• 한국항공우주학회지
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• 제45권9호
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• pp.734-745
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• 2017

달 착륙선의 항법 시스템은 자율 정밀 항법 성능을 확보하기 위해 관성측정기와 별추적기, 고도계, 속도계, 지형상대항법 카메라 등 다양한 항법용 전장부품으로 구성되는데 착륙선의 착륙 시나리오와 임무 요구 성능에 따라 적합한 성능의 항법용 전장부품 선정이 필요하다. 본 논문에서는 달 착륙선에 요구되는 항법용 전장부품의 사양을 공분산해석을 통해 분석하였다. 77차 상태변수로 구성되는 기준 시스템 오차모델과 센서의 측정모델을 정의하고 착륙선의 임무 요구 성능은 90m($3{\sigma}$) 착륙 위치 정확도를 요구하는 정밀탐사 임무와 6km($3{\sigma}$)의 착륙 오차가 허용되는 영역탐사 임무로 구분하였다. 자율항법 시작 시점에 따라 PDI(Powered descent initiation)와 DOI(Deorbit initiation) 시나리오로 나누고 항법용 전장부품의 조합과 착륙 시나리오에 따른 성능 분석을 통해 가상의 임무 요구 성능을 만족하기 위한 항법 시스템의 요구사양을 도출하였다.

• 로봇학회논문지
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• 제19권3호
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• pp.287-292
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• 2024

The initial suppression of fires is critical to protecting human and material resources. In response to this, fire prevention and suppression systems using artificial intelligence and robot technology have recently been studied. In particular, an autonomous driving system that detects a fire using CNN is attracting attention. These systems respond quickly in the event of a fire, enabling initial fire suppression. However, since the conventional system is not equipped with a fire suppression function, direct intervention of firefighters is required. (1) To overcome these limitations, we propose an autonomous fire detection robot system equipped with a fire suppression function ROS-based firefighting system called 'ADEFS' (Autonomous-Detect & Extinguish-Fire Service). (2) The system performs three tasks to detect and extinguish. Tasks are to run the Ros-based SLAM Navigation, YOLO-CNN, and Four-degree freedom manipulator connected to the fire extinguishing pump. (3) Through this, early response in the event of a fire can minimize damage to life and property and can reduce labor costs, which can also be expected to reduce costs for companies.

• 대한임베디드공학회논문지
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• 제6권5호
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• pp.303-309
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• 2011

In this paper, an intelligent force control technique is applied to an autonomous helicopter. Although most research on the autonomous helicopter system is about navigation and control, force control of an autonomous helicopter system is quite new and not presented yet. After controlling the position of the helicopter by the LQR method, force control is applied. The adaptive impedance force control algorithm is introduced and tested to regulate the desired force under unknown location and stiffness of the environment. To compensate for uncertainty from outer disturbance, a neural network is added to form an intelligent force control framework. Simulation studies show that the proposed force control algorithm works well.

• 로봇학회논문지
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• 제5권2호
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• pp.120-126
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• 2010

This paper presents to study the path tracking method of AGV(autonomous guided vehicle) which has a laser guidance system. An existing automatic guided vehicles(AGVs) which were able to drive on wired line only had a automatic guidance system. However, the automatic guidance systems that those used had the high cost of installation and maintenance, and the difficulty of system change according to variation of working environment. To solve such problems, we make the laser guidance system which is consisted of a laser navigation and gyro, encoder. That is robust against noise, and flexible according to working environment through sensor fusion. The laser guidance system can do a perfect autonomous driving. However, the commercialization of perfect autonomous driving system is difficult, because the perfect autonomous driving system must recognize the whole environment of working space. Hence, this paper studied the path tracking of AGV using laser guidance system without wired line. The path tracking method is consisted of virtual path generation method and driving control method. To experiment, we use the fork-type AGV which is made by ourselves, and do a path tracking experiments repeatedly on same experimental environment. In result, we verified that proposed system is efficient and stable for actual fork-type AGV.

• 한국정보통신학회논문지
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• 제24권11호
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• pp.1417-1423
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• 2020

본 논문에서는 수중에서 운동하는 무인잠수정의 경로점 유도법칙을 제안한다. 시선각 유도법칙과 수선경로 오차를 줄여가는 경로추종 유도법칙을 조합하여 효과적인 경로점 유도법칙을 설계하였고, 수선경로 오차의 거리에 따라 제어이득을 변화시켜 시스템의 안정성을 증가시켰다. 또한, 관성항법장치와 도플러속도계를 이용한 복합항법 시스템의 성능을 확인할 수 있는 HILS를 구성하였다. 같은 경로점 및 목표점을 입력 후 HILS 수행결과와 실해역 주행시험 결과를 비교하여, 제안한 유도법칙 및 HILS가 올바르게 구성되어 있음을 확인하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.51-55
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• 1997

This study is devote to developing navigation filter for detecting sensor failure in multi-sensor navigation system. In multi-sensor navigation system, Kalman filter is generally used to fuse data of each sensors. Sensor failure is fatal in case that the sensor is used as external measurement of Kalman filter therefore detection and recovery of sensor failure is one the important feature of navigation filter. Generally each sensors have its specific feature in measuring navigational information. Fuzzy theory is proposed to detect external sensor failure and provide valid external measurement to Kalman filter avoiding filter divergence and instability. This idea is applied to Autonomous Underwater Vehicle(AUV) which has two navigation sensor i. e self contained inertial sensor and acoustic external sensor. 2 dimensional simulation result shows acceptable failure detection and recovery

• 한국항행학회논문지
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• 제22권5호
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• pp.391-399
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• 2018

V2X 통신이란 차량이 유무선망을 통해 다른 차량, 인프라, 네트워크, 보행자 등과 같은 객체들과 정보를 교환하는 기술이다. V2X 통신 기술은 최근 꾸준히 연구되어 왔으며 자율주행 차량 기술과 결합된 자율협력주행 기술에 중요한 역할을 수행해왔다. 자율주행 차량은 V2X 통신을 통해 외부 정보를 수신함으로써 차량 센서의 인식범위를 확장시키고 보다 안전하고 자연스런 자율주행을 지원할 수 있다. 이러한 자율협력주행 차량을 공공도로에서 운행하기 위해서는 V2X 보안통신의 신뢰성이 사전에 검증되어야 한다. 본 논문에서는 자율협력주행을 위한 V2X 보안통신에 대한 테스트 시나리오와 테스트 절차를 제안하고 검증 결과를 제시한다.

• Journal of Positioning, Navigation, and Timing
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• 제8권1호
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• pp.31-40
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• 2019

In recent years, Intelligent Transport Systems (ITS) and Autonomous Vehicle Technology have actively studied around the world. In order to achieve the purpose of Advanced Driver Assistance System (ADAS) and Autonomous Vehicle Technology, it must be obtained accurate and reliable positioning. However, the problem of positioning in the urban area is a low position accuracy caused by the reduction of the number of visible satellites due to high buildings. In this paper, we analyzed the availability of precise positioning system in urban area are using GPS/BDS integrated system. For this study, GPS and BDS satellite signals were collected using two low-cost receivers in the open sky and a designed software based platform for precise positioning performance analysis. And we analyzed the precise positioning performance by changing the mask angle considering the urban area. From the results, it can be confirmed that the performance of precise positioning of GPS only and BDS only decrease in the environment where mask angle is $40^{\circ}$ to $45^{\circ}$, however, GPS/BDS integrated system maintains high performance of precise positioning.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.475-475
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• 2000

This paper describes the construction of an autonomous mobile robot with functions of collision avoidance and speech recognition that is used for teaching path of the robot. The human voice as a teaching method provides more convenient user-interface to mobile robot. For safe navigation, the autonomous mobile robot needs abilities to recognize surrounding environment and avoid collision. We use u1trasonic sensors to obtain the distance from the mobile robot to the various obstacles. By navigation algorithm, the robot forecasts the possibility of collision with obstacles and modifies a path if it detects dangerous obstacles. For these functions, the robot system is composed of four separated control modules, which are a speech recognition module, a servo motor control module, an ultrasonic sensor module, and a main control module. These modules are integrated by CAN(controller area network) in order to provide real-time communication.

• Journal of Positioning, Navigation, and Timing
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• 제12권2호
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• pp.129-140
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• 2023

Autonomous driving systems are likely to be operated in various complex environments. However, the well-known integrated Global Navigation Satellite System (GNSS)/Inertial Navigation System (INS), which is currently the major source for absolute position information, still has difficulties in accurate positioning in harsh signal environments such as urban canyons. To overcome these difficulties, integrated Visual/Inertial/GNSS (VIG) navigation systems have been extensively studied in various areas. Recently, a Compressed-State Constraint Kalman Filter (CSCKF)-based VIG navigation system (CSCKF-VIG) using a monocular camera, an Inertial Measurement Unit (IMU), and GNSS receivers has been studied with the aim of providing robust and accurate position information in urban areas. For this new filter-based navigation system, on the basis of time-propagation measurement fusion theory, unnecessary camera states are not required in the system state. This paper presents a performance evaluation of the CSCKF-VIG system compared to other conventional navigation systems. First, the CSCKF-VIG is introduced in detail compared to the well-known Multi-State Constraint Kalman Filter (MSCKF). The CSCKF-VIG system is then evaluated by a field experiment in different GNSS availability situations. The results show that accuracy is improved in the GNSS-degraded environment compared to that of the conventional systems.