• 전기학회논문지
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• 제65권5호
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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.

• International Journal of Automotive Technology
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• 제6권5호
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• pp.475-481
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• 2005

This paper deals with the algorithm of estimating the longitudinal speed of a braking vehicle using measurements from an accelerometer and a standard wheel speed sensor. We evolve speed estimation algorithms of increasing complexity and accuracy on the basis of experimental tests. A final speed estimation algorithm based on a Kalman filtering is developed to reduce measurement noise of the wheel speed sensor, error of the tire radius, and accelerometer bias. This developed algorithm can give peak errors of less than 3 percent even when the accelerometer signal is significantly biased.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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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.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.469-477
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• 1996

In order to maintain a constant ratio between the ground wheel and fed shaft of planters, a feedback control unit was designed to drive the feed shaft in proportional to the ground speed. The fifth wheel was used as a ground speed sensor for the control unit. Using this control unit a feed shaft driving system was developed and tested both in the laboratory and field to evaluate it performance . The test results showed that the system drove the feed shaft in proportional to the ground speed in the normal planting speed range of 0.5 -0.8m/s with an error of less than 5%.

• 한국정밀공학회지
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• 제29권6호
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• pp.600-606
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• 2012

Upon investigation of the damaged wheels for high speed train it was determined that the damage was caused by rolling contact fatigue during operation of train. The major problems that railway vehicle system using wheel-rail has to face during operation of railway vehicle are rolling contact fatigue, cracks in wheels, cracks in rails and wheel-rail profile wear. If these deficiencies are not controlled at early stages the huge economical problems due to unexpected maintenance cost in railway vehicle can be happened. Also, If the accurate knowledge of contact conditions between wheel and rail can be evaluated, the damage of wheel can be prevented and the maintenance operation can save money. This paper presents the applicability of electro-magnetic technique to the detection and sizing of defects in wheel. Under the condition of continuous rolling contact fatigue the damage of wheel has continuously monitored using the applied sensor. It was shown that the usefulness of the applied sensor was verified by twin disc test and the measured damaged sizes showed good agreement with the damaged sizes estimated by electro-magnetic technique.

• Journal of Biosystems Engineering
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• 제21권4호
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• pp.399-405
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• 1996

In order to maintain a constant speed ratio between the tractor and attached seed planter, a feedback control unit to rotate the feed shaft of the planter in proportional to the ground speed of the tractor was designed. The fifth wheel was used as a ground speed sensor for the unit. Using this control unit a feed shaft driving system was developed and tested to estimate its performance both in laboratory and fields. The test results showed that the system rotates the feed shaft proportionally to the ground speed in the range of the normal planting speed of 0.5-0.8m/s with errors less than 5%.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.728-732
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• 2004

The purpose of this study is to examine wheel load variations on the bridge. It had been reported that wheel load variations involved un-sprung mass, sprung mass and train running speed, but there are no examples that measured in the running speed actuality track. In this experiment, Attach measurement sensor to equal distance on the track and measured wheel loads by using a dynamic shear strain technique.

• Tribology and Lubricants
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• 제30권3호
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• pp.183-188
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• 2014

In this paper, we present our analysis of tribological failure examples for an anti-lock brake system(ABS) in a car. The study range of this paper is to improve the quality of ABS system by analyzing with sensor, computer, actuator and oil lines. In the first example, the brake leak from hydraulic supply line in a caliper on the rear left side of the ABS hydraulic modulator. This produces the sponge phenomenon, where the car does not brake even when the driver operates the brake pedal. The hydraulic unit operating ABS is actuator that play role regulating drive condition according with the oil pressure supplied with wheel of a car. In the second example, the service man does not completely tighten the fixed bolt after repairing the car. This causes the ABS warning lamp to light up as the ABS wheel speed sensor cannot detect whether the ABS has been activated. In the third example, the ABS electronic control unit is separated from the soldered part of the inner circuit board. Consequently, the ABS fails in control because the ABS motor pump receives no-signal for the hydraulic unit. The wheel speed sensor has to large durability because of giving signal of acting condition to computer by detected the acceleration and deceleration of wheel of a car. In the fourth example, the ABS warning lamp lights up of when cracks propagate in the circuit board soldering part. The circuit of this computer is very important part for input and output the operating signal of system. Such failures can aggravate the durability of the ABS. Thus, the ABS needs to be optimized to eliminate malfunction phenomenon.

• 대한토목학회논문집
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• 제26권3D호
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• pp.461-467
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• 2006

노면에 차량 검지센서를 설치하여 개별차량의 속도자료를 수집하는 경우, 일반적으로 일정거리가 이격되게 설치한 두 개 이상의 차량 검지센서간의 반응시간을 활용하여 차량의 속도를 산출하게 된다. 본 논문에서는 차로당 센서 1개만을 설치하여 개별차량의 속도 산출을 함에 있어, 기존 방법인 파형의 기울기를 이용하여 속도 추정하는 방법(Case 1)과 평균차량길이를 적용한 속도산출(Case2), 새로 고안한 방법인 단일 테이프스위치(Tape Switch) 센서를 수평형으로 설치하고 평균축거를 적용하여 속도 추정하는 방법(Case 3), 그리고 테이프스위치 센서를 사선형으로 설치하고 차량의 평균윤거(Mean of tread)를 적용하여 속도 추정하는 방법(Case 4)에 대한 속도 추정정확도를 평가하였다. 4가지 방식 각각에 대해 현장에서 센서를 설치하고 기준값과 속도추정 값을 비교 분석을 했으며, 평가지표로는 등가계수(Equality Coefficient), 절대오차백분율(MAPE)을 통하여 평가하였다. 평가결과는 Case1 > Case 4 > Case 2, 3 순으로 양호한 결과를 보이는 것으로 분석되었다.

• 한국ITS학회 논문지
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• 제13권1호
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• pp.99-108
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• 2014

최근 들어, 차량 제어 기술의 집약체라 할 수 있는 자율 주행 차량에 관한 관심이 증대되고 있다. 특히, 자율 주행 차량의 안정적인 주행과 직결되는 자기 위치 인식 기술에 관한 연구가 꾸준히 진행되어져 왔으며, GPS가 갖는 한계점을 보완하기 위한 다양한 추측항법 기술이 소개되어져왔다. 하지만 기존의 추측항법들은 추가적으로 센서를 장착해야하는 단점과 차량 거동의 급격한 변화로 인하여 자기 위치 인식 정확도가 떨어진다는 단점을 가진다. 따라서 본 논문에서는 기존의 추측항법의 단점을 보완하기 위하여 대부분의 차량에 장착되어 있는 휠속 센서(Wheel Speed Sensor)를 활용하고, 휠속 센서에서 계측된 값을 토대로 타이어 슬립율(Slip ratio)을 추정하여 차량의 급격한 거동 변화에 대응하기 위한 새로운 개념의 슬립율 기반의 추측항법 알고리즘을 개발하였다. 기존의 추측항법 알고리즘과의 성능을 비교 평가하기 위해서 차량의 거동이 급격하게 변화하는 상황이 포함된 시뮬레이션 환경을 구성하여 그 결과를 비교하였다.