Beat Effect in Machining Chatter: Analysis and Detection

2020 ◽  
pp. 1-35
Author(s):  
Yuxin Sun ◽  
Longyang Ding ◽  
Chao Liu ◽  
Zhenhua Xiong ◽  
Xiang-Yang Zhu
Keyword(s):  
Wavelet Packet ◽  
Damping Ratio ◽  
Cutting Tools ◽  
Detection Methods ◽  
False Alarms ◽  
Chatter Detection ◽  
Machining Processes ◽  
Significance Level ◽  
Machining Chatter ◽  
Finish Cutting

Abstract In machining processes, regenerative chatter is an unstable vibration which adversely affects surface finish, cutting tools and spindle bearings. Under some cutting conditions, the beat effect, an interference pattern between two periodical vibrations of slightly different frequencies, has been a common phenomenon where the amplitude of chatter vibration tends to increase and decrease periodically. Until now, few studies have been conducted to analyze the beat effect in machining chatter. On the other hand, researchers have developed various chatter detection methods with the objective to timely avoid detrimental effects induced by chatter. However, none of existing chatter detection methods in the literature has ever considered the beat effect. The neglect of the beat effect will adversely affect the effectiveness of these methods and even result in false alarms. In this paper, the significance level and the mechanism of the beat effect in turning chatter are analyzed by the stability lobe diagram and time domain simulation. Afterward, a multiscale wavelet packet entropy (MWPE) method is proposed to detect machining chatter regardless of the occurrence of the beat effect. The determination strategy of the scale factor in the MWPE is presented based on the beat period, whose relationship with the damping ratio and spindle speed is derived analytically in orthogonal turning scenarios. Finally, machining tests are conducted to verify the feasibility and effectiveness of the proposed chatter detection method with respect to the presence and absence of the beat effect.

scholarly journals In-Process Chatter Detection Using Signal Analysis in Frequency and Time-Frequency Domain

Machines ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 24
Author(s):  
Michele Perrelli ◽  
Francesco Cosco ◽  
Francesco Gagliardi ◽  
Domenico Mundo
Keyword(s):  
Wavelet Packet ◽  
Cutting Tools ◽  
Poor Quality ◽  
Machining Process ◽  
Surface Finishing ◽  
Work Piece ◽  
Chatter Detection ◽  
Machining Processes ◽  
Time Frequency ◽  
Working Parameters

All machining processes involve vibrations generated by structural sources such as a machine’s moving parts or by the interaction between cutting tools and work-pieces. Relative vibrations between the work-pieces and the cutting tool are the most relevant from the point of view of the regenerative chatter phenomenon. In fact, these vibrations can lead to a chip yregeneration effect, which results in unwanted consequences, rapidly degenerating towards a very poor quality of surface finishing or, in case of severe chatter conditions, to machine-tool or work-piece damage. In the past decades, two different approaches for chatter avoidance were proposed by the scientific community, and they are commonly referred to as Out-of-Process (OuP) and in-Process (iP) solutions. The OuP solutions are off-line approaches, which allow to properly set the working parameters before machining starts. Ip solutions are on-line techniques, which allow to dynamically change the working parameters during machining by using single or multiple sensors. By monitoring the machining process, iP algorithms try to keep the machining process in stable working conditions while keeping high productivity levels. This study dealt with a novel iP chatter-detection strategy based on the Power Spectral Density (PSD) analysis and on the Wavelet Packet Decomposition (WPD) of different sensor signals. The preliminary results demonstrate the stability and feasibility of proposed indicators for chatter detection in industrial application.

scholarly journals Dispositivos De Interrupcion Subia (Dis) Para El Analisis De Raices Viruta

2014 ◽  
Vol 2 (2) ◽  
Author(s):  
Diego Alejandro Neira Moreno
Keyword(s):  
Cutting Tool ◽  
Cutting Tools ◽  
Scientific Research ◽  
Cutting Process ◽  
Work Piece ◽  
Mechanical Forces ◽  
Machining Processes ◽  
Research Instrument ◽  
Machined Parts ◽  
Interaction Phenomena

El estudio de las variables y efectos derivados del mecanizado provee herramientas de conocimiento tendientes a optimizar el uso de las herramientas y los procedimientos de maquinado industrial. Este artículo de reflexión aborda el uso de los dispositivos de interrupción súbita (DIS) como herramientas de obtención de raíces de viruta para la investigación científica del mecanizado industrial, y para el estudio de los efectos derivados de la interacción entre las herramientas de corte y el material de trabajo, en función de los cambios microestructurales del material de trabajo, dependientes de la temperatura producida y los esfuerzos mecánicos de la herramienta de corte durante el mecanizado. Mediante la reflexión se destaca la importancia de los DIS como instrumentos de investigación científica en la manufactura, ya que estos permiten obtener muestras de viruta para estudiar las variables incidentes en el maquinado y a partir de esta evidencia, proponer alternativas para optimizar la fabricación de piezas y la integridad de las herramientas empleadas en el proceso.AbstractThe study of the variables and effects derived from the machining processes brings the knowledge needed to optimize the use of machining tools and procedures. This article is an opinion piece about the use of quick stop devices (QSD) as a scientific research instrument in machining projects to obtain chip roots, to study the interaction phenomena between cutting tool and work piece material that depends on temperature and the mechanical forces produced by the cutting tool during the cutting process. This article deals about how important the QSD are as a research instruments in manufacture because with this instruments it is possible to analyze the machining variables, based on the evidences bring by the chip roots obtained with the instrument. It is possible to propose optimization alternatives in the manufacture of machined parts and the integrity of cutting tools.

Assessment of the Adequacy of the Definition of Cutting Forces for the Purpose of Minimizing Energy Consumption in Machining Processes

2019 ◽  
Vol 945 ◽  
pp. 556-562
Author(s):  
A.G. Kondrashov ◽  
D.T. Safarov ◽  
R.R. Kazargeldinov
Keyword(s):  
Energy Consumption ◽  
Cutting Force ◽  
Cutting Forces ◽  
Metal Cutting ◽  
Electrical Power ◽  
Cutting Tools ◽  
Precise Determination ◽  
Machining Processes ◽  
Milling Operations ◽  
Cutting Equipment

Minimizing energy consumption in the processing of parts on metal-cutting equipment is most effective at the stage of designing the content of operations. Important in this process is the precise determination of the initial parameters - cutting forces. This parameter allows you to plan both energy consumption and perform additional calculations for the deformation of the tooling and workpiece in order to predict the geometric accuracy of the machined part. The article presents the results of experiments on measuring the circumferential cutting force during milling operations of an aluminum alloy workpiece with an end mill. The measurements were carried out by an indirect method - by recording the electrical power on the spindle and then calculating the circumferential cutting force. Theoretical analysis of the methods of calculation of cutting forces showed significant differences between the results obtained by domestic methods and recommendations of world manufacturers of cutting tools. Statistical analysis of the results of calculations based on reference data and measurements made it possible to assess the adequacy of the known methods for calculating cutting forces in order to minimize energy consumption in operations of processing parts on metal-cutting equipment

An auxiliary approach to the experimental study on chip control: A kinematically simulated test

1998 ◽  
Vol 212 (2) ◽  
pp. 159-166 ◽  
Author(s):  
N Fang
Keyword(s):  
Experimental Study ◽  
High Speed ◽  
Cutting Tools ◽  
Three Dimensional ◽  
Experimental Period ◽  
Machining Processes ◽  
Chip Breaking ◽  
Chip Flow ◽  
Simulated Test ◽  
On Chip

Traditionally, cutting tools made of sintered carbides or high-speed steels are used to cut a variety of metal materials in the experimental study on chip control. One of the existing problems is that, in most cases, it is difficult to make, in a laboratory, cutting tools with a three-dimensionally shaped chip breaking groove for use in the follow-up experiments. Turning to tool manufacturers, who use the powder metallurgy techniques of tool making for help, usually leads to a long experimental period and high cost. An auxiliary approach to the experimental study on chip control, called a kinematically simulated test (KST), is proposed in this present work to overcome the above shortcoming of the traditional method employed in the experimental study on chip control. A plexiglass-made cutting tool is employed to cut a commercially available paraffin wax to simulate some kinematic phenomena (such as chip flow and chip curl) which take place during practical machining processes. After the applied range of KST has been illustrated, two examples of applying KST are given. One is the application of KST to chip flow research. The other is optimizing the geometry of the chip breaking groove of a tool insert by means of KST. Both examples involve the making of the chip breaking grooves with the three-dimensional shape and geometry.

Synthesis of Cutting Tool Placement, Orientation and Motion Based on Surface Analysis

2000 ◽  
Author(s):  
C. G. Jensen ◽  
J. K. Hill ◽  
K. A. White
Keyword(s):  
Tool Path ◽  
Cutting Tool ◽  
A Priori ◽  
Cutting Tools ◽  
Detection Algorithm ◽  
Detection Methods ◽  
Machined Surface ◽  
Mathematical Basis ◽  
Five Axis ◽  
Verification Techniques

Abstract Engineers and designers use a wide variety of curve and surface formulations to describe products. The process of producing the physical shape of these products has remained essentially unchanged for many years. Traditionally, the process of finish surface machining has been error prone and inefficient due in large part to the mathematical basis used to control the positioning, orientation and movement of cutting tools in five-axis machining centers. This paper presents swept silhouette curvature matching algorithms for positioning and orienting a cutter such that tool and surface curvatures match. Formulations are given for both flat and filleted end mill cutters. The benefits of curvature matching are: reduction of local machining errors, reduction or elimination of grinding of the finished machined surface, and the improvement of machine tool efficiency. Examples are given that compare curvature matching to traditional machining methods. The paper concludes by discussing current research into a priori gouge detection methods based on intersection contact between the cutting tool and the design surface or the lower tolerance-bound offset surface to the design surface. An a priori gouge detection algorithm is necessary for the development of optimal tool motion and the reduction of time spent in tool path editing and verification. Techniques involving collinear normals, Bézier clipping, triangulation, normal intersection and swept volumes are suggested as techniques for examining the positional and translational tool gouge problem.

Intrusion Detection of Cyber-Physical Attacks in Manufacturing Systems: A Review

2019 ◽  
Author(s):  
Mingtao Wu ◽  
Young B. Moon
Keyword(s):  
Intrusion Detection ◽  
Manufacturing Systems ◽  
High Volume ◽  
Cyber Attacks ◽  
Intrusion Detection Systems ◽  
Detection Methods ◽  
False Alarms ◽  
Alert Correlation ◽  
Acoustic Image ◽  
Detection Systems

Abstract Cyber-physical manufacturing system is the vision of future manufacturing systems where physical components are fully integrated through various networks and the Internet. The integration enables the access to computation resources that can improve efficiency, sustainability and cost-effectiveness. However, its openness and connectivity also enlarge the attack surface for cyber-attacks and cyber-physical attacks. A critical challenge in defending those attacks is that current intrusion detection methods cannot timely detect cyber-physical attacks. Studies showed that the physical detection provides a higher accuracy and a shorter respond time compared to network-based or host-based intrusion detection systems. Moreover, alert correlation and management methods help reducing the number of alerts and identifying the root cause of the attack. In this paper, the intrusion detection research relevant to cyber-physical manufacturing security is reviewed. The physical detection methods — using side-channel data, including acoustic, image, acceleration, and power consumption data to disclose attacks during the manufacturing process — are analyzed. Finally, the alert correlation methods — that manage the high volume of alerts generated from intrusion detection systems via logical relationships to reduce the data redundancy and false alarms — are reviewed. The study show that the cyber-physical attacks are existing and rising concerns in industry. Also, the increasing efforts in cyber-physical intrusion detection and correlation research can be utilized to secure the future manufacturing systems.

scholarly journals The Critical Raw Materials in Cutting Tools for Machining Applications: A Review

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1377 ◽  
Author(s):  
Antonella Rizzo ◽  
Saurav Goel ◽  
Maria Luisa Grilli ◽  
Roberto Iglesias ◽  
Lucyna Jaworska ◽  
...  
Keyword(s):  
Cutting Tool ◽  
Raw Materials ◽  
Single Point ◽  
Cutting Tools ◽  
Mitigation Measures ◽  
Mechanical Processing ◽  
Machining Processes ◽  
Contact Mode ◽  
Mechanical Machining ◽  
Critical Raw Materials

A variety of cutting tool materials are used for the contact mode mechanical machining of components under extreme conditions of stress, temperature and/or corrosion, including operations such as drilling, milling turning and so on. These demanding conditions impose a seriously high strain rate (an order of magnitude higher than forming), and this limits the useful life of cutting tools, especially single-point cutting tools. Tungsten carbide is the most popularly used cutting tool material, and unfortunately its main ingredients of W and Co are at high risk in terms of material supply and are listed among critical raw materials (CRMs) for EU, for which sustainable use should be addressed. This paper highlights the evolution and the trend of use of CRMs) in cutting tools for mechanical machining through a timely review. The focus of this review and its motivation was driven by the four following themes: (i) the discussion of newly emerging hybrid machining processes offering performance enhancements and longevity in terms of tool life (laser and cryogenic incorporation); (ii) the development and synthesis of new CRM substitutes to minimise the use of tungsten; (iii) the improvement of the recycling of worn tools; and (iv) the accelerated use of modelling and simulation to design long-lasting tools in the Industry-4.0 framework, circular economy and cyber secure manufacturing. It may be noted that the scope of this paper is not to represent a completely exhaustive document concerning cutting tools for mechanical processing, but to raise awareness and pave the way for innovative thinking on the use of critical materials in mechanical processing tools with the aim of developing smart, timely control strategies and mitigation measures to suppress the use of CRMs.

scholarly journals Automatic Fire and Smoke Detection Method for Surveillance Systems Based on Dilated CNNs

Atmosphere ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1241
Author(s):  
Yakhyokhuja Valikhujaev ◽  
Akmalbek Abdusalomov ◽  
Young Im Cho
Keyword(s):  
Cost Effective ◽  
Classification Performance ◽  
Detection Methods ◽  
False Alarms ◽  
Surveillance Systems ◽  
Smoke Detection ◽  
Detection Systems ◽  
Number Of False Alarms ◽  
Unseen Data ◽  
Vision Detection

The technologies underlying fire and smoke detection systems play a crucial role in ensuring and delivering optimal performance in modern surveillance environments. In fact, fire can cause significant damage to lives and properties. Considering that the majority of cities have already installed camera-monitoring systems, this encouraged us to take advantage of the availability of these systems to develop cost-effective vision detection methods. However, this is a complex vision detection task from the perspective of deformations, unusual camera angles and viewpoints, and seasonal changes. To overcome these limitations, we propose a new method based on a deep learning approach, which uses a convolutional neural network that employs dilated convolutions. We evaluated our method by training and testing it on our custom-built dataset, which consists of images of fire and smoke that we collected from the internet and labeled manually. The performance of our method was compared with that of methods based on well-known state-of-the-art architectures. Our experimental results indicate that the classification performance and complexity of our method are superior. In addition, our method is designed to be well generalized for unseen data, which offers effective generalization and reduces the number of false alarms.

scholarly journals Novel Integration of CAPP in a G-Code Generation Module Using Macro Programming for CNC Application

Machines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 61
Author(s):  
Trung Kien Nguyen ◽  
Lan Xuan Phung ◽  
Ngoc-Tam Bui
Keyword(s):  
Process Planning ◽  
Code Generation ◽  
Manufacturing Industry ◽  
New Technologies ◽  
Cutting Tools ◽  
Machining Processes ◽  
Machining Features ◽  
Computer Aided Process Planning ◽  
Technical Requirements ◽  
G Code

In the modern manufacturing industry, the role of computer-aided process planning (CAPP) is becoming increasingly crucial. Through the application of new technologies, experience, and intelligence, CAPP is contributing to the automation of manufacturing processes. In this article, the integration of a proposed CAPP system that is named as BKCAPP and G-code generation module provides a completed CAD–CAPP–CNC system that does not involve any manual processing in the CAM modules. The BKCAPP system is capable of automatically performing machining feature and operation recognition processes from design features in three-dimensional (3D) solid models, incorporating technical requirements such as the surface roughness, geometric dimensions, and tolerance in order to provide process planning for machining processes, including information on the machine tools, cutting tools, machining conditions, and operation sequences. G-code programs based on macro programming are automatically generated by the G-code generation module on the basis of the basic information for the machining features, such as the contour shape, basic dimensions, and cutting information obtained from BKCAPP. The G-code generation module can be applied to standard machining features, such as faces, pockets, bosses, slots, holes, and contours. This novel integration approach produces a practical CAPP method enabling end users to generate operation consequences and G-code files and to customize specific cutting tools and machine tool data. In this paper, a machining part consisting of basic machining features was used in order to describe the method and verify its implementation.

Research and Application of Carbide Blade Surface Quality Primitive Digital Automatic Detection

2014 ◽  
Vol 971-973 ◽  
pp. 1700-1705
Author(s):  
Xue Jun Tian ◽  
Zhi Peng Dong ◽  
Feng Ye
Keyword(s):  
Hard Alloy ◽  
Rapid Detection ◽  
Production Efficiency ◽  
Surface Defects ◽  
Cutting Tools ◽  
Production Quality ◽  
Detection Methods ◽  
Compute Unified Device Architecture ◽  
Blade Surface ◽  
Device Architecture

Hard alloy has been widely applied as a type of cutter material and cemented carbide cutting tools have become the main tools for processing enterprises in our country. During the blade production process, traditional artificial detection methods for surface defects can't satisfy the demands of production quality and production efficiency any longer. Online automation rapid detection has been realized based on the Compute Unified Device Architecture (CUDA) by utilizing the computing capability of GPU.

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