• 대한인간공학회지
• /
• 제28권3호
• /
• pp.63-71
• /
• 2009

A car navigation system as an in-vehicle route guidance information (RGI) offers a state-of-the-art technological solution to driver navigation in an unfamiliar area. However, the RGI is provided by some pre-determined options in terms of the interface between a driver and a car navigation system. Drivers occasionally pass the target intersection owing to non- or late- recognizing it. This paper is examined the position of driver's turn signal operation and intersection recognition approaching at the target intersection which is difficult to identify, as a fundamental research on developing the additional RGI connecting with the turn signal control. The field experiment was conducted to measure distances of the turn signal operation and the intersection recognition from the target intersection according to left turns, right turns, and landmarks at adjacent intersection. And glance behavior to the car navigation display was evaluated by using an eye camera. The results of the field study indicate that, most case of driving, drivers operate the turn signal until 40m to 50m before coming to the target intersection. The driving simulator experiment was performed to examine the effectiveness of providing the additional RGI when drivers did not operate the turn signal approaching at the target intersection based on the results of the field study. To provide the additional RGI is effective for the intersection identification and recognition, and expected to improve the traffic safety and the comfort for drivers.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 하계종합학술대회 논문집(3)
• /
• pp.5-8
• /
• 2002

In this paper, we propose the self-autonomous algorithm for mobile robot system. The proposed mobile robot system controlled by Personal Digital Assistant(PDA) can follow the target at regular intervals. The mobile robot can evaluate the distance between robot and target with ultrasonic sensors, transmits the distance to the PDA. The velocity and direction decided in PDA are transmitted to the mobile robot with wireless LAN communication. Considering the state, velocity-changing and distance-maintenance, of the mobile robot, driving velocity and direction are applied. For safety, the velocity of the mobile robot is changed step by step. As a result, we confirm the ability of following the target with proposed mobile robot.

• Journal of Power Electronics
• /
• 제3권1호
• /
• pp.62-67
• /
• 2003

Recently, photovoltaic system has been studied widely as a renewable energy system, because it does not produce environmental pollution and it has infinity energy source from the sun. A study on photovoltaic system has a lot of problems like as reappearance and repetition of some situation in the laboratory experiment for development of MPPT algorithm and islanding detection algorithm. because output characteristics of solar cell are varied by irradiation and surface temperature of solar cell. Therefore, the assistant equipment which emulates the solar cell characteristics which can be controlled arbitrarily by researcher is require to the researchers for reliable experimental data. In this paper, the virtual implement of solar cell (VISC) system is proposed to solve these problems and to achieve reliable experimental result on photovoltaic system. VISC system emulates the solar cell output characteristics, and this system can substitute solar cell in laboratory experiment system. To realize the VISC, mathematical model of solar cell is studied for driving converter and the DC/DC converters are compared in viewpoint of tracking error using computer simulation. Output dynamic characteristic of PV array is varied by irradiation and PWM converter performance is studied using PSIM simulator.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
• /
• pp.639-643
• /
• 2001

Recently, photovoltaic system has been studied widely as a renewable energy system, because it does not produce environmental pollution and it has infinity energy source from the sun. A study on photovoltaic system has a lot of problems like as reappearance and repetition of some situation in the laboratory experiment for development of MPPT algorithm and islanding detection algorithm, because output characteristics of solar cell are varied by irradiation and surface temperature of solar cell. And this system is consisted a lot of solar cell unit. Therefore, the assistant equipment which emulates the solar cell characteristics which can be controlled arbitrarily by researcher is require to the researchers for reliable experimental data. In this paper, the virtual implement of solar cell (VISC) system is proposed to solve these problems and to achieve reliable experimental result on photovoltaic system. VISC system emulates the solar cell output characteristics, and this system can substitute solar cell in laboratory experiment system. To realize the VISC, mathematical model of solar cell is studied for driving converter and the DC/DC converters are compared in viewpoint of tracking error using computer simulation. And then analysis of parallel and series characteristics was done for combination of VISC model.

• 제어로봇시스템학회논문지
• /
• 제19권11호
• /
• pp.1036-1042
• /
• 2013

In this paper, an elderly assistance system is developed based on Xenomai, a real-time development framework cooperating with the Linux kernel. A Kinect sensor is used to recognize the behavior of the elderly and A-star search algorithm is implemented to find the shortest path to the person. The mobile robot also generates a trajectory using a digital convolution operator which is based on a Bezier curve for smooth driving. In order to follow the generated trajectory within the control period, we developed real-time tasks and compared the performance of the tracking trajectory with that of non real-time tasks. The real-time task has a better result on following the trajectory within the physical constraints which means that it is more appropriate to apply to an elderly assistant system.

• 한국산학기술학회논문지
• /
• 제12권6호
• /
• pp.2793-2800
• /
• 2011

본 연구에서는 범용 이동정보통신기기인 스마트폰을 플랫폼으로 하는 차선이탈경보 애플리케이션을 개발하고 최적화하였다. 최근 안전주행지원 솔루션 중 하나인 차선이탈경보시스템이 상용화되고 있지만, 고성능의 전용 플랫폼을 필요로 하기 때문에 시장에 쉽게 진입하지 못하고 있다. 본 연구에서는 스마트폰인 iPhone 3GS를 플랫폼으로 하는 차선이탈경보 애플리케이션으로 개발하고 처리 속도를 최적화하였다. 효율적인 영상처리를 위해서 OpenCV를 사용하였고, 차선인식을 위해서는 차선의 기하학적 특징을 고려한 Hough Transform 기반의 휴리스틱 알고리즘이 고안되었다. 차선이탈경보 애플리케이션은 매킨토시 컴퓨터에서 Xcode 3.2.4 개발툴을 사용하여 개발되었고, 스마트폰에 다운로드하여 실제 도로에서 실험하였다. 실험결과 1.52fps의 처리 속도를 보였고, 최적화 작업을 통해 처리 속도를 3.84fps까지 향상시켰다. 향후 차선인식 알고리즘 보완, 추가 최적화 작업 및 고성능 스마트폰 플랫폼 채택 등을 통해 스마트폰용 차선이탈경보 애플리케이션을 상용화할 계획이다.

• 한국정밀공학회지
• /
• 제28권11호
• /
• pp.1265-1271
• /
• 2011

These days the number of aged and disabled people is increasing rapidly. But most of the disabled or the aged who have the ability to work, want to engage in economic activities and solve social restrictions as well as their bad financial conditions. This paper concerns about the tracking control of an electric wheelchair robot for welfare vehicle where the seat and electric wheelchair are separated and electric wheelchair robot must be autonomously controlled without the help of assistant. So the aged or the disabled people can drive welfare vehicle by himself by adopting this system. Therefore the concept of both an autonomous driving of electric wheelchair and path tracking robots is required in this system. Finally we suggested fuzzy controller in order to control the path tracking of electric wheelchair robot and compared the capability of the proposed controller with conventional PID controller.

• 경영정보학연구
• /
• 제19권4호
• /
• pp.135-156
• /
• 2017

지능형 개인비서(Intelligent Personal Assistant, IPA)는 다양한 기능을 수행함에도 불구하고 사용자의 실제 이해가 기대보다 낮고 아직은 사용량이 많지 않다는 지적을 받고 있다. 본 연구는 이러한 지능형 개인비서의 사용의도에 영향을 미치는 요인을 밝히기 위하여 기술수용모형(Technology Acceptance Model)과 혁신확산이론(Innovation Diffusion Theory)과 정보시스템 성공모형(Information System Success Model)을 기반으로, 지능형 개인비서의 기능특성을 포함하는 통합 연구모형을 제안하였다. 개발된 통합모형의 가설검증을 위해 지능형 개인비서를 실제 사용하고 있는 사용자들을 대상으로 수집된 203부의 설문 데이터를 PLS 구조방정식을 사용하여 실증분석 하였다. 연구결과, 혁신확산이론에서 도출된 IPA 혁신특성(상대적 이점, 적합성, 관찰 가능성)은 모두 지각된 유용성에 유의한 긍정적 영향을 미치는 것으로 조사되었으며, 정보시스템 성공모형을 통해 도출된 IPA 품질특성(시스템 품질, 정보 품질) 중 정보 품질은 지각된 유용성과 지각된 용이성에 모두 긍정적 영향을 미치는 요인으로 조사되었다. 마지막으로 IPA 기능특성(지각된 지능, 지각된 개인화) 중 지각된 지능 또한 지각된 유용성과 지각된 용이성에 긍정적 영향을 미치며, 지능형 개인비서의 사용의도를 높이는 주요 요인으로 나타났다. 본 연구의 시사점과 향후 연구과제는 연구결과로 정리하였다.

• 정보과학회 논문지
• /
• 제44권1호
• /
• pp.44-50
• /
• 2017

보행자 검출은 수년간 광범위하게 연구된 문제이며, 자율주행 자동차와 운전자 보조시스템에서 매우 중요한 역할을 차지하고 있다. 특히, 계층적 분류기[1]와 Histogram of Gradient[2]특징벡터 등 영상기반의 보행자 검출기법과 ConvNet같이 deep model을 이용하여 검출하는 기법들이 연구되었고 검출성능은 꾸준히 상승하였다. 하지만 보행자 검출은 작은 오차에도 생명과 연관된 문제를 야기할 수 있기 때문에, 자율주행 시스템의 보행자검출 오차율은 더욱 낮출 필요가 있다. 따라서 본 연구에서는 Faster R-CNN 응용 기법에 새로 개발한 데이터 학습 모델을 적용하여 보행자 검출 오류를 줄이는 기법을 제안한다. 그리고 기존에 제안된 모델들과 비교를 통해, 보행자 검출에 있어 제안된 방법의 우수성을 보이고자 한다.

• 로봇학회논문지
• /
• 제11권3호
• /
• pp.172-182
• /
• 2016

Lane-level vehicle positioning is an important task for enhancing the accuracy of in-vehicle navigation systems and the safety of autonomous vehicles. GPS (Global Positioning System) and DGPS (Differential GPS) are generally used in navigation service systems, which however only provide an accuracy level up to 2~3 m. In this paper, we propose a 3D vision based lane-level positioning technique which can provides accurate vehicle position. The proposed method determines the current driving lane of a vehicle by tracking the 3D position of traffic signs which stand at the side of the road. Using a stereo camera, the 3D tracking paths of traffic signs are computed and their projections to the 2D road plane are used to determine the distance from the vehicle to the signs. Several experiments are performed to analyze the feasibility of the proposed method in many real roads. According to the experimental results, the proposed method can achieve 90.9% accuracy in lane-level positioning.