• 한국항해항만학회지
• /
• 제35권10호
• /
• pp.785-791
• /
• 2011

본 논문에서는 소형 선박용 관성측정장치(Inertial Measurement Unit, IMU) 개발에 적합한 MEMS(Micro-Electro Mechanical System) 기반의 관성 센서 평가와 선정에 관하여 기술했다. 먼저, 오일러 공식에 기초한 관성 센서의 오차 모델과 잡음 모델을 정의하고, 앨런 분산(Allan Variance) 기법과 몬테카르로(Monte Carlo) 시뮬레이션 기법을 도입하여 관성 센서를 평가하였다. ADIS16405, SAR10Z, SAR100Grade100, LIS344ALH, ADXL103 등 다섯 가지 관성 센서에 대한 평가결과, ADIS16405의 자이로와 가속도계를 조합한 경우 오차가 가장 작게 나타났는데, 600 초 경과시 속도 오차의 표준편차가 약 160 m/s, 위치 오차의 표준편차가 약 35 km로 나타났다. 평가를 통해 ADIS16405 관성 센서가 IMU 구축에 최적임을 알았고, 이러한 오차 감소 방법에 대해서 참고문헌을 조사하여 검토하였다.

• 센서학회지
• /
• 제22권1호
• /
• pp.54-64
• /
• 2013

In this study, we developed a falling recognition system to transmit SMS data through CDMA communication using a three axises acceleration sensor and a two axises gyro sensor. 5 healthy men were selected into a control group, and the fall recognition system using the three axises acceleration sensor and the two axises gyro sensor was devised to conduct an experiment. The system was attached to the upper of their sternum. According to the experiment protocol, the experiment was carried out 3 times repeatedly divided into 3 specific protocols: falling during gait, falling in stopped state, and falling in everyday life. Data obtained in the falling recognition system and LabVIEW 8.5 were used to decide if falling corresponds to that regulated in an analysis program applying an algorithm proposed in this study. In addition, results from falling recognition were transmitted to designated cellular phone in a SMS (Shot Message Service) form. These research results show that an erroneous detection rate of falling reached 19% in applying an acceleration signal only; 6% in applying an angular velocity; and 2% in applying a proposed algorithm. Such finding suggests that an erroneous detection rate of falling is improved when the proposed algorithm is applied incorporated with acceleration and angular velocity. In this study therefore, we proposed that a falling recognition system implemented in this study can make a contribution to the recognition of falling of the aged or the disabled.

• 제어로봇시스템학회논문지
• /
• 제19권2호
• /
• pp.158-163
• /
• 2013

The fusion of the GPS (Global Positioning System) and DR (Dead Reckoning) is widely used for position and latitude estimation of vehicles such as a mobile robot, aerial vehicle and marine vehicle. Among the many types of aerial vehicles, grater focus is given on the quad-rotor and accuracy of the position information is becoming more important. In order to exactly estimate the position information, we propose the fusion method of GPS and Gyroscope sensor using the DEKF (Dual Extended Kalman Filter). The DEKF has an advantage of simultaneously estimating state value and a parameter of dynamical system. It can also be used even if state value is not available. In order to analyze the performance of DEKF, the computer simulation for estimating the position, the velocity and the angle in a circle trajectory of quad-rotor was done. As it can be seen from the simulation results using own proposed DEKF instead of EKF on own fusion method in the navigation of a quad-rotor gave better performance values.

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

• Advances in aircraft and spacecraft science
• /
• 제4권1호
• /
• pp.53-64
• /
• 2017

Aerospace Launch Vehicles (ALV) are generally designed with high reliability to operate in complete security through fault avoidance practices. However, in spite of such precaution, fault occurring is inevitable. Hence, there is a requirement for on-board fault recovery without significant degradation in the ALV performance. The present study develops an advanced fault recovery strategy to improve the reliability of an Aerospace Launch Vehicle (ALV) navigation system. The proposed strategy contains fault detection features and can reconfigure the system against common faults in the ALV navigation system. For this purpose, fault recovery system is constructed to detect and reconfigure normal navigation faults based on the sliding mode observer (SMO) theory. In the face of pitch channel sensor failure, the original gyro faults are reconstructed using SMO theory and by correcting the faulty measurement, the pitch-rate gyroscope output is constructed to provide fault tolerant navigation solution. The novel aspect of the paper is employing SMO as an online tuning of analytical fault recovery solution against unforeseen variations due to its hardware/software property. In this regard, a nonlinear model of the ALV is simulated using specific navigation failures and the results verified the feasibility of the proposed system. Simulation results and sensitivity analysis show that the proposed techniques can produce more effective estimation results than those of the previous techniques, against sensor failures.

• 정보과학회 컴퓨팅의 실제 논문지
• /
• 제23권3호
• /
• pp.148-155
• /
• 2017

본 논문에서는 스마트폰 내 가속도, 자기장, 자이로스코프 센서들을 이용해 사용자의 걸음과 걸음 수를 인식하는 시스템을 개발하였다. 센서 데이터 분석을 통해 사용자의 걸음을 스마트폰을 손에 든 상황과 주머니에 넣은 상황에서의 걸음 패턴으로 분류하고 이를 추출할 수 있는 알고리즘을 사용하여 걸음 수 인식의 정확성을 개선하였다. 알고리즘을 적용한 결과 손에든 상황에서 96%, 주머니에 넣은 상황에서 95.5% 수준의 걸음 수 인식 정확도를 보였으며, 나머지 터치 스크린, 위아래 반복 흔들기, 앉아서 일어서기, 오른쪽 왼쪽 흔들기와 같은 행위로 인해 발생하는 6%의 오차를 확인하였다.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2013년도 추계학술대회
• /
• pp.1048-1050
• /
• 2013

모바일 기기와 스마트폰은 급속하게 중앙의 컴퓨터와 통신 네트워크 기기로 변화하고 있다. 최근에는 스마트폰은 프로그램이 가능하며 가속도, 전자나침판, 자이로스코프, GPS, 마이크, 카메라와 같은 저가의 고성능 내장형 센서들과 함께 출시되고 있다. 본 논문에서는 무선 가스 센싱 서비스 구조를 분석하고 스마트폰과 웹 서버를 이용한 가스 센서 모니터링 서비스를 개발한다.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2018년도 추계학술발표대회
• /
• pp.430-433
• /
• 2018

This paper proposes the Kalman filter (KF) with optical flow method to estimate the position and the velocity of unmanned aerial vehicles (UAVs) in the absence of global positioning system (GPS). A downward-looking camera, a gyroscope and an ultrasonic sensor are fused to compensate the measurement from optical-flow method. To overcome the problem of dealing with noise in onboard sensors, the KF is incorporated to efficiently predict the velocity and estimate the position. Basic mechanisms of optical flow and the KF are introduced and experiments are conducted to show how the techniques involved improve the estimations.

• 한국전자통신학회논문지
• /
• 제19권2호
• /
• pp.473-482
• /
• 2024

공중화장실에 존재하는 위험요소를 식별하기 위하여 가상현실로 공중화장실을 구현하였다. 가상현실 공중화장실에 대한 평가를 통하여 실제 공중화장실의 위험요소를 도출하고자 하였다. 이를 위하여 가상현실 공중화장실을 체험하는 사용자가 휴대한 스마트폰 내장 센서 중에 3-축 가속도 센서와 자이로센서가 있는데, 이 센서가 보내오는 데이터를 분석함으로써 시공간 요소 중에서 사용자에게 영향을 주는 요소를 도출하되, 해당 요소가 위험요인이 되는지 여부가 데이터 분석을 기반으로 하는 평가 알고리즘에 의거하여 이루어졌음을 보였다.

• 대한인간공학회지
• /
• 제31권5호
• /
• pp.637-646
• /
• 2012

Objective: The aim of this study was to develop the adaptive device for severe physical disabilities using smart device in the driving simulator and its performance evaluation. Development of appropriate driving adaptive device for the people with serious physical limitation could contribute to maintain their community mobility. Background: There is lack of adaptive driving devices for the people with disabilities in Korea. However, if smart device systems like iPod and iPhone are used for driving a car, the people with serious physical limitations can improve their community mobility. Method: Both gyroscope and accelerometer from iPod were used to measure the tilted angle of the smart device for driving. Customized Labview program was also used to control three axis motors for steering wheel, accelerator and brake pedals. Thirteen subjects were involved in the experiment for performance evaluation of smart device in simulator. Five subjects had driver licenses. Another four subjects did not have driver licenses. Others were people with disabilities. Results: Average driving score of the normal group with driver license in the simulator increased 46.6% compared with the normal group without driver license and increased 30.4% compared with the disabled group(p<0.01). There was no significant difference in the average driving score between normal group without driver license and disabled group(p>0.05). Conclusion: The normal group with driver license showed significantly higher driving score than other groups. The normal group without driver license and disabled group could improve their driving skills with training in simulator. Application: If follow-up studies would be continued and applied in adapted vehicle for on road environment, many people with more severe disabilities could drive and improve the quality of life.