scholarly journals Optimization of the setup position of a workpiece for five-axis machining to reduce machining time

2020 ◽  
Vol 12 (12) ◽  
pp. 168781402097554
Author(s):  
Ching-chih Wei ◽  
Wei-chen Lee
Keyword(s):  
Optimization Problem ◽  
Machining Time ◽  
Optimal Position ◽  
Rotary Axes ◽  
Machine Interference ◽  
Workpiece Setup ◽  
Five Axis ◽  
The Relationship ◽  
Interference Problems

Five-axis machining is commonly used for complicated features due to its advantage of rotary movement. However, the rotary movement introduces nonlinear terms in the kinematic transform. The nonlinear terms are related to the distance between the cutter location (CL) data and the intersection of the two rotary axes. This research studied the possible setup positions after the toolpaths have been generated, and the objective was to determine the optimal setup position of a workpiece with minimal axial movements to reduce the machining time. We derived the kinematic transform for each type of five-axis machines, and then, defined an optimization problem that described the relationship between the workpiece setup position and the pseudo-distance of the axial movements. Eventually, an optimization algorithm was proposed to search for the optimal workpiece setup position within the machinable domain, which is already concerned with over-traveling and machine interference problems. In the end, we verified the optimal results with a case study with a channel feature, which was real cutting on a table-table type five-axis machine. The results show that we can save the axial movements up to 16.76% and the machining time up to 10.70% by setting up the part at the optimal position.

Optimal Workpiece Setup for Time-Efficient and Energy-Saving Five-Axis Machining of Freeform Surfaces

2016 ◽  
Vol 139 (5) ◽  
Author(s):  
Ke Xu ◽  
Kai Tang
Keyword(s):  
Energy Consumption ◽  
Alternative Energy ◽  
Tool Path ◽  
Machining Time ◽  
Freeform Surfaces ◽  
Significant Saving ◽  
Energy Consumption Model ◽  
Consumption Model ◽  
Workpiece Setup ◽  
Five Axis

Energy consumption in five-axis machining of freeform surfaces can be considerably large for large-size parts. This paper presents a study on how to setup the workpiece in order to minimize the energy consumption without modifying the toolpath itself. For an arbitrary freeform workpiece, the way how it is setup on the working table highly affects the machine's kinematic behavior, which dominates the overall processing time and energy consumption. Taking into account the speed and acceleration limit of each axis of the machine, we first establish the energy consumption model as a function of the workpiece setup. However, this original model involves certain critical physically pertinent coefficients (such as the moment of inertial of a rotary table) which are usually unavailable in practice. Instead, by exploring insightful geometric characteristics of the five-axis machine, an alternative energy consumption model is established which is independent of those hard-to-obtain coefficients. A simple algorithm is then designed to optimize this model. Both computer simulations and physical cutting experiments demonstrate that, when compared with an arbitrary setup, the optimized workpiece setup is able to achieve a significant saving (as much as 50%) in both energy consumption and total machining time, both using a same tool path.

Kinematics-based five-axis trochoidal milling process planning for deep and curved 3D slots

2021 ◽  
pp. 1-30
Author(s):  
Zhaoyu Li ◽  
Dong He ◽  
Ke Xu ◽  
Fubao Xie ◽  
Kai Tang
Keyword(s):  
Machine Tool ◽  
Tool Path ◽  
Electric Energy ◽  
Milling Process ◽  
Heat Accumulation ◽  
Machining Time ◽  
Rotary Axes ◽  
Planning Algorithm ◽  
The One ◽  
Five Axis

Abstract Trochoidal (TR) milling is a popular means for slotting operation. Attributing to its unique circular shaped path pattern, TR milling avoids the full tool-workpiece engagement, which helps reduce the cutting heat accumulation and hence slow down the tool wear. While traditionally TR milling is only used for machining 2.5D cavities, it has now been extended to machining genuine 3D curved cavities under the realm of five-axis machining. However, since for a typical five-axis machine tool the rotary axes have a much larger moment of inertial than the three linear axes, to reduce both the total machining time and the consumed electric energy (for driving the machine tool), it is desirable to minimize the use of the two rotary axes (particularly the one with the worst moment of inertial) when planning a TR tool path for a given 3D cavity. Unfortunately, due to the newness of five-axis TR machining, there has no published reports on this subject. In this paper, we present a five-axis TR tool path planning algorithm for machining an arbitrary 3D curved cavity, which will consider the kinematical characteristics of the five-axis machine tool and try to minimize the use of the kinematically worst rotary axes, while tending to all the required constraints such as the threshold on the cutting force. Both computer simulation and physical cutting experiments of the proposed method have been conducted, and the results give a preliminary confirmation on the feasibility and advantages of the proposed method.

Kämpfe um Bergbau und die Möglichkeiten demokratischer Transformation

2017 ◽  
Vol 47 (189) ◽  
Author(s):  
Kristina Dietz
Keyword(s):  
Direct Democracy ◽  
Social Power ◽  
Political Agenda ◽  
The Political ◽  
Liberal Democratic ◽  
Political Effects ◽  
Mining Project ◽  
National Governments ◽  
The Relationship

The article explores the political effects of popular consultations as a means of direct democracy in struggles over mining. Building on concepts from participatory and materialist democracy theory, it shows the transformative potentials of processes of direct democracy towards democratization and emancipation under, and beyond, capitalist and liberal democratic conditions. Empirically the analysis is based on a case study on the protests against the La Colosa gold mining project in Colombia. The analysis reveals that although processes of direct democracy in conflicts over mining cannot transform existing class inequalities and social power relations fundamentally, they can nevertheless alter elements thereof. These are for example the relationship between local and national governments, changes of the political agenda of mining and the opening of new spaces for political participation, where previously there were none. It is here where it’s emancipatory potential can be found.

Interactive acculturation of Turkish-Belgian parents and children in Flanders: A case study of Beringen

2019 ◽  
Vol 16 (3) ◽  
pp. 417-428
Author(s):  
Özgün Ünver ◽  
Ides Nicaise
Keyword(s):  
Early Childhood ◽  
Maternal Employment ◽  
Domain Specificity ◽  
Specific Context ◽  
Childhood Education ◽  
Parents And Children ◽  
Education And Care ◽  
The Relationship ◽  
The Town

This article tackles the relationship between Turkish-Belgian families with the Flemish society, within the specific context of their experiences with early childhood education and care (ECEC) system in Flanders. Our findings are based on a focus group with mothers in the town of Beringen. The intercultural dimension of the relationships between these families and ECEC services is discussed using the Interactive Acculturation Model (IAM). The acculturation patterns are discussed under three main headlines: language acquisition, social interaction and maternal employment. Within the context of IAM, our findings point to some degree of separationism of Turkish-Belgian families, while they perceive the Flemish majority to have an assimilationist attitude. This combination suggests a conflictual type of interaction. However, both parties also display some traits of integrationism, which points to the domain-specificity of interactive acculturation.

The Relationship between Working Environment and Internship Satisfaction Level: A Case Study Of A 4-Star Hotel Restaurant In Germany

2019 ◽  
Vol 2 (4) ◽  
pp. 276-291
Author(s):  
Chatarina Natalia Putri
Keyword(s):  
Career Development ◽  
Working Hours ◽  
Learning Opportunities ◽  
Working Environment ◽  
The Other ◽  
Satisfaction Level ◽  
Supervisory Support ◽  
Support Organization ◽  
The Relationship

There are many factors that can lead to internship satisfaction. Working environment is one of the factors that will result to such outcome. However, many organizations discarded the fact of its importance. The purpose of this study is to determine whether there is a significant relationship between working environment and internship satisfaction level as well as to determine whether the dimensions of working environment significantly affect internship satisfaction. The said dimensions are, learning opportunities, supervisory support, career development opportunities, co-workers support, organization satisfaction, working hours and esteem needs. A total of 111 questionnaires were distributed to the respondents and were processed by SPSS program to obtain the result of this study. The results reveal that learning opportunities, career development opportunities, organization satisfaction and esteem needs are factors that contribute to internship satisfaction level. In the other hand, supervisory support, co-workers support and working hours are factors that lead to internship dissatisfaction. The result also shows that organization satisfaction is the strongest factor that affects internship satisfaction while co-workers support is the weakest.

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