Time Domain Coupled Simulation between Behavior of Machine Tool Drive Systems and Cutting Force in End-milling Operation

2016 ◽  
Vol 2016.11 (0) ◽  
pp. D17
Author(s):  
Shin NOGUCHI ◽  
Ryuta SATO ◽  
Keiichi SHIRASE
Keyword(s):  
Machine Tool ◽  
Cutting Force ◽  
Time Domain ◽  
End Milling ◽  
Coupled Simulation ◽  
Milling Operation ◽  
Drive Systems

FRACTAL-BASED ANALYSIS OF THE VARIATIONS OF CUTTING FORCES ALONG DIFFERENT AXES IN END MILLING OPERATION

Fractals ◽  
2018 ◽  
Vol 26 (06) ◽  
pp. 1850089 ◽  
Author(s):  
HAMIDREZA NAMAZI ◽  
ALI AKHAVAN FARID ◽  
TECK SENG CHANG
Keyword(s):  
Fractal Dimension ◽  
Cutting Force ◽  
Cutting Forces ◽  
End Milling ◽  
Fractal Theory ◽  
Radial Force ◽  
Machining Conditions ◽  
Feed Force ◽  
Milling Operation ◽  
Force Signal

Analysis of cutting forces in machining operation is an important issue. The cutting force changes randomly in milling operation where it makes a signal by plotting over time span. An important type of analysis belongs to the study of how cutting forces change along different axes. Since cutting force has fractal characteristics, in this paper for the first time we analyze the variations of complexity of cutting force signal along different axes using fractal theory. For this purpose, we consider two cutting depths and do milling operation in dry and wet machining conditions. The obtained cutting force time series was analyzed by computing the fractal dimension. The result showed that in both wet and dry machining conditions, the feed force (along [Formula: see text]-axis) has greater fractal dimension than radial force (along [Formula: see text]-axis). In addition, the radial force (along [Formula: see text]-axis) has greater fractal dimension than thrust force (along [Formula: see text]-axis). The method of analysis that was used in this research can be applied to other machining operations to study the variations of fractal structure of cutting force signal along different axes.

Simulation Technologies for the Development of an Autonomous and Intelligent Machine Tool

2013 ◽  
Vol 7 (1) ◽  
pp. 6-15 ◽  
Author(s):  
Keiichi Shirase ◽  
◽  
Keiichi Nakamoto ◽  
Keyword(s):  
Fault Detection ◽  
Machine Tool ◽  
Cutting Force ◽  
Milling Process ◽  
Planning System ◽  
Cutting Force Prediction ◽  
Intelligent Machine ◽  
Milling Operation ◽  
Digital Copy ◽  
Copy Milling

An autonomous and intelligent machine tool have been developed to solve fundamental issues with the current command method using NC programs, and simulation technologies for its realization have been introduced. The process planning system introduced here, various process plans can be created, and the best process plan can be selected to achieve flexible machining operations in accordance with changes in production planning. Digital Copy Milling, digitizing the principle of copy milling, has opened up new possibilities for machine tool control. The NC machine tool can be directly controlled with the 3D CAD data of the product shape in Digital CopyMilling. Direct machining without the need to create an NC program before milling operation, adaptive control which changes the cutting conditions in accordance with the cutting load during milling operation, and fault detection in the cutting load and avoiding tool breakages can be performed through Digital Copy Milling. Themilling process simulator with integrated milling shape simulator and cutting force simulator provides new functions. Simultaneous cutting force prediction with milling operation provides the possibility of milling process control and fault detection by comparing the measured cutting force with the predicted one.

Customized End Milling Operation of Dental Artificial Crown Without CAM Operation

2018 ◽  
Vol 12 (6) ◽  
pp. 947-954 ◽  
Author(s):  
Isamu Nishida ◽  
◽  
Ryo Tsuyama ◽  
Ryuta Sato ◽  
Keiichi Shirase
Keyword(s):  
Cutting Force ◽  
Real Time ◽  
End Milling ◽  
Feed Speed ◽  
High Productivity ◽  
Nc Program ◽  
Milling Operation ◽  
Machine Control ◽  
Copy Milling ◽  
Tool Motion

A new methodology to generate instruction commands for real-time machine control instead of preparing NC programs is developed under the CAM-CNC integration concept. A machine tool based on this methodology can eliminate NC program preparation, achieve cutting process control, reduce production lead time, and realize an autonomous distributed factory. The special feature of this methodology is the generation of instruction commands in real time for the prompt machine control instead of NC programs. Digital Copy Milling (DCM), which digitalizes copy milling, is realized by referring only to the CAD model of the product. Another special feature of this methodology is the control of the tool motion according to the information predicted by a cutting force simulator. This feature achieves both the improvement in the machining efficiency and the avoidance of machining trouble. In this study, the customized end milling operation of a dental artificial crown is realized as an application using the new methodology mentioned above. In this application, the CAM operation can be eliminated for the NC program generation, and tool breakage can be avoided based on the tool feed speed control from the predicted cutting force. The result shows that the new methodology has good potential to achieve customized manufacturing, and can realize both high productivity and reliable machining operation.

A Structured Linear Quadratic Gaussian Based Control Design Algorithm for Machine Tool Controllers Including Both Feed Drive and Process Dynamics

2005 ◽  
Vol 11 (7) ◽  
pp. 949-983 ◽  
Author(s):  
E. M. Elbeheiry ◽  
W. H. Elmaraghy ◽  
H. A. Elmaraghy
Keyword(s):  
Machine Tool ◽  
Cutting Force ◽  
End Milling ◽  
Cross Coupling ◽  
Control Input ◽  
Linear Quadratic ◽  
Linear Quadratic Gaussian ◽  
Design Algorithm ◽  
Design And Optimization ◽  
Model Driven

A new extension of the stochastic linear quadratic Gaussian (LQG) regulator problem is developed and used for the design of new suboptimal cross-coupling controllers for machine tool drives. This new extension allowed us to combine both the drive and the cutting dynamics into a unified model driven by the static and the dynamic portions of the cutting force. The dynamic portion of the cutting force is considered as a stochastic random process in end milling contouring processes. The outputs of the axes are corrected by the cutting tool deflections which result from the cutting force-workpiece resistance interactive dynamics. Most importantly, the LQG extension developed here is directly applicable to the design and optimization of centralized, decentralized, and hierarchical machine tool controllers that have previously appeared in the literature. This is possible because our extension allows the assignment of a different control structure for each control input even if more than one control input are contributing to the same axis. Furthermore, the method admits each controller to function in any chosen subset of the available measurements. Thus, it provides us with a powerful means for designing any of the above-mentioned controllers using the same approach. The results of our suboptimal cross-coupling controllers were magnificent when compared to the commercially available positioning controllers.

DECODING OF THE RELATION BETWEEN FRACTAL STRUCTURE OF CUTTING FORCE AND SURFACE ROUGHNESS OF MACHINED WORKPIECE IN END MILLING OPERATION

Fractals ◽  
2019 ◽  
Vol 27 (04) ◽  
pp. 1950054 ◽  
Author(s):  
HAMIDREZA NAMAZI ◽  
ALI AKHAVAN FARID ◽  
TECK SENG CHANG
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Surface Quality ◽  
End Milling ◽  
Complex Structure ◽  
Dry Machining ◽  
End Mill ◽  
Milling Operation ◽  
Machining Operations

Analysis of the surface quality of workpiece is one of the major works in machining operations. Variations of cutting force is an important factor that highly affects the quality of machined workpiece during operation. Therefore, investigating about the variations of cutting forces is very important in machining operation. In this paper, we employ fractal analysis in order to investigate the relation between complex structure of cutting force and surface roughness of machined surface in end milling operation. We run the machining operation in different conditions in which cutting depths, type of cutting tool (serrated versus square end mills) and machining conditions (wet and dry machining) change. Based on the obtained results, we observed the relation between complexity of cutting force and surface roughness of generated surface of machined workpiece due to engagement with the flute surface of end mill, in case of using square end mill in dry machining condition, and also in case of using serrated end mill in wet machining condition. The fractal approach that was employed in this research can be potentially examined in case of other machining operations in order to investigate the possible relation between complex structure of cutting force and surface quality of machined workpiece.

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