Selection and Sequencing of Machining Processes for Prismatic Parts using Process Ontology Model

강무진,김경하,이태문,정창호,엄광호,박면웅,김재관 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.17 No.3

An essential part of process planning is to select the appropriate manufacturing processes and to determine their order from manufacturing knowledge. Ontology technology is considered an effective alternative for knowledge representation. Some studies have suggested a good process knowledge representation model based on heavyweight ontology, but this has inevitably resulted in limited scalability. Other studies have proposed frameworks to reason the appropriate machining processes for a feature, but have not sufficiently taken into account the manufacturing requirements. This paper thus presents an approach to select and sequence the machining processes for features using an ontology-based representation model as well as the corresponding inference rules. The ontology includes concepts including features, machining process, process capability with relevant properties, and relationships between concepts. The reasoning mechanism deduces a set of appropriate machining processes for individual features. Among these is the most appropriate final process determined by matching the accuracy requirements of a specific feature with the capability of the candidate processes. The preceding machining process is then selected so that the precedence relationship constraint between the processes is met until no further precedent processes are required. The proposed approach is neutral in that it is not subject to a specific restriction, such as a particular tool maker, and therefore can provide an interoperable and reusable platform.

A Classification of Multi-Axis Features based on Manufacturing Process

강무진,김경하,엄광호,박면웅,김재관 한국정밀공학회 2014 International Journal of Precision Engineering and Vol. No.

A machining feature can be regarded as the shape of the removal volume through a cutting process, which represents somemanufacturing attributes of a part. Since the machining feature can play a crucial role in process planning, it is desirable to namemachining features in such a way that a clear correlation between machining features and machining methods are reflected in thefeature classification. However, most researches dealing with this topic do not clearly show the relationship between machiningfeatures and machining processes. On the other hand, no consensus on the feature classification method exists yet, which causesconfusion when using the term “feature”. As a result, use of the features has not been very helpful in manufacturing preparation suchas machining process selection. In this paper, classification methods of multi-axis machining features known in relevant literaturesare studied firstly. Secondly, machining characteristics of various features are investigated to find out the relationship betweenmachining features and machining methods. Thirdly, based on the machining methods of features, a logical classification scheme ofmulti-axis machining features is proposed. And finally, the proposed feature taxonomy is verified through applying to an examplepart with multi-axis machining features.

A classification of multi-axis features based on manufacturing process

강무진,김경하,엄광호,박면웅,김재관 한국정밀공학회 2014 International Journal of Precision Engineering and Vol.15 No.10

A machining feature can be regarded as the shape of the removal volume through a cutting process, which represents somemanufacturing attributes of a part. Since the machining feature can play a crucial role in process planning, it is desirable to namemachining features in such a way that a clear correlation between machining features and machining methods are reflected in thefeature classification. However, most researches dealing with this topic do not clearly show the relationship between machiningfeatures and machining processes. On the other hand, no consensus on the feature classification method exists yet, which causesconfusion when using the term “feature”. As a result, use of the features has not been very helpful in manufacturing preparation suchas machining process selection. In this paper, classification methods of multi-axis machining features known in relevant literaturesare studied firstly. Secondly, machining characteristics of various features are investigated to find out the relationship betweenmachining features and machining methods. Thirdly, based on the machining methods of features, a logical classification scheme ofmulti-axis machining features is proposed. And finally, the proposed feature taxonomy is verified through applying to an examplepart with multi-axis machining features.

가공공정 모니터링이 가능한 치과용 크라운 가공기 개발

이종항,허우석 한국산학기술학회 2022 한국산학기술학회논문지 Vol.23 No.5

Dental crowns are shaped by machining with a five-axis machine using the CNC(Computer Numerical Control) program. On the other hand, an operator is required to monitor the machining process consistently when the CNC program is used. Thus, there is a need to monitor the machining process to increase the machining efficiency and achieve smart machines with artificial intelligence functions in the future. This paper proposes a new sensor installation method that can easily produce acquisition machining process information during machining. The continuous monitoring of the machining process using this sensor was assessed. The bearing temperature and rotational speed were monitored using a thermocouple and inverter for the motor controller. In addition, a three-axis load cell was used to monitor the spindle vibration and tool wear. In particular, the load cell was installed between the spindle and the vertical column to avoid interference by signal lines between the tool and the workpiece. Monitoring the temperature, rotational speed, spindle vibration, and tool wear using these sensors allowed the machining process to be assessed while machining the crown without an operator. Moreover, the developed machine tool for dental-crown showed a machining accuracy of less than 30 micrometers. 치과용 크라운의 형상은 5축 가공기의 CNC 프로그램에 의해서 가공된다. 이 CNC 프로그램에 의한 가공은 작업자가 가공공정을 항상 모니터링 할 필요가 있다. 미래에 인공지능 기능을 갖춘 스마트 공작기계를 구현하기 위해서는 가공공정을 모니터링 할 수 있는 능력을 갖추고 가공 효율을 높일 필요가 있다. 본 연구에서는 치과용 크라운 가공 중 가공공정 정보를 용이하게 수집할 수 있는 새로운 센서 설치법을 제안하고, 이 센서를 이용하여 가공공정을 지속적으로 모니터링 할 수 있는 가능성을 확인하였다. 스핀들 베어링에 열전대를 설치하여 베어링의 온도를 모니터링하고, 모터 제어용 인버터로 부터 회전수를 모니터링 한다. 또한, 3축 로드셀을 사용하여 스핀들 진동과 공구마모를 모니터링 한다. 특히 로드셀은 공구와 공작물 사이의 신호선에 의한 간섭을 회피할 수 있도록 스핀들과 상하 이송용 컬럼 사이에 설치된다. 이러한 센서들에 의하여 온도, 회전수, 스핀들 진동, 그리고 공구마모를 모니터링 한 결과, 작업자의 도움 없이도 크라운을 가공하면서 충분히 가공공정을 감시할 수 있었다. 또한, 개발된 치 가공기는 30 micrometer 이하의 가공오차를 갖는다.

Morphing technology for generating intermediate roughing models in multi-axis machining for complex parts

Han Feiyan,Wei Juan,Zhang Chuanwei,Peng Xianlong 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.1

In multi-axis milling of the aviation complex parts, establishing accurate machining process model is a key technology to realize intelligent processing. In order to obtain accurate machining process model of the aviation complex parts, a method based on morphing technology to construct intermediate process models of multi-axis roughing is proposed. Firstly, the theoretical basis for morphing technology is introduced, and the mathematical model of three hermite transfinite interpolation for morphing technology is established. Then the process constraint which impacts the geometry of the intermediate process model is analyzed in morphing technology. According to the analysis of the process constraint to design the process parameters, and the process parameters with constraints are introduced to the morphing technology to construct the process models. Finally, a validation is conducted on a complex aviation parts. The example shows that the method can able to construct the intermediate process models of complex structure parts for multi-axis rough machining under the condition of controlling the machining allowance, and also can shorten the total processing time of the complex parts, to a certain extent, the processing efficiency is improved.

A High Efficiency and Low Carbon Oriented Machining Process Route Optimization Model and Its Application

Zhaohui Deng,Lishu Lv,Wenliang Huang,Yangdong Shi 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.6 No.1

This paper aims to reduce the carbon emission of the manufacturing process and to achieve the low carbon optimization decision of the machining process route. Carbon emission was analyzed from the perspective of material flow, energy flow and environmental flow, and the machining process route carbon efficiency model was established based on the one from per unit cutted-volume. A multi-objective machining process route optimization model was established based on the genetic algorithms (GA), and the minimum processing time (high efficiency) and the optimal carbon efficiency (low carbon) were set as the optimization objectives. An experiment case study was performed on grinding carriage box, and a comparison was given between the optimized process and traditional process. The results indicate the resultant process route from the proposed algorithm, which verifies to reduce the processing time and increase the carbon efficiency.

대체공정이 있는 기계-부품 그룹의 형성 - 자기조직화 신경망을 이용한 해법-

전용덕(Yong-Deok Jeon) 한국산업경영시스템학회 2016 한국산업경영시스템학회지 Vol.39 No.3

The group formation problem of the machine and part is a critical issue in the planning stage of cellular manufacturing systems. The machine-part grouping with alternative process plans means to form machine-part groupings in which a part may be processed not only by a specific process but by many alternative processes. For this problem, this study presents an algorithm based on self organizing neural networks, so called SOM (Self Organizing feature Map). The SOM, a special type of neural networks is an intelligent tool for grouping machines and parts in group formation problem of the machine and part. SOM can learn from complex, multi-dimensional data and transform them into visually decipherable clusters. In the proposed algorithm, output layer in SOM network had been set as one-dimensional structure and the number of output node has been set sufficiently large in order to spread out the input vectors in the order of similarity. In the first stage of the proposed algorithm, SOM has been applied twice to form an initial machine-process group. In the second stage, grouping efficacy is considered to transform the initial machine-process group into a final machine-process group and a final machine-part group. The proposed algorithm was tested on well-known machine-part grouping problems with alternative process plans. The results of this computational study demonstrate the superiority of the proposed algorithm. The proposed algorithm can be easily applied to the group formation problem compared to other meta-heuristic based algorithms. In addition, it can be used to solve large-scale group formation problems.

Laser-Assisted Hybrid Processes: A Review

이춘만,우완식,김동현,오남석 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.17 No.2

Today, hybrid processes have a great influence on various material process fields due to factors such as improvements in the machinability and reductions of process forces. Also, the development of hybrid processes represents a new opportunity for the growth of manufacturing technology. Hybrid processes are developed to enhance the advantages of individual processes. The effect of hybrid processes is better than the sum of the advantages of a single process. Many researchers have studied a number of approaches to combine various manufacturing processes. Specifically, since the development of the laser, it has been applied in various engineering fields. Moreover, interest in laser and non-laser hybrid processes is recently increasing in various industries. The laser is a type of non-contact thermal energy technology and is used in material processing. The laser heat source can be used for the heating and preheating of various materials. In this paper, the laser is selected as an energy source and laser-assisted hybrid processes over the past five years are reviewed, including those related to machining, welding and coating processes. The last part of this paper discusses the trends in future research on laser-assisted hybrid processes.

레이저 미세 가공 시스템 설계 프로세스 개발 연구

문성욱(Seong-Wook Moon),박영원(Young-Won Park),남기중(Gi-jung Nam) 한국레이저가공학회 2007 한국레이저가공학회 학술대회 논문집 Vol.2007 No.-

  In this paper laser micro machining system design process for commercialization is suggested. The constructed system design process is properly adjusted for laser micro machining area after tailoring engine process of system engineering process such as requirement analysis, functional analysis and allocation, system synthesis and system optimization process. In the current laser machining system design, system components and specifications are determined on the basis of experimental experience which a laser is being used in machining some materials as well as the current machining and research trend. In this paper, however, systematic process is suggested in addition to experimental experience, which the laser and system components and their specifications are decided in the process of definition of functional requirements and engine design variables of system to satisfy the customer"s requirements.

Electrochemical Magnetic Abrasive Machining of AISI304 Stainless Steel Tubes

Kesarbhai Bhikhabhai Judal,Vinod Yadava 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.

This work presents the characteristics of advanced abrasion based hybrid machining process consisting of electrochemical dissolution and magnetic abrasive machining process. The cylindrical electrochemical magnetic abrasive machining (C-EMAM) setup was developed and mounted as an attachment on lathe for high efficiency machining of cylindrical jobs. Experiments were conducted to explore the performance of the process on AISI-304 stainless steel tubes using unbonded magnetic abrasives. The effect of various process parameters viz. rotational speed of the workpiece, current to the electromagnet, electrolytic current and frequency of vibration on material removal and surface roughness were investigated. The electrochemical process has major contribution in material removal, whereas magnetic abrasive machining helps in reduction in surface roughness. This process has higher machining efficiency particularly at high value of electrolytic current and high rotational speed.