레이저 펄스 부호화를 이용한 원거리 고해상도 3D 스캐닝 라이다

김건정,박용완,Kim, Gunzung,Park, Yongwan 한국광학회 2016 한국광학회지 Vol.27 No.4

본 논문에서는 DS-OCDMA(direct sequence optical code division multiple access)와 스캐닝 방식의 MEMS (microelectromechanical system) 거울을 이용하여 픽셀별로 스캐닝하는 라이다 시스템(light detection and ranging, LIDAR)의 설계와 시뮬레이션 결과를 기술한다. 제안하는 라이다는 $848{\times}480$ 해상도의 거리 영상을 1초에 60번 측정한다. 영상을 구성하는 각각의 픽셀마다 픽셀 정보와 체크섬을 DS-OCDMA로 부호화한 레이저 펄스로 방출하므로, 반사파를 검출하기 위하여 대기할 필요없이 연속으로 거리 측정이 가능하다. MEMS 거울은 부호화된 레이저 펄스를 반사하여 측정을 원하는 방향으로 보내기 위한 용도로 사용한다. 하나의 거리 영상을 구성하는 픽셀 정보의 처리가 모두 완료되면, 픽셀 개개의 반사파 비행시간을 이용하여 포인트 클라우드를 생성한다. This paper presents the design and simulation of a three-dimensional pixel-by-pixel scanning light detection and ranging (LIDAR) system with a microelectromechanical system (MEMS) scanning mirror and direct sequence optical code division multiple access (DS-OCDMA) techniques. It measures a frame with $848{\times}480$ pixels at a refresh rate of 60 fps. The emitted laser pulse waves of each pixel are coded with DS-OCDMA techniques. The coded laser pulse waves include the pixel's position in the frame, and a checksum. The LIDAR emits the coded laser pulse waves periodically, without idle listening time to receive returning light at the receiver. The MEMS scanning mirror is used to deflect and steer the coded laser pulse waves to a specific target point. When all the pixels in a frame have been processed, the travel time is used by the pixel-by-pixel scanning LIDAR to generate point cloud data as the measured result.

RSSI를 이용한 향상된 TDOA와 Pattern Matching 간의 선택적 실내 측위에 관한 연구

허수정,김재현,박용완,Hur, Soo-Jung,Kim, Jea-Hyun,Park, Yongwan 대한임베디드공학회 2013 대한임베디드공학회논문지 Vol.8 No.1

This paper researches location estimating method in CDMA system. Previously proposed positioning algorithms are difficult to estimate accurate position in indoor environments, and possible to limited position. This paper proposes enhanced algorithm using received PN pilot signals from base stations to enhance previous algorithms. For estimating position, we set the threshold value and use over the threshold value in received signals. After selecting signals, we estimate position using TDOA algorithm. And the cases which TDOA algorithm cannot use to estimate position, we use Pattern Matching algorithm. The proposed method system showed the improved performance in estimating parameters and locating positions by computer simulations.

2D 라이다 데이터베이스 기반 장애물 분류 기법

이무현,허수정,박용완,Lee, Moohyun,Hur, Soojung,Park, Yongwan 대한임베디드공학회 2015 대한임베디드공학회논문지 Vol.10 No.3

We propose obstacle classification method based on 2D LIDAR(Light Detecting and Ranging) database. The existing obstacle classification method based on 2D LIDAR, has an advantage in terms of accuracy and shorter calculation time. However, it was difficult to classifier the type of obstacle and therefore accurate path planning was not possible. In order to overcome this problem, a method of classifying obstacle type based on width data of obstacle was proposed. However, width data was not sufficient to improve accuracy. In this paper, database was established by width, intensity, variance of range, variance of intensity data. The first classification was processed by the width data, and the second classification was processed by the intensity data, and the third classification was processed by the variance of range, intensity data. The classification was processed by comparing to database, and the result of obstacle classification was determined by finding the one with highest similarity values. An experiment using an actual autonomous vehicle under real environment shows that calculation time declined in comparison to 3D LIDAR and it was possible to classify obstacle using single 2D LIDAR.

다중 안테나 기반 위상 차이를 이용한 AOA 측위 기법

박익현,유국열,박용완,Park, Ik-Hyun,Yoo, Kook-Yeol,Park, Yongwan 대한임베디드공학회 2013 대한임베디드공학회논문지 Vol.8 No.2

In this paper, we have studied the performance of the AOA (Angle of Arrival) in multi-antenna systems for LBS (Location Based Services) and we also analyzed the performance of the AOA in SISO (Single Input Single Output) in multipath environments and their differences. The adequacy of AOA positioning in new communication environments was determined. Currently used positioning methods in 3G communication environment has been developed based on SISO. However, the accuracy of SISO-based TOA (Time of Arrival), TDOA (Time Difference of Arrival), AOA positioning techniques degraded in multipath environments. The communication system will be changed and developed. According to enhanced positioning techniques are required. Using antenna characteristics and the phase difference between antennas of LTE-Advanced standard's key technique MIMO system AOA positioning, and SISO based AOA positioning performance were analyzed. We found that AOA technique potential for use based on Multiple antenna systems by computer simulations.

패턴매칭 알고리즘의 측위 성능 분석 및 데이터베이스 구축 알고리즘을 이용한 정확도 향상 방법

주영환(Yeonghwan Ju),박용완(Yongwan Park) 대한전자공학회 2009 電子工學會論文誌-TC (Telecommunications) Vol.46 No.4

현재 위치기반서비스(LBS : Location Based Service)를 위해 사용되고 있는 위치측위 방식은 GPS 기반의 측위 방식과 이동통신망을 이용한 네트워크 기반의 측위기술들이 있다. 그러나 GPS와 네트워크기반의 측위 방식은 비가시선 효과(NLOS)와 중계기에 의한 전파 지연 발생 때문에 위치측위 정확도가 저하되는 문제점이 있다. 이러한 단점을 보완하기 위해 현재 CDMA 시스템에서는 패턴매칭(Pattern Matching)알고리즘을 사용한다. 패턴매칭 알고리즘은 GPS에 의한 위치측위 시 측정된 RF 신호의 전파 특성을 측위 된 위치와 함께 데이터베이스로 구축하여, 사용자의 측위 요청이 있을 때 수신신호의 전파특성과 데이터베이스를 비교하여 위치를 제공하는 방식이다. 그러나 패턴매칭 알고리즘은 GPS 신호를 수신할 수 없는 음영 지역과 실내에서는 데이터베이스가 구축되어지지 않는다. 패턴매칭 알고리즘은 데이터베이스의 위치 정보가 위치측위를 요청하는 사용자의 위치를 결정하기 때문에 데이터베이스가 구축이 되지 않는 지역에서는 측위정확도의 오차가 발생하게 된다. 따라서 본 논문에서는 현재 CDMA 시스템에서 사용하는 패턴매칭 알고리즘의 위치측위 성능을 분석하고 패턴매칭 알고리즘을 이용한 위치측위 시스템의 성능을 향상시키기 위해서 신호세기 예측 알고리즘을 이용하여 현재 구축이 되지 않은 지역의 데이터베이스를 구축하기 위한 알고리즘을 제안하였다. 제안하는 알고리즘으로 데이터베이스가 없는 지역의 신호세기를 예측하여 데이터베이스를 구축한 후 패턴매칭 알고리즘의 위치측위 성능을 분석하였다. Currently, positioning methods for LBS(Location Based Service) are GPS and network-based positioning techniques that use mobile communication networks. In these methods, however, the accuracy of positioning decreases due to the propagation delay caused by the non-line-of-sight (NLOS) effect and the repeater. To address this disadvantage, the CDMA system uses Pattern Matching algorithm. The Pattern Matching algorithm constructs a database of the propagation characteristics of the RF signals measured during the GPS positioning along with the positioned locations, so that the location can be provided by comparing the propagation characteristics of the received signals and the database, upon a user’s request. In the area where GPS signals are not received, however, a database cannot be constructed. There are problem that the accuracy of positioning decreases due to the area without a database Because Pattern Matching algorithm depend on database existence. Therefore, this paper proposed a pilot signal strength prediction algorithm to enable construction of databases for areas without databases, so as to improve the performance of the Pattern Matching algorithm. The database was constructed by predicting the pilot signals in the area without a database using the proposed algorithm, and the Pattern Matching algorithm analysed positioning performance.

지능형 자동차의 적응형 제어를 위한 차선인식

김현구,주영환,이종훈,박용완,정호열,Kim, Hyeon-Koo,Ju, Yeonghwan,Lee, Jonghun,Park, Yongwan,Jeong, Ho-Yeol 대한임베디드공학회 2009 대한임베디드공학회논문지 Vol.4 No.4

Currently, most automobile companies are interested in research on intelligent autonomous vehicle. They are mainly focused on driver's intelligent assistant and driver replacement. In order to develop an autonomous vehicle, lateral and longitudinal control is necessary. This paper presents a lateral and longitudinal control system for autonomous vehicle that has only mono-vision camera. For lane detection, we present a new lane detection algorithm using clothoid parabolic road model. The proposed algorithm in compared with three other methods such as virtual line method, gradient method and hough transform method, in terms of lane detection ratio. For adaptive control, we apply a vanishing point estimation to fuzzy control. In order to improve handling and stability of the vehicle, the modeling errors between steering angle and predicted vanishing point are controlled to be minimized. So, we established a fuzzy rule of membership functions of inputs (vanishing point and differential vanishing point) and output (steering angle). For simulation, we developed 1/8 size robot (equipped with mono-vision system) of the actual vehicle and tested it in the athletics track of 400 meter. Through the test, we prove that our proposed method outperforms 98 % in terms of detection rate in normal condition. Compared with virtual line method, gradient method and hough transform method, our method also has good performance in the case of clear, fog and rain weather.

시간 선택 채널에서의 QO-STBC를 위한 피드백 결정 검출기

왕우상(Youxiang Wang),박용완(Yongwan Park) 한국통신학회 2009 韓國通信學會論文誌 Vol.34 No.12

원거리 전기 자동차의 다중 충전을 위한 레이저 파워 빔 기반의 무선 전력 전송 시스템

엄정숙,김건정,최정희,박용완,Eom, Jeongsook,Kim, Gunzung,Choi, Jeonghee,Park, Yongwan 대한임베디드공학회 2016 대한임베디드공학회논문지 Vol.11 No.6

This paper presents the design and simulation of a laser power beaming (LPB) system for an electric vehicle that establishes an optimal power transmission path based on the received signal strength. The LPB system is possible to transfer power from multiple transmitters to a single receiver according to the characteristics of the laser and the solar panel. When the laser beams of multiple transmitters aim at a solar panel at the same time, the received power is the sum of all energy at a solar panel. Our proposed LPB system consists of multiple transmitters and multiple receivers. The transmitter sends its power characteristics as optically coded pulses with a class 1 laser beam and powers as a high-intensity laser beam. By using the attenuated power level, the receiver can estimate the maximum receivable powers from the transmitters and select optimal transmitters. Throughout the simulation, we verified the possibility that different LPB receivers were achieved their required power by the optimal allocation of the transmitter among the various transmitters.

Complex Singed-Singed LMS 적응 알고리즘을 사용한 간섭제거 중계기(ICS)연구

이성재(Seongjae Lee),박용완(Yongwan Park),홍승모(Seungmo Hong) 大韓電子工學會 2011 電子工學會論文誌-TC (Telecommunications) Vol.48 No.10

최근 들어 이동통신 서비스가 광범위가 사용되고 서비스 지역이 확대됨에 따라 서비스 품질 유지를 위한 서비스 영역의 확장이 요구 되어 짐에 따라 중계기의 역할은 계속적으로 증가하고 비교적 설치가 용이하고 위치 제약이 적으며 비용 측면에서 운영 비용이 절감되는 ICS(Interference Cancellation System) 중계기가 요구되어진다.. 하지만 적용되어지는 적응 알고리즘의 필터 업데이트 시 연산량의 증가로 인해 하드웨어 복잡도가 증가하게 되어 구현 시 많은 어려움이 따른다. 본 논문에서는 궤환되는 경로가 존재하는 경우. 기저대역 신호처리를 활용한 ICS 중계기에서 궤환 간섭 신호를 제거를 위한 연산량이 대폭줄여 하드웨어 복잡성을 감소시키는 Complex Signed sign LMS 적응 알고리즘을 제안한다. 제안된 알고리즘의 성능 평가를 위해 Static 채널 환경 하에서 WCDMA 신호를 이용하여 ICS 시스템에 대한 알고리즘을 모의실험 한 결과 수렴속도 및 수렴 오차 측면에서 우수한 성능을 통해 구현시 요구되어지는 연산량을 크게 줄여 하드웨어 복잡도를 줄일 수 있는 효과를 볼 수있게 되었다. In recent years mobile communication service is used extensively as a larger service area for the maintenance of quality of service required by the expansion of service areas and As the ever-increasing role in relays and the location is relatively easy to install and less constrained costs operating cost savings in terms of ICS(Interference Cancellation System) repeaters are required. However an adaptive algorithm that is applied when updating the filter due to the increase in volume of operations increase the complexity of hardware implementation is fraught with many difficulties. In this paper if there is a path that feedback. ICS repeater utilizing baseband signal processing for the removal of interfering signals from the feedback operation significantly reducing the amount of reducing hardware complexity Complex Singed Signed LMS adaption algorithm is proposed. Proposed algorithm for evaluating the performance of Static channel WCDMA signal environment for the ICS the results of the simulation algorithm convergence speed and better performance in therms of convergence errors that are required through the implementation of the operation greatly reduces the amount of hardware complexity able to reduce the effect was visible.

지상 라이다 스캐너의 상호 간섭 발생 실험과 특성 분석에 관한 연구

김건정(Gunzung Kim),엄정숙(Jeongsook Eom),박용완(Yongwan Park) 한국통신학회 2015 한국통신학회 학술대회논문집 Vol.2015 No.1