scholarly journals Constant Cutting Force Control for CNC Machining Using Dynamic Characteristic-Based Fuzzy Controller

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Hengli Liu ◽  
Taiyong Wang ◽  
Dong Wang
Keyword(s):  
Cutting Force ◽  
Dynamic Characteristic ◽  
Fuzzy Controller ◽  
Cnc Machining ◽  
Machining Process ◽  
Feed Speed ◽  
Control Rules ◽  
Power Bond Graph ◽  
Adaptive Control Algorithm ◽  
Constant Cutting Force Control

This paper presents a dynamic characteristic-based fuzzy adaptive control algorithm (DCbFACA) to avoid the influence of cutting force changing rapidly on the machining stability and precision. The cutting force is indirectly obtained in real time by monitoring and extraction of the motorized spindle current, the feed speed is fuzzy adjusted online, and the current was used as a feedback to control cutting force and maintain the machining process stable. Different from the traditional fuzzy control methods using the experience-based control rules, and according to the complex nonlinear characteristics of CNC machining, the power bond graph method is implemented to describe the dynamic characteristics of process, and then the appropriate variation relations are achieved between current and feed speed, and the control rules are optimized and established based on it. The numerical results indicated that DCbFACA can make the CNC machining process more stable and improve the machining precision.

The Monitoring System for Stability of CNC Machining Based on cDAQ and LabVIEW

2014 ◽  
Vol 1039 ◽  
pp. 177-182
Author(s):  
Man Meng ◽  
Wen Jun Zhang ◽  
Peng Chong Wang ◽  
Denis Niedenzu ◽  
Ying Zhong Tian
Keyword(s):  
Monitoring System ◽  
Online Monitoring ◽  
Cnc Machining ◽  
Machining Process ◽  
Depth Of Cut ◽  
Feed Speed ◽  
Online Monitoring System ◽  
Main Factors ◽  
The Stability

In recent years, researching the stability of the CNC machining process is a hotpot in CNC industry. Based on cDAQ and labVIEW, online monitoring system is presented, meanwhile, both software structure and hardware structure are introduced in detail. Researches show that vibration and pressure are the main factors for the quality of the flatness. By studying the relative vibration between the spindle and the platform in the Z axis direction, as well as the shifty pressure that tool works on the flatness of the workpiece, four experiments are designed in this paper under different technological conditions including free moving, Axial Depth of cut, speed and feed speed, which verify the reliability of the online monitoring system.

Research on CNC Process Parameters Optimization Based on Process Planning Knowledge

2011 ◽  
Vol 411 ◽  
pp. 398-402 ◽  
Author(s):  
Xiao Bing Gao ◽  
Yan Xue ◽  
Fu Jia Wu
Keyword(s):  
Cutting Force ◽  
Process Parameters ◽  
End Milling ◽  
Parameters Optimization ◽  
Cnc Machining ◽  
Machining Process ◽  
Work Piece ◽  
Cnc Milling ◽  
Dynamic Cutting Force ◽  
Radial Depth

CNC milling process parameters is the key issue to improve quality and productivity of product and save cost. Especially, in the end milling of the pockets, the radial depth and real feed vary as the end mill moves along the corner. This will result in the unstable of the cutting force and the bad accuracy of the milled pockets. In this paper, according to analysis of CNC machining process, the model of dynamic cutting force based on knowledge in the end milling of the pockets is established, which is predicted by the model of cutting force coefficient. The optimization milling parameters can be calculated in terms of the model of dynamic cutting force in the pockets, work piece material properties. In the end, the experiment proves the process of optimization.

Online Fuzzy Intelligent Control Based on Resultant Cutting Force in the End Milling

2011 ◽  
Vol 219-220 ◽  
pp. 61-65
Author(s):  
Mao Yue Li ◽  
Hong Ya Fu ◽  
Zhen Yu Han
Keyword(s):  
Cutting Force ◽  
Feed Rate ◽  
Fuzzy Controller ◽  
End Milling ◽  
Production Quality ◽  
Machining Parameters ◽  
Machining Time ◽  
Status Monitoring ◽  
Control Rules ◽  
Improve Production Quality

To improve production quality and reduce machining time, machining parameters need to be monitored and adjusted automatically in milling. An integrated controller which is modular, configurable and based on OMAC, is established. The hardware platform, resultant cutting force constraint and its fuzzy control rules have been introduced in detail. In the fuzzy controller designed, two inputs and one output are used with five fuzzy sets for the controller, and the output rate of feed-rate can be changed from 50% to 200%. This controller has the abilities of reducing fluctuation range of cutting force, adjusting feed-rate intelligently, which is a part of CNC system. The experiment results show it can realize the real time status monitoring with this system, reduce the cutting force fluctuation, and adjust the feed-rate intelligently during machining.

Research on the Impact of CNC Servo Dynamic Characteristic for the On-Line Detection Precision

2014 ◽  
Vol 511-512 ◽  
pp. 286-289
Author(s):  
Cheng Rong Pian ◽  
Qing Zhang ◽  
Nan Wu
Keyword(s):  
Dynamic Characteristic ◽  
Error Model ◽  
Cnc Machining ◽  
Machining Process ◽  
Cnc Machine Tools ◽  
Line Detection ◽  
Detection Accuracy ◽  
Cnc Machine ◽  
On Line ◽  
The Impact

CNC machine tools are widely used in precision machining and automation production. The on-line detection technology provides an efficient testing method for quality control in CNC machining process. And the CNC servo dynamic characteristic is an important factor affecting the accuracy of on-line detection. In order to study the effects of servo dynamic characteristic, CNC servo system mathematical model was set up, probe system error model was established based on probe measuring time sequence and on-line detection error model was built. The cylindrical feature measurement example shows that on-line detection accuracy is improved through the secondary trigger measurement method and the probe path planning.

Modeling of Self-Induced Vibrations that Occur During the Machining Process of Casting Patterns with the Use of The Fuzzy-Neural Networks Method

2013 ◽  
Vol 58 (3) ◽  
pp. 871-875
Author(s):  
A. Herberg
Keyword(s):  
Neural Networks ◽  
Control System ◽  
Network Structure ◽  
Fuzzy Systems ◽  
Fuzzy Neural Networks ◽  
Cnc Machining ◽  
Machining Process ◽  
Modeling Process ◽  
Fuzzy Neural ◽  
Takagi Sugeno

Abstract This article outlines a methodology of modeling self-induced vibrations that occur in the course of machining of metal objects, i.e. when shaping casting patterns on CNC machining centers. The modeling process presented here is based on an algorithm that makes use of local model fuzzy-neural networks. The algorithm falls back on the advantages of fuzzy systems with Takagi-Sugeno-Kanga (TSK) consequences and neural networks with auxiliary modules that help optimize and shorten the time needed to identify the best possible network structure. The modeling of self-induced vibrations allows analyzing how the vibrations come into being. This in turn makes it possible to develop effective ways of eliminating these vibrations and, ultimately, designing a practical control system that would dispose of the vibrations altogether.

scholarly journals Serrated Chips Formation in Micro Orthogonal Cutting of Ti6Al4V Alloys with Equiaxial and Martensitic Microstructures

Micromachines ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 197 ◽  
Author(s):  
ZeJia Zhao ◽  
Suet To ◽  
ZhuoXuan Zhuang
Keyword(s):  
Cutting Force ◽  
Unit Length ◽  
Orthogonal Cutting ◽  
Machining Process ◽  
Orthogonal Machining ◽  
Large Yield ◽  
Power Spectral ◽  
Straight Line ◽  
Serrated Chips ◽  
Electropulsing Treatment

The formation of serrated chips is an important feature during machining of difficult-to-cut materials, such as titanium alloy, nickel based alloy, and some steels. In this study, Ti6Al4V alloys with equiaxial and acicular martensitic microstructures were adopted to analyze the effects of material structures on the formation of serrated chips in straight line micro orthogonal machining. The martensitic alloy was obtained using highly efficient electropulsing treatment (EPT) followed by water quenching. The results showed that serrated chips could be formed on both Ti6Al4V alloys, however the chip features varied with material microstructures. The number of chip segments per unit length of the alloy with martensite was more than that of the equiaxial alloy due to poor ductility. Besides, the average cutting and thrust forces were about 8.41 and 4.53 N, respectively, for the equiaxed Ti6Al4V alloys, which were consistently lower than those with a martensitic structure. The high cutting force of martensitic alloy is because of the large yield stress required to overcome plastic deformation, and this force is also significantly affected by the orientations of the martensite. Power spectral density (PSD) analyses indicated that the characteristic frequency of cutting force variation of the equiaxed alloy ranged from 100 to 200 Hz, while it ranged from 200 to 400 Hz for workpieces with martensites, which was supposedly due to the formation of serrated chips during the machining process.

scholarly journals Modeling of Cutting Force in the Turning of AISI 4340 Using Gaussian Process Regression Algorithm

2021 ◽  
Vol 11 (9) ◽  
pp. 4055
Author(s):  
Mahdi S. Alajmi ◽  
Abdullah M. Almeshal
Keyword(s):  
Gaussian Process ◽  
Cutting Force ◽  
Predictive Accuracy ◽  
Gaussian Process Regression ◽  
Machining Process ◽  
Support Vector ◽  
Process Data ◽  
Cutting Force Prediction ◽  
Artificial Neural Network Ann ◽  
Aisi 4340

Machining process data can be utilized to predict cutting force and optimize process parameters. Cutting force is an essential parameter that has a significant impact on the metal turning process. In this study, a cutting force prediction model for turning AISI 4340 alloy steel was developed using Gaussian process regression (GPR), support vector machines (SVM), and artificial neural network (ANN) methods. The GPR simulations demonstrated a reliable prediction of surface roughness for the dry turning method with R2 = 0.9843, MAPE = 5.12%, and RMSE = 1.86%. Performance comparisons between GPR, SVM, and ANN show that GPR is an effective method that can ensure high predictive accuracy of the cutting force in the turning of AISI 4340.

Optimization of turn-milling process in roughing and finishing regimes: Trade-off between productivity, cutting force and surface integrity

2021 ◽  
pp. 095440892199851
Author(s):  
Ebrahim Hosseini ◽  
Shafiqur Rehman ◽  
Ashkan Alimoradi
Keyword(s):  
Cutting Force ◽  
Desirability Function ◽  
Milling Process ◽  
Machining Process ◽  
Hybrid Machining ◽  
Trade Off ◽  
Hybrid Machining Process ◽  
Process Factors ◽  
Turn Milling ◽  
Selection Of

Turn-milling is a hybrid machining process which used benefits of interrupted cutting for proceeding of round bars. However, number of controllable parameters in the hybrid process is numerous that makes optimizing the process complicated. In the present study, an optimization work has been proposed to investigate the trade-off between production rate and cutting force in roughing regime as well surface roughness and tensile residual stress in finishing regime. Number of 43 experiments based on response surface methodology was designed and carried out to gather required data for development of quadratic empirical models. Then, the adequacy and importance of process factors were analyzed using analysis of variances. Finally, desirability function was used to optimize the process in rough and finish machining regimes. The obtained results showed that selection of eccentricity and cutter speed at their maximum working range can effectively enhance the quality characteristics in both the roughing and finishing regimes.

Surface Roughness and Cutting Force Components Evaluation in Hard Turning by Differently Shaped Cutting Tools

2016 ◽  
Vol 862 ◽  
pp. 26-32 ◽  
Author(s):  
Michaela Samardžiová
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Hard Turning ◽  
Cutting Tool ◽  
Single Point ◽  
Machining Process ◽  
Tool Geometry ◽  
Machined Surface ◽  
Cutting Force Components ◽  
Force Components

There is a difference in machining by the cutting tool with defined geometry and undefined geometry. That is one of the reasons of implementation of hard turning into the machining process. In current manufacturing processes is hard turning many times used as a fine finish operation. It has many advantages – machining by single point cutting tool, high productivity, flexibility, ability to produce parts with complex shapes at one clamping. Very important is to solve machined surface quality. There is a possibility to use wiper geometry in hard turning process to achieve 3 – 4 times lower surface roughness values. Cutting parameters influence cutting process as well as cutting tool geometry. It is necessary to take into consideration cutting force components as well. Issue of the use of wiper geometry has been still insufficiently researched.

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