• 항공우주기술
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• 제11권2호
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• pp.39-48
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• 2012

인공위성에 사용되는 자이로 센서는 출력 형태에 따라 누적형, 증분형, 각속도 제공형 등으로 나눌 수 있다. 이들 중 누적각을 제공하는 자이로는 보통 이진 카운터를 사용하며 누적각이 카운터의 최대값을 넘어서는 경우는 롤오버(Roll-over) 하도록 설계되어 있다. 이로 인해 각속도를 계산하는 과정에 제한 사항이 발생하며 계산할 수 있는 각속도는 센서 자체가 측정할 수 있는 영역보다 작은 영역으로 제한된다. 본 연구에서는 누적각을 제공하는 자이로 센서의 일반적인 각속도 계산 방법을 소개하고 일반적인 방법이 가지는 최대측 정영역의 한계를 넘어서는 각속도를 계산할 수 있는 방법을 제안한다. 제안된 방법은 입력 각속도의 변화에 제한이 있는 경우에만 적용이 가능하며 입력 각속도의 변화와 확장 가능한 영역의 범위를 정량적으로 유도하였다. 마지막으로 모의실험을 통하여 제안된 방법의 타당성을 검증하였다.

• Journal of Electrical Engineering and Technology
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• 제9권1호
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• pp.334-343
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• 2014

In this paper, we suggest a method to improve the fusion of an accelerometer and gyro sensor by using a Kalman filter to produce a more high-quality respiration signal to supplement the weakness of using a single accelerometer. To evaluate our proposed algorithm's performance, we developed a chest belt-type module. We performed experiments consisting of aerobic exercise and muscular exercises with 10 subjects. We compared the derived respiration signal from the accelerometer with that from our algorithm using the standard respiration signal from the piezoelectric sensor in the time and frequency domains during the aerobic and muscular exercises. We also analyzed the time delay to verify the synchronization between the output and standard signals. We confirmed that our algorithm improved the respiratory rate's detection accuracy by 4.6% and 9.54% for the treadmill and leg press, respectively, which are dynamic. We also confirmed a small time delay of about 0.638 s on average. We determined that real-time monitoring of the respiration signal is possible. In conclusion, our suggested algorithm can acquire a more high-quality respiration signal in a dynamic exercise environment away from a limited static environment to provide safer and more effective exercises and improve exercise sustainability.

• 한국항해항만학회지
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• 제35권2호
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• pp.121-130
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• 2011

The localization of vehicle is an important part of an unmanned vehicle control problem. Pseudolite ultrasonic system(PUS) is the method to find an absolute position with a high accuracy by using ultrasonic sensor. And Gyro is the inertial sensor to measure yaw angle of vehicle. PUS can be able to estimate the position of mobile robot precisely, in which errors are not accumulated. And Gyro is a more faster measure method than PUS. In this paper, we suggest a more accuracy method of calculating PUS which is numerical analysis approach named Newtonian method. And also propose the fusion method to increase the accuracy of estimated angle on moving vehicle by using PUS and Gyro integrated system by Kalman filtering. To control the 4WS unmanned vehicle, the trajectory following algorithm is suggested. And the new concept arbitration of goal controller is suggested. This method considers the desirability function of vehicle state. Finally, the performances of Newtonian method and designed controller were verified from the experimental results with the 4WS vehicle scaled 1/10.

• 한국항해항만학회지
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• 제37권4호
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• pp.329-335
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• 2013

This paper is to develop the position error equations including the attitude errors, the errors of nadir and ship's heading, and the errors of ship's position in the free-gyro positioning and directional system. In doing so, the determination of ship's position by two free gyro vectors was discussed and the algorithmic design of the free-gyro positioning and directional system was introduced briefly. Next, the errors of transformation matrices of the gyro and body frames, i.e. attitude errors, were examined and the attitude equations were also derived. The perturbations of the errors of the nadir angle including ship's heading were investigated in each stage from the sensor of rate of motion of the spin axis to the nadir angle obtained. Finally, the perturbation error equations of ship's position used the nadir angles were derived in the form of a linear error model and the concept of FDOP was also suggested by using covariance of position error.

• 한국정밀공학회지
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• 제29권11호
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• pp.1199-1206
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• 2012

Recently, technologies to help the elderly or disabled people who have difficulty in walking are being developed. In order to develop these technologies, it is necessary to construct a system that gathers the gait data of people and analysis of these data is also important. In this research, we constructed the development of sensor system which consists of pressure sensor, three-axis accelerometer and two-axis gyro sensor. We used k-means clustering algorithm to classify the data for characterization, and then calculated the symmetry index with histogram which was produced from each cluster. We collected gait data from sensors attached on two subjects. The experiment was conducted for two kinds of gait status. One is walking with normal gait; the other is walking with abnormal gait (abnormal gait means that the subject walks by dragging the right leg intentionally). With the result from the analysis of acceleration component, we were able to confirm that the analysis technique of this data could be used to determine gait symmetry. In addition, by adding gyro components in the analysis, we could find that the symmetry index was appropriate to express symmetry better.

• 전기학회논문지
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• 제67권7호
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• pp.871-877
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• 2018

In this paper, we propose a triple nested PID control scheme for stable hovering of a quadrotor and propose a complementary filter based sensor fusion technique to improve the performance of attitude, altitude and velocity measurement. The triple nested controller has a structure in which a double nested attitude controller that has the angular velocity PD controller in inner loop and the angular PI controller in outer loop, is nested in a velocity control loop to enable stable hovering even in the case of disturbance. We also propose a sensor fusion technique by applying a complementary filter in order to reduce the noise and drift error included in the acceleration and gyro sensor and to measure the velocity by fusing image, gyro, and acceleration sensor. In order to verity the performance, we applied the proposed control and measurement scheme to hovering control of quadrotor.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2018년도 제58차 하계학술대회논문집 26권2호
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• pp.503-504
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• 2018

전 세계 스마트폰 보급량은 지속적으로 증가하고 있으며 고급형 스마트폰 보다는 센서를 제거해 원가를 절감한 보급형 스마트폰이 더 많이 보급될 것으로 예측되고 있다. 본 논문에서는 자이로 센서가 없을 때의 위치 기반의 방향 탐지 방법으로써 위치를 기반으로 한 벡터를 이용하여 방향을 탐지하고, 높이 축에 대한 제한, 위치 변화 없는 회전에 대한 제한 등의 제약들을 개선할 후속 연구의 방향성을 제시한다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2014년도 춘계학술발표대회
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• pp.1020-1022
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• 2014

In this paper, we present a method for smartphone users to have a better user experience when playing 3D mobile games using the gyro sensor. We designed the rotation of the virtual camera in the game world to be proportional to the real-world's rotation. We have also made the sensitivity configuration possible for users to manipulate.

• 한국전자통신학회논문지
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• 제12권4호
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• pp.599-606
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• 2017

본 논문에서는 유모차 안전사고를 줄이기 위하여 유모차 자동 브레이크 시스템을 설계, 제작하였다. 아두이노를 기반으로 초음파센서를 이용하여 운전자 손의 핸들 접촉 유무를 판단하고, 자이로 센서로 유모차의 현재 기울어진 정도를 검출하도록 설계하였다. 다음 유모차 운전자의 손이 인식되지 않고 기울기가 특정각도를 넘어가면 서보모터가 작동하여 유압식 브레이크를 작동시켜 내리막길에서의 사고를 방지하도록 설계, 제작하였다. 끝으로 현재 상태표시 및 브레이크 원격제어가 가능하도록 스마트폰 기반의 어플리케이션을 개발하였다.

• 한국항해항만학회지
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• 제29권7호
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• pp.611-614
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• 2005

This paper is to develop the position error equation of in the free-gyro positioning system by using two free gyros. First, the determination of a position is analyzed on the ellipsoid of the Earth and the type of the errors is defined Finally the position error equation is introduced and developed, based on the definition of the type of errors which may be involved in the FPS.