scholarly journals An Open Modular Architecture Controller Based Online Chatter Suppression System for CNC Milling

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Zhenyu Han ◽  
Hongyu Jin ◽  
Maoyue Li ◽  
Hongya Fu
Keyword(s):  
Cutting Parameters ◽  
Cnc Milling ◽  
Modular Architecture ◽  
Part Quality ◽  
Chatter Suppression ◽  
Command Generation ◽  
Force Signal ◽  
Milling Chatter ◽  
The Relationship ◽  
Acceleration Signals

In milling processes, chatter is a kind of sudden relative vibration appearing between the cutter and the workpiece, which results in poor part quality, accelerated tool wear, and shortened spindle life. In this paper, an open modular architecture controller (OMAC) of machine tool which integrates the algorithms including chatter recognition, compensation command generation, and execution is proposed with the aim of providing an integrated solution for milling chatter suppression in CNC kernel. To effectively identify chatter, experiments are designed to determine the optimal installation place of accelerometer and then triaxial cutting forces and acceleration signals are compared to see which are more sensitive to chatter onset. In terms of data processing, 16 sampling points in time domain are chosen to perform online fast Fourier transform (FFT) in consideration of signal effectiveness and computational efficiency. To implement real-time chatter suppression in CNC kernel, a simplified dynamic model of milling system is used to obtain the relationship between chatter frequency and spindle speed. Finally, an adaptive control module which completes force signal extraction and processing by FFT and has the ability to modify related cutting parameters is designed to interact with other modules in OMAC where data acquisition thread and interpolation thread are synchronized. The proposed system is experimentally validated.

A Model-Based Computationally Efficient Method for On-Line Detection of Chatter in Milling

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Lei Ma ◽  
Shreyes N. Melkote ◽  
James B. Castle
Keyword(s):  
Cutting Force ◽  
Efficient Method ◽  
Frequency Estimation ◽  
Chip Thickness ◽  
Computationally Efficient ◽  
Model Based ◽  
Chatter Suppression ◽  
Force Signal ◽  
Regeneration Effect ◽  
Milling Chatter

This paper presents a model-based computationally efficient method for detecting milling chatter in its incipient stages and for chatter frequency estimation by monitoring the cutting force signals. Based on a complex exponentials model for the dynamic chip thickness, the chip regeneration effect is amplified and isolated from the cutting force signal for early chatter detection. The proposed method is independent of the cutting conditions. With the aid of a one tap adaptive filter, the method is shown to be capable of distinguishing between chatter and the dynamic transients in the cutting forces arising from sudden changes in workpiece geometry and tool entry/exit. To facilitate chatter suppression once the onset of chatter is detected, a time domain algorithm is proposed so that the dominant chatter frequency can be accurately determined without using computationally expensive frequency domain transforms such as the Fourier transform. The proposed method is experimentally validated.

Efficient CNC Tool Path Planning Using Point Cloud

2018 ◽  
Author(s):  
Sumedh Ghogare ◽  
S. S. Pande
Keyword(s):  
Path Planning ◽  
Point Cloud ◽  
Tool Path ◽  
Planning Process ◽  
Cnc Milling ◽  
Tool Path Planning ◽  
Planning Strategy ◽  
Part Quality ◽  
Nc Program ◽  
Cutter Path

This paper reports the development of an efficient iso-scallop tool path planning strategy for machining of freeform surfaces on a three axis CNC milling center using the point cloud as the input. Boundary of the point cloud is chosen as the Master Cutter Path, using which the scallop points are computed. Adjacent side tool paths are computed using these scallop points and the path planning process is completed till the entire surface is covered. The system generates post-processed NC program in ISO format which was extensively tested for various case studies. The results were compared with the iso-planar tool path strategy from commercial software. Our system was found to generate efficient tool path in terms of part quality, productivity and storage memory.

Study on Surface Roughness Based on Dynamic Minimum Thickness of Cut

2011 ◽  
Vol 88-89 ◽  
pp. 34-37
Author(s):  
Kuai Ji Cai
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Atomic Force Microscope ◽  
Surface Quality ◽  
Experimental Verification ◽  
Cutting Parameters ◽  
Minimum Thickness ◽  
Atomic Force ◽  
Relationship Of ◽  
The Relationship

The relationship of the friction coefficient and the MTC were discussed, and the MTC and its effects on surface roughness were a theoretical analysised and experimental verification by AFM (atomic force microscope). The results show that the theoretical MTC tends to be minimal value then before the adhering effect to reach remarkable. Appropriate adjustments cutting parameters, the cutting process can always micro-cutting phase to reach the steady-thin chip, and no plowing phenomenon. So the surface residues highly were reduced and higher surface quality was achieved.

A Study on Chip Breakage in Mini-Pore Vibration Drilling for Hard-to-Cut Material of Austenitic Stainless Steel

2010 ◽  
Vol 455 ◽  
pp. 548-552
Author(s):  
J.S. Zhou ◽  
Bang Yan Ye ◽  
Xing Yu Lai
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Cutting Parameters ◽  
Processing Parameters ◽  
Chip Breaking ◽  
Vibration Drilling ◽  
On Chip ◽  
Vibration Parameters ◽  
The Relationship ◽  
Chip Breakage

This research aims to improve the method of Mini-pore Drilling superimposed an axis vibration for hard-to-cut material of Austenitic Stainless Steel 1Cr18Ni9Ti, as well as to make it easier for the chips to be discharged. A mathematical model of vibration drilling is presented, and the relationship between the vibration parameters and cutting parameters to generate little and short broken-chips in vibration drilling is investigated, analyzed and verified by experiments. The results show that when the processing parameters meet the conditions given in this article, stable and reliable chip-breaking can be achieved. The results provide a theoretical guidance to achieve chip-breaking in mini-pore vibration drilling for hard-to-cut material.

scholarly journals Macro- and mesoscale pattern interdependencies in complex networks

2019 ◽  
Vol 16 (159) ◽  
pp. 20190553 ◽  
Author(s):  
M. J. Palazzi ◽  
J. Borge-Holthoefer ◽  
C. J. Tessone ◽  
A. Solé-Ribalta
Keyword(s):  
Complex Networks ◽  
Empirical Evidence ◽  
Structural Properties ◽  
Modular Architecture ◽  
Modular Networks ◽  
As Species ◽  
Species Abundances ◽  
Organizational Patterns ◽  
Natural Combination ◽  
The Relationship

Identifying and explaining the structure of complex networks at different scales has become an important problem across disciplines. At the mesoscale, modular architecture has attracted most of the attention. At the macroscale, other arrangements—e.g. nestedness or core–periphery—have been studied in parallel, but to a much lesser extent. However, empirical evidence increasingly suggests that characterizing a network with a unique pattern typology may be too simplistic, since a system can integrate properties from distinct organizations at different scales. Here, we explore the relationship between some of these different organizational patterns: two at the mesoscale (modularity and in-block nestedness); and one at the macroscale (nestedness). We show experimentally and analytically that nestedness imposes bounds to modularity, with exact analytical results in idealized scenarios. Specifically, we show that nestedness and modularity are interdependent. Furthermore, we analytically evidence that in-block nestedness provides a natural combination between nested and modular networks, taking structural properties of both. Far from a mere theoretical exercise, understanding the boundaries that discriminate each architecture is fundamental, to the extent that modularity and nestedness are known to place heavy dynamical effects on processes, such as species abundances and stability in ecology.

Laser Cutting Quality of the Ceramic Slabs

2006 ◽  
Vol 505-507 ◽  
pp. 847-852 ◽  
Author(s):  
Xu Yue Wang ◽  
Wen Ji Xu ◽  
Ren Ke Kang ◽  
Yi De Liang
Keyword(s):  
Laser Power ◽  
Laser Cutting ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Incident Laser Power ◽  
Focal Position ◽  
Geometrical Features ◽  
The Relationship ◽  
Cutting System

An experimental analysis is presented which investigates the relationship between cutting parameters and the volume of material removal as well as its cutting quality on a Nd:YAG laser cutting system. The parameters that varied on two testing thickness during cutting include cutting speed, incident laser power and focal position in a continuous through cut. Various trends of the kerf geometrical features in terms of the varying process parameters are analyzed and shown to be reasonable. Discussions are also given on kerf geometry control in situations with cutting parameters. It shows that the effects of varying parameters such as cutting speed, laser power and focal position on cutting kerf width, surface roughness, and striation that have provided a deeper understanding of the laser machining.

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