• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1597-1600
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• 1997

Most autonomous mobile robots view things only in front of them. As a result they may collide against objects moving from the side or behind. To overcome the problem we have built an Active Omni-directional Range Sensor that can obtain omni-directional depth data by a laser conic plane and a conic mirror. Also we proposed a self-localization algorithm of mobile robot in unknown environment by fusion of Odometer and Active Omn-directional Range Sensor.

• 한국정밀공학회지
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• 제12권8호
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• pp.73-85
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• 1995

The sensor system to measure the distance precisely from the center of the sensor system to the obstacle is needed to recognize the surrounding environments, and the sensor system is to be calibrated thoroughly to get the range information exactly. This study covers the calibration of the active range sensor which consists of camera and laser slit emitting device, and provides the equations to get the 3D range data. This can be possible by obtaining the extrinsic parameters of laser slit emitting device through image processing the slits measured during the constant distance intervals and the intrinsic parameters from the calibration of camera. The 3D range data equation derived from the simple geometric assumptions is proved to be applicable to the general cases using the calibration parameters. Also the exact 3D range data were obtained to the object from the real experiment.

• 한국정밀공학회지
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• 제16권1호통권94호
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• pp.253-264
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• 1999

Most autonomous mobile robots view only things in front of them, and as a result, they may collide with objects moving from the side or behind. To overcome this problem. an Active Omni-directional Range Sensor System has been built that can obtain an omni-directional range data through the use of a laser conic plane and a conic mirror. Also, mobile robot has to know its current location and heading angle by itself as accurately as possible to successfully navigate in real environments. To achieve this capability, we propose a self-localization algorithm of a mobile robot using an active omni-directional range sensor in an unknown environment. The proposed algorithm estimates the current position and head angle of a mobile robot by a registration of the range data obtained at two positions, current and previous. To show the effectiveness of the proposed algorithm, a series of simulations was conducted and the results show that the proposed algorithm is very efficient, and can be utilized for self-localization of a mobile robot in an unknown environment.

• 제어로봇시스템학회논문지
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• 제5권4호
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• pp.437-445
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• 1999

Most autonomous mobile robots view only things in front of then, and as a result, they may collide with objects moving from the side or behind. To overcome this problem, an active omni-directional range sensor system has been built that can obtain an omni-directional depth map through the use of a laser conic plane and a conic mirror. In the navigation of the mobile robot, the proposed sensor system produces a laser conic plane by rotating the laser point source at high speed: this creates a two-dimensional depth map, in real time, once an image is captured. The results obtained from experiment show that the proposed sensor system is very efficient, and can be utilized for navigation of mobile robot in an unknown environment.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.824-827
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• 1996

Most autonomous mobile robots view things only in front of them. As a result, they may collide against objects moving from the side or behind. To overcome the problem we have built an Active Omni-directional Range Sensor that can obtain omnidirectional depth data by a laser conic plane and a conic mirror. In the navigation of the mobile robot, the proposed sensor system makes a laser conic plane by rotating the laser point source at high speed and achieves two dimensional depth map, in real time, once an image capture. The experimental results show that the proposed sensor system provides the best potential for navigation of the mobile robot in uncertain environment.

• 센서학회지
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• 제27권3호
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• pp.160-164
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• 2018

In this paper, a wide dynamic range complementary metal-oxide-semiconductor (CMOS) image sensor with the adjustable sensitivity by using cascode metal-oxide-semiconductor field-effect transistor (MOSFET) and inverter is proposed. The characteristics of the CMOS image sensor were analyzed through experimental results. The proposed active pixel sensor consists of eight transistors operated under various light intensity conditions. The cascode MOSFET is operated as the constant current source. The current generated from the cascode MOSFET varies with the light intensity. The proposed CMOS image sensor has wide dynamic range under the high illumination owing to logarithmic response to the light intensity. In the proposed active pixel sensor, a CMOS inverter is added. The role of the CMOS inverter is to determine either the conventional mode or the wide dynamic range mode. The cascode MOSFET let the current flow the current if the CMOS inverter is turned on. The number of pixels is $140(H){\times}180(V)$ and the CMOS image sensor architecture is composed of a pixel array, multiplexer (MUX), shift registers, and biasing circuits. The sensor was fabricated using $0.35{\mu}m$ 2-poly 4-metal CMOS standard process.

• 한국군사과학기술학회지
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• 제18권5호
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• pp.517-524
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• 2015

In this paper, we propose a new target tracking filter architecture using active and passive sensors in underwater environment. A passive sensor for target tracking needs a bearing measurement of target. And target tracking filter for using passive sensor has the observability problem. On the other hand, an active sensor does not have the problem associated with system observability problem because an active sensor uses bearing and range measurement. In this paper, the tracking filter algorithm that could be used in the active and passive sensor system is proposed to analyze maneuvering target and to improve target tracking performance. The proposed tracking filter algorithm is tested by a series of computer simulation runs and the results are analyzed and compared with existing algorithm.

• 센서학회지
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• 제22권4호
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• pp.256-261
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• 2013

This paper presents an extension of the dynamic range in a complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) using a stacked photodiode and feedback structure. The proposed APS is composed of two additional MOSFETs and stacked P+/N-well/P-sub photodiodes as compared with a conventional APS. Using the proposed technique, the sensor can improve the spectral response and dynamic range. The spectral response is improved using an additional stacked P+/N-well photodiode, and the dynamic range is increased using the feedback structure. Although the size of the pixel is slightly larger than that of a conventional three-transistor APS, control of the dynamic range is much easier than that of the conventional methods using the feedback structure. The simulation and measurement results for the proposed APS demonstrate a wide dynamic range feature. The maximum dynamic range of the proposed sensor is greater than 103 dB. The designed circuit is fabricated by the $0.35-{\mu}m$ 2-poly 4-metal standard CMOS process, and its characteristics are evaluated.

• 한국자기학회지
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• 제23권5호
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• pp.159-165
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• 2013

능동형 자기센서는 근거리에서 정확한 표적 탐지가 가능하지만 대상 표적 관점에서는 이러한 센서의 위협을 극복할 수 있는 마땅한 대항책이 없기 때문에 세계 각국의 수중유도무기에서 기폭신관용 센서로 널리 사용하고 있다. 하지만 근래에는 표적의 명중률 향상을 위한 목적으로 능동형 자기센서의 표적 탐지거리를 증대시키는 것에 대한 요구가 끊임없이 제기되고 있다. 표적 탐지거리를 증대시키는 방법 중의 하나는 송신기의 코어 형상 최적화를 통한 송신 코어의 자기소거인자를 최소화하고, 이를 통해서 송신기 출력을 향상시키는 것이다. 따라서 본 논문에서는 수중유도무기에 적용되는 능동형 자기센서의 송신출력 향상을 위한 송신기 코어 형상 설계와 관련하여 유한요소해석 및 실세 제작된 송신기를 대상으로 비교 시험을 수행하였고, 그 결과 송신기 코어의 형상은 송신 출력 향상에 매우 중요한 인자임을 확인하였다.

• 센서학회지
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• 제24권2호
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• pp.79-82
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• 2015

This paper proposes a novel complementary metal oxide semiconductor (CMOS) active pixel sensor (APS) and presents its performance characteristics. The proposed APS exhibits a linear-logarithmic response, which is simulated using a standard $0.35-{\mu}m$ CMOS process. To maintain high sensitivity and improve the dynamic range (DR) of the proposed APS at low and high-intensity light, respectively, two additional nMOSFETs are integrated into the structure of the proposed APS, along with a photogate. The applied photogate voltage reduces the sensitivity of the proposed APS in the linear response regime. Thus, the conversion gain of the proposed APS changes from high to low owing to the addition of the capacitance of the photogate to that of the sensing node. Under high-intensity light, the integrated MOSFETs serve as voltage-light dependent active loads and are responsible for logarithmic compression. The DR of the proposed APS can be improved on the basis of the logarithmic response. Furthermore, the reference voltages enable the tuning of the sensitivity of the photodetector, as well as the DR of the APS.