Multi task selection including part mix, tool allocation and process plans in CNC machining centers using new binary PSO

2012 ◽  
Author(s):  
Kusum Deep ◽  
Pinkey Chauhan ◽  
Millie Pant
Keyword(s):  
Cnc Machining ◽  
Task Selection ◽  
Process Plans ◽  
Tool Allocation ◽  
Binary Pso

A Long-Term-Memory Account of Asymmetric Task-Selection Costs

2011 ◽  
Author(s):  
Ulrich Mayr ◽  
Dave Kuhns ◽  
Ashley Berns
Keyword(s):  
Long Term Memory ◽  
Task Selection ◽  
Term Memory

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.

Review of Research on Hydrostatic Bearings

2020 ◽  
Vol 13 ◽  
Author(s):  
Xiaodong Yu ◽  
Yu Wang ◽  
Junfeng Wang ◽  
Wenkai Zhou ◽  
Hongwei Bi ◽  
...  
Keyword(s):  
High Speed ◽  
Static Pressure ◽  
Development Trend ◽  
Cnc Machining ◽  
Pressure Effects ◽  
Cnc Machine Tools ◽  
Future Research ◽  
Theoretical Formula ◽  
Hydrostatic Bearing ◽  
Hydrostatic Bearings

Background: Hydrostatic bearings have the advantages of strong bearing capacity, good stability, small friction coefficient and long life. The performance of liquid hydrostatic bearings directly affect the accuracy and efficiency of CNC machining equipment. The performance is conducive to the development of CNC machine tools towards high speed and heavy load, so it is necessary to sort out and summarize the existing research results. Objective: This study summarizes the current development status of hydrostatic bearings and explains the development trend of hydrostatic bearings. Methods: According to the recently published journal articles and patents, the recent experimental research on hydrostatic thrust bearings is summarized. This paper summarizes many factors that affect the performance of hydrostatic bearings, and discusses the causes of various factors on hydrostatic bearings. Finally, future research on hydrostatic bearings is presented. Results: The study discusses experimental methods, simulation processes, and experimental results. Conclusion: This study can produce dynamic and static pressure effects by changing the structure of the oil cavity of the hydrostatic bearing. This effect can make up for the static pressure loss. By improving the theoretical formula and mathematical model and proposing a new simulation method, the accuracy of the hydrostatic bearing simulation is satisfied; the future development trend of the hydrostatic bearing is proposed.

scholarly journals A Feedrate Planning Method for the NURBS Curve in CNC Machining Based on the Critical Constraint Curve

2021 ◽  
Vol 11 (11) ◽  
pp. 4959
Author(s):  
Peng Guo ◽  
Yijie Wu ◽  
Guang Yang ◽  
Zhebin Shen ◽  
Haorong Zhang ◽  
...  
Keyword(s):  
Planning Method ◽  
Cnc Machining ◽  
Arc Length ◽  
Kinematic Constraint ◽  
Nurbs Curve ◽  
Planning Strategy ◽  
Feedrate Planning ◽  
Curvature Constraint ◽  
Planning Methods ◽  
The Relationship

The curvature of the NURBS curve varies along its trajectory, therefore, the commonly used feedrate-planning method, which based on the acceleration/deceleration (Acc/Dec) model, is difficult to be directly applied in CNC machining of a NURBS curve. To address this problem, a feedrate-planning method based on the critical constraint curve of the feedrate (CCC) is proposed. Firstly, the problems of existing feedrate-planning methods and their causes are analyzed. Secondly, by considering both the curvature constraint and the kinematic constraint during the Acc/Dec process, the concept of CCC which represents the relationship between the critical feedrate-constraint value and the arc length is proposed. Then the CCC of a NURBS curve is constructed, and it has a concise expression conforming to the Acc/Dec model. Finally, a feedrate-planning method of a NURBS curve based on CCC and the Acc/Dec model is established. In the simulation, a comparison between the proposed method and the conventional feedrate-planning method is performed, and the results show that, the proposed method can reduce the Acc/Dec time by over 40%, while little computational burden being added. The machining experimental results validate the real-time performance and stability of the proposed method, and also the machining quality is verified. The proposed method offers an effective feedrate-planning strategy for a NURBS curve in CNC machining.

Sign in / Sign up

Export Citation Format

Share Document