Analysis of vibration response and machining quality of hybrid robot based UD-CFRP trimming

2021 ◽  
pp. 095440542098609
Author(s):  
Yan Zhang ◽  
Hao Li ◽  
Xuda Qin ◽  
Jie liu ◽  
Zhuojie Hou
Keyword(s):  
High Performance ◽  
Vibration Response ◽  
Industrial Robots ◽  
Force Characteristic ◽  
Surface Waviness ◽  
Machined Surface ◽  
Machining Quality ◽  
3D Surface Roughness ◽  
Machined Surface Quality ◽  
Vibration Responses

To fulfill the demands of higher precision, better quality, and more flexibility, the usage of high-performance industrial robots is rapidly increased in aerospace industry. Considering the anisotropic and inhomogeneous characteristics of composite materials, this study focuses mainly on dynamic response investigation of a newly designed hybrid robot (named as TriMule) in CFRP trimming process and its influence on the machined quality. First, combined with the cutting force characteristic, the vibration responses of tool center point (TCP) under the dynamic excitation were obtained. The influences of robotic TCP vibration on machined surface quality with different fiber orientations, including surface waviness, cavity, 3D surface roughness, and depth of affected zone, are first studied by comparing hybrid robot and machine tool. From experiment results, it can be concluded the proposed TCP vibration response model has sufficient prediction accuracy. Meanwhile, it is found that larger robotic vibration response is accompanied by higher surface waviness, bigger surface cavity, and greater affected zone. Results also showed that the fiber orientation and milling style are two essential factors that affect robot vibration and machining quality during CFRP trimming.

scholarly journals Effects of deep cryogenic treatment on WC-Co cutter performances in milling of superalloy GH536

2020 ◽  
Vol 12 (5) ◽  
pp. 168781402091849
Author(s):  
Dong Liu ◽  
Li Gao ◽  
Peng Zhou
Keyword(s):  
Tool Wear ◽  
High Performance ◽  
Cryogenic Treatment ◽  
Experimental Result ◽  
Deep Cryogenic Treatment ◽  
Machined Surface ◽  
The Poor ◽  
Machined Surface Quality ◽  
Milling Operation ◽  
Depth Analysis

GH536 has been widely employed as one kind of high-performance materials; however, the poor machinability of GH536 especially substantial tool wear can still be considered as a problem. On the contrary, deep cryogenic treatment can be considered as an effective heat treatment to improve the milling cutter performances. Considering few studies that investigated the deep cryogenic treatment of the WC-Co cutters, this article experimentally investigated the effects of deep cryogenic treatment on WC-Co cutter performances in milling of superalloy GH536. The detailed discussion in terms of the microhardness before milling, the cutting forces during milling, and the tool wear and the machined surface quality after milling operation were performed based on the in-depth analysis of the experimental result comparison between the deep cryogenic treatment and the conventional tools. Some key findings were given in the end to conclude this work.

Convolutional Neural Network Design for Improvement of Machining Quality Monitoring

2021 ◽  
Author(s):  
Ting-Yu Chang ◽  
Jen-Yuan (James) Chang
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
Production Efficiency ◽  
Machined Surface ◽  
Additional Signal ◽  
Machining Quality ◽  
Proposed Model ◽  
Machined Surface Quality ◽  
Predicted Values ◽  
The Cost

Abstract Automatically monitoring finishing quality by computers can achieve efficient product quality management and can improve overall production efficiency. To be able to offer quantitative measures and to achieve this goal, this paper discusses and suggests the utilization of artificial intelligence (AI) technology to predict product finishing quality by use of signals such as vibrations captured by accelerometers generated during manufacturing. To reduce the cost of inspecting products one by one, a deep one-dimensional convolutional neural network (CNN) is proposed to predict machined surface quality. In this method, dense residual skip-connections are used to improve the complexity of the model to improve the accuracy of predicted values. With the adaptation of the pooling layer in the proposed model, it is observed that the number of parameters used in the model is greatly reduced. Not only the predicted accuracy is optimized with the proposed model, the parameters that need to be stored and the computation resource that is consumed in the inference stage are significantly reduced as well. Compared with methods reported in the literature, through calibrated experimental verifications, the proposed model used in this work can improve the prediction accuracy by 10 percent, without any additional signal preprocessing efforts. The work presented in this paper is thought to have engineering implications in quantifying machining quality in the machine tools industry.

Improving Efficiency in Robot Assisted Belt Grinding of High Performance Materials

2014 ◽  
Vol 907 ◽  
pp. 139-149 ◽  
Author(s):  
Eckart Uhlmann ◽  
Florian Heitmüller
Keyword(s):  
Gas Turbines ◽  
High Performance ◽  
Scale Effects ◽  
Turbine Blades ◽  
Repair Process ◽  
Industrial Robots ◽  
Robot Assisted ◽  
Belt Grinding ◽  
Economy Of Scale ◽  
The Individual

In gas turbines and turbo jet engines, high performance materials such as nickel-based alloys are widely used for blades and vanes. In the case of repair, finishing of complex turbine blades made of high performance materials is carried out predominantly manually. The repair process is therefore quite time consuming. And the costs of presently available repair strategies, especially for integrated parts, are high, due to the individual process planning and great amount of manually performed work steps. Moreover, there are severe risks of partial damage during manually conducted repair. All that leads to the fact that economy of scale effects remain widely unused for repair tasks, although the piece number of components to be repaired is increasing significantly. In the future, a persistent automation of the repair process chain should be achieved by developing adaptive robot assisted finishing strategies. The goal of this research is to use the automation potential for repair tasks by developing a technology that enables industrial robots to re-contour turbine blades via force controlled belt grinding.

scholarly journals The Comparative Study on Cutting Performance of Different-Structure Milling Cutters in Machining CFRP

2018 ◽  
Vol 8 (8) ◽  
pp. 1353
Author(s):  
Tao Chen ◽  
Fei Gao ◽  
Suyan Li ◽  
Xianli Liu
Keyword(s):  
Carbon Fiber ◽  
Cutting Force ◽  
Surface Quality ◽  
Cutting Edge ◽  
Cutting Performance ◽  
Machining Process ◽  
Carbon Fiber Composites ◽  
Machined Surface ◽  
Milling Cutter ◽  
Machined Surface Quality

Carbon fiber reinforced plastic (CFRP) is typically hard to process, because it is easy for it to generate processing damage such as burrs, tears, delamination, and so on in the machining process. Consequently, this restricts its wide spread application. This paper conducted a comparative experiment on the cutting performance of the two different-structure milling cutters, with a helical staggered edge and a rhombic edge, in milling carbon fiber composites; analyzed the wear morphologies of the two cutting tools; and thus acquired the effect of the tool structure on the machined surface quality and cutting force. The results indicated that in the whole cutting, the rhombic milling cutter with a segmented cutting edge showed better wear resistance and a more stable machined surface quality. It was not until a large area of coating shedding occurred, along with chip clogging, that the surface quality decreased significantly. At the stage of coating wear, the helical staggered milling cutter with an alternately arranged continuous cutting edge showed better machined surface quality, but when the coating fell off, its machined surface quality began to reveal damage such as groove, tear, and fiber pullout. Meanwhile, burrs occurred at the edge and the cutting force obviously increased. By contrast, for the rhombic milling cutter, both the surface roughness and cutting force increased relatively slowly.

Research on Grinding Force of Zirconia Internal Grinding with Resin Bond Diamond Wheel

2016 ◽  
Vol 1136 ◽  
pp. 30-35
Author(s):  
He Wang ◽  
Ke Zhang ◽  
Yu Hou Wu ◽  
Hong Song
Keyword(s):  
Grain Size ◽  
Surface Quality ◽  
Diamond Wheel ◽  
Grinding Force ◽  
Wheel Speed ◽  
Zirconia Ceramic ◽  
Machined Surface ◽  
Research Results ◽  
Internal Grinding ◽  
Machined Surface Quality

The zirconia parts are limited by machined surface quality. The grinding force is one of the most important parameters of grinding and has effects on surface quality. The MK2710 grinder and resin bond diamond wheels were used in zirconia grinding. The grinding force was obtained by Kistler dynamometer. The paper focused on wheel speed and grain size on grinding force, and examined the surface by SEM. The research results indicated that decreasing the grain size, the grinding force increased and the surface quality improved, and increasing wheel speed could decrease grinding force to improve grinding surface quality. The results can improve zirconia ceramic parts surface quality and promote application.

Experimentelle Posenanalyse am Bearbeitungsroboter*/Pose dependancy of machining robots

2016 ◽  
Vol 106 (05) ◽  
pp. 347-353
Author(s):  
A. Karim ◽  
A. Waibel ◽  
A. Lechler
Keyword(s):  
Experimental Analysis ◽  
Industrial Robots ◽  
Machining Quality ◽  
First Results ◽  
Erste Ergebnisse

Die Verbesserung der Bearbeitungsqualität stellt einen aktuellen Forschungsschwerpunkt bei der spanenden Bearbeitung mit Industrierobotern dar. Dabei hängt die Bearbeitungsqualität des Werkstücks wesentlich von der eingenommenen Pose des Roboters ab. Der Fachbeitrag stellt die Durchführung einer experimentellen Analyse zur Bestimmung der Bearbeitungsqualität in unterschiedlichen Posen vor. Erste Ergebnisse werden ebenfalls präsentiert.   The improvement of machining quality is an actual focus of research in the area of machining with industrial robots. The machining quality that can be achieved is strongly dependant on the robot‘s pose. In the course of this paper the execution of experimental analysis for the determination of machining quality at different poses as well as first results are presented.

Study on Improving Accuracy in Robotic Milling of Aluminum Alloy

2018 ◽  
Author(s):  
Shaochun Sui ◽  
Kai Guo ◽  
Jie Sun ◽  
Yiran Zang
Keyword(s):  
Aluminum Alloy ◽  
Industrial Robot ◽  
Vibration Signal ◽  
Industrial Robots ◽  
Machining Process ◽  
Cnc Machine ◽  
Machined Surface ◽  
Improving Accuracy ◽  
High Level ◽  
Monolithic Components

Nowadays, the application of using industrial robots in manufacture is a diminutive due to its own low rigidity and low stiffness. This leads to high level of vibrations that limits the quality and the precision of the workpiece. So they are usually used for welding, grinding and paint shop. However, the potential of industrial robot applications in machining has be realized. The volume of monolithic components is large and there are many issues in machining process such as geometric tolerance and quality of machined surface. In such cases the traditional CNC machine is replaced by industrial robots, which will reduce the production cost, reduce labor and increase the efficiency. In this paper, the milling experiment of 7050-T7451 aeronautical aluminum alloy was carried out by using industrial robot KR210 R2700. In addition, the experiment was employed to study the influence of milling speed, feed-rate, cutting depth and cutting width on vibrations, surface roughness was also measured to evaluate the machining quality. Besides, the axis of angle was changed which led to the different industrial robot’s postures. The vibration signal of different postures was acquired, which was used to analysis the optimal workspace of industrial robot. The best process parameters were obtained, which will play a guiding significance on the actual production.

Vibration Signature Analysis of a Rotor Bearing System Using Response Surface Method

2009 ◽  
Author(s):  
P. K. Kankar ◽  
Satish C. Sharma ◽  
S. P. Harsha
Keyword(s):  
Response Surface ◽  
Response Surface Method ◽  
High Speed ◽  
Vibration Response ◽  
Radial Clearance ◽  
System Response ◽  
Surface Waviness ◽  
Surface Method ◽  
Rotor Bearing ◽  
Bearing System

The vibration response of a rotor bearing system is extremely important in industries and is challenged by their highly non-linear and complex properties. This paper focuses on performance prediction using response surface method (RSM), which is essential to the design of high performance rotor bearing system. Response surface method is utilized to analysis the effects of design and operating parameters on the vibration response of a rotor-bearing system. A test rig of high speed rotor supported on rolling bearings is used. Vibration response of the healthy ball bearing and ball bearings with various faults are obtained and analyzed. Distributed defects are considered as surface waviness of the bearing components. Effects of internal radial clearance and surface waviness of the bearing components and their interaction are analyzed using design of experiment (DOE) and RSM.

Evaluation of DPI Change Impact on Laser Machined Surface Quality

2014 ◽  
Vol 474 ◽  
pp. 369-374
Author(s):  
Jana Knedlova ◽  
Libuše Sýkorová ◽  
Vladimír Pata ◽  
Martina Malachová
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Laser Micromachining ◽  
Technological Parameters ◽  
Machined Surface ◽  
Machined Surface Quality ◽  
Machined Surface Roughness ◽  
Change Impact

The article focuses on the field of PMMA laser micromachining at change of the technological parameters. The aim was to evaluate machined surface roughness at different setting of DPI definition (number of dots paths on square inch). Commercial CO2laser Mercury L-30 by firm LaserPro, USA was used for experimental machining. Ray of laser could be focused on mark diameter d=185 mm.

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