• Journal of the Korean Society of Industry Convergence
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• v.20 no.4
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• pp.307-311
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• 2017

Ultra short pulse laser processing with the PI (polyimide) substrate is conducted to increase flexibility and radius of curvatures. A femtosecond laser is used to perform micro machining by minimizing the heat effect in PI substrate. The laser processing according to the parameters, such as fabricated line width, depth, laser power, distance between lines, is carried out to understand the characteristics of fabricated lines. A bending test is carried out to evaluate bending shapes and the radius of curvature after bending and spreading it 1000 times. The results demonstrates that the radius of curvature decreases in deepen lines and increases with the augment of the number of the fabricated lines, and distance between lines.

• Journal of the Korean Society of Industry Convergence
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• v.19 no.4
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• pp.206-215
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• 2016

Delta parallel robots are now widely used for high-speed applications. However, typical Delta robots, such as ABB Flexpicker suffer from rotating axis with passive prismatic joint subjected to critical speed and so requiring careful maintenance. In this paper, a novel 4-DOF high-speed parallel robot with four legs is presented, which consists of three legs with 90 degree arrangement for translational motions and one remaining leg with rack & pinion gears for rotational motion. The inverse kinematics, velocity, acceleration, statics, and inverse dynamics have been analyzed. From the workspace analysis and inverse dynamics simulation for 0.43 sec cycle time, the 4-axis parallel robot prototype with 12kg payload has been designed. In the future research, computed torque control methods will be developed for the prototype.

• Journal of the Korean Society of Industry Convergence
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• v.19 no.4
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• pp.198-205
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• 2016

For the study on the ion exchange of nickel hexacyanoferrate(NiHCNFe) electrode with the several cations, the film of hexacyanoferrate was prepared on the bare nickel surface by the electrochemical and chemical methods in the solution composed with 5mM K3Fe(CN)6 and 100mM KNO3. To compare the capability of the ion exchange of NiHCNFe film electrode, the repeated cyclic voltammograms were measured in the 0.5M cation nitrate solutions at $25^{\circ}C$ and pH7. It was found that the capacity of the electrochemically derivatized NiHCNFe reduced in the rate of 0.5~0.7%/cycle and was nearly exhausted at the 150th potential cycle. Better result was obtained from that the capacity loss of the chemically assembled NiHCNFe was less than 0.02%/cycle for 5,000cycles. Furthermore, the residual capacity was more than 30% at the 5,000th cycle.

• Journal of the Korean Society of Industry Convergence
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• v.19 no.4
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• pp.193-197
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• 2016

There are many hoppers in the actual industrial plants such as grain hoppers in agricultural companies, surge hoppers in steel companies, and so on. In general, they are time-delay systems so that their level control is not easy. Thus, they have been manually controlled to avoid the overflow and empty out. In this paper, we proposed Fuzzy PID controller for level control of hopper systems. To show the effectiveness of the proposed scheme, some simulation results are given.

• Journal of the Korean Society of Industry Convergence
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• v.19 no.4
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• pp.167-175
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• 2016

We present a method for improving adaptability of Learning from Demonstration (LfD) strategy by combining the LfD and Particle Swarm Optimization (PSO). A trajectory generated from an LfD is modified with PSO by minimizing a fitness function that considers constraints. Finally, the final trajectory is suitable for a task and adapted for constraints. The effectiveness of the method is shown with a target reaching task with a manipulator in three-dimensional space.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.1
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• pp.37-44
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• 2018

In this work, a 4-DOF industrial robot system with three translational and one rotational motions which is widely used in palletizing applications is developed. In order for small robot manufacturing companies to develop their own robot systems for CNC machining and/or general automations, the analysis and design methods of a 4-DOF robot manipulator are presented and the development of a PC-based robot controller with EtherCAT are introduced. It is noted that the robot controller is developed by using Simulink Real-Time, which can provide an integrated environment of easier control algorithm development and data logging. Through position control and accuracy/repeatability measurement results, the developed robot prototype has comparable performances with commercial counterparts. In the future works, the advanced functions of industrial robots such as kinematic calibration, vibration suppression control, computed torque control, etc. will be investigated.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.1
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• pp.1-8
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• 2018

The purpose of this study is to develop a high-strength, high-toughness, thin-walled aluminum shock absorber housing product by applying a high vacuum die casting method to improve internal gas defect and formability. The analysis program dedicated for the casting was used because it was too costly and time-consuming to adopt the gating system design. The final casting plan was designed based on the flow pattern of the material filled into the mold and the result of air pressure and air pocket after the material was completely filled in the mold. Gaty shape was designed as a split type. The runner was designed to have the same shape as the initial inlet curve of the cavity, and the flow of the molten metal was prevented from turbulent flow. The most favorable results were obtained when the injection speed was $V_2=4.0m/s$. Defects on pores were reduced by applying high vacuum level inside the mold.

• Journal of the Korean Society of Industry Convergence
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• v.18 no.2
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• pp.129-138
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• 2015

This study describe a new method to control posture and velocity for a wheeled mobile robot using visual feedback control method with a position based visual feedback. To slove the problem of vibration phenomena which were shown in the previous researches using a simple switching function based on a threshold, the proposed visual servo control law introduces the fusion function based on a blending function. The chattering problem and rapid motion of the mobile robot can be eliminated. And we consider the nonlinearity of the wheeled mobile robot unlike the previous visual servo control laws using linear control methods to improve the performances of the visual servo control law. The proposed posture control law using visual servoing is verified by a theoretical analysis and simulation and experimental results.

• Journal of the Korean Society of Industry Convergence
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• v.18 no.2
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• pp.119-128
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• 2015

In this paper, we propose a new motion control technology to design robust control system of industrial robot. The system modeling of robotic manipulation tasks with constraints is presented, and the control architecture for unconstrained and constrained motion system with parametric uncertainties is synthesized. The optimal reference of robot manipulator is generated by the reference controller as a discrete state system and the control behavior of constrained system which has poor modeling information and time-invariant constraint function is improved motion control system is successfully evaluated by experiment to the desired tasks.

• Journal of the Korean Society of Industry Convergence
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• v.18 no.2
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• pp.75-81
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• 2015

This study proposes an articulated robot control system using an on/off-line robot graphic simulator with multiple networks. The proposed robot control system consists of a robot simulator using OpenGL, a robot controller based on a DSP(TMS320) motion board, and the server/client communication by multiple networks. Each client can control the real robot through a server and can compare the real robot motion with the virtual robot motion in the simulation. Also, all clients can check and analyze the robot motion simultaneously through the motion image and data of the real robot. In order to show the validity of the presented system, we present an experimental result for a 6-axis vertical articulated robot. The proposed robot control system is useful, especially, in the industrial fields using remote robot control as well as industrial production automation with many clients.