feedback. Then, the appropriate controller is designed to ensure the closed-loop control performance of each type of system based on the idea of ADRC. In these control frameworks, the extended state observers (ESO) estimate and compensate for unmodeled dynamics, parameter perturbations, variable cutting load, and other uncertainties. For the signal-feedback system, the modified ADRC with an acceleration feedforward term is used directly to regulate the load/table position response. However, for the double-feedback system, the ADRC is applied only to the motor position control, and a simple PI controller is used to achieve the accurate position control of the load. In addition, based on ADRC feedback linearization, a novel equivalent-error-model based feedforward controller is designed to further improve the command following performance of the double-feedback system. The experimental results demonstrate that the proposed controllers of both systems have better tracking performance and robustness against the external disturbance compared with the conventional P-PI controller.

scholarly journals Positioning Errors Measurement of CNC Machine Tools Based on J-DBB Method

2021 ◽  
Vol 11 (24) ◽  
pp. 11770
Author(s):  
Tao Sun ◽  
Wen Wang ◽  
Zhanfeng Chen ◽  
Yewen Zhu ◽  
Kaifei Xu ◽  
...  
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Degree Of Freedom ◽  
Ball Screw ◽  
Cnc Machine Tools ◽  
Positioning Error ◽  
Cnc Machine Tool ◽  
Spherical Joint ◽  
Cnc Machine ◽  
Positioning Errors

Due to the errors of the servo system and the errors of the ball screw drive system, the positioning errors inevitably occur in the process of CNC machine tools. The measurement of traditional equipment is limited by a fixed measurement radius and a single degree of freedom, which can only be measured within a fixed plane. In this paper, four different positioning errors of CNC machine tools are first measured at full scale by using J-DBB (a modified double ball bar with one spherical joint connecting two bars) method. The J-DBB device uses a three-degree-of-freedom spherical joint as a connecting part, which realizes that the measurement radius can be continuously changed, and the measurement space is a spatial sphere. First, the principle of the J-DBB method is briefly introduced. Next, four typical positioning errors of CNC machine tools are analyzed and examined, which contain the uniform contraction error of ball screw and linear grating, periodic error of the ball screw and linear grating, interference of measurement devices error, and opposite clearance error. In the end, the trajectories of the CNC machine tool spindle with a single positioning error are simulated by using the J-DBB method. The results reveal that this method can be used for the positioning error of machine tools, which helps to better understand the spatial distribution of CNC machine tool errors and provides guidance for the reasonable selection of working areas to improve the machining accuracy of parts.

The Printed Machine Tool for Micro Machining

2014 ◽  
Vol 1018 ◽  
pp. 433-440 ◽  
Author(s):  
Christoph Batke ◽  
Karl Heinz Wurst ◽  
Armin Lechler ◽  
Alexander Verl
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Ball Screw ◽  
Work Piece ◽  
Micro Machining ◽  
Motion Generation ◽  
Alternative Drive ◽  
Space Saving ◽  
Cost Efficient ◽  
Ball Screw Drives

Machine tools for micro machining are so far not adapted to work piece sizes and process forces. They feature hardly any modularity and do not allow reconfiguration in a significant process change. One possibility to adapt the machines is to produce them from plastic or composite materials through generative methods. This “printed” machine is a reconfigurable, monolithic module, in which drives are integrated. By a cooperative motion generation, larger workspaces can be realized while the installation spaces decreases. This gives the possibility to use alternative drive technologies for example piezo-drives. Based on these methods, two small generatively produced machine tools are designed. These machine tools use two different drive principles. The first machine tool is equipped with ball screw drives which are cost efficient and space saving. The second machine tool uses piezo-actuators, which are very dynamic in motion generation. Further has to be examined, which tolerances and rigidities are needed at critical points and which parts can be produced generatively and which in a conventional way.

scholarly journals Measurements of Temperature of CNC Machine Tool Ball Screw Utilising IR Method

2017 ◽  
Vol 22 (3) ◽  
pp. 769-777 ◽  
Author(s):  
J. Zapłata
Keyword(s):  
Temperature Distribution ◽  
Machine Tool ◽  
Test Bench ◽  
Temperature Sensors ◽  
Ball Screw ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Key Factors ◽  
Thermal Errors ◽  
Feed Axis

AbstractIn numerous papers it is proposed to use IR measurements of feed axis ball screw temperature distribution in order to compensate CNC machine tool thermal errors. The paper aims to validate reliability of the IR measurements in application to the feed axes ball screws. The identification of key factors influencing the accuracy of the IR measurements of ball screw temperature distribution has been conducted. A test-bench utilizing a ball screw assembly with built-in temperature sensors was introduced and the experimental data are presented along with conclusions.

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.

Experimental Evaluation of the Thermal Machine Tool Behavior for Model Updating

2012 ◽  
Vol 6 (2) ◽  
pp. 125-136 ◽  
Author(s):  
Jörg E. Franke ◽  
◽  
Tobias Maier ◽  
Franziska Schäfer ◽  
Michael F. Zaeh ◽  
...  
Keyword(s):  
Machine Tool ◽  
Experimental Evaluation ◽  
Machine Tools ◽  
Model Updating ◽  
Environmental Parameters ◽  
Simulation Models ◽  
Feed Drives ◽  
Thermal Displacements ◽  
Thermal Influence

Thermally induced deviations are one of the most important issues for modern machine tools’ accuracy. Therefore, the numerical determination of the thermal machine behavior is becoming an essential part of the development process. The thermal models are highly dependent on the applied loads and boundary conditions. The experimental determination of the thermal machine tool behavior is therefore a critical point. Consequently, this paper presents an experimental evaluation of the thermal behavior of machine tools for model updating. In order to identify the thermal machine properties, temperature distributions as well as thermal displacements were detected. The experiments addressed the thermal influence of environmental parameters, the heat generation of main and feed drives and the cutting process. The tests were carried out on two different machine types, a lathe and a milling machine. Specific machining tasks were developed for each analysis to assure realistic load cases. The temperature and displacement measurements presented in this paper provide a strong parameter base for future thermal simulation models.

Research on MFBD Modeling Method for a Gantry Machining Center Beam Components

2011 ◽  
Vol 188 ◽  
pp. 487-492 ◽  
Author(s):  
Q.J. Yang ◽  
D.N. Li ◽  
L.L. Kong ◽  
K. Li
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
High Speed ◽  
Modeling Method ◽  
Ball Screw ◽  
Machining Processes ◽  
Element Analysis ◽  
Machining Center ◽  
Body Dynamics ◽  
Multi Body

In modern machining processes, Gantry Machining Center is one of the most important machine tools. Moreover, beam components directly relate to the overall performance. From multi-body simulation (MBS) and finite element analysis (FEA) respectively, the paper discusses current state of the multi-body dynamics modelling of the machine tool components in domestic and overseas. In this paper, We adopt a method, the multi-flexible body dynamics(MFBD) modeling method for machine tool transmission components (linear guidance and ball screw drives) in software Recurdyn, to create the conditions for MFBD simulation analysis of the beam components system. Much more, it provides a way of MFBD modelling for machine tools components in both the high-speed and high-performance.

scholarly journals Application of Multisensor Information Fusion Technology in the Measurement of Dynamic Machining Errors of Computer Numerical Control (CNC) Machine Tools

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Xiaoping Li ◽  
Yonghong Deng ◽  
Xuezhe Li
Keyword(s):  
Neural Network ◽  
Machine Tool ◽  
Monitoring System ◽  
Condition Monitoring ◽  
Error Compensation ◽  
Machine Tools ◽  
Cnc Machine Tools ◽  
Cnc Machine ◽  
Condition Monitoring System ◽  
The Mathematical Model

A CNC machine tool is process control equipment integrating machine, electricity, and liquid, which makes its fault diagnosis complex and special due to its own advanced, complex, and intelligent characteristics. Traditional diagnostic methods rely on the engineering experience of technical personnel, which incorporates human subjective factors, and can only perform qualitative analysis, resulting in low diagnostic efficiency. And through a single sensor to detect and diagnose the machine tool, the accuracy and credibility of the decision are low, and the system is also weak against interference. In this paper, we first summarize the composition and working principle of CNC machine tools and analyze the working condition signals generated by CNC machine tools and the sensors that collect the signals and decide to use a multisensor multisignal fusion-based approach to monitor the machine tool status. It is possible to obtain more effective and valuable information from the observed information through multiple sensors so that the goal of fusion can be achieved. In this paper, a multisensor fusion technique based on wavelet transform and neural network fusion is applied to a machine tool condition monitoring system. The theoretical basis of wavelet analysis and neural network is introduced, and the composition of the condition monitoring system and the process of applying multisensor fusion technology based on wavelet analysis and neural network in the condition monitoring system are given. A complete software and hardware system for online monitoring of CNC machine tools is established. In order to improve the accuracy of the mathematical model, the use of a neural network to fit the nonlinear data and the use of coarse set theory to simplify the relevant data can effectively solve the accurate establishment of the mathematical model in the error compensation method. The thermal error compensation method for CNC machine tools is proposed based on rough set theory, ant colony algorithm, and neural network. This paper first investigates the current development of error compensation technology for CNC machining centers, analyzes the various error sources of CNC machine tools, and finds out the influencing factors affecting the errors of CNC machine tools.

Model of a CNC Feed Drive for On-Site Tuning of the Controllers for Single Axis Motion

2016 ◽  
Vol 841 ◽  
pp. 133-138
Author(s):  
Radu Eugen Breaz ◽  
Sever Gabriel Racz ◽  
Octavian Bologa ◽  
Melania Tera
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Cnc Machine Tools ◽  
Simulation Tool ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Feed Drive ◽  
Feed Drives ◽  
Contouring Accuracy ◽  
High Degree

The accuracy of CNC machine-tools is heavily influenced by the correct tuning of the feed drives controllers. While an initial tuning is performed by the machine-tool manufactures, in time the values have to be changed by the user in order to preserve positioning and contouring accuracy of the machine. This paper presents a model of a CNC feed drive, for a particular CNC machine-tool, but with a high degree of generality. The objective is to provide the user the necessary knowledge, together with a simple, yet accurate simulation tool, in order to assist him in the process of tuning the controllers.

Integration von Machine Vision in Kugelgewindespindeln*/Integration of machine vision in ball screw drives – Integrated system for condition monitoring of ball screw drives

2019 ◽  
Vol 109 (07-08) ◽  
pp. 605-610
Author(s):  
T. Schlagenhauf ◽  
J. Hillenbrand ◽  
B. Klee ◽  
J. Fleischer
Keyword(s):  
Early Detection ◽  
Machine Vision ◽  
Condition Monitoring ◽  
Machine Tools ◽  
Integrated System ◽  
Ball Screw ◽  
Camera System ◽  
Ball Screw Drives

Unvorhergesehene Maschinenausfälle von Werkzeugmaschinen durch natürlichen Verschleiß sind häufig auf den Kugelgewindetrieb zurückzuführen. Für eine frühzeitige Erkennung der auftretenden Schäden, präsentiert dieser Beitrag einen Ansatz für die Überwachung von Spindeln von Kugelgewindetrieben mittels integriertem Kamerasystem. Ziel ist die frühzeitige Detektion von Schäden, die auf der Spindeloberfläche erscheinen, um entsprechende Wartungsmaßnahmen abzuleiten.   Unforeseen failures of machine tools due to wear are often caused by ball screws. To allow for an early detection of damage, this article presents an approach for monitoring ball screw spindles using an integrated camera system. The aim is to detect initial defects that appear on the spindle surface and derive appropriate maintenance measures.

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