• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.283-283
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• 2000

In this paper, we deals with a decentralized control scheme with input compensation form for gantry crane systems. By considering the gantry crane's characteristics, the system is decentralized into two subsystems such as the travelling and sway subsystem, and the hoisting subsystem. For decentralizing the system, a simple algorithm is proposed using observability canonical form. The decentralized subsystems include unknown input which coupled with other subsystems and actuator failures. These unknown input and actuator failures are estimated by using PI observation techniques and those estimated values are used to construct an input compensation form. Lastly, the proposed decentralized control scheme far the gantry crane systems is verified by crane simulation.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.4
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• pp.281-287
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• 2001

In this paper, we deal with a decentralized control scheme with input compensation form for gantry crane systems. By considering the gantry cranes characteristics, the system is decentralized into two subsystems, the travelling and swaying subsystem and the hoisting subsystem. For decentralizing the system, a simple algorithm is proposed using the observability canonical form. The decentralized subsystems include unknown inputs that one coupled with other subsystems and actuator failures. These unknown input and actuator failures are estimated by using PI observation techniques. And those estimated values are used to construct an input compensation form. Finally, the proposed decentralized control scheme for the gantry crane systems is verified by crane simulation.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.133-136
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• 1987

This paper presents a new algorithm of optimal measurement system by using band matrix characteristic respectively for state estimation. A performance index of measurement system is established to reflect relation among measurement sets, probability of measurement failure and cost of individual meter installation. Selection ranking in the candidates of measurement sets is composed to guarantee the observability for any any single meter outage. Performance index sensitivity is introduced and recursive formula which based on the matrix inversion lemma used for selection. The proposed algorithm is composed of successive addition algorithm, successive elimination algorithm and combinatorial algorithm. The band matrix characteristic could save in memory requirements and calculate the performance index faster than earlier.

• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1705-1714
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• 2018

This paper develops a novel controller called iterative learning sliding mode (ILSM) to control linear and nonlinear fractional-order systems. This control applies a combination structures of continuous and discontinuous controller, conducts the system output to the desired output and achieve better control performance. This controller is designed in the way to be robust against the external disturbance. It also estimates unknown parameters of fractional-order systems. The proposed controller unlike the conventional iterative learning control for fractional systems does not need to apply direct control input to output of the system. It is shown that the controller perform well in partial and complete observable conditions. Simulation results demonstrate very good performance of the iterative learning sliding mode controller for achieving the desired control objective by increasing the number of iterations in the control loop.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.8
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• pp.774-778
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• 2008

The inaccuracy of inertial sensors used in low cost IMU's limits the usage to ARS, at best. Sensor fusion technologies are widely used to overcome this problem. GPS is the most popular secondary sensor, but GPS alone cannot fully compensate the IMU errors in the initial alignment process and rectilinear flights. This paper presents a new concept of aiding the low cost IMU with the sun line of sight vector. The simulation and experimental results in this paper proves that aiding of INS/GPS with the sun line of sight vector increases the observability and improves accuracy remarkably.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.1
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• pp.12-20
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• 2002

To control the noise of an enclosed sound field, we built a state space model using the acoustic modal parameter description. Using the state space model, we can investigate the controllability and observability, and find an appropriate position of control speaker and microphone to control sound field of the enclosed space. We implemented LQR(linear quadratic regulator) controller and reduced order observer to reduce the first acoustic mode. Experiments showed satisfactory results of 4∼10 dB reduction of magnitude of the first acoustic mode, and support the feasibility of the proposed scheme to lightly damped acoustic field.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1383-1384
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• 2015

In this paper, a dynamics model embedded navigation filter is newly suggested for underwater autonomous systems without position or attitude aid. In order to ensure the observability on the INS errors, the hydrodynamics of the underwater vehicle is incorporated with the INS attitude error. This approach allows us to estimate and compensate the INS errors in spite of using external velocity sensor. Through the simulation, the performance and effectiveness of the proposed scheme are demonstrated.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.489-489
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• 2000

Recently, Reinforcement Learning(RL) methods have been used far teaming problems in Partially Observable Markov Decision Process(POMDP) environments. Conventional RL-methods, however, have limited applicability to POMDP To overcome the partial observability, several algorithms were proposed [5], [7]. The aim of this paper is to extend our previous algorithm for POMDP, called Labeling Q-learning(LQ-learning), which reinforces incomplete information of perception with labeling. Namely, in the LQ-learning, the agent percepts the current states by pair of observation and its label, and the agent can distinguish states, which look as same, more exactly. Labeling is carried out by a hash-like function, which we call Labeling Function(LF). Numerous labeling functions can be considered, but in this paper, we will introduce several labeling functions based on only 2 or 3 immediate past sequential observations. We introduce the basic idea of LQ-learning briefly, apply it to maze problems, simple POMDP environments, and show its availability with empirical results, look better than conventional RL algorithms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.1
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• pp.11-19
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• 1992

This paper proposes a reduced order method which reduces passband error by changing controllability and observability gramian based on weighted functions in the linear time invariant system. In the case that the 4-order model is the reduced to 3-order model in the low-pass filter, the QEI in the proposed method is improved to 6.15724 compared to 10.16464 in the balanced realization method and the sensitivity is improved to 5.45962 compared to 7.790568. The frequency property curves show that the proposed method is superior to the balanced realization method.

• Journal of the Korean Home Economics Association
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• v.42 no.9
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• pp.177-193
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• 2004

The purpose of this study was to explore consumer behavior of perfume products. Data were collected through 7 focus group interviews with 33 female consumers whose ages ranged between the 20's and 40's. According to analysis of groups divided by age and frequency of use, some group differences were found in information source, purchase place, consideration factors, fragrance preference, etc. The study results indicated that perfume consumption behaviors could be explained in part by the innovation adoption and communication theories. Especially, relative advantage, compatibility, observability, and trialability were important factors influencing consumers' adoption of new perfume. Also, many respondents used perfume as a tool to present their own image and identity, as well as to send messages regarding their mood and condition to others.