Using the Segmented Iterative Learning Control Method to Generate Volumetric Error-Compensated Part Programs for Three-Axis CNC Milling Machine Tools

2018 ◽  
Vol 2 (3) ◽  
pp. 53 ◽  
Author(s):  
Ying-Chen Lu ◽  
Syh-Shiuh Yeh
Keyword(s):  
Error Compensation ◽  
Iterative Learning Control ◽  
Machine Tools ◽  
Tool Path ◽  
Cnc Milling ◽  
Volumetric Error ◽  
Cnc Milling Machine ◽  
Working Volume ◽  
Part Program ◽  
Rate Of Improvement

This study proposes using the iterative learning control method to adjust the volumetric error-compensated tool path, where the working volume motion accuracy of three-axis computerized numerical control (CNC) milling machine tools is increased by segmented modification of the part program. As the three-axis CNC milling machine tools generally have volumetric error of working volume, this study refers to the measured and established table of volumetric errors and uses the method of the modifying part program for volumetric error compensation of machine tools. This study proposes using part-program single-block positioning segmented for volumetric error compensation, as the generated compensated part program with multiple compensated blocks can effectively compensate the volumetric error of working volume in the tool moving process. In terms of the compensated tool path computing method, this study uses the iterative learning control (ILC) method and refers to compensated tool path and volumetric errors along the compensated tool path for iterative computation. Finally, a part program with multiple blocks is modified by the converged optimal compensated tool path, in order that the modified part program has higher-precision volumetric error compensation effect. The simulation result shows that the rate of improvement of error of the volumetric error compensation method proposed in this study is 70%. The result of cutting tests shows that the average rate of improvement of the straightness error of the test workpiece is 60%, while the average rate of improvement of height error is 80%. Therefore, the results of simulation and cutting tests can prove the feasibility of using the ILC method for segmented modification of the volumetric error-compensated part programs proposed in this study.

Volumetric error modeling and compensation considering thermal effect on five-axis machine tools

2012 ◽  
Vol 227 (5) ◽  
pp. 1102-1115 ◽  
Author(s):  
Yi Zhang ◽  
Jianguo Yang ◽  
Sitong Xiang ◽  
Huixiao Xiao
Keyword(s):  
Error Compensation ◽  
Machine Tools ◽  
Data Communication ◽  
Zero Point ◽  
Compensation System ◽  
Error Modeling ◽  
Volumetric Error ◽  
Position Errors ◽  
Homogeneous Transformation Matrix ◽  
Five Axis

This article intends to provide an error compensation system for five-axis machine tools. A volumetric error model is established with homogeneous transformation matrix method, from which compensation values of both orientation and position errors can be obtained. Thirty-seven errors on a five-axis machine tool are classified into three categories – functional, random, and negligible errors, among which the effect of the first one on volumetric accuracy is considered as great enough to be included in this model. Some typical modeling methods are discussed on positioning and straightness errors, considering both geometric and thermal effects. Then, we propose a compensation implementation technique based on the function of external machine zero point shift and Ethernet data communication protocol for machine tools. Finally, laser diagonal measurements have been conducted to validate the effectiveness of the proposed volumetric error compensation system.

scholarly journals Modular fastening system and tool–holder working unit for incremental forming

2019 ◽  
Vol 299 ◽  
pp. 05005
Author(s):  
Melania Tera ◽  
Claudia–Emilia Gîrjob ◽  
Cristina–Maria Biriș ◽  
Mihai Crenganiș
Keyword(s):  
Machine Tools ◽  
Incremental Forming ◽  
Industrial Robot ◽  
Industrial Robots ◽  
Cnc Milling ◽  
End Effector ◽  
Tool Holder ◽  
Cnc Milling Machine ◽  
Milling Machines ◽  
Sheet Metal Workpiece

Incremental forming can be usually unfolded either on CNC milling machine–tools or serial industrial robots. The approach proposed in this paper tackles the problem of designing a modular fastening system, which can be adapted for both above mentioned technological equipment. The fastening system of the sheet–metal workpiece is composed of a fixing plate and a retaining plate. The fixing and retaining plates will be made up of different individual elements, which can be easily repositioned to obtain different sizes of the part. Moreover, the fastening system has to be able to be positioned either horizontally (to be fitted on CNC milling machines) or vertically (to be fitted on industrial robots. The paper also presents the design of a tool–holder working unit which will be fitted on KUKA KR 210 industrial robot. The working unit will be mounted as end–effector of the robot and will bear the punch, driving it on the processing toolpaths.

Experimental Study on a New Method of Double Side Incremental Forming

2008 ◽  
Author(s):  
Yongjun Wang ◽  
Ying Huang ◽  
Jian Cao ◽  
N. Venkata Reddy
Keyword(s):  
Tool Path ◽  
Incremental Forming ◽  
Single Point ◽  
Cnc Milling ◽  
Analysis Model ◽  
Surface Machining ◽  
Cnc Milling Machine ◽  
Geometrical Features ◽  
New Process ◽  
Sheet Metal Incremental Forming

This paper presents a new configuration for sheet metal incremental forming using DSIF (Double Sided Incremental Forming) to overcome the limitation of single point incremental forming (SPIF). The new process can produce geometrical features on either side of the initial plane of the sheet without changing setup. A component having such challenging features is selected to demonstrate the capabilities of the proposed method and a contour tool path is generated using UniGraphics (UG) surface machining module and formed by mounting the new setup on a CNC milling machine. The final formed shape was scanned and compared to the designed profile. In addition, two more components having cylindrical and spherical geometries are formed to study the effect of geometry on the accuracy of the component that can be produced by using the proposed method. A simple analysis model has been developed to explain the effect of squeezing and stretching to the part elongation during the DSIF process.

The Study of Tool Wear Performance on Pocket Milling Strategy

2014 ◽  
Vol 699 ◽  
pp. 64-69 ◽  
Author(s):  
A.B. Mohd Hadzley ◽  
A. Siti Sarah ◽  
R. Izamshah ◽  
M.R. Nurul Fatin
Keyword(s):  
Tool Wear ◽  
Tool Path ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Cnc Milling ◽  
Wear Performance ◽  
Pocket Milling ◽  
Cnc Milling Machine ◽  
Radial Depth ◽  
Wet Condition

The increasing productivity demand in machining industry has lead for fast material removal machining technique of pocket milling using different tool path strategies. This project aims to study about the effect of different tool path strategies on tool wear when machining aluminium alloy 7076. Five milling strategies were evaluated outward helical, inward helical, back and forth, offset on part one-way and offset on part zigzag. CATIA V5R19 was used to setup milling path and the machining experiments were carried out on a HAAS’ 3 axis CNC milling machine. The machining was held under wet condition with 2500 rpm cutting speed, 800 mm/min feed rate, 2 mm radial depth of cut and 2 mm axial depth of cut. The results showed that the best tool path strategies are inward helical and offset on part one-way, while the worst tool path strategy is outward helical. Failure to evacuate chip during pocket milling is the main reason to cause rapid tool wear due to temperature rise and higher contact time and area of cutting tool with the chip. Results from this experiment help to guide the machinist to perform pocket milling effectively.

scholarly journals CNC milling of EVA foam with varying hardness for custom orthotic shoe insoles and process parameter optimization

2019 ◽  
Vol 13 (3) ◽  
pp. 5347-5370
Author(s):  
P. W. Anggoro ◽  
A. A. Anthony ◽  
B. Bawono ◽  
J. Jamari ◽  
A. P. Bayuseno ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Tool Path ◽  
Hybrid Approach ◽  
Machining Parameters ◽  
Cnc Milling ◽  
Cnc Milling Machine ◽  
Step Over ◽  
High Degree ◽  
Shoe Insoles ◽  
Eva Foam

CNC milling strategy of EVA foam with varying hardness to provide a high degree of surface roughness of orthotic shoe insoles is presented in this work. Machining parameters (tool path strategy, spindle speed, feed rate, and step over) in addition to hardness material and wide tolerance insoles were optimized using a hybrid approach of Taguchi-Response Surface Methodology (TM-RSM). The aim of this research was to develop mathematical models and determine the optimum machining parameters which could be applied for the CNC milling of EVA foam as the insoles. Experiments were performed on a CNC milling machine with a standard milling cutter and run under dry coolants. The effects of the six parameters on the average values of surface roughness were initially analyzed by an S/N ratio of TM. Optimal conditions were established from the TM and then used to determine the optimum values in RSM modeling. The final results indicate the significant improvement of percentages (0.24% and 4.13%) in the surface roughness of the insoles obtained with TM-RSM as compared to the TM analysis. It is envisaged the present study would add to the understanding of production for orthotic shoe insoles through CNC milling.

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