• Title/Summary/Keyword: Part Orientation

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A neural network method for recognition of part orientation in a bowl feeder (보울 피이더에서 신경 회로망을 이용한 부품 자세 인식에 관한 연구)

  • 임태균;김종형;조형석;김성권
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10a
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    • pp.275-280
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    • 1990
  • A neural network method is applied for recognizing the orientation o f individual parts being fed from a bowl feeder. The system is designed in such a way that a part can be discriminated and sorting according to every possible stable orientation without implementing any a mechanical tooling. The operation of the bowl feeder is based on a 2D image obtained from an array of fiber optic sensor located on the feeder track. The acquired binary image of a moving and vibrating part is used as input to a neural network which, in turn, determines t he orientation of the part. The main task of the neural network, here is to synthesize the appropriate internal discriminant functions for the part orientation using the part features. A series of the experiments reveals several promising points on performance. Since the operation of the feeder is highly programmable, it is well suited for feeding and sorting small parts prior to small batch assembly work.

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Determination of Optimal Build-up Direction for Stereolithographic Rapid Prototyping (SLA를 이용한 신속 시작작업에서 최적 성형방향의 결정)

  • Hur, Junghoon;Lee, Kunwoo
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.4
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    • pp.163-173
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    • 1996
  • Stereolithography is a process used to rapidly produce polymer components directly form a computer representation of the part. There are several considerations to be made for the efficient use of the process. Especially, the build-up orientation of part critically affects the part accuracy, total build time and the volume of support structures. The purpose of tis study is to determine the optimal build-up part orientation for the SLA process with improving part accuracy, and minimizing total build time and the volume of support structures. The forst factor is related to the area of surfaces whioch have staircase protrusions after solidification, the second factor is related to the total number of layers, and the third factor is related to the area of the surfaces which need to be supported with support structures. An algorithm is developed to calculate the staircase area, quantifying the process errors by the volume of materials supposed to be removed or added to the part, and the optimal layer thickness for the SLA system which can handle the variable layer thickness. So the optima l part orientation is determined based on the user's selections of primary criter- ion and the optimal thickness of layers is calculated at any part orientations.

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Determination of Optimal Build Orientation Based on Satisfactory Degree Theory for RPT

  • Zhao, Jibin;Liu, Weijun;Wu, Jianhuang
    • International Journal of CAD/CAM
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    • v.6 no.1
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    • pp.51-58
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    • 2006
  • In rapid prototyping, the optimal part orientation during fabrication is critical as it can improve part accuracy, minimize the requirement for supports and reduce the production time. Through investigating the geometric issues of STL model and process planning of RPM, This paper establishes optimizing model based on the considerations of staircase effect, support area and production time. The general satisfactory degree function is constructed employing the multi-objective optimization theory based on the general satisfactory degree principle. The best part-building orientation is obtained by solving the function employing generic algorithm. Experiment shows that the methods can effective resolve the part-building orientation in RP.

Determination of Part Orientation and Packing in SLS Process (SLS에서의 자동적인 조형자세 및 배치 결정에 관한 연구)

  • Hur, Sung-Min;Chang, Pok-Keun;Choi, Kyung-Hyun;Lee, Seok-Hee
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.11
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    • pp.139-147
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    • 1999
  • Rapid Prototyping has made a drastic change in all industries which needs to reduce the time for the development of new products. Orientation and packing in rapid prototyping is considered as the most important factors to maximize the utilization of space in the build chamber and reduce build time. However, the decision of these parameter is mainly dependant on the operators's experience. This paper presents the methodology to find the optimal build layout considering an orientation and packing of multiple parts in SLS processing. Each part is represented as a voxel structure to deal with the inefficiency in a bounding box approach. Test results show that the adapted BL algorithm with a genetic algorithm(GA) can be applicable to a real industry.

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SLA를 이용한 신속 시작작업에서 최적 성형방향의 결정

  • 허정훈;이건우
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.04a
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    • pp.552-558
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    • 1995
  • Stereolithography is a process used to rapidly produce polymer components directly from a computer-representation of the part. There are several considerations to be made for the efficient use of te process. Especially, the build-up orientation of part critically affect to the part accuracy, total build time and the volume of support structures. Te purpose of this study is to determine the optimal build-up part orientation for the SLA process with improving part accuracy, minimizing total build time, and the volume of supprot structures. The first factor is related to the area of surfaces which have staircase protrusions after solidification, the second factor is related to the total number of layers, and the third factor is related to the area of the surfaces which need to be supported with support structures. An algorithm is developed to calculate the staircase area with quantifying the process planning errors that the volume of materials is supposed to be removed or added to the part, and the optimal layer thickness for the SLA system whichcan hadle the variable layer thickness in different orientations achieved by rotating the given part to the specified finite directions. So the optimal part orientation is determined based on the user's selections of primary criterion and the optimal thickness of layers is calculated at any part orientations.

Determining Optimal Build Orientation in Fused Deposition Modeling for Minimizing Post Machining by Using Genetic Algorithm. (FDM(Fused Deposition Modeling) part의 후가공 최소화를 위한 최적성형방향 결정)

  • 안대건;김호찬;양화준;이일엽;장태식;정해도;이석희
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.18-21
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    • 2003
  • Fused Deposition Modeling (FDM) parts are made by piling up thin layers that cause the stair stepping effect at the surface of FDM parts. This effect brings about poor surface roughness of the part and requires additional post machining such as manual finishing that is detrimental to the part geometry and time consuming. Determining optimal build orientation for FDM parts can be one solution to minimize the post machining. However, by using the CAD model, calculating the optimal build orientation is impractical due to heavy computing process. In order to calculate the optimal build orientation with high speed. the surface roughness model based on measured data and interpolation is newly developed in this research. Also. the genetic algorithm (GA) is applied for acquiring reliable solution. Finally, It is verified from the test that the presented approach is very efficient for reducing the additional post machining process fer FDM parts.

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Design of Gate Locations, Molding Conditions, and Part Structure to Reduce the Warpage of Short-Fiber Reinforced Injection Molded Part (단섬유 보강 사출성형품의 휨 감소를 위한 게이트 위치, 성형 조건 및 제품 구조 설계)

  • Choi, D.S.
    • Transactions of Materials Processing
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    • v.17 no.6
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    • pp.443-448
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    • 2008
  • Fiber reinforced injection molded parts are widely used in recent years because of their improved properties of materials such as specific stiffness, specific strength, and specific toughness. The demand for products with high precision is increasing and it is important to minimize the warpage of the products. The warpage of short-fiber reinforced product is caused by anisotropy induced by fiber orientation as well as the residual stresses induced during the molding process. In order to reduce the warpage of the part, it is important to achieve successful mold design, processing control, and part design. In the present study, the design of gating system, molding condition, and part structure were carried out and verified with numerical analysis using a commercial CAE code Moldflow. The numbers and locations of gates were iteratively determined, and the molding conditions which can decrease the warpage of the part were investigated. Finally, slight structural modification of the part was conducted to reduce the locally concentrated warpage.

Determining Machinability and Setup Orientation for Five-axis NC Machining of Free Surfaces (머신 컨피규레이션에 따른 자유곡면의 5 축 가공성과 셋업 자세)

  • Kang, Jae-Kwan;Suh, Suk-Hwan
    • Journal of Korean Institute of Industrial Engineers
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    • v.21 no.1
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    • pp.67-84
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    • 1995
  • Five-axis NC machining is advanced machining technology by which highly geometrically complicated parts can be machined accurately with high machinability. In this paper, we investigate the problems of determining the machinability and part setup orientation for a given surface models. We first develop kinematic model of the five-axis machines based on the axis configuration, then develop algorithms for determining the feasibility of machining by one setup(machinability) and the part orientation for the C,A and A,B type configuration. The machinability is determined by computationally efficient procedure for finding the intersection between the feasible area on the sphere and the numerical map called binary spherical map(BSM), and the part setup is chosen such that the rotational range is minimized among the feasible configurations. The developed algorithms are tested by numerical simulations, convincing they can be readily implemented on the CAD/CAM system as an automated process planner giving the efficient machine type and setup for NC machining.

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Parallel-Jaw Grasp Planning of Polygonal Parts in Uncertain Dynamic Environments (불확실 동적 환경에서 다각형 부품의 평행-턱 파지 계획)

  • Han, Inhwan;Cho, Jeongho
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.4
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    • pp.126-135
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    • 1997
  • A sensorless motion planner which succeeds in grasping a polygonal part firmly into a desired orientation has been developed through the dynamic analysis. The analytical results on the impact process with friction are used for modeling the contact motionduring the parallel-jaw grasp operation, which is com- posed of the pushing and the squeezing process. The developed planner succeeds in grasping a part into a specified orientation in the face of uncertainties of initial position and orientation of the part, motion direction of the finger, and the physical parameters such as the coefficients of friction and restitution. The motion planner has been fully implemented into a viable package on the computer system, and verified experimentally. The motion of parts is recorded using a high-speed video camera, and then compared to the results of the planner and the graphic simulation results that illustrate the simulated motion of the grasp operation.

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Mechanical Properties of Insulator FRP Rod According to the Winding Orientation of Glass Fiber (유리섬유의 배향에 따른 전기절연용 FRP의 강도특성)

  • Park, Hyo-Yeol;Gang, Dong-Pil;Han, Dong-Hui;Pyo, Hyeon-Dong;Kim, Tae-Ok
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.49 no.6
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    • pp.321-327
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    • 2000
  • FRP has been used very much as high strength and electrical insulation materials. The fiber contributes the high strength and modulus to the composite. The main roles of the matrix in composite materials like FRP are to transmit and distribute stresses among the individual fibers. The fiber orientation in FRP has a great effect on the strength of FRP because the strength of FRP mainly depends on the strength of fiber. In this study, compressive and bending stresses of FRP rods were simulated and measured according to the winding orientation of glass fiber. Inner part of FRP was made unidirectionally by pultrusion method and outer part of FRP was made by filament winding method to give fiber orientation to the FRP. The shear stresses had great effect on the strength of FRP although the stress of parallel direction of FRP was much higher. The tendency of compressive and bending strengths with glass fiber orientation was different each other.

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