• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.5
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• pp.895-901
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• 2016

Nowadays, the axle counter has been developed to the wide range of the track circuit blocks as well as the wheel detection device. The axle counter, as becoming an important device for the high speed railway, must be guaranteed in accordance with the safety. With considering the safety and the high speed, performance evaluation a wheel detection sensor is described in this paper. To increase the safety, digital proximity sensor instead of analog is employed in the wheel detection sensor. Therefor the wheel detection sensor can minimize noisy signals caused by the harsh railway environments. And, to meet the high speed railway requirements, the performance of the wheel detection sensor is also successfully verified using the speed simulator at the velocity 500Km/h.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.172-177
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• 1998

An experimental study on the prediction of grinding wheel wear by dual detection methods was conducted by the laser displacement and acoustic emission(AE) system. The laser displacement sensor was located above the head of the grinding wheel and the AE sensor was set under the workpiece, where the wheel were condition can be detected. It was found that the dual detection methods by laser displacement system and AE system made it possible to predict the wheel wear. From the experiments, the root mean square(RMS) values both methods was found to be proportional to the grinding wheel wear.

• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.405-407
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• 2000

The most generally implemented method to detect the ground speed of the railway vehicles is to use the rotary type speed sensor attached to wheel axle. The Slip or sliding phenomenon on the railway vehicles occurs frequently caused by the weak viscosity of the wheel. Thus, precisely to control the car, the slip/sliding detection system is required. In this paper we proposed for the speed data management system, which uses rotary type speed sensor. Proposed speed management system can detect the slip/sliding with wheel axle as well as correct the generated speed error during in error time, to provide accurate speed and precise location data. The effectiveness for adapting to the railway system is clarified by the computer simulation.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.45.3-45
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• 2001

This paper deal with a fault detection algorithm for front wheel passenger car systems by using robust $H{\infty}$ control theory. Firstly, we present a unified formulation of vehicle dynamics for front wheel car systems and transform this formulation into state space form. Also, by considering the cornering stiffness which depends on the tyre-road contact conditions, a multiplicative uncertainty for vehicle model is described. Next, the failures of sensor and actuator for vehicle system are defined in which the fault .lter is considered. From the nominal vehicle model, an augmented system includes the multiplicative uncertainty and the model of fault filter is proposed. Lastly by using $H{\infty}$ norm property the fault detect conditions are deefi.ned, and the actuator and sensor failures are detected and isolated by designing the robust $H{\infty}$ controller, respectively.

• International Journal of Contents
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• v.12 no.1
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• pp.44-48
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• 2016

Driver fatigue is a major cause of fatal road accidents and has significant implications in road safety. In recent years, researchers have investigated steering wheel grip force as an alternative method to detect driver fatigue noninvasively and in real time. In this study, a fatigue detection system was developed by monitoring the grip force and changes in the grip force were measured while participants' engaged in an interactive simulated driving task. The study also measured the participants' subjective sleepiness to ensure the validity of measuring grip force. The results indicated that while participants engaged in a driving task, steering wheel grip force decreased and subjective sleepiness increased concurrently over time. The possible applications of the driver fatigue detection system by steering wheel grip force and future guidelines are discussed.

• Journal of Sensor Science and Technology
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• v.7 no.4
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• pp.225-233
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• 1998

The principle, design, and application of a gear-tooth sensor for the rough environmental conditions such as high temperatures of up to $150^{\circ}C$ are studied. The rotation of a tooth wheel is detected by a couple of Hall elements manufactured on the SIMOX wafer by a methode of differential detection using bipolar silicon technology. The product sensitivity of the Hall element is about 510 V/AT over a wide temperature range of $-40^{\circ}C{\sim}150^{\circ}C$. The differential Hall sensor makes the maximum possible distance between sensor and tooth wheel wider than that when single Hall element is used over a wide temperature range, and the maximum detectable distance is 4.5mm at driving current of 4mA.

• Journal of the Korean Society for Railway
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• v.10 no.1 s.38
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• pp.1-6
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• 2007

Railway wheels in service are regularly checked by ultrasonic testing, acoustic emission and eddy current testing method and so on. However, ultrasonic testing is sometimes inadequate for sensitively detecting the cracks in railway wheel which is mainly because of the fact of crack closure. Recently, many researchers have actively fried to improve precision for defect detection of railway wheel. The development of a nondestructive measurement tool for wheel defects and its use for the maintenance of railway wheels would be useful to prevent wheel failure. The induced current focusing potential drop(ICFPD) technique is a new non-destructive tasting technique that can detect defects in railway wheels by applying on electro-magnetic field and potential drops variation. In the present paper, the ICFPD technique is applied to the detection of surface and internal defects for railway wheels. To defect the defects for railway wheels, the sensor for ICFPD is optimized and the tests are carried out with respect to 4 surface defects and 6 internal defects each other. The results show that the surface crack depth of 0.5 mm and internal crack depth of 0.7 mm in wheel tread could be detected by using this method. The ICFPB method is useful to detect the defect that initiated in the tread of railway wheels

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.5
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• pp.1-8
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• 2006

The Steer-By-Wire(SBW) system replaces complex mechanical linkages of the current steering system with electric motors, sensors, and electronic control units. However, the SBW system should guarantee its safety and reliability before commercialization, and therefore, a reliable and robust fault-tolerant technology has to be implemented. This paper proposes a fault-tolerant control algorithm for the SBW system. Based on careful analysis on propagation effects of sensor faults, a reliable fault-tolerant control strategy has been developed. The fault-tolerant controller consists of a fault detection part that monitors and detects faults in the steering wheel and road wheel sensors, and a reconfiguration part that switches to normal sensor signal based on fault detection information. It has been demonstrated by simulation that the proposed algorithm detects sensor faults accurately and enables reliable steering control under various dynamic fault situations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.1043-1044
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• 2010

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.9
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• pp.1324-1328
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• 2013

The reason of train location detection is generally the train interval control between the railway stations and the train path control in the railway station yard in order to avoid train collision. It is very important to know the train location for shortening the train headway, and improving the efficiency of railway maintenance as well as the safe operation of trains. Therefore, the accurate detection of train location is the prerequisite technology in railway signalling system. The track circuit and the wheel sensor of rolling stock have been used to detect the train location widely in urban railway as well as high speed train. The track circuit is continuously monitored by electrical equipment to detect the absence of the train and the tachometer and encoder is used for the wheel sensor to measure the train speed. But speed sensor failures are frequent due to the extremely harsh operating conditions encountered in rail vehicle. The CBTC(Communication based Train Control) system has been used in urban railway system recently. But the installation of CBTC system is very high and the modification of design is difficult. This paper deals with the feasibility of new train location detection method using magnetic sensors.