Steering Performance Evaluation of Active Steering Bogie to Reduce Wheel Wear on Test Line

허현무,신유정,안다훈,함영삼 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.9

When a railway vehicle runs on a curved section, wear of wheels and rails occur. This is due to the attack angle of the wheel on the rails that occurs because the steering function of the bogie is insufficient. To overcome these problems, we developed an active steering bogie equipped with an electro-mechanical type of active steering system. The prototype of active steering bogie was manufactured and installed on a test train that operated in sections with many curved sections. Steering performance tests for the test train were carried out on commercial line as the test line. As a result of the test, the performance of curvature radius estimation of the active steering bogie showed a very good performance, with only 2.4% error compared with the track design value. The performance of steering angle implementation of the passive bogie running on the curved section is very poor, but that of the active steering bogie is very good. And the lateral force of the wheel, which is directly related to the wheel wear when running on the curved section, showed a maximum 88.1% reduction of the lateral force. Therefore, considering the test results of the active steering bogie in the test line, the steering performance of the active steering bogie developed for reducing the wheel and rail wear is evaluated to be very good. And the wear of wheel measured after test run was 0.54 mm flange wear in passive bogie, but flange wear was not occurred in active steering bogie.

대차 주행시험대상에서의 윤축 거동에 대한 연구

허현무,박준혁,유원희,박태원 대한기계학회 2007 環境管理學會誌 Vol.2007 No.5

The critical speed of railway bogie related to the stability of the railway rolling-stock is important. Testing of the dynamic performance of bogie is conducted using a roller rig in a laboratory in place of field testing on track. This roller rig is composed of two rollers equivalent to track and used to test the dynamic characteristics of vehicle. But, the geometrical characteristics of the wheel/roller contact on the roller rig are different from those of the wheel/rail contact because the longitudinal radius of roller is not infinite compared with rail. This difference has influence on the wheelset behavior and the critical speed of bogie. Therefore in this paper, we have studied the behavior of wheelset and bogie on the roller rig for railway bogie testing with the purpose of developing the scaled roller rig. As an analysis results, it has been shown that the critical speed of bogie on the roller rig is slightly lower than that of bogie on track.

철도차량용 댐퍼 고장 진단방법 제안 및 진단 성능 평가

허현무 한국철도학회 2021 한국철도학회논문집 Vol.24 No.4

Condition-based maintenance technologies are applied for efficient maintenance and are directly related to railway vehicle operation safety. In particular, railway vehicle dampers are a core component of the suspension system, and this directly impacts on dynamic stability, vibration, and the ride comfort of vehicles. Normal-state maintenance is always essential. For condition-based damper maintenance, it is important to develop diagnostic technologies that can diagnose abnormalities or faults of dampers in real time. Here, we propose a practical diagnostic method to diagnose faults by analyzing the damping performance of dampers in real time while operating under a vehicle-mounted state, which is completely different from traditional vehicle dynamics model-based diagnostic methods or from statistical analysis based on fault data. Self-diagnostic damper prototypes and diagnostic processors were manufactured, and fault diagnosis performance was evaluated for damper prototypes that imitate faults. As a result, the diagnostic rate representing the normal ratio of the total measurement data was 96.5% for normal dampers, 66.4% for abnormal dampers with distortion of the attenuation force, and 0% for fault dampers with no attenuation force. It is therefore confirmed that the proposed damper fault diagnostic method is valid by showing excellent fault diagnostic performance.

철도차량 능동조향기술 적용에 따른 주행안전성 평가

허현무,신유정,안다훈,함영삼,박준혁,이재찬 한국철도학회 2019 한국철도학회논문집 Vol.22 No.4

In order to analyze the effect of active steering on running behavior when using active steering technologyto improve poor steering performance of existing railway vehicles, a test run with an active steering bogie was conducted. As a result of the test, it was found that the lateral force and derailment coefficient of the wheel tend to decreasesignificantly due to the active steering control. Especially, the reduction effect is large in curved sections with smallradius of curvature. According to the active steering control, the derailment coefficient is remarkably reduced to aboutone third of that of the passive state. The wheel lateral force is significantly reduced and the lateral force distributionis distributed to a more stable region than is the case in the passive state. Although the wheel unloading ratio with activesteering control did not change much, the reduction of the wheel unloading ratio was slightly improved. Therefore, ithas been confirmed through experiments that active steering technology has the effect of not only reducing the transversepressure in curved sections but also improving derailment safety.

로봇의 최소시간계획을 위한 알고리듬의 개선 및 실험

허현무,김호룡 대한기계학회 1990 대한기계학회 춘추학술대회 Vol.- No.-

소음 진동 및 마모 저감을 위한 차륜답면형상 설계

허현무 한국소음진동공학회 2007 한국소음진동공학회 세미나 Vol.2007 No.6

자동차 실내소음 저감을 위한 능동소음제어 시스템 개발 및 성능시험연구

허현무,홍석윤 한국소음진동공학회 1995 한국소음진동공학회 강습회 Vol.1995 No.9

객차의 현가장치 변수가 상하진동에 미치는 영향

허현무,권영필,최경진,Hur, Hyun-Moo,Kwon, Young-Pil,Choi, Kyung-Jin 대한기계학회 2002 大韓機械學會論文集A Vol.26 No.7

The purpose of this study is to analyze the effects of the parameters of the suspension system in railway rolling-stock for KT-23 type passenger vehicle. According to the results of simulation and the field test, Optimal condition was obtained for the stiffness ratio of the primary spring and the secondary of the suspension system. When the stiffness ratio was increased, the vibration was increased on the car body and decreased on the bogie, and ride quality are getting worse because of increase of the vertical natural frequency of the car body. The results of this study are usefull to improve the technology of the ride quality of KT-23 type vehicle.

Steering Performance Evaluation of Active Steering System for a Railway Vehicle by Simulating Real Track Running

허현무,안다훈,신유정 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.10

An active steering system was developed to solve problems such as severe wheel, rail wear, noise and dust generation due to insufficient steering performance of EMU running on an urban railroad section with a large number of curved sections. An electromechanical type active steering system for EMU was designed and a prototype was manufactured. As a result of the performance test of the components for the active steering system, the target design specification was satisfied. Prior to the performance test with test vehicle equipped with the active steering system on test track, the steering control test simulating real track running was conducted, excellent steering performance was noted. The thrust force of the driving unit was also shown to be below the maximum thrust force of the prototype throughout most parts of the track. These results confirm that the simulation test can predict the feasibility of the steering control on the test track for the active steering test vehicle through this simulation test.

전동차 현가구조에 따른 동적거동특성 분석

허현무,노학락 한국산학기술학회 2020 한국산학기술학회논문지 Vol.21 No.11

Urban railroad vehicles carry many passengers and are the core of an urban railroad transportation system. Therefore, the dynamic performance of the vehicle must be ensured. Dynamic behaviors such as the vibration and ride comfort of railway vehicles are affected by the structure of the suspension system. We analyzed the dynamic behavior of a railway vehicle according to the suspension system of an urban railway vehicle, which is mainly operated in Korea. For two types of vehicles with different suspension structures, the vibration of the vehicles on railway tracks was measured, and dynamic behavior characteristics such as vibration, ride, and vibration reduction rate were analyzed. The result of the test shows that the vibration performance of the body is superior to that of B-bogie in the lateral direction and that of A-bogie in the vertical direction. Overall, the ride quality of the A-bogie car is superior to that of B-bogie. When analyzing the vibration attenuation rate of primary suspension system, the vibration attenuation performance of B-bogie with coil spring was superior to that of A-bogie with a conical rubber spring. The secondary suspension system has better vibration attenuation performance for A-bogie with air springs compared to coil springs. 다수의 승객을 운송하는 도시철도 전동차는 도시 철도교통시스템의 핵심이다. 따라서 차량의 동적성능이 확보가 차량 안전 확보 및 승객서비스 차원에서 선행되어야 한다. 철도차량의 진동, 승차감과 같은 동적거동은 현가시스템 구조 및 현가요소에 따라 크게 영향을 받는다. 철도차량의 현가시스템은 윤축과 대차간 1차현가시스템, 대차와 차체간 2차현가시스템으로 구성되어 있다. 본 논문에서는 국내에서 운용되고 있는 전동차 현가구조에 따른 전동차의 동적거동에 대하여 분석하고자 한다. 현가구조가 상이한 2종류의 전동차에 대하여 실제 선로에서 동일 주행조건으로 주행시험을 수행하였으며 차량의 진동을 계측하였고 진동과 승차감, 진동감쇠율과 같은 동적거동 특성을 분석하였다. 시험결과, 차체 진동성능은 좌우방향은 B대차가, 상하방향은 A대차가 상대적으로 우수하게 나타났다. 승차감은 전반적으로 A대차가 B대차에 비하여 우수하게 나타났다. 진동감쇠율을 보면, 1차현가시스템은 고무스프링이 적용된 A대차에 비하여 코일스프링이 적용된 B대차의 진동감쇠 성능이 우수하며 2차현가시스템은 코일스프링에 비하여 공기스프링이 적용된 A대차의 진동감쇠 성능이 우수하다. 본 논문의 결과는 향후 철도차량 신차 설계 과정에서 현가구조 설계 및 현가요소 선정 시, 유용한 자료로 활용될 것이라 기대된다.