• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.507-509
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• 2023

본 논문에서는 DSP (Digital Signal Processing)를 이용한 차량용 레이다 수평안정화장치 구동 전략을 제안한다. 지대공 유도 미사일용 차량용 레이다는 전방향으로 일정 속도로 회전하며 감시정찰 임무를 수행한다. 수평안정화장치는 4세트의 수평구동모듈을 이용하여 차량 플랫폼의 수평을 유지하여 레이다의 안정적인 회전을 가능하게 한다. 이를 실시간으로 구현하기 위해 임베디드시스템인 DSP를 적용하여 경사도를 측정하고, 구동모듈에 구동 명령을 인가하여 수평을 유지한다. 수평구동모터는 감속기를 통하여 모터 토크를 증가시켜 수평 안정 동작을 수행한다. 본 논문에서는 수평구동모듈 1세트를 모델링하여 수평안정화장치를 축소 구현한다. 제안하는 구동 전략의 유효성은 시뮬레이션으로 입증한다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.7
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• pp.599-605
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• 2017

For an unmanned vehicle to be driven on the off-road terrain, it is necessary to consider the vehicle's stability. This paper suggests a path tracking controller for simulation of real-time vehicle stability analysis. The path tracking controller uses the preview distance to track the given trajectory. The disturbance moment is estimated using the yaw moment observer, and this information is used for compensation in the yaw moment control. On a curved path, the vehicle's desired velocity is determined from the curvature of the path. Because the vehicle is equipped with six independent motor driven wheels, the driving torques are distributed on all the wheels. The effectiveness of the path tracking controller is verified using ADAMS/MATLAB co-simulation.

• The Korean Journal of Rheology
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• v.11 no.2
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• pp.112-121
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• 1999

An MR(Magneto-Rheological) fluids damper is designed and applied to vibration suppression of a 1/4 car model. The damping constant of MR damper changes according to input current which is controlled in a semi-active way. Several control algorithms are compared in simulations and experiments. The advantage of the proposed Frequency shaped LQ control is that passenger comfort is emphasized in the range of 4~8Hz and driving safety is emphasized around the resonance frequency of unsprung mass.

• Journal of Korean Society of Transportation
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• v.26 no.3
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• pp.179-186
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• 2008

It is crucial in traffic flow management to maintain productivity and the traffic stability at the same time especially under congested traffic conditions. This issue has not been explicitly addressed under the intelligent transportation system environments. However, the ubiquitous transportation system environments make it possible to collect the data for each vehicle's position and velocity and to perform more sophisticated traffic flow management at individual vehicle or platoon level through V2V and V2I communications. In this paper, a preventive traffic flow management scheme is proposed, in which the objective is to maintain traffic flow stability while the productivity of the system is not decreased. The management scheme is proposed based on Greenshield's model because it is simple and easy to handle. It is considered that further research should be performed to evaluate the various traffic flow models.

• Proceedings of the KSR Conference
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• 1999.11a
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• pp.574-581
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• 1999

비선형 임계속도를 주행시험대를 이용하여 측정하였으며 비선형 임계속도가 관성에 의한 과도 현상이 아님을 확인하기 위하여 주행속도를 연속 그리고 불연속적으로 감가속 하면서 선형 및 비선형 임계속도를 측정하였다. 또한 차량의 안정성을 간편하게 예측할 때 대차모델만을 사용하던 종래의 방법이 타당한지 확인하였으며 차량의 임계속도와 응답주파수를 예측하기 위하여 산업체에서 사용되던 간편 식들의 정확성을 검토한 결과 다음의 결과를 도출할 수 있었다. (중략)

• Journal of the Korean Society for Railway
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• v.13 no.4
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• pp.363-370
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• 2010

This paper describes the evaluation of structural integrity and dynamic characteristic of inertial load test equipments for performance test of railway vehicle propulsion control system. The propulsion control system of railway vehicle has to be confirmed of safety and reliability prior to its application. Therefore, inertial load test equipments were designed through theoretical equation for performance test of propulsion control system. The structural analysis of inertial load test equipments was conducted using Ansys v11.0 and the dynamic characteristic was evaluated using Adams. The results showed that the structural integrity of inertial load test equipment was satisfied with a safety factor of 10.2 on the bearing part under combined load. Also, the structural stability of flywheel according to dynamic simulation was secured by the maximum oscillation displacement within 0.83mm.

• Journal of Korean Society of Transportation
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• v.27 no.3
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• pp.161-168
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• 2009

The ubiquitous transportation system environments make it possible to collect each vehicle's position and velocity data and to perform more sophisticated traffic flow management at individual vehicle or platoon level through V2V and V2I communication. It is necessary to develop a new traffic management paradigm to take advantage of the ubiquitous transportation system environments. This paper proposed a preventive congestion management algorithm for uninterrupted flow, whose goal is to minimize the incident potential and maximize the productivity by maintaining traffic flow stability. The algorithm includes the following steps: Processing the raw data to produce the 3-dimension speed/flow/density profile and to produce the platoon profile and the shock wave profile, Determining the traffic state and the flow stability based on the processed data, Deciding the desirable speed the according the traffic flow state, and finally Providing the desirable speed information. It remains as further work to perform field experiments and calibrate the algorithm parameters.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06b
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• pp.112-115
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• 2010

차량전장용 소프트웨어에 대한 합리적인 설계 및 테스트가 중요해졌다. 차량전장용 소프트웨어의 신뢰성을 검증하기 위해 AUTOSAR Conformance Test 표준이 마련되었는데, AUTOSAR Conformance Test 표준에는 테스트 대상, 테스트 커버리지, 테스트 요구조건 & 케이스 정의 및 테스트 아키텍처 환경에 대한 정의방법을 기술하고 있다. 본 논문에서는 차량전장용 소프트웨어의 안정성을 테스트하기 위해 소프트웨어가 저장되는 EEPROM 메모리에 대한 시뮬레이션 테스트를 수행하였으며, AUTOSAR 표준에 맞게 제작된 EEPROM Abstraction 시뮬레이션 모듈을 이용하였다. 또한 EEPROM Abstraction 시뮬레이션 모듈 위에서 AUTOSAR Conformance Test 표준에 정의된 적합성 테스트를 수행하기 위한 테스트 어댑터와 타겟 어댑터의 기능을 기술하고, EEPROM Abstraction 시뮬레이션 모듈에서 리얼타임 요소를 만족하기 위해 필요한 개선 사항을 제안하고자 한다.

• Proceedings of the KIEE Conference
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• 2008.04a
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• pp.115-116
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• 2008

최근 급속하게 증가하는 차량과 함께 운전자에게 보다 편리함과 안정성을 제공하기 위하여 첨단 안선 차량(ASV : Advanced Safety Vehicle)에 대한 연구가 활발히 이루어지고 있다. 본 논문에서는 그 중 한 분야인 카메라를 통한 자량 인식으로써, 전방 차량의 그림자를 이용하여 차량을 검출하고자 한다. 실험 절차는 크게 두 가지 단계로 나누어지며, 첫 번째 단계로는, 카메라를 통해 들어오는 도로 영상 이미지를 명도 값을 기반으로 영상을 차례로 분할하여 차량의 그림자를 나타낸다. 두 번째 단계로는, 선행 작업을 통해 얻어진 차량의 수평 그림자 성분을 이미지 안에서 탐색하여 차량의 위치를 검출하게 된다. 이에 제안된 방식을 검증하기 위해 CCD카메라를 이용하여 도로영상을 촬영하고, 컴퓨터 모의실험을 통해 전방차량이 검출됨을 보였다.

• The Journal of Engineering Geology
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• v.31 no.3
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• pp.367-380
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• 2021

This study evaluated the stability through a three-dimensional numerical analysis method when a natural cave exists under a road in operation in Jeju Island. In order to confirm the geometric and geotechnical characteristics of the Jeju natural cave passing under the road, existing geotechnical survey reports were collected, and were studied the characteristics. In order to evaluate the effect of vehicle vibration loading on the natural cave in Jeju, three-dimensional numerical analysis was performed considering discontinuities. Through this, the stability of roads and caves with respect to vehicle speed and the depth of cover (distance from the road to the top of the natural cave) was evaluated and countermeasures were suggested. In order to secure the long-term stability of the Jeju natural cave that penetrates the lower part of the road, it was evaluated that systematic management such as long-term measurement management, reinforcement measures, and emergency measures would be necessary depending on the depth of the cover.