• 로봇학회논문지
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• 제16권2호
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• pp.112-121
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• 2021

Unlike a typical small-sized robot navigating in a free space, an autonomous vehicle has to travel in a designated road which has lanes to follow and traffic rules to obey. High-Definition (HD) maps, which include road markings, traffic signs, and traffic lights with high location accuracy, can help an autonomous vehicle avoid the need to detect such challenging road surroundings. With space constraints and a pre-built HD map, a new type of path planning algorithm can be conceived as a substitute for conventional grid-based path planning algorithms, which require substantial planning time to cover large-scale free space. In this paper, we propose an obstacle-avoiding, cost-based planning algorithm in a continuous space that aims to pursue a globally-planned path with the help of HD map information. Experimentally, the proposed algorithm is shown to outperform other state-of-the-art path planning algorithms in terms of computation complexity in a typical urban road setting, thereby achieving real-time performance and safe avoidance of obstacles.

• Journal of Biosystems Engineering
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• 제31권6호
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• pp.489-499
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• 2006

Since the application of chemicals in confined spaces under the canopy of an orchard is hazardous work, it is needed to develop an autonomous guidance system for an orchard sprayer. The autonomous guidance system developed in this research could steer the vehicle by tracking an overhead guidance rail, which was installed on an existing frame structure. The autonomous guidance system consisted of an 80196 kc microprocessor, an inclinometer, two interface circuits of actuators for steering and ground speed control, and a fuzzy control algorithm. In addition, overhead guidance rails for both straight and curved paths were devised, and a trolley was designed to move smoothly along the overhead guidance rails. Evaluation tests showed that the experimental vehicle could travel along the desired path at a ground speed of 30 $\sim$ 50 cm/s with a RMS error of 5 cm and maximum deviation of less than 12 cm. Even when the vehicle started with an initial offset or a deflected heading angle, it could move quickly to track the desired path after traveling 2 $\sim$ 3 m. The vehicle could also complete turns with a curvature of 1 m. However, at a ground speed of 50 cm/s, the vehicle tended to over-steer, resulting in a zigzag motion along the straight path, and tended to turn outward from the projected line of the guidance rail.

• 감성과학
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• 제21권1호
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• pp.17-34
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• 2018

스스로 완벽하게 목적지까지 주행하는 완전 자율주행 자동차 시대가 가까운 미래에 도래할 것으로 예상되면서 자동차 산업은 1800년대 후반에 자동차가 탄생한 이래 큰 변화를 꾀해야 할 중대한 전환기를 맞이하고 있다. 완전 자율주행 자동차는 단순한 이동수단의 개념을 넘어 생활공간으로 정의되어지며, 앞으로 실내공간을 중심으로 큰 변화가 나타나게 될 것이라고 전망되고 있으나 완전 자율주행 자동차 실내공간 디자인에 대한 기존 연구는 미비한 실정이다. 이에 본 연구는 생활공간이라는 개념에 적합하도록 사용자의 감성적 경험을 충족시켜줄 수 있는 근본적인 디자인 요소인 실내행위에 대한 분석을 통해 실내공간 디자인 방안을 제안하고자 한다. 이를 위해 완전 자율주행 자동차의 실내행위에 대한 소비자 의식을 조사하였다. 분석 결과 국내 소비자들은 완전 자율주행 자동차 내에서 '수면 및 휴식', 'TV 및 영화 시청', '음악감상' 등 개인 중심 행위 중에서도 휴식 및 감상 활동과 관련된 실내행위에 대한 필요성을 인지하고 있었으며, 본 연구 결과를 바탕으로 완전 자율주행 자동차 실내공간 디자인 방안을 제안하였다. 본 연구는 소비자 니즈(needs)를 정량적 방법으로 분석하여 실내공간 디자인 방안을 새로운 시각으로 제시한 선도적인 연구라는 점에서 중요한 의미를 지닌다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집B
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• pp.295-300
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• 2001

In recent years, as changing the habit of eating, the pathology in the colon grows up annually. For that reason, the colonoscopy is generalized. But it requires much time to acquire a dexterous skill to perform an operation. And the procedure is painful to the patient. Therefore, biomedical and robotic researchers are developing a locomotive colonoscope that can travel safely in colon. In this paper, we propose a novel design and concept of semi-autonomous colonoscope and two actuators for the micro robot. The micro robot comprises camera and LED for diagnosis, steering system to pass through the loop, pneumatic actuator and bow-shaped flexible supporters to control a contact force and to keep the space between colon wall and the actuator. For actuating mechanism, we suggest two models. One is based on the reaction force, and the other is impact force. In order to validate the concept and the performance of the actuators, we carried out the preliminary experiments in rigid pipes.

• 센서학회지
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• 제28권3호
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• pp.164-170
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• 2019

In this paper, a lane detection and tracking algorithm based on vision sensors and employing a robust filter for inner edge detection is proposed for developing a lane departure warning system (LDWS). The lateral offset value was precisely calculated by applying the proposed filter for inner edge detection in the region of interest. The proposed algorithm was subsequently compared with an existing algorithm having lateral offset-based warning alarm occurrence time, and an average error of approximately 15ms was observed. Tests were also conducted to verify whether a warning alarm is generated when a driver departs from a lane, and an average accuracy of approximately 94% was observed. Additionally, the proposed LDWS was implemented as an embedded system, mounted on a test vehicle, and was made to travel for approximately 100km for obtaining experimental results. Obtained results indicate that the average lane detection rates at day time and night time are approximately 97% and 96%, respectively. Furthermore, the processing time of the embedded system is found to be approximately 12fps.

• 에너지공학
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• 제29권3호
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• pp.86-90
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• 2020

이 논문은 네트워크로 연계된 에너지 클라우드, 에너지 커뮤니티 그리고 스마트시티에 참여한 프로슈머 머신들 간의 전력 직거래에 있어 위치증명방식이 적용된 블록체인 네트워크 기반 거래 시스템에 대한 고찰이다. 이 시스템은 위치증명기반 블록체인 네트워크 기술을 활용하여 자율 이동 중 전력 구매에 의한 배터리 재충전으로 장거리 이동이 가능해 질 수 있는 물류 배송 드론, 전력 구매와 판매가 모두 가능한 자율주행 전기 자동차 그리고 고정형태로 전력생산 및 판매가 가능한 태양광 가로등 및 전기충전기들 간의 전력 거래 시 인간의 개입 없이 머신들 간 최적 전력거래 매칭 및 정산 신뢰성을 제공 할 수 있다. 또한 다수이면서 서로 다른 공간에 존재하기 때문에 발생되는 다양한 거래 가격, 정책 그리고 인센티브들이 산재할 것으로 예상되는 에너지 클라우드를 경유하는 자율 운행 머신들 간의 사물 간 전력 직거래 비즈니스 모델을 소개한다.

• 제어로봇시스템학회논문지
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• 제8권4호
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• pp.345-350
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• 2002

In recent years, as changing the habit of eating, the pathology in the colon grows up annually. The colonoscopy is generalized, but if requires much time to acquire a dexterous skill to perform an operation and the procedure is painful to the patient. biomedical and robotic researchers are developing a locomotive colonoscope that can travel safe1y in colon. In this paper, we propose a new actuator and concept of semi-autonomous colonoscope. The micro robot comprises camera and LED for diagnosis, steer- ing system to pass through the loop, pneumatic actuator and bow-shaped flexible supporters to control a contact force and to pass over haustral folds in colon. For locomotion of semi-autonomous colonoscope, we suggest an actuator that is based on impact force between a cylinder and a piston. In order to validate the concept and the performance of the actuator, we carried out the simulation of moving characteristics and the preliminary experiments in rigid pipes and on the colon of pig.

• 한국정밀공학회지
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• 제31권4호
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• pp.319-326
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• 2014

Accurate estimation of the robot's position has an important role in autonomous navigation. Odometry is one of the most widely used techniques for mobile robot positioning. However, odometry has a well-known drawback that the position errors are accumulated when the travel distance increases. The UMBmark method is the conventional odometry calibration scheme for two wheel differential mobile robots. In the UMBmark method, the approximations for small angles are used in order to simplify the calculations. In this paper, we propose the new calibration scheme by using experimental orientation errors. Kinematic parameters can be calculated accurately without approximations by using experimental orientation errors. The numerical simulation and experimental results show that the odometry accuracy can be improved by the proposed method.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.713-716
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• 2000

In this study, we present a mobile robot for ultrasonic scanning of weldment. magnetic Caterpillar mechanism is selected in order to travel on the inclined surface and vertical wall. A motion control board and motor driver are developed to control four DC-servo motors. A virtual device driver is also developed for the purpose of communicating between the control board and a host PC with Dual 'port ram. To provide the mobile robot with stable and accurate movement, PID control algorithm is applied to the mobile robot control. And a vision system for detecting the weld-line are developed with laser slit beam as a light source. In the experiments, movement of the mobile robot is tested inclined on a surface and a vertical wall.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.178.3-178
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• 2001

This paper is concerned with designing a neural network based navigator that is optimized in a user-defined sense for a mobile robot using ultrasonic sensors to travel to a goal position safely and efficiently without any prior map of the environment. The neural network has a dynamically reconfigurable structure that not only can optimize the weights but also the input sensory connectivity in order to meet any user-defined objective. Therefore, in this research, we can select an optimal subset of sensory inputs that results in the best performance related to both navigation and structural complexity. Further, this research uses the manually trained initial population and the modular neural network to alleviate ...