Stepwise 동기화 지원을 위한 CMOS 이미지 센서 Firmware 설계 및 개발

박현문,박수현,이명수,서해문,박우출,장윤정,Park, Hyun-Moon,Park, Soo-Huyn,Lee, Myung-Soo,Seo, Hae-Moon,Park, Woo-Chool,Jang, Yun-Jung 한국시뮬레이션학회 2008 한국시뮬레이션학회 논문지 Vol.17 No.4

최근 CMOS 이미지 센서가 저전력, 저가격, 소형화를 이루면서 이를 이용한 하드웨어 및 응용 소프트웨어 연구가 활발하게 이루어지고 있다. 하지만CMOS이미지 센서 제품들은 하드웨어에 비해 아직 응용 소프트웨어 및 펌웨어의 완성도에서 여러 가지 문제를 가진다. CMOS 이미지 센서 기반 폴링 기법은 불필요한 메시지 교환으로 인해 비효율적인 동기화 문제 및 전송 지연이 일정 수준으로 높아지면 데이터 재전송에 대한 오버헤드가 크다. 이러한 이유로 폴링 방식의 구조적 안정성(structural stability)에 문제점을 가진다. 본 논문에서는 MCU를 통한 펌웨어 기반의 고속 동기화 기법으로 폴링 주기를 세분화하여 Stepwise 동기화 기법을 제안하고, 인터럽트 방식을 적용하여 재접속 및 데이터 전송을 개선하였다. 결과적으로 제안한 기법이동기화 시간 및 에러 커넥션에서 20% 이상 뛰어난 성능을 보여주는 것으로 나타났다. 또한 CMOS 이미지 센서 기반의 C328R 보드와 저전력 MCU인 ATmega128L을 이용한 보드를 개발하고, 제공 소프트웨어와 제안된 펌웨어의 카메라 모듈과 동기화 시간 및 에러 커넥션(Error Connection) 등을 비교, 분석하였다. Lately, since Complementary Metal Oxide Semiconductor(CMOS) image sensor system has low power, low cost and been miniaturized, hardware and applied software studies using these strengths are being carrying on actively. However, the products equipped with CMOS image sensor based polling method yet has several problems in degree of completeness of applied software and firmware, compared with hardware’s. CMOS image sensor system has an ineffective synchronous problem due to superfluous message exchange. Also when a sending of data is delayed continually, overhead of re-sending is large. So because of these, it has a problem in structural stability according to Polling Method. In this study, polling cycle was subdivided in high-speed synchronization method of firmware -based through MCU and synchronization method of Stepwise was proposed. Also, re-connection and data sending were advanced more efficiently by using interrupt way. In conclusion, the proposed method showed more than 20 times better performance in synchronization time and error connection. Also, a board was created by using C328R board of CMOS image sensor-based and ATmega128L which has low power, MCU and camera modules of proposed firmware were compared with provided software and analyzed in synchronization time and error connection.

다중 SL-AVS 동기화 유지기법

박현문,박수현,서해문,박우출,Park, Hyun-Moon,Park, Soo-Huyn,Seo, Hae-Moon,Park, Woo-Chool 한국시뮬레이션학회 2009 한국시뮬레이션학회 논문지 Vol.18 No.3

Due to the many advantages including low price, low power consumption, and miniaturization, the CMOS camera has been utilized in many applications, including mobile phones, the automotive industry, medical sciences and sensoring, robotic controls, and research in the security field. In particular, the 360 degree omni-directional camera when utilized in multi-camera applications has displayed issues of software nature, interface communication management, delays, and a complicated image display control. Other issues include energy management problems, and miniaturization of a multi-camera in the hardware field. Traditional CMOS camera systems are comprised of an embedded system that consists of a high-performance MCU enabling a camera to send and receive images and a multi-layer system similar to an individual control system that consists of the camera's high performance Micro Controller Unit. We proposed the SL-AVS (Small Size/Low power Around-View System) to be able to control a camera while collecting image data using a high speed synchronization technique on the foundation of a single layer low performance MCU. It is an initial model of the omni-directional camera that takes images from a 360 view drawing from several CMOS camera utilizing a 110 degree view. We then connected a single MCU with four low-power CMOS cameras and implemented controls that include synchronization, controlling, and transmit/receive functions of individual camera compared with the traditional system. The synchronization of the respective cameras were controlled and then memorized by handling each interrupt through the MCU. We were able to improve the efficiency of data transmission that minimizes re-synchronization amongst a target, the CMOS camera, and the MCU. Further, depending on the choice of users, respective or groups of images divided into 4 domains were then provided with a target. We finally analyzed and compared the performance of the developed camera system including the synchronization and time of data transfer and image data loss, etc.

실시간 교통 정보 제공을 위한 LBI 시스템 모델 개발

박현문,박우출,박수현,Park, Hyun-Moon,Park, Woo-Chool,Park, Soo-Huyn 한국시뮬레이션학회 2010 한국시뮬레이션학회 논문지 Vol.19 No.2

This study presents an RTS(Real-time Traffic System) based on an LBS(Location Based Service) using 5.8~5.9GHz RSU(Road Side Unit). The proposed LBI(Location based Broadcast system on ITS) is a local information-based service supported by RSU for drivers, which has a feature of convergence between T-DMB system and ITS-based RTS. The convergence of local broadcasting station and ITS is realized by two-way communication and supports LBS(Location Based Service) by identifying of vehicle's location using RSU. Real-time information delivery and various services could be provided by information exchanges between LMM and local broadcasting stations. Furthermore, conventional technical limitations have been solved mutually such as transmission area limitation in RTS and one-way communication problem in T-DMB. This support real-time two-way communication to each driver. Therefore, it can be expected that traffic dispersion effects and services expansion for drivers by RTS and LBI. Finally, it is proposed to built and implement test-bed around institute.

실내에서 보정노드를 통한 위치추정 기법

박현문(Hyun-Moon Park),신수영(Soo-Young Shin),남궁정일(Jung-Il Namgung),박수현(Soo-Huyn Park) 한국멀티미디어학회 2008 멀티미디어학회논문지 Vol.11 No.2

센서 네트워크를 이용한 위치 추정은 많은 연구가 되어왔다 실내 혹은 실외에서 위치추정 방식의 차이를 고려한 방법이 연구되고 있다. 실외의 위치 추정에서 RSSI(Received Signal Strength Indication) 값을 통하여 단일 시간 동안 일정하게 한 분포를 가지기 때문에 추론이 가능하지만, 실내는 다중경로와 간섭이 실외 보다 높고, 그 밖에 다른 변수로 인해 추론하기가 어렵다. 논문에서는 이동평균과 K-means 알고리즘을 통해 다중경로와 간섭으로 변화된 RSSI 정보를 보정하고, 단일 시간 동안 수신된 수신신호의 집단에서 신뢰성을 가진 RSSI의 값에 대한 추론을 제안한다. 또한 위치추정에서 보정노드를 이용하여 네트워크에 속한 고정 노드에 가중치를 두는 방법을 제안하고, 네트워크 재설정을 통해 기존의 방식을 시스템 상에서 새롭게 구현하여 위치인지에 대한 효율성을 비교 평가한다. The location estimation using sensor network has been considerably researched. The methods taking the differences of the forms of location estimation between indoors and outdoors into consideration have been studied. While it is possible for outdoor location to be estimated because outdoor location estimation has a consistent distribution during unit period through the value of RSSI(Received Signal Strength Indication) on outdoor location estimation, Indoor location estimation is difficult since multi-path and interference indoors are higher than those outdoors and indoor location estimation can be affected by other factors. In this paper, we revise the information of RSSI changed by multi-path and interference through the Moving Average method and K-means algorithm and propose the method of estimation for the value of RSSI with reliability in the group of signals received during unit period. We also suggest the way to put some weights on fixed nodes in network using a snooping node on location estimation and then evaluate the efficiency of location awareness as compared with the existing method by implementing proposed method on system through the reconfiguration of network.

듀얼 슈퍼 클러스터 헤드 해양 센서 네트워크 라우팅 프로토콜

장영일,신수영,박현문,박수현,Chang, Young-Il,Shin, Soo-Young,Prak, Hyun-Mun,Park, Soo-Huyn 한국시뮬레이션학회 2006 한국시뮬레이션학회 논문지 Vol.15 No.4

무선 센서 네트워크는 다양한 분야에서 연구되고 있다. 그 중 해양 센서 네트워크는 해양 환경 감시와 같은 다양한 목적으로 사용 될 수 있다. 그러나 무선 센서 네트워크는 주로 지상에서 연구된다. 기존에 지상에서의 연구는 해양에 적용하기에 부적합하다. 따라서, 해양 환경을 고려한 해양 센서 네트워크 구조를 제안한다. 본 논문에서는 해양 센서 네트워크에 클러스터링 기법과 기능별 노드 구축을 적용하였다. 각 클러스터는 클러스터 데이터를 수집하여 전송한다. 이중의 슈퍼 클러스터 헤드는 각각 수신한 클러스터 데이터를 베이스 스테이션에 전송한다. 제안한 해양 음파 센서 네트워크 라우팅 알고리즘을 구현하고, 테스트 베드를 구축하여 클러스터 데이터의 수신율을 분석한다. Wireless Sensor Network (WSN) is researched in various filed. Underwater Sensor Network (UWSN) is used various purpose such as underwater environment monitoring. But, WSN is researched in the terrestrial that uses mainly radio frequency, The existing terrestrial research is incongruent to apply to underwater. Therefore, we propose UWSN architecture that considers underwater environment. In this paper, UWSN applied cluster technique and functional node constructs. Each cluster collects and sends cluster data. Dual super cluster head receives cluster data and transmits each in the base-station. We implement WSN routing algorithm, and construct test-bed and analyze cluster data receive rate.

센서 네트워크 기반의 지능형 교통 시스템 지원을 위한 RWIS 구현

박현문(Hyun-Moon Park),박수현(Soo-Huyn Park),박우출(Woo Chool Park),서해문(Hae-Moon Seo) 한국통신학회 2010 韓國通信學會論文誌 Vol.35 No.3