• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.8
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• pp.570-578
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• 1988

In order for a robot to carry out a precise assembly task with compliant motion, a force/torque sensor is needed. The output of the cross-bar structured force / torque sensor which is used in a peg-in-hole insertion task and attached to a SCARA type robot, is analzed. First, the relationship between the sensor outputs and the force / torque components obtained by the outputs is investigated. Second, in a peg-in-hole insertion task, the sensor outputs changing with the contact position of the peg and the hole, are analyzed. Also, the relative position of the peg and the hole is obtained from the sensor outputs. The peg-in-hole insertion task is successfully executed, using a SCARA type robot with a wrist force / torque sensor manufactured in our laboratory and the compliance algorithm from the results of this paper.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.162-162
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• 2000

We describe a new optical-type guide sensor for AGV. It is robust the disturbance of the light. The developed optical-type guide sensor is very useful in the clean room environment where the light disturbance is very critical through the hole on the surface of the floor.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.2
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• pp.83-90
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• 2004

This paper describes investigations of the UHF(Ultra High Frequency) PD(Partial Discharge) measuring technology designed for monitoring of PD in high power apparatus. Based on the spiral antenna theory, the hole type sensor for GIS with metal flange spacer and injection type sensor for oil filled transformer are developed. The experimental results show measurement characteristics of the PD sensor for several artificial defects in gas-insulated system(GIS) and oil transformer. Moreover, we proposed the new $\phi$-f-q method for the purpose of condition assessment of high power apparatus.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.9
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• pp.1248-1255
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• 2003

Pressure coefficient in a rotating discharge hole was measured to gain insight into the influence of rotation on the discharge characteristics of rotating discharge holes. Pressures inside the hole were measured by a telemetry system that had been developed by the authors. The telemetry system is characterized by the diversity of applicable sensor type. In the present study, the telemetry system was modified to measure static pressure using piezoresistive pressure sensors. The pressure sensor is affected by centrifugal force and change of orientation relative to the gravity. The orientation of sensor installation for minimum rotating effect and zero gravity effect was found out from the test. Pressure coefficients in a rotating discharge hole were measured in longitudinal direction as well as circumferential direction at various rotating speeds and three different pressure ratios. From the results, the behaviors of pressure coefficient that cannot be observed by a non-rotating setup were presented. It was also shown that the discharge characteristics of rotating discharge hole is much more influenced by the Rotation number irrespective of pressure ratio.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1638-1640
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• 2003

In the recent years, UHF PD measuring technique for detecting partial discharges was proved the effective method for Gas Insulated Switchgear (GIS). However, in case of GIS with a metal flange around insulating spacer, UHF PD measurement using typical external UHF PD sensor is difficult. In this paper, a novel hole-type UHF PD sensor based on Archimedean spiral antenna theory has been proposed and realized. All spacers with metal flange have small hole in order to inject epoxy. Using the novel hole-type UHF PD sensor, it makes detection possible to PD signal that are emitted through the epoxy injection hole. Additionally, the measuring characteristic of UHF PD signals from several artificial defects in GIS and the novel ${\Phi}$-f-q pattern analysis technology are discussed.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.410-413
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• 1993

Chamferless peg-in-hole process of the cylindrical type parts using force/torque sensor and vision sensor is analyzed and simulated in this paper. Peg-in-hole process is classified to the normal mode (only position error) and tilted mode(position and orientation error). The tilted mode is sub-classified to the small and the big tilted mode according to the relative orientation error. Since the big tilted node happened very rare, most papers dealt with only the normal or the small tilted mode. But the most errors of the peg-in-hole process happened in the big tilted mode. This problem is analyzed and simulated in this paper using the force/torque sensor and vision senor. In the normal mode, fuzzy logic is introduced to combine the data of the force/torque sensor and vision sensor. Also the whole processing algorithms and simulations are presented.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.244-248
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• 1987

The force/torque sensor for robot is developed. The compliance algorithm for peg-in-hole insertion task using the forec/troque sensor is developed. The system consists of an IBM PC, robot, force/torque sensor, strain meter, A/D board, and interface board. The IBM PC functions as a main processor and the robot controller as a slave processor. The sensor is constructed to measure $T_x$, $T_y$, $F_z$ which are necessary to precisely execute a peg-in-hole insertion task by SCARA type assembly robot. The outputs of sensor are analyzed. On the basis of the analysis, compliance algorithm for peg-in-hole insertion task is developed. Some comments concerning the development of wrist force/torque sensor and compliance algorithm are given.

• Korean Journal of Materials Research
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• v.29 no.12
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• pp.764-773
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• 2019

The gas response characteristic toward C₂H₅OH has been demonstrated in terms of copper-vacancy concentration, hole density, and microstructural factors for undoped/Li(I)-doped CuO thin films prepared by sol-gel method. For the films, both concentrations of intrinsic copper vacancies and electronic holes decrease with increasing calcination temperature from 400 to 500 to 600 ℃. Li(I) doping into CuO leads to the reduction of copper-vacancy concentration and the enhancement of hole density. The increase of calcination temperature or Li(I) doping concentration in the film increases both optical band gap energy and Cu2p binding energy, which are characterized by UV-vis-NIR and X-ray photoelectron spectroscopy, respectively. The overall hole density of the film is determined by the offset effect of intrinsic and extrinsic hole densities, which depend on the calcination temperature and the Li(I) doping amount, respectively. The apparent resistance of the film is determined by the concentration of the structural defects such as copper vacancies, Li(I) dopants, and grain boundaries, as well as by the hole density. As a result, it is found that the gas response value of the film sensor is directly proportional to the apparent sensor resistance.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2265-2267
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• 2005

We present detailed studies of externally applicable UHF PD sensors for a metal covered epoxy barrier with a small opening of epoxy injection-hole. The sensors were attached at the surface of injection hole of a metal covered epoxy barrier. 3-Dimensional electro magnetic simulations were performed to analyze electric-field distribution of the GIS and epoxy barrier with injection hole. Sensor structures were designed and analyzed using the 3-D EM simulator then fabricated for experimental verification. Sensor performance was measured in terms of spectral response and detected peak power. Real scale GIS and epoxy barriers were used to test and measure various aspect of performance of the sensors.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.3
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• pp.80-86
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• 2008

Recently, controlled auto ignition(CAI) in gasoline engines are drawing more attentions due to its extremely low level of NOx emissions and potentials in lowering the fuel consumption rate. The one of the key techniques for realizing CAI combustion in engines is the control of valve system. Since the valve linkage system with higher complexity, or even earn-less valve systems, such as electro-hydraulic and electro-magnetic system, are adopted in CAI engines, it is not easy to estimate the valve lift profile from earn profiles. Therefore new measurement techniques for valve lift in CAI engines have been tried and tested. In this paper, hole type valve lift sensor was developed and tested to check the applicability in CAI engines. The valve lifts could be obtained from the sensor signal, which depends on the distance from the sensor to magnet attached to valve. Various engine speeds, ranging from 2,000 to 6,000 rpm, and valve lifts, maximum up to 9.7 mm, were tested. It was found that the sensor output for valve lift had accuracy of 98% in comparison with the basic specifications of valve lift through improvements of sensor driving circuit.