• 동력기계공학회지
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• 제3권1호
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• pp.50-54
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• 1999

In order to reject the steady-state tracking error, it is common to introduce integral compensators in servosystems for constant reference signals. However, if the mathematical model of the plant is exact and no disturbance input exists, the integral compensation is not necessary. From this point of view, a two-degree-of-freedom(2DOF) servosystem has been proposed, in which integral compensation is effective only when there is modeling error for disturbance input. The present paper considers the design problem of 2DOF servosystem incorporating an observer. It is shown that if a state feedback gain and a observer gain satisfy a condition, the integral effect does not appear when modeling error or disturbance input exists. This result means that the servosystem does not behave as a 2DOF servosystem.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
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• pp.663-668
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• 1986

State variables of an observer were made use of to realize the optimal position control of a hydraulic servosystem with the inherent nonlinearities. The range of eigenvalues of an observer suitable for the hydraulic servosystem was investigated through computer simulation. The effect of direct state feedback of hydraulic servosystem was compared with that of estimated state feedback using observer to ascertain the possibility of performance increase using observer.

• Journal of Mechanical Science and Technology
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• 제14권11호
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• pp.1198-1205
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• 2000

A two-degrees-of-freedom servosystem for step-type reference signals has been preposed, in which the integral compensation is effective only when there is a modeling error or a disturbance input. this paper considers robust stability of the servosystem incorporating an observer against both structured and unstructured uncertainties of the plant. A condition is obtained as a linear matrix inequality, under which the servosystem is robustly stable independently of the gain of the integral compensator. This result implies that we can tune the gain to achieve a desirable transient response of the servpsystem preserving robust stability. An example is presented to demonstrate that under the robust stability condition, the transient response can be improved by increasing the gain of the integral compensator.

• 한국해양공학회지
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• 제13권3B호
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• pp.91-98
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• 1999

In order to reject the steady-state tracking error, it is common to introduce integral compensators in servosystems for constant reference signals. However, if the mathematical model of the plant is exact and no disturbance input exists, the integral compensation is not necessary. From this point of view, a two-degree-of-freedom(2DOF) servosystem has been proposed, in which the integral compensation is effective only when there is a modeling error or a disturbance input. The present paper considers a synthesis problems of this 32DOF servosystem with direct transfer term in the system representation. And, a method how we may obtain a gain such that desirable transient response is achieved, is proposed in the presence of the modelling error and disturbance input.

• 한국해양공학회지
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• 제13권3B호
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• pp.99-105
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• 1999

In order to reject the steady-state tracking error, it is common to introduce integral compensators in servosystems for constant reference signals. However, if the mathematical model of the plant is exact and no disturbance input exists, the integral compensation is not necessary. From this point of view, a two-degree-of-freedom(2DOF) servosystem has been proposed, in which the integral compensation is effective only when there is a modeling error or a disturbance input. The present paper considers a robust stability of this 2DOF servosystem with nonlinear type uncertainty in the system, and a robust stability condition for the servosystem is introduced. This result guarantees that if the plant uncertainty is in the permissible set defined by the condition, gain tuning can be carried out to suppress the influence of the plant uncertainties and disturbance inputs.

• 대한기계학회논문집
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• 제11권5호
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• pp.781-788
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• 1987

본 연구에서는 제어대상으로 설정된 유압서어보 시스템은 비선형 시스템이므 로, 실제로 측정한 상태변수와 관측기에서 추정한 상태변수를 비교하여 이들이 서로 일치하는 것을 보임으로써 관측기에서 추정한 다른 상태변수들에 대한 신뢰도를 높일 수 있다. 따라서 본논문에서는 전차수 관측기를 사용한 경우에 대하여 고찰한다.

• Journal of Advanced Marine Engineering and Technology
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• 제20권2호
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• pp.125-125
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• 1996

In order to reject the steady-state tracking error, it is common to introduce integral compensators in servosystems for constant reference signals. However, the mathematical model of the plant is exact and no disturbance input exists, the integral compensation is not necessary. From this point of view, a two-degree-of-freedom(2DOF) servosystem has been proposed, in which the integral compensation is effective only when there is a modeling error or a disturbance input. The present paper considers robust stability of this 2DOF servosystem to the unstructured uncertainty of the controlled plant. A robust stability condition is obtained using Riccati inequality, which is independent of the gain of the integral compensator. An example is presented, which demonstrates that the tracking response of the 2DOF servosystem with uncertainty becomes faster when the integral gain made larger under the robust stability condition.

• Journal of Advanced Marine Engineering and Technology
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• 제20권2호
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• pp.57-62
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• 1996

In order to reject the steady-state tracking error, it is common to introduce integral compensators in servosystems for constant reference signals. However, the mathematical model of the plant is exact and no disturbance input exists, the integral compensation is not necessary. From this point of view, a two-degree-of-freedom(2DOF) servosystem has been proposed, in which the integral compensation is effective only when there is a modeling error or a disturbance input. The present paper considers robust stability of this 2DOF servosystem to the unstructured uncertainty of the controlled plant. A robust stability condition is obtained using Riccati inequality, which is independent of the gain of the integral compensator. An example is presented, which demonstrates that the tracking response of the 2DOF servosystem with uncertainty becomes faster when the integral gain made larger under the robust stability condition.

• 수산해양기술연구
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• 제32권1호
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• pp.59-66
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• 1996

This paper considers robust stability and transient behavior of the Two - Degree - of - Freedom(2DOF) servosystem. A class of uncertainties allowed in the plant model is obtained, to which the servosystem is robustly stable for any gain of the integral compensator. This result implies that if the plant uncertainty is the allowable set defined by the condition, a high - gain compensation can be carried out preserving stability to achieve a high - speed tracking response. The transient behavior attainable by the limit of the high - gain compensation is calculated using the singular perturbation approach.

• 대한기계학회논문집
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• 제12권2호
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• pp.215-220
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• 1988

본 연구에서는 비례제어하였을 때 정정한 시스템(K=1.0)과 진동 현상을 보이는 시스템(K=20)을 제어대상으로 설정한 후, 관측기의 상태변수를 이용하여 이들을 피이드백 제어하였을 때 응답 특성이 개선될 수 있는지를 조사하고자 한다.