• 한국소음진동공학회논문집
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• 제20권10호
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• pp.953-959
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• 2010

This paper deals with the process to identify the exciting forces generated from a rotary compressor. The equation of motion of a rigid compressor supported by several mounts was derived with 6 degree of freedom. The mass moment of inertia of compressor and the stiffness of rubber mounts were also identified by experiments. The exciting force at the center of mass of the compressor were estimated from the acceleration data measured at compressor shell. The piping system connected to the compressor was modeled. The acceleration of a pipe was predicted numerically by using the predicted exciting force. The numerical results showed good agreement with experimental results, which validated the identified exciting force.

• 로봇학회논문지
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• 제17권3호
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• pp.288-295
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• 2022

This study shows a system identification method of a balancing loading device for a stair climbing delivery robot. The balancing loading device is designed as a 2-axes gimbal structure and is interpreted as two independent pendulum structures for simplifying. The loading device's properties such as mass, moment of inertia, and position of the center of gravity are changeable for luggage. The system identification process of the loading device is required, and the controller should be optimized for the system in real-time. In this study, the system identification method is based on least squares method to estimate the unknown parameters of the loading device's dynamic equation. It estimates the unknown parameters by calculating them that minimize the error function between the real system's motion and the estimated system's motion. This study improves the accuracy of parameter estimation using a null space solution. The null space solution can produce the correct parameters by adjusting the parameter's relative sizes. The proposed system identification method is verified by the simulation to determine how close the estimated unknown parameters are to the real parameters.

• 한국산업융합학회 논문집
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• 제8권4호
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• pp.205-212
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• 2005

This paper presents the application of system identification approaches for the load carrying capacity evaluation of composite PCI girder bridges based on the result of field test. For these problems, the moment of inertia of cross-sectional area and the natural frequency of bridge were used as structural parameters, the SAP2000 program for the structural analysis and the SLP method for the minimum error. As a result, it is found that the proposed algorithm for this study appears applicable to real structures with reasonable complexity. It is shown that the introduction of approximate quadratic equations is more realistic and timesaving than the common methods.

• 전력전자학회논문지
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• 제6권3호
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• pp.282-290
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• 2001

유도전동기의 고성능 응답을 얻기 위해서는 전동기 매개변수의 정확한 추정이 필수적이다. 본 논문에서는 고정자(회전자)저항, 고정자(회전자)누설 인덕턴스, 상호 인덕턴스, 관성 모멘트와 같은 매개변수들을 오프라인으로 측정하였다. 고정자(회전자) 저항과 고정자(회전자) 누설 인덕턴스는 정지좌표계의 방정식들로부터 측정한 반면, 상호 인덕턴스는 스칼라 제어 상태에서 측정되었다. 마지막으로, 확장 칼만필터를 이용하여 회전자 역시 상수를 온라인 상에서 동정하였다. 본 논문에서 언급하는 추정알고리즘들의 유용성을 보이기 위해 실험결과들을 제시하였다.

• 전력전자학회논문지
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• 제14권2호
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• pp.150-159
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• 2009

일반적으로 드럼 세탁기의 구동 효율은 주로 세탁 시간에 영향을 받는다. 이러한 세탁 시간은 세탁물의 양과 종류에 따라 결정된다. 비록 세탁물의 종류는 사용자에 의해 쉽게 입력이 가능하지만 세탁물의 양은 사용자가 입력하기 힘들다. 이 때문에 세탁물의 양을 추정하는 구간이 존재하며 추정된 세탁물의 양에 따라 세탁 행정의 시간이 결정된다. 따라서 본 논문은 정확한 세탁물의 양을 측정하기 위해 관성 추정기를 사용한 부하 추정 알고리즘을 제안한다. 제안된 알고리즘은 실제 세탁기에 적용이 가능하도록 저가형 위치 센서를 사용하는 PMSM 구동회로를 통해 실험하였다. 그리고 실제 세탁 부하 조건과 일치하도록 드럼 세탁기에 세탁물을 인가하여 부하추정을 실험하였다.

• 전기학회논문지
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• 제56권4호
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• pp.730-738
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• 2007

As well known when the linear machine is operated between two points repeatedly under positioning control, there are various positioning error at the moment of zero speed owing to the non-linear disturbance like as unpredictable friction force. To remove this positioning error, a simple least order disturbance observer is introduced and is actually implemented in this study. Due to this simple algorithm the over-all machine system can be modified to simple arbitrary given one-mass load without any disturbance. So, the total construction process for positioning control system is much easier than old one. Moreover, to generate a proper effective position profile with the limited actual machine force, a very powerful on-line mass identification algorithm using the load force estimator is presented. In the proposed mass identification algorithm, the exact load mass can be calculated during only one moving stage under a normally generated position profile. All presented algorithm is verified with experimental result with commercial linear servo machine system.

• 한국정밀공학회지
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• 제21권11호
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• pp.209-218
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• 2004

The purpose of this paper is to suggest a practical and simple method for the identification of the joint mechanical properties and to apply it to human knee joints. The passive moment at a joint was modeled by three mechanical parts, that is, a gravity term, a linear damper term and a nonlinear spring term. Passive pendulum tests were performed in 5 fat and 5 thin men. The data of pendulum test were used to identify the mechanical properties of joints through sequential quadratic programming (SQP) with random initial values. The identification was successful where the normalized root-mean-squared (RMS) errors between the simulated and experimental joint angle trajectories were less than 10％. The parameter values of mechanical properties obtained in this study agreed with literature. The inertia, gravity and the damping constant were greater at fat men, which indicates more resistance to body movement and more energy consumption fer fat men. The suggested method is noninvasive and requires simple setup and short measurement time. It is expected to be useful in the evaluation of joint pathologies.

• 한국통신학회논문지
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• 제21권1호
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• pp.291-299
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• 1996

이 논문에서는 다층 구조 고차 신경회로망을 이용하여 로봇 메니퓰레이터와 같이 관성이 크고 복잡한 특성을 갖는 시스템을 효과적으로 동정화하는 새로운 방법을 제안한다. 로봇 메니퓰레이터의 위치 및 속도와 미리 정해준 기준 점들 사이의 차이를 나타내는 특정 성능 지수 함수를 최소화하는 방법을 이용하여 동정화 과정에 필요한 신경회로망의 학습에 이용되는 입력 데이터를 설계하는 방법을 설명한다. 사람의 팔과 같이 비교적 큰 관성을 갖는 2축 로봇 매니퓰레이터를 이용한 컴퓨터 시뮬레이션으로부터 제안된 방법이 복잡한 특성을 갖는 시스템의 동정화에 필요한 입력 데이터를 효과적으로 설계할 수 있음을 보인다.

• 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.

• 한국군사과학기술학회지
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• 제4권2호
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• pp.157-178
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• 2001

In this paper, the nonlinear control of high precision pointing stabilization system using feedback-linearization design methodology based on system parameter identification is discussed. Modern nonlinear servomechanism theory is adapted to cope with the hard nonlinearities inherent in the turret system. The mathematical models of electrical turret driving system to develop a high performance control algorithm are derived, and the parameter estimation algorithm identifying the unknown system parameters such as vicious and coulomb frictions, stiffness and inertia is developed. Through computer simulation and experiments, it is shown that pointing and tracking accuracy and stabilization against the wideband stochastic disturbance induced by vehicle running on the bump course are improved. Therefore, it is considered the proposed nonlinear control technique is effective in counteracting the nonlinearities and disturbances.