가상현실이란 디지털로 표현된 가상 환경을 뜻하며 인터넷 쇼핑, 아바타 등 기본적으로 디지털 환경을 일컫는 단어이며, 최근에는 머리에 장착하는 디스플레이(HMD : Head Mounted Display)의 등장으로 사용자가 현실과 유사한 환경을 직접 경험하는 체험형 콘텐츠로서 의미를 확장했다. 현재 가상현실은 게임을 비롯한 힐링 콘텐츠, 관광, 군사 시뮬레이션 다양한 분야에서 주목받고 있으며 HMD의 보급 또한 활발하다. 사용자가 가상현실 콘텐츠를 체험하기 위해서는 몇 가지 제약이 발생하는데, 사용자의 시야가 차단되 현실공간감각이 상실된다. 따라서 기존에 사용되었던 입력장치인 키보드, 마우스 등의 사용에 어려움이 있으며 HMD를 개발하는 개발사들은 위의 문제를 해결하고자 가상현실 체험에 특화된 핸드트래킹 디바이스를 제공한다. 하지만 이 또한 상호작용, 이동, 제스처가 손에 집중되어있어 가상환경에 익숙하지 않은 이용자의 사용자 편의가 낮다. 본 논문은 이러한 이동의 문제를 아두이노를 통해 제작한 발 트레킹 디바이스로 이동을 분리시켜 해결하고자 하였다. IMU의 각속도계와 가속도계를 이용해 다리의 궤적을 측정하려 하였고, 이때 발생한 오차는 상보필터를 통해 해결하였다. 또한 기본적으로 발생하는 센싱-통신-연산 과정에서의 노이즈는 두가지 이동평균기법과 생략평균값을 이용해 안정화 시켰다. 사용자는 해당 장비와 Oculus Rift를 착용하고 Unity3d환경으로 구축된 실험환경에서 임무 수행 속도, 이동방향 오차율등을 측정해 기존 HMD컨트롤러와 본 논문에서 제시하는 컨트롤러를 비교 검증했다. 실험 결과 임무 수행 속도와 이동 오차율 모두에서 본 논문에서 제시하는 장치가 우수한 데이터를 제공하였다. 본 실험 결과를 토대로 이동조작 분리가 높은 접근성을 제공한다는 것을 확인하였다. 본 논문은 HMD 이동 컨트롤러를 포함한 이후 개발되는 다양한 사용자 제스처 인식 컨트롤러에도 적용 가능할것으로 보인다.

The author introduces a test platform system that has been developed for variable-speed control moment gyroscopes(VCMGs). VCMGs are important actuators for spacecraft attitude control. The test platform consists of two VCMGs driven by servo motors and sensor modules. The control program has been coded by the NI LabVIEW. Accelerometers and gyros have been used to measure the attitude angle and angular speed of the platform. The 2nd order low pass filters have effectively filtered out noises from measurements. Wheel speeds and gimbal angles have been controlled satisfactory by PI control. Through some tests, moment generation has been verified. The moment has been generated as commanded. However, friction effect by a ball bearing, that supports the platform’s rotation, has been not negligible. As further studies, friction reduction will be studied. In conclusion, this test platform will be used for engineering education and research.

본 연구에서는 교통사고나 뇌졸중 등에 의해 상지의 장애를 가지는 장애인을 대상으로 하여, 인터넷의 브라우저와 같은 소프트웨어를 사용 할 수 있는 컴퓨터 인터페이스로서 자이로센서를 이용한 무선 자이로 마우스시스템를 개발하고, 임상평가를 통해 그 유용성을 확인하고자 한다. 시스템 개발에 있어서 주안점은, 첫째, 장애인의 경우 휠체어나 침대에 누워서 마우스 조작을 할 수 있도록 시스템의 무선화하는 것, 둘째, 착탈의 용이성과 미관을 위하여 센서를 헤드 밴드에 삽입하는 것, 셋째, 컴퓨터 운영체제에게 클릭신호를 전달하기 위하여, C5~C6 환자들의 경우에는 클릭 스위치를 사용하고, C4환자의 경우에는 고개의 끄덕임을 검출하도록 하는 것이다. 개발된 시스템을 척수손상으로 인한 상지 장애인을 대상으로 평가실험을 실시하였다. 그 결과 시행횟수가 증가할수록 상하/좌우 이동시의 목표위치에 대한 실제위치의 오차가 감소하고, 1분당 클릭률이 증가하는 경향을 확인하였다. 이로부터, 개발된 무선 자이로마우스 시스템은 환자의 반복사용을 통해 그 유용성이 증가할 것을 알 수 있다.

This paper introduces a Feedback Linearization (FL) controller to eliminate the gyro effect on a quadrotor UAV. In order to control the attitude of the quadrotor, the second model equation was differentiated to the 4-th order to induce the control input to be revealed, and then a new control input was derived based on the attitude transformation equation with a gyro effect. For the initial quick posture control of the quadrotor, the existing yaw control was replaced with a separate controller. The simulation was conducted with an experiment in which FL control to remove the gyro effect was applied to the quadrotor and an experiment without removing the gyro effect, from the experimental results, the maximum error seen in each axial direction of the quadrotor was x = 0.22 m, y = 0.20 m, z = 0.16 m. Through the proposed method, the effect of the FL controller for controlling the gyro effect of the quadrotor was confirmed.

This study proposes a measurement method using angular sensors to measure deformation and displacement of bridges. The proposed measurement method consists of gyroscope sensors and data processor to transform angular to vertical displacement. This study contains experimental evaluation to verify the applicability of the proposed method. 3-points bending tests were conducted on a small-sized girder specimen. The displacements were measured with both conventional LVDT and gyroscope sensor to compare the accuracy of the proposed method. It is estimated that the method using gyroscope shows some noise in data, but the method using gyroscope has advantages to measure the vertical displacement. Therefore if the sampling rate and synchronizing problems can be approved, it can be a good alternative measuring method for the deformation of the bridges.

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.

This paper presents a sensitivity optimization of a MEMS (microelectromechanical systems) gyroscope for a magnet-gyro system. The magnet-gyro system, which is a guidance system for a AGV (automatic or automated guided vehicle), uses a magnet positioning system and a yaw gyroscope. The magnet positioning system measures magnetism of a cylindrical magnet embedded on the floor, and AGV is guided by the motion direction angle calculated with the measured magnetism. If the magnet positioning system does not measure the magnetism, the AGV is guided by using angular velocity measured with the gyroscope. The gyroscope used for the magnet-gyro system is usually MEMS type. Because the MEMS gyroscope is made from the process technology in semiconductor device fabrication, it has small size, low-power and low price. However, the MEMS gyroscope has drift phenomenon caused by noise and calculation error. Precision ADC (analog to digital converter) and accurate sensitivity are needed to minimize the drift phenomenon. Therefore, this paper proposes the method of the sensitivity optimization of the MEMS gyroscope using DEAS (dynamic encoding algorithm for searches). For experiment, we used the AGV mounted with a laser navigation system which is able to measure accurate position of the AGV and compared result by the sensitivity value calculated by the proposed method with result by the sensitivity in specification of the MEMS gyroscope. In experimental results, we verified that the sensitivity value through the proposed method can calculate more accurate motion direction angle of the AGV.

이 논문은 자유자이로의 방향보존성을 이용하여 위치를 결정하는 방법을 이론적으로 유도한 것이다. 즉, 임의 위치에서 두 대의 자유자이로 회전축의 경사각과 기준 위치로부터 측정한 경과 시간을 기본 요소로 하여 위치를 결정하는 시스템을 제시하고 이 시스템을 구축할 때 나타나는 문제점을 열거하였다.

This paper described the method and the result of making a dynamic fiber optic gyrocompass measuring the heading angles of ships by processing the output signal from a constant rotating fiber optic sensor and also showed the measurement to test the performance of our system. Considerig an economical view we designed and ordered a cheap medium grade fiber densors increased not fiber length but the diameter of a fiber sensing loop. The scale factor and noise was 267mV/deg/s and 2 deg/hr/Hz(1Σ), respectively. We made the dynamic fiber optic gyrocompass by this sensor. We measured the heading angles in an arbitrary direction to evaluate the accuracy of our system and the root mean square error was 0.4˚. Moreover, we measured the angles ineach direction of 45˚. successive rotation to know whether this system has distoritions in a specific direction or not and the root mean square error in this case was 0.5˚.

This paper describe the method and the result of making a fiber optic gyrocompass measuring the heading angles of a ship with a fiber optic sensor. As the method seeking for the heading angles, it is possible to get the heading angles by measuring the output signals from a stationary fiber optic sensor in at least three directions such as a heading direction and other two directions having phase difference Φ1 and Φ2 to the heading. We made the static fiber optic gyrocompass by a high performance fiber optic sensor having scale factor of 210mV/deg/s and resolution of 0.5deg/hr using this principle. The accuracy of this system was 0.29˚ from 20 numbers of data measuring the arbitrary heading angle.

In this study, an interface is developed in compliance with the standards which is made by National M.E.A in U.S.A for transmitting the Marine Gyrocompass information. The interface consists of Bearing Signal Transfer, Bearing Signal Demodulator, Bearing Signal Discriminator, Bearing Counter and, Informatioin Tranmitter. The results are as follows : The transmission of bearing information was achieved successfully on the Marine RADAR by the interface tranmitting for the Marine Gyrocompass. And, newly proposed phase-detector in Bearing Signal Discriminator which method is forcibly reset the previous data of D-T Flip Flop can be solved the problems of the delay in phase discrimination and the unstableness in the boundary areas of input signal.

In this study, the self test-system for the marine Gyrocompass was developed and the obtained results are summarized as follows : 1) Utilizing the newly developed self-test system, the time length for observing the transient state of Gyrocompass reading which has been over 4 hours can be reduced to less than 20 minutes. In addition, the dynamic characteristics of the Gyrocompass can be measured within 2 hours after starting the system. 2) Prior test and diagnosis was done by checking all parameters recurrently with period of 2.5minutes. 3) Testing and diagnosis results was shown in graphic mode and could be transmitted to INMARSAT unit using personal computer. 4) The results of the newly designed trouble algorithm for the system was found to be applicable under arbitrary given conditions.

As a basic study for enhancing the sensitivity of the follow-up system of the marine gyrocompass, the geometric characteristics of the deflection sensor were investigated and the theoretical model of it was formulated. The output signal voltage of the deflection sensor was esamined by changing the attitude of gyrosphere against follow-up container. The characteristics of the output are found to be indentical with those of the distance difference versus the relative azimuthal deflection of the gyrosphere against the follow up container. On the base of the theoretical model, some useful points for the design of the deflection sensor are suggested as following : 1. When the difference between semidiamter of gyrophere and that of the follow-up container decreases, the sensitivity of deflection sensor increases. 2. If the semidiameter difference of two spheres is constant, the sensitivity of deflection sensor is proportional to the magnitude of the semidiamter of each sphere. 3. The farther the gyrosphere is deviated from the center of follow-up container, the higher the sensitivity of deflection sensor is. 4. It is recommendable that the value of the datum deflection of the electrodes on the gyrosphere should be within the range between 4˚ and 16˚deviated from north-south line.

One of the main purposes of the marine gyrocompass follow-up system is to preserve the sensitive part from the wandering error due to the frictional or torsional torque around the vertical axis. This error can be diminished through the rapid follow-up action, which minimizes the relative azimuthal angular displacement between the sensitive and follow-up parts and shortens the duration of the same displacement. But an excessive rapidity of the follow-up action would result in a sustained oscillation to the system. Therefore, to design a new type of the follow-up system, the theoretical annlysis of the problems concerned should be studied systematically by introducing the control theory. This paper suggest a concrete procedure for the optimal adjustment of the gyrocompass follow-up system, utilizing the mathematic model and the stability informations formerly investiaged by the author. For theoptimal determination of the adjustable paramfter K, the performance index(P.I.), ITSE(Intergral of the Time multiplied by the Squared Error) is proposed, namely, P.I. = ʃ0∞ t · e2(t)dt where t is time and e(t) means control error. Then, the optimal parameter minimizing the performance index is calculated by means of Parseval's theorem and numerical computation, and the validity of the obtained optimal value of the parameter Ka is examined and confirmed through the simulations and experiments. By using, the proposed method, the optimal adjustment can be performed deterministically. But, this can not be expected in the conventional frequency domain analysis. While the Mps of the original system vary to the extent of from 0.98 to 46.27, Mp of the optimal system is evaluated as 1.1 which satisfies the generally accepted frequency domain specification.