• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.4
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• pp.138-144
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• 2010

This research deals with multiple Gantry-type assembly machines for the optimization of PCB assembly line. The automated assembly machine has 6 nozzles which can linearly move the X axis and the Y axis different from the turret type assembly machine. Each machine is optimized while considering the whole line balancing of three machines in assembly process simultaneously. Simulation models are developed using AutoMod for comparison study with single machine operation cases under various conditions such as types and total number of components to evaluate the proposed method.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.7
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• pp.656-662
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• 2008

A cost-function based on manipulability and compatibility is designed to determine assembly motions of two cooperating manipulators. Assembly motions are planned along the direction maximizing performance indices to improve control performance of the two manipulators. This paper proposes bimanual task compatibility by defining cost functions. The proposed cost functions are applied and compared to the bimanual assembly task. The problem is formulated as a constrained optimization considering assembly constraints, position of the workpieces, and kinematics and redundancy of the bimanual robot. The proposed approach is evaluated with simulation of a peg-in-hole assembly with an L-shaped peg and two 3-dof manipulators.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.2
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• pp.144-151
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• 2005

We propose an optimization method to reduce the assembly time of chip mounters. Feeder arrangement and assembly sequence are determined considering the multiple feeder assignment. The problem is divided into two sub-problems: feeder arrangement problem and assembly sequence problem. We present mathematical model for each sub-problem. The clustering algorithm and assignment algorithm are applied to solve the feeder arrangement problem. The assignment algorithm and connection algorithm are applied to solve the assembly sequence problem. Simulation results are then presented to verity the usefulness of the proposed method.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.3
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• pp.122-133
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• 1999

Overlap, excessive wide gaps, and errors between blocks during erection process increases cost and man-hour. In this paper, a system to simulate the assembly process is suggested and a plane block assembly of welding deformation with gravity is simulated in consideration of assembly order, deformations and errors occurring in the cutting and forming processes are not considered and welding deformations are acquired by equivalent stiffness and load method from experiments and hull double bottom plane block is assembled on a assembly order by panel method. It is certified that according to the order of assembly, intermediate product shape affects rigidity which affects welding deformations. Assembly order must be considered in the assembly process. It is certified that the gravity has important role in the assembly process.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.242.1-242.1
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• 2014

The electron cyclotron resonance plasma source with a belt-type magnet assembly (BMA) is designed for effective plasma confinements. For characterizing the plasma source, the plasma parameters are measured by Langmuir probe. However, the plasma parameters and the motion of charged particles near the ECR zone are not easy to diagnostics, because of the high plasma density and temperature. Thus, as an alternative method, the electromagnetic simulation of the plasma source has been performed by using three-dimensional particle-in-cell and Monte Carlo collisional (PIC-MCC) simulation codes. For considering the limitation of simulation resources and time, the periodic boundary condition is applied and the coulomb collision is neglected. In this paper, we present the results of 3D PIC simulations of ECR plasmas with BMA and we compare them with the experimental results.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.3
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• pp.298-308
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• 2000

In this paper a new two-arm cooperative assembly(or insertion) algorithm is proposed. As a force-guided control method for the cooperative assembly the adaptive accommodation controller is adopted since it does not require any complicated contact state analysis nor depends of the geometrical complexity of the assembly parts. Also the RMRC(resolved motion rate control) method using a relative jacobian is used to solve inverse kinematics for two manipulators. By using the relative jacobian the two cooperative redundant manipulators can be formed as a new single redundant manipulator. Two arms can perform a variety of insertion tasks by using a relative motion between their end effectors. A force/torque sensing model using an approximated penetration depth calculation a, is developed and used to compute a contact force/torque in the graphic assembly simulation . By using the adaptive accommodation controller and the force/torque sensing model both planar and a spatial cooperative assembly tasks have been successfully executed in the graphic simulation. Finally through a cooperative assembly task experiment using a humanoid robot CENTAUR which inserts a spatially bent pin into a hole its feasibility and applicability of the proposed algorithm verified.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3648-3658
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• 2023

The early localization of a fuel subassembly with a failed (wet rupture) fuel pin is very important in reactors to limit the associated radiological and operational consequences. This requires a fast and reliable system for failure detection and their localization in the core. In the Prototype Fast Breeder Reactor, the system specially designed for this purpose is Failed Fuel Location Modules (FFLM) housed in the control plug region. It identifies a failed sub-assembly by detecting the presence of delayed neutrons in the sodium from a failed sub-assembly. During the commissioning phase of PFBR, it is mandatory to demonstrate the FFLM effectiveness. The paper highlights the engineering and physics design aspects of FFLM and the integrated simulation towards its function demonstration with a source assembly containing a perforated metallic fuel pin. This test pin mimics a MOX pin of 1 cm² of geometrical defect area. At 10% power and 20% sodium flow rate, the counts rate in the BCCs of FFLM system range from 75 cps to 145 cps depending upon the position of DN source assembly. The model developed for the counts simulation is applicable to both metal and MOX pins with proper values of k-factor and escape coefficient.

• Journal of Korea Multimedia Society
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• v.15 no.1
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• pp.148-165
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• 2012

Applying maintenance simulation using virtual mockup in product design phase enables maintainability test before prototyping physical products, and it is expected to reduce product development costs. The simulation results can be reused as contents of service manuals and RAM (Reliability, Availability, Maintainability) analysis data. Maintenance simulation should provide realistic representation of physical property of virtual product, assembly relation between parts and manipulation process to verify feasibility of product design. The simulation system should be extended to collaborative virtual environment to perform collaborative maintenance procedures. In this paper, the three layered system architecture and the physics based collaborative interaction technique are proposed to extend current maintenance simulation into collaborative virtual environment. The proposed system was implemented as ViMMS (Virtual Mockup Maintenance Simulation system), and compared with case study results of VADE (Virtual Assembly Design Environment). As a result, the ViMMS encompassed broader range of maintenance tasks by using physics based collaborative interaction technique.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1411-1414
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• 1997

It is essential to obtain a distane informaion in order to completely execute assembly tasks such as a grasping and an insertion. In this paper, we propose a method estimating a measurement distance from a sensor to an object through using the omni-directional image sensing system for assembly(OISSA) and show its features and feasibility by a computer simulation. The method, utilizing a forwarded motion stereo technique, is simple to search the corresponding points and possible to immediatiely obtain a three-dimensional 2.pi.-shape information.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.336-341
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• 1993

Automatic Assembly Systems(AAS) are a class of systems exhibiting concurrency, asynchronicity and distributedness, and can be modeled by Petri Nets. In this paper, we design two types of configuration of part-assembly system in the car manufacturing line, as an example of AAS. And, we make a modeling the system by utilizing Extended Petri Nets, simulation as varying machine parameters, and analysis of operation status. These enable to present the information of optimal status and various problems occurring in the system for achieving high production rate.