• Journal of Positioning, Navigation, and Timing
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• 제11권2호
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• pp.119-126
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• 2022

This paper presents a method to reduce the vibration-induced noise effect of an inertial measurement device mounted on a self-driving vehicle. The inertial sensor used in the GNSS/INS integrated navigation system of a self-driving vehicle is fixed directly on the chassis of vehicle body so that its navigation output is affected by the vibration of the vehicle's engine, resulting in the degradation of the navigational performance. Therefore, these effects must be considered when mounting the inertial sensor. In order to solve this problem, this paper proposes to use an in-house manufactured vibration suppression device and analyzes its impact on reducing the vibration effect. Experimental test results in a static scenario show that the vibration-induced noise effect is more clearly observed in the lateral direction of the vehicle, but can be effectively suppressed by using the proposed vibration suppression device compared to the case without it. In addition, the dynamic positioning test scenario shows the position, speed, and posture errors are reduced to 74%, 67%, and 14% levels, respectively.

• Journal of Positioning, Navigation, and Timing
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• 제4권3호
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• pp.141-150
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• 2015

In this study, a Global Navigation Satellite System (GNSS) / Inertial Navigation System (INS) / odometer / barometer integrated navigation system that uses a commercial navigation device including Micro Electro Mechanical Systems (MEMS) accelerometer and gyroscope in addition to GNSS, odometer information obtained from a vehicle, and a separate MEMS barometer sensor was implemented, and the performance was verified. In the case of GNSS and GNSS/INS integrated navigation system that are generally used in a navigation device, the performance would deteriorate in areas where GNSS signals are not available. Therefore, an integrated navigation system that calculates a better navigation solution in areas where GNSS signals are not available compared to general GNSS/INS by correcting the velocity error of GNSS/INS using an odometer and by correcting the cumulative altitude error of GNSS/INS using a barometer was suggested. To verify the performance of the navigation system, a commercial navigation device (Softman, Hyundai Mnsoft, http://www.hyundai-mnsoft.com) and a barometer sensor (ST Company) were installed at a vehicle, and an actual driving test was performed. To examine the performance of the algorithm, the navigation solutions of general GNSS/INS and the GNSS/INS/odometer/barometer integrated navigation system were compared in an area where GNSS signals are not available. As a result, a navigation solution that has a smaller position error than that of GNSS/INS could be obtained in the area where GNSS signals are not available.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.861-862
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• 2008

One of trend of portable devices is convergence with other devices, especially with navigation system. This converged system is generally called PND (Personal Navigation Device). This detachable device is developed for personal entertainment in everyday life and navigation system when deriving, so it should meet the specification of vehicle thermal environment, anti-vibration as well as the anti-shock by sudden drop. In this paper, the way to design the hard disk drive damper with CAE, is introduced to get a reliable system from the beginning of the design step.

• 제어로봇시스템학회논문지
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• 제15권3호
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• pp.315-322
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• 2009

This paper explains a control and navigation algorithm of a 6-DOF gait rehabilitation robot, which can allow a patient to navigate in virtual reality (VR) by upper and lower limbs interactions. In gait rehabilitation robots, one of the important concerns is not only to follow the robot motions passively, but also to allow the patient to walk by his/her intention. Thus, this robot allows automatic walking velocity update by estimating interaction torques between the human and the upper limb device, and synchronizing the upper limb device to the lower limb device. In addition, the upper limb device acts as a user-friendly input device for navigating in virtual reality. By pushing the switches located at the right and left handles of the upper limb device, a patient is able to do turning motions during navigation in virtual reality. Through experimental results of a healthy subject, we showed that rehabilitation training can be more effectively combined to virtual environments with upper and lower limb connections. The suggested navigation scheme for gait rehabilitation robot will allow various and effective rehabilitation training modes.

• 제어로봇시스템학회논문지
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• 제20권8호
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• pp.807-814
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• 2014

In this paper, we proposed a haptic navigation system which used the tactile data for the user guides of the mobile robot to the reference point via tele-operation in unknown blind environment. This navigation system can enable a mobile robot to avoid obstacles and move to the reference point, according to the direction provided by the device guides through a haptic device consisting of a vibration motor in a blind environment. There are a great deal of obstacles in real environments, and so mobile robots can avoid obstacles by recognizing the exact position of each obstacle through the superposition of an ultrasonic sensor. The navigation system determines the direction of obstacle avoidance through an avoidance algorithm that uses virtual impedance, and lets users know the position of obstacles and the direction of the avoidance through the haptic device consisting of 5 vibration motors. By letting users know intuitionally, it lets the mobile robot precisely reach the reference point in unknown blind environment. This haptic device can implement a haptic navigation system through the tactile sensor data.

• 한국항행학회논문지
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• 제15권1호
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• pp.25-31
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• 2011

최근에는 NMEA 2000 프로토콜이 SOLAS 선박의 실시간 네트워크 장비의 표준으로 인증 된다. 본 논문에서는 항해 필수 장비인 초음파 센서를 이용한 NMEA 2000이 탑재된 2차원 풍향 풍속계를 개발하였다. 개발된 시스템은 NMEA 2000 장비와의 연결을 테스트하기 위해 수심, 속도, GPS 장비로 구성된 NMEA 2000 네트워크에 연결하였으며, 기존에 제작된 타사 풍향 풍속계와 비교하기 위해 기능시험을 수행하였다.

• 제어로봇시스템학회논문지
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• 제13권3호
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• pp.249-255
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• 2007

Under the situation of a fire, it is difficult for a rescue robot to use sensors such as vision sensor, ultrasonic sensor or laser distance sensor because of diffusion, refraction or block of light and sound by dense smoke. But, braille blocks that are installed for the visaully impaired at public places such as subway stations can be used as a map for autonomous mobile robot's localization and navigation. In this paper, we developed a laser sensor stan device which can detect braille blcoks in spite of dense smoke and integrated the device to the robot developed to carry out rescue mission in various hazardous disaster areas at KIST. We implemented MCL algorithm for robot's attitude estimation according to the scanned data and transformed a braille block map to a topological map and designed a nonlinear path tracking controller for autonomous navigation. From various simulations and experiments, we could verify that the developed laser sensor device and the proposed localization method are effective to autonomous tracking of braille blocks and the autonomous navigation robot system can be used for rescue under fire.

• Spatial Information Research
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• 제23권4호
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• pp.47-56
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• 2015

최근 스마트폰 내비게이션의 그룹주행, 위치공유 등 다양한 최신 기능을 사용하기 위해서 스마트폰 내비게이션을 이용하는 사람들이 많이 증가하였다. 하지만, 스마트폰에는 다양한 목적을 가진 많은 앱이 설치되기 때문에 하나의 앱이 사용할 수 있는 저장 공간이 한정적이다. 그래서 내비게이션 전용기기에서 맵매칭을 수행하기 위해 사용되는 용량이 큰 도로네트워크 데이터를 스마트폰에 저장할 수 없기 때문에 맵매칭을 할 수 없다. 또한, 외부 GPS 장치를 사용하지 않는 스마트폰의 경우 내비게이션 전용기기에 비해 GPS 위치측위가 부정확하다. 이러한 문제점으로 스마트폰 내비게이션은 정확한 위치 안내를 하지 못하고 있다. 이에 본 연구의 목적은 스마트폰 내비게이션에서 정확한 위치 안내를 위해 내비게이션 전용기기에서 사용되는 도로네트워크 정보를 새로운 도로네트워크 포맷 설계 및 변환으로 용량을 감소시키고 운전자의 운전 패턴 데이터를 데이터베이스화하여 기존 내비게이션 전용기기 맵매칭 보다 정확한 맵매칭을 하는 것이다. 결과적으로 맵매칭이 어려운 여러 도로가 만나는 교차로, 고속도로에 인접한 좁은 도로, GPS 오차가 많이 발생하는 빌딩 숲 등에서 내비게이션 전용기기와 비교분석을 통해 스마트폰에서 기존 내비게이션 전용기기보다 80% 이상의 작은 저장 공간의 사용으로 보다 정확한 맵매칭이 가능했으며 향후 내비게이션뿐만 아니라 GPS 위치측위와 지도를 사용하는 다양한 앱에서 더욱 정확한 위치기반 서비스가 가능할 것으로 판단된다.

• 한국CDE학회논문집
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• 제9권4호
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• pp.277-285
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• 2004

In this paper, a 2 DOF haptic yawing joystick for use as the navigation input device in virtual environments is introduced. The haptic yawing joystick has 360° range for yawing motion and ±100° for pitching motion. The device can support weights of up to 26N for χ axis and 10N for axis with 10kHz of sampling rate. The size of the haptic yawing joystick is so small that it can be assembled on armrest of an arm chair and has relatively larger work space than other conventional 2 DOF joysticks. For the haptic yawing joystick, an ellipse navigation algorithm using the user's velocity in the virtual navigation is proposed. The ellipse represents the velocity of the user. According to the velocity of the navigator, the ellipse size is supposed to be changed. Since the path width of navigation environments is limited, the ellipse size is also limited. The ellipse navigation algorithm is tested in 2 dimensional virtual environments. The test results show that the average velocity of the navigation with the algorithm is faster than the average navigation velocity without the algorithm.

• 정보처리학회논문지D
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• 제15D권5호
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• pp.609-620
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• 2008

모바일 단말에서의 맵 데이터 활용 서비스는 내비게이션, 위치기반서비스 등 그 활용 범위가 다양해지고 있다. 이러한 모바일 단말에서 저장/관리되는 맵 데이터의 크기는 갈수록 커져 수 GB에 이른다. 기존 내비게이션 시스템의 경우, 리소스 제약으로 인해 모바일 단말의 성능을 최대로 활용하기 위하여 맵 데이터를 읽기 최적화된 물리적인 저장형식(PSF: Physical Storage Format)으로 저장 관리하고 있다. 즉, 맵 데이터가 변경된 경우 변경된 부분만의 업데이트가 불가능하여 전체 데이터를 업데이트해야 하는 단점이 있다. 일반적으로 2 GB 데이터를 모바일 단말의 플래시메모리에 기록하는 시간은 수십 분이 소요된다. 따라서 본 연구에서는 이러한 기존의 내비게이션용 맵 데이터의 부분 업데이트가 불가능한 점을 해결하고자 모바일 공간 DBMS을 개발하였다. 그리고, 모바일 공간 DBMS에서의 내비게이션 서비스의 성능을 보장하기 위한 기법을 제시하고 실험을 통하여 이를 검증하였다.