• 한국산업정보학회논문지
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• 제22권5호
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• pp.25-30
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• 2017

본 논문에서는 초음파 센서를 이용한 저비용 장애물 인식 장치를 개발한다. 개발된 장애물 인식 장치는 시각 장애인들이 보행시 장애물을 인식하는 데 쓰일 수 있도록 한다. 장애물의 인식 여부는 내장된 모터의 진동을 통하여 시각 장애인들에게 인식이 가능하도록 한다. 뿐만 아니라 장애물의 거리에 따라 대상자에게 장애물 인식 유무에 대해 시간차를 두고 고지하여 대상자가 장애물에 대해 적절한 반응을 수행할 수 있도록 한다. 마이크로 컨트롤러 제어를 통한 펄스 신호를 이용하여 장애물에 대한 반사파를 통해 장애물의 존재 유무와 거리를 탐지하며 펄스 신호를 이용한 반사파 탐지는 반복 수행을 통해 인식률을 높인다. 개발된 장애물 인식 장치는 $30^{\circ}$ 내외의 전방 탐지각을 나타내고, 2cm-30cm의 탐지거리를 가지며 일상적인 보행 조건에서 동작이 가능함을 실험을 통해 입증하였다.

• 한국도시철도학회논문집
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• 제6권4호
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• pp.269-278
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• 2018

철도용 지장물검지장치는 2004년 고속철도와 함께 도입되어 산사태, 낙석 및 과선교로 부터의 낙하물과 같은 장애물에 의한 사고를 예방하고 있다. 다만 기존의 시스템은 검지선의 단선 여부에 대한 사항밖에 검지가 불가능 하여 산사태나 과선교 위로의 물체 낙하 등에 대한 검지에 제약이 있는 것이 사실이다. 이에 이번 연구에서는 OTDR, 광펜스 및 검지용 카메라로 구성되어 개선된 지장물검지시스템을 제안한다. 이 연구에서 제안하는 시스템은 단선 상태에 대한 검지 이외에도 광펜스에 대한 가압 및 특정지역에 대한 영상 검지가 가능하도록 구성된다. 개발 시스템의 핵심부인 광펜스 및 OTDR에 대한 프로토타입 시작품을 제작하고 기능시험을 실시하였으며, 개선된 검지 능력을 입증하기 위한 결과들을 획득하였다. 추후 연구에서는 현장함 설계 및 환경시험을 실시할 예정이며 이후 현장 시험을 진행할 예정이다.

• 제어로봇시스템학회논문지
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• 제9권12호
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• pp.1009-1018
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• 2003

In a park or street, we can see many people Jogging or walking with their dogs chasing their masters. In the previous study, an entertainment robot, CARTRI that imitates the dog's behavior was created. The robot's task was chasing a moving goal that was recognized as the master. The physical structure of the CARTRI robot was three-wheel type locomotion system. The sensor system which could detect the position of the master in the outdoor space, was consists of a signal transmitter which was held by the master and five ultrasonic receivers which were mounted on the robot. In the experiment, the robot could chase a human walking in outdoor space like a park. But it could not avoid obstacles and its behavior was only goal-chasing behavior because of the limit of the sensor system. In this study, an improved RF-ultrasonic sensor system which can detect both goal and obstacle is developed in order to enable the CARTRI robot to carry out various behavior. The sensor system has increased angle resolution by using eight ultrasonic receivers instead of five in the previous study. And it can detect obstacle by using reflective type ultrasonic sensors. The sensor system is designed so that detection of goal and obstacle could be conducted in one sampling period. The Performance of the developed sensor system is evaluated through experiments.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.454-457
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• 2004

AGV for FMS must be detected an obstacle. Therefore, many studies have been advanced, and recently, the ultra sonic sensor is used for this. However, the new method has to be developed because the ultra-sonic-sensor has many problems as a noise in factory, an directional error and detection of the obstacle size. So, we study the fast stereo vision system that can give more information to obstacles for intelligent AGV system. For this, the simulated AGV system was made with two CCD cameras in front to get the stereo images, and the threshold process by color information (intensity and chromaticity) and structure stereo matching method were constructed.

• 한국정밀공학회지
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• 제25권2호
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• pp.65-71
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• 2008

In this paper, we propose a new driving mode control algorithm for a mobile robot based on obstacle detection. The robot has a variable geometry single-tracked mechanism, so it can maximize a contact length with ground for the adaptability to off-road and puesue a stable system due to the lower center of gravity. However this robot system embodied passive type according to operator. In this reason, several problems are detected. So, this research presents a new method of obstacle detection using PSD infrared sensors and translates the variable tracks on the best suited driving mode actively. And experimental results about mentioned are presented.

• 전기학회논문지
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• 제62권12호
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• pp.1813-1819
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• 2013

Existing level crossing obstacle detecting system was installed using a laser beam. Level crossing obstacle detecting system using a laser beam that has been a problem in relation to safety and maintainability failure according to weather conditions. We proposed laser radar level crossing obstacle detecting system as a way to overcome problem, and we developed an algorithm for this. Level crossing obstacle detecting system using a laser radar sensor algorithm is robust to external environment and a shadow zone does not exist. Sensor part of the laser radar level crossing obstacle detecting system of these is made up by the image processing unit and laser radar sensor, it operations by receiving train entering information from the control unit. In this paper, we proposed a detecting algorithm with calculation of the size of the laser radar sensor. Based on this, we were performance test on the basis of the scenario by making a prototype. In the future, laser radar level crossing obstacle detecting system to ensure the safety and reliability through the field test.

• 전자공학회논문지S
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• 제34S권11호
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• pp.126-137
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• 1997

This paper describes the algorithm which can estimate road following direction and deetect obstacle using a monocular vision system. This algorithm can estimate the course of vehicle using the vanishing point properties and detect obstacle by statistical method. The proposed algorithm is composed of four steps, which are lane prediction, lane extraction, road following parameter estimation and obstacle detection. It is designed for high processing speed and high accuracy. The former is achieved by a small area named sub-windown in lane existence area, the later is realized by using connected edge points of lane. We would like to present that the new mehod can detect obstacle using the simple statistical method. The paracticalities of the processing speed, the accuracy of the algorithm and proposing obstacle detection method, have been justified through the experiment applied VTR image of the real road to the algorithm.

• 대한의용생체공학회:의공학회지
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• 제29권5호
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• pp.384-391
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• 2008

For use in the guide system for the people who are visually impaired, an obstacle searching device using synchronous ultrasonic wave emission was proposed and developed. Generally, the conventional obstacle detection methods use the ultrasonic distance measuring device with successive scan method. However, the scan method causes a theoretical error and it couldn't estimate accurate obstacle distances. The proposed synchronous firing method use the plural number of ultrasonic sensors which emit ultrasonic wave simultaneously and estimate the distance to the closest obstacle relatively accurately. We analytically analyzed the errors of the conventional and proposed methods and compared the quantitative differences of the errors. The differences verified by obstacle search experiments. Using the proposed ultrasonic wave synchronous firing method, 3 dimensional obstacle location estimating device was designed and implemented. The results of the 3 dimensional obstacle detecting experiments showed the proposed method had good performances and it would be sufficiently use in the guide system for the people who are visually impaired.

• 한국항공운항학회지
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• 제5권1호
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• pp.65-79
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• 1997

본 연구에서는 항공기의 지상활주에 필요한 측방 경보장치를 구현 하였다. 장치는 장애물 검출부, 송신부, 수신부, 그리고 경보부로 구성하였다. 장애물 검출부는 40KHz대의 초음파에 의한 펄스비행법을 채택하였고 송/수신부는 447 MHz 대의 RF모듈을 사용하였다. 경보부는 컴퓨터를 사용하여 수신된 거리 데이터로부터 경보를 한다. 검출장치는 주날개의 좌우측 끝과 수평 안정판의 좌/우측 끝에 장착한다. 장애물 검출거리는 10m로 설정하였다. 실험 결과 만족한 결과를 얻을 수 있었다.

• 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.