• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2004년도 제29회 추계학술대회 발표논문집
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• pp.122-125
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• 2004

폐, 간 등의 상 복부에 위치한 종양의 방사선 조사 체적은 호흡에 의한 종양의 이동을 포함하기 때문에 방사선 조사체적이 증가되어 방사선 독성 및 정상조직 선량이 증가하게 된다. 이러한 문제점을 극복하기 위해 동 팬텀과 초음파센서를 이용하여 호흡운동에 의한 환자 체표면의 움직임을 획득하고, 획득한 데이터의 역 값을 이용해 환자침대를 조절해줄 수 있는 호흡운동 조절 방사선치료 기술을 개발하고자 한다. 호흡운동에 의한 환자 체표면의 움직임을 평가하기 위해 제작한 팬텀은 조정기(BS II, 20 Mhz, 8K Byte), 센서(Ultra-Sonic, range 3 cm${\sim}$3 m), Computer(RS232C), Servo Motor (Torque 2.3 Kg)등으로 구성하였고, 제어와 구동을 위한 획득-보정-분석 프로그램을 작성하였다. 최대 2 cm 범위 내에서 팬텀을 움직이게 하였고, 팬텀의 움직임과 보정이 순차적으로 일어나도록 프로그램 하였으며, x, y, z가 연속적으로 움직이도록 구성하였다. 임의의 움직임 데이터(유격이 2 cm이 되도록 하여 3차원 데이터 형태)를 입력하여 동 팬텀을 조정하고, 동시에 팬텀 움직임을 초음파 센서를 이용하여 획득한 후, 두 데이터 간의 비교, 분석을 시행하였다. 이후 쥐(Guinea-pig, about 500g)를 이용하여 호흡운동에 의한 환자 체표면의 움직임을 획득한 후 획득한 데이터의 역 값으로 팬텀을 구동시킴으로써 실시간 호흡운동 조절 방사선치료 기술을 평가하였다. 팬텀 실험에서 3 차원 입력데이터에 대한 팬텀 보정 데이터 간의 정확성을 시간에 대한 거리 값으로 비교한 결과 ${\pm}$1% 이내의 정확성을 알 수 있었고, 이에 필요한 보정시간은 2.34 ${\times}$ 10-4 초임을 알 수 있었다. 또한 동물 실험에서도 동일한 방법으로 시간에 대한 거리 그래프와 획득-보정 간의 지연 시간 등을 분석한 결과 팬텀 데이터와 같은 결과를 얻을 수 있었다. 팬텀, 동물 실험 모두에서 시간에 대한 거리 값과 각각의 경우에 획득-보정 간의 지연 시간을 분석한 결과 데이터 값은 ${\pm}$1%이내에서 일치하였으며, 데이터 획득-보정 지연 시간은 2.34 ${\times}$ 10-4 초 이내 즉, 실시간으로 얻을 수 있어 새로운 호흡운동 조절 방사선치료 기술의 임상적용에의 가능성을 확인할 수 있었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.95.1-95
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• 2002

<1. New level meter inside the fuel tank> Ultrasound level sensors are widely applied as level meters of liquid tank. Measurement instrument of level between water and fuel is developed. Since the fuel is inflammable, the sensor system doesn't allow to include any electric circuit inside the fuel tank. The optical cable sensor can satisfy this explosive condition. The measurement method with ultrasonic sensor is attached on the tank wall or tank manhole lid. The pressure sensor can't be applied inside the gasoline fuel tank. An ultra-sonic sensor doesn't detect a enough signal reflected from water level deep under gasoline fuel. The pressure sensor is difficult to measure the height o...

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1475-1478
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• 2004

This paper describes map building for the path planning to avoid obstacles with vision sensor and ultrasonic sensor. We get the 2 dimensional information from the processed images of CCD sensor and 1 dimensional range information from ultrasonic sensor. I proposed a way to generate the map which contains these two kinds of information in the program. And we made the biped robot which have 20 DOF with these sensors and get good experimental result to prove the validity of the proposed method.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제11권4호
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• pp.280-285
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• 2011

Recently, with the development of service robots and the concept of ubiquitous, the position estimation of mobile objects has received great interest. Some of the localization schemes are introduced, which provide the relative location of the moving objects subjected to accumulated errors. To implement a real time localization system, a new absolute position estimation method for a mobile robot in indoor environment is proposed. Design and implementation of the localization system comes from the usage of active beacon systems (based upon RFID technology). The active beacon system is composed of an RFID receiver and an ultra-sonic transmitter. The RFID receiver gets the synchronization signal from the mobile robot and the ultra-sonic transmitter sends out the traveling signal to be used for measuring the distance. Position of a mobile robot in a three dimensional space can be calculated basically from the distance information from three beacons and the absolute position information of the beacons themselves. In some case, the mobile robot can acquire the ultrasonic signals from only one or two beacons, due to the obstacles located along the moving path. In this paper, a position estimation scheme using fewer than three sensors is developed. Also, the extended Kalman filter algorithm is applied for the improvement of position estimation accuracy of the mobile robot.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.543-547
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• 2005

In this paper, we designed a intelligent autonomous driving robot by using Fuzzy algorithm. The object of designed robot is recognition of obstacle, avoidance of obstacle and safe arrival. We append a suspension system to auxiliary wheel for improvement in stability and movement. The designed robot can arrive at destination where is wanted to go by the old and the weak and the handicapped at indoor hospital and building.

• 한국군사과학기술학회지
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• 제15권1호
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• pp.9-15
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• 2012

This paper shows an effective scanning trajectory for a mine detection device that is one of the mission equipments of unmanned ground vehicle. The mine detection device is composed of a mine-detection sensor, and a 4 DOF manipulator enabling sensor position control. There are three modes that manage the mine detection device: passive, semi-automatic, and automatic. The automatic mode is used the most. This paper suggests a scanning method that makes shape of 8. This method prevents missing target area and enhances scanning speed when the mine detection device scans the ground surface in automatic mode. The suggested method is verified by simulations and experiments.

• 제어로봇시스템학회논문지
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• 제16권3호
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• pp.239-244
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• 2010

This paper is to present map building of mobile robot using RFID (Radio Frequency Identification) technology and ultrasonic sensor. For mobile robot to perform map building, the mobile robot needs its localization and accurate driving in space. In this reason, firstly, kinematic modeling of mobile robot under non-holonomic constrains is introduced. Secondly, based on this modeling, a tracking controller is designed for tracking a given path based on backstepping method using Lyapunov function. The Lyapunov function is also introduced for proving the stability of the designed tracking controller. Thirdly, 2D map building is performed by RFID system, mobile robot system and ultrasonic sensors. The RFID mobile robot system is composed of DC motor, encoder, ultra sonic sensor, digital compass, RFID receiver and RFID antenna. Finally, the path tracking simulation results and map building experimental results are presented to show the effectiveness of the designed controller.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2019-2023
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• 2005

In this paper, an autonomous omni directional cleaning robot which recognizes an obstacle and a battery charger is introduced. It utilizes a robot vision, ultra sonic sensors, and infrared sensors information along with appropriate algorithm. Three omni-directional wheels make the robot move any direction, enabling a faster maneuvering than a simple track typed robot. The robot system transfers command and image data through Blue-tooth wireless modules to be operated in a remote place. The robot vision associated with sensor data makes the robot proceed in an autonomous behavior. An autonomous battery charger searching is implemented by using a map-building which results in overcoming the error due to the slip on the wheels, and camera and sensor information.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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• pp.70-74
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• 1998

This paper describes a method for recognition of two-dimensional position of an object by use of aerial ultra-sonic sensor and signal processing technique, which would become a help for blind person or self-mobile robot. First, we have developed a method for measuring the time difference between the transmitted and the received burst wave by use of one ultrasonic transmitter and three receivers. Secondly, a new method is developed for measuring the distance to an object by use of M-sequence correlation method. Thirdly, a measurement method to obtain the position of an object is described by use of phase-arrayed ultrasonic sensor, which gives us a wide-range position determination in a short time.

• 한국정밀공학회지
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• 제19권8호
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• pp.147-154
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• 2002

In this paper, a path navigation algorithm through use of a sensor platform is proposed. The sensor platform is composed of two electric motors which make panning and tilting motions. An algorithm for computing a real path and an obstacle length is developed by using a scanning method that controls rotation of the sensors on the platform. An Autonomous Robot Vehicle(ARV) can perceive the given path by adapting this algorithm. A sensor scanning method is applied to the sensor platform for using small numbers of sensor. The path navigation algorithm is composed of two parts. One is to perceive a path pattern, the other is used to avoid an obstacle. An optimal controller is designed for tracking the reference path which is generated by perceiving the path pattern. The ARV is operated using the optimal controller and the path navigation algorithm. Based on the results of actual experiments, this algorithm for an ARV proved sufficient for path navigation by small number of sensors and for a low cost controller by using the sensor platform with a scanning method.