• 센서학회지
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• 제8권2호
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• pp.139-147
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• 1999

본 논문에서는 관성 항법 장치 및 동작 제어 장치 능에서 회전 각속도를 검출하기 위하여 널리 사용되는 동조 자이로스코프의 새로운 각속도 검출방법을 제시하였다. 제안된 방법은 자이로스코프의 모델을 사용하여 재평형 루프의 설계를 수행함으로써 기존의 PI제어 방법만을 사용하였을 경우보다 외부 입력에 대하여 속도 검출을 위한 픽업단의 회전각도가 과도 및 정상 상태에서 작은 검출각을 유지시킨 상태에서 입력 각속도를 검출할 수 있으며 이에 따라 자유 자이로스코프의 기계적인 변경 없이도 시스템의 동작 범위를 매우 넓히는 것이 가능함을 보였다. 제안된 방법을 사용한 동조자이로스코프 시스템의 모델 및 전달 특성을 제시하였으며 최종적으로 컴퓨터 모의실험 모델 및 그 결과를 제시하여 그 타당성을 확인하였다.

• 한국구조물진단유지관리공학회 논문집
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• 제19권2호
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• pp.60-67
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• 2015

유한요소모델 개선은 구조물의 설계검증, 손상추적, 내하력 평가 등 다양하게 활용되고 있는 기법이다. 일반적인 유한요소모델 개선은 구조물에서 계측된 가속도응답으로부터 구조물의 고유진동수와 모드형상을 구하고, 이를 바탕으로 모델을 개선하게 된다. 이와 같은 가속도응답기반 유한요소모델 개선은 구조물의 병진 자유도를 고려하기 때문에 물리적인 체계를 추정하는데 있어서 매우 적합하지만, 회전 자유도 상에서 변화하는 구조물의 경계조건을 판별하기에는 어려움이 있다. 최근 센서 기술의 개발로 인하여 저렴한 가격, 높은 정확성의 자이로센서들이 개발되고 있으며, 그에 따라 구조물의 회전 자유도에 관한 정보 획득이 용이해지고 있다. 본 연구에서는 이를 바탕으로 가속도와 각속도 응답을 함께 이용하는 데이터 융합 기반 유한요소모델 개선 기법을 제안하였다. 가속도와 각속도를 모두 활용한 데이터융합기법은, 가속도만 사용한 기존의 유한요소 모델 기법보다 구조물의 경계조건 판별에 정확한 정보를 제공한다. 본 논문에서는 단순보 모델을 이용한 수치 시뮬레이션을 통해서, 제안한 가속도와 각속도 데이터 융합기반의 유한요소모델 개선 기법의 성능을 검증하였다.

• 소음진동
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• 제5권3호
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• pp.313-325
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• 1995

Two active/passive vibration dampers were designed to control a cantilever beam first mode of vibration. The active element was a piezoelectric polymer, polyvinlidene fluoride (PVDF). The passive damping was provided by the application of a viscoelastic layer on the surface of the steel beam. Two substantially different damper configurations were designed and tested. One damper consisted of a piezoelectric actuator bonded to one face of the beam, with a viscoelastic layer applied to the other surface of the beam. The second one was composed of a layer viscoeastic layer with one surface bonded to the beam, and with other being constrained by nine piezoelectric actuators connected in parallel. A control law based on the sign of the angular velocity of the cantilever beam was implemented to control the beam first mode of vibration. The piezoelectric sensor output was digitally differentiated to obtain the transverse linear velocity, and its sign was used in the control algorith. Two dampers provided the system a damping increase of a factor of four for the first damper and three for the second damper. Both dampers were found to work well at low levels of vibration, suggesting that they can be used effectively to prevent resonant vibrations in flexible structure from initiating and building up.

• International Journal of Control, Automation, and Systems
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• 제2권4호
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• pp.435-449
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• 2004

In this paper, a novel anti-sway control system that uses an inclinometer as a sway sensor is investigated. The inclinometer, when compared with a vision system, is very cheap, durable, and easy to maintain, while providing almost the same performance. A number of observers to estimate the angular velocity of the load and the trolley velocity are presented. A state feedback controller with an integrator is designed. After a time-scale analysis, a 1/4-size pilot crane of a rail-mounted quayside crane was constructed. The performance of the proposed control system was verified with a real rubber-tired gantry crane at a container terminal as well as with the constructed pilot crane. Experimental results are provided.

• Journal of Power Electronics
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• 제11권5호
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• pp.743-750
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• 2011

This article deals with the sensor-less control of a DC Motor via a SEPIC Converter-Full Bridge combination powered through solar panels. We simultaneously regulate, both, the output voltage of the SEPIC-converter to a value larger than the solar panel output voltage, and the shaft angular velocity, in any of the turning senses, so that it tracks a pre-specified constant reference. The main result of our proposed control scheme is an efficient linear controller obtained via Lyapunov. This controller is based on measurements of the converter currents and voltages, and the DC motor armature current. The control law is derived using an exact stabilization error dynamics model, from which a static linear passive feedback control law is derived. All values of the constant references are parameterized in terms of the equilibrium point of the multivariable system: the SEPIC converter desired output voltage, the solar panel output voltage at its Maximun Power Point (MPP), and the DC motor desired constant angular velocity. The switched control realization of the designed average continuous feedback control law is accomplished by means of a, discrete-valued, Pulse Width Modulation (PWM). Experimental results are presented demonstrating the viability of our proposal.

• 전기학회논문지
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• 제63권2호
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• pp.277-283
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• 2014

This paper proposes robot localization using Fuzzy-Extended Kalman Filter algorithm of the mobile robots equipped with least sensors. In order to improve the accuracy of the localization, we usually add the sensors or equipment. However, it increases the simulation time and expenses. This paper solves this problem using only the odometer and ultrasonic sensors to get the localization with the Fuzzy-Extended Kalman Filter algorithm method. By inputting the robot's angular velocity, sensor data variation, and residual errors into the fuzzy algorithm, we get the sensor weight factor to decide the sensor's importance. The performance of the designed method shows by the simulation and Pioneer 3-DX mobile robot test in the indoor environment.

• 재활복지공학회논문지
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• 제11권3호
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• pp.231-238
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• 2017

본 연구에서는 개인 피트니스를 수행하는 과정에서 건강관리와 운동효과를 증대시킬 수 있도록 운동동작을 분석하는 방법을 제안하였다. 본 연구에서는 사용자가 밴드 형태의 가속도, 각속도, 지자계 모듈이 장착된 운동 센서를 착용하고 피트니스 운동 중에 발생하는 신호를 획득하고 운동동작을 분석하였다. 본 논문에서 제시한 기법을 활용하여 세 가지 저항성 운동의 동작을 분석하였으며 이는 기존의 연구결과와 일치함을 확인하였다. 저항성 운동 상황에서 생성된 데이터로부터 개인화된 운동정보를 가공할 수 있는 기술을 확보하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1190-1193
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• 2004

The purpose of this study is to evaluate the possibility of identifying joint damping property through commercially available isokinetic ergometer (BIODEX). The proposed method is to estimate the damping torque of the knee joint from the difference between the external joint torque for maintaining isokinetic movement and the gravity torque of the lower leg. The damping torque was estimated at various joint angular velocities, from which the damping property would be derived. Measurement setup was composed of the BIODEX system with an external force sensor and Labview system. Matlab was used in the analysis of the damping property. The experimental result showed that the small variation in angular velocity due to acceleration and deceleration of the crank arm resulted in greater change of inertial torque than the damping torque, so that the estimation of damping property from the isokinetic movement is difficult.

• Smart Structures and Systems
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• 제7권2호
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• pp.103-116
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• 2011

This paper is concerned with the trajectory tracking and vibration suppression of a single-link flexible arm by using piezoelectric materials. The dynamics of a single flexible arm with PZT patches as sensor and actuator is derived using extended Hamilton's principle. Resulting equations show that the coupled beam dynamics including beam vibration and its rigid in-plane rotation takes place in two different time scales. By using singular perturbation theory, the system dynamics is divided into two subsystems. Then, a composite control scheme is elaborated that makes the orientation of the arm track a desired trajectory while suppressing its vibration. The proposed controller has two parts: one is a tracking controller designed for the slow (rigid) subsystem, and the other one is a stabilizing controller for the fast (flexible) subsystem. The outputs considered for the system are angular position of the hub and voltage of the sensor mounted on the structure. To avoid requiring further measurements of beam vibration and also angular velocity of the hub for the fast and slow control laws, respectively, two sliding mode observers for estimating the unknown states are also designed.

• 대한전기학회논문지:시스템및제어부문D
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• 제53권10호
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• pp.703-713
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• 2004

This paper presents the new obstacle avoidance method that is composed of vision and sonar sensors, also a navigation algorithm is proposed. Sonar sensors provide poor information because the angular resolution of each sonar sensor is not exact. So they are not suitable to detect relative direction of obstacles. In addition, it is not easy to detect the obstacle by vision sensors because of an image disturbance. In This paper, the new obstacle direction measurement method that is composed of sonar sensors for exact distance information and vision sensors for abundance information. The modified splitting/merging algorithm is proposed, and it is robuster for an image disturbance than the edge detecting algorithm, and it is efficient for grouping of the obstacle. In order to verify our proposed algorithm, we compare the proposed algorithm with the edge detecting algorithm via experiments. The direction of obstacle and the relative distance are used for the inputs of the fuzzy controller. We design the angular velocity controllers for obstacle avoidance and for navigation to center in corridor, respectively. In order to verify stability and effectiveness of our proposed method, it is apply to a vision and sonar based mobile robot navigation system.