• International Journal of Automotive Technology
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• 제7권3호
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• pp.315-320
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• 2006

We have developed an active front steering system(AFS) with a planetary gear train, which can vary the steering gear ratio according to the vehicle speed and improve vehicle stability by superimposing steering angle. We conducted vehicle tests showing that co-operated control of AFS with ESP can improve vehicle stability by direct control of tire slip angle and that steering reaction torque during AFS intervention can be compensated by torque compensation using electric power steering.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 전력전자학술대회 논문집
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• pp.17-18
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• 2014

전기자동차는 내연기관 대신 배터리를 동력으로 하여 전기모터를 구동하는 방식으로, 배터리를 충전하기 위해서는 차량 탑재형 충전기(OBC)가 필요하다. 자동차라는 특성상 OBC는 2단 AC/DC 컨버터로 구성되어 있다. 역률 보정을 위한 PFC 단과 절연과 충전을 위한 DC/DC 컨버터로 구성되어 있다. 손실을 최소화하기 위해 고전압을 이용한 링크 캐패시터가 필수적이고, 그 캐패시터는 전력밀도가 큰 고전압 전해 캐패시터가 사용된다. 하지만, 전해 캐패시터는 그 수명이 온도와 리플 전류에 따른 ESR 발열과 주변온도에 따라 좌우된다. 따라서 본 논문에서는 6.6kW 차량용 탑재형 충전기를 위한 링크 캐패시터용 고전압 전해 캐패시터의 최적 설계 방법을 제안한다.

• 한국자동차공학회논문집
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• 제22권3호
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• pp.143-147
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• 2014

The ECU which is operating inductive actuator like motor or solenoid should be designed with considering the heat removal performance and the EMC performance. In most cases, these two performances are trade-off. Especially, the metal cover with plastic housing for improving heat removal performance can affect EMC performance by coupling the noise source to harness cable and connector. Therefore, after analyzing the EMC effectiveness of the metal cover, countermeasures for EMC noise reduction should be established. In this paper, by simulating and testing of AHB Gen3 ECU, the influence of the metal cover to EMC performance is analyzed. And based on this result, we propose solutions for EMC noise reduction.

• 오토저널
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• 제31권2호
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• pp.42-51
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• 2009

• International Journal of Automotive Technology
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• 제8권4호
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• pp.493-504
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• 2007

This paper proposes a stereo vision-based forward obstacle detection and distance measurement method. In general, stereo vision-based obstacle detection methods in automotive applications can be classified into two categories: IPM (Inverse Perspective Mapping)-based and disparity histogram-based. The existing disparity histogram-based method was developed for stop-and-go applications. The proposed method extends the scope of the disparity histogram-based method to highway applications by 1) replacing the fixed rectangular ROI (Region Of Interest) with the traveling lane-based ROI, and 2) replacing the peak detection with a constant threshold with peak detection using the threshold-line and peakness evaluation. In order to increase the true positive rate while decreasing the false positive rate, multiple candidate peaks were generated and then verified by the edge feature correlation method. By testing the proposed method with images captured on the highway, it was shown that the proposed method was able to overcome problems in previous implementations while being applied successfully to highway collision warning/avoidance conditions, In addition, comparisons with laser radar showed that vision sensors with a wider FOV (Field Of View) provided faster responses to cutting-in vehicles. Finally, we integrated the proposed method into a longitudinal collision avoidance system. Experimental results showed that activated braking by risk assessment using the state of the ego-vehicle and measuring the distance to upcoming obstacles could successfully prevent collisions.

• 한국자동차공학회논문집
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• 제17권3호
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• pp.54-61
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• 2009

Lane keeping assistant system (LKAS) could save thousands of lives each year by maintaining lane position and is regarded as a promising active safety system. The LKAS is expected to reduce the driver workload and to assist the driver during driving. This paper proposes a model based predictive controller for the LKAS which requires cooperative driving between the driver and the assistance system. A Hardware-In-the-Loop-Simulator (HILS) is constructed for its evaluation and includes Carsim, Matlab Simulink and a lane detection algorithm. The single camera is mounted with the HILS to acquire the monitor images and to detect the lane markers. The simulation is conducted to validate the LKAS control performance in various road scenario.

• 한국자동차공학회논문집
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• 제17권1호
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• pp.50-57
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• 2009

Lane Keeping Assistant Systems (LKAS) require the cooperative operation between drivers and active steering angle/torque controllers. An LKAS is proposed in this study such that the desired reference path generation (DRPG) system generates the desired path to minimize the trajectory overshoot. Based on the reference path from the DRPG system, an optimal controller is designed to minimize the cost function. A HIL (Hardware In the Loop) simulator is constructed to evaluate the proposed LKAS system. The single camera is mounted on the simulator and acquires the monitor images to detect lane markers. The performance of the proposed system is evaluated by HIL system using the Carsim and the Matlab Simulink.

• 한국멀티미디어학회논문지
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• 제21권9호
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• pp.1099-1109
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• 2018

Most of the automotive electronic systems are equipped with control software. ISO 26262 standard has been published to prevent unreasonable risk due to E/E system malfunction. And many automotive companies apply ISO 26262 for safe series product. In ISO 26262 standard, the product quality improves through deductive and inductive safety analysis in all processes including system and software development phase. However, there are few studies on software safety analysis than systems. In the paper, we study the software FMEA(Failure Mode Effect Analysis) technique for product quality of vehicular embedded software. And we propose an effective guideline of software FMEA as EPB industrial practice.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2018년도 추계학술발표대회
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• pp.37-38
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• 2018

자동차 시스템의 전자화로 자동차에서 소프트웨어가 차지하는 비중은 점차 증가하고 있다. 소프트웨어는 안전필수 시스템에서 중요한 위치를 차지하며, 소프트웨어의 오동작은 심각한 손실 또는 재난을 일으키는 원인이 될 수 있다. 최근 자동차 시스템은 자율주행차량을 목표로 하여 센서융합과 협조제어가 많아지고 있다. 센서와 협조제어 정보는 시스템의 자율화에 중요한 부분을 차지하지만 현재 산업구조에서는 관련 부분에 대한 검증이 쉽지 않다. 본 논문에서는 현재 상황에서 발생할 수 있는 현상들을 살펴보고 안전한 자동차 개발을 위해 우리가 나아가야 할 방향을 고찰한다.

• 대한기계학회논문집A
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• 제41권5호
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• pp.421-426
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• 2017

본 연구에서는 횡등방성 특성을 갖는 인쇄회로기판(PCB)의 물성 예측을 위한 방법을 제안하였다. 등방성 소재와 달리 횡등방성 소재의 물성 취득을 위한 별도의 시험기준은 없으며, PCB와 같이 적층된 형태의 박판 구조물에 대해서는 재료시험 또한 쉽지가 않다. 모달시험을 통해 취득한 모달 파라미터와 상용 소프트웨어인 $OptiStruct^{(R)}$의 치수 최적화 기법을 활용, 시험-해석 간 주파수 차이를 최소화시키는 강성행렬 성분을 도출하여 기계적 물성을 예측하였다. 또한 주파수 별 모드형상을 MAC(Modal Assurance Criteria) 값을 기준으로 비교, 검토하여 예측 물성에 대한 유효성을 확인하였다. 제안된 방법은 향후 PCB를 포함하는 전장제품의 설계검증을 위한 구조해석에 확대 적용될 것으로 기대한다.