• 제어로봇시스템학회:학술대회논문집
• /
• 1993.10a
• /
• pp.491-497
• /
• 1993

In MIMO design, input and output units are different from each other. By this reason, the effect of larger units to smaller one is not trivial and there is no method of proper scaling, optimal scaling. In this paper, robust stability of MIMO LQG/LTR design are analised when the plnat inputs and outputs are scalled. The upper bound of model error to guarantee the robust stability is obtained, and gain margin and phase margins are computed with respect to scalling matrices.

• Journal of applied mathematics & informatics
• /
• v.19 no.1_2
• /
• pp.19-32
• /
• 2005

It is shown that the problem of minimizing (maximizing) a quadratic cost functional (quadratic gain functional) given the dynamics dx = (fx + gu)dt + hdb(t, a) where b(t, a) is a fractional Brownian motion of order a, 0 < 2a < 1, can be solved completely (and meaningfully!) by using the dynamical equations of the moments of x(t). The key is to use fractional Taylor's series to obtain a relation between differential and differential of fractional order.

• 전기의세계
• /
• v.29 no.4
• /
• pp.256-259
• /
• 1980

A singular pertubation theory is applied to obtain an approximate solution for suboptimal control of nuclear reactors with spatially distributed parameters. The inverse of the neutron velocity is regarded as a small perturbing parameter, and the model, adopted for simplicity, is a cylindrically symmetrical reactor whose dynamics are described by the one group diffusion equation with one delayed neutron group. The Helmholtz mode expansion is used for the application of the optimal theory for lumped parameter systems to the spatially distributed parameter systems. An asymptotic expansion of the feedback gain matrix is obtained with construction of the boundary layer correction up to the first order.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.37 no.3
• /
• pp.146-154
• /
• 1988

The computer simulation of speed and phase control system has been carried out in this study. The load of permanent magnet type synchronous motor is not constant in this system. The cost function method has been used in obtaining the optimal gain of PI controller and the rotor position angle of phase controller has been compensated depending on the load and speed variation. This analysis also shows that the current of d-axis component is zero under the variable a load conditions and the torque per unit current can be maximized.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2001.10a
• /
• pp.156-159
• /
• 2001

Recently, side scan sonar system has been developed and operated to survey cable laying, sunken bodies, geometry of sea bottom and so on. It uses the acoustic signals, which are emitted from two transducer arrays, left and right sides, to get geometric information of the specified area. This system consists of transceiver board, towed body, deck unit and GPS receiver. The transceiver board, nested in a watertight canister, controls the transmitting and receiving of the acoustic pulses from transducer arrays. After receiving the scattered signals, it processes BP(Band Pass) filtering, AGC(Automatic Gain Control), TVG(Time Varying Gain) and Heterodyne. The deck init has the signal processing part, A/D converter, power supplier, and real-time monitoring part. The towed body has been designed to satisfy the optimal hydrodynamic behavior during towing, In this paper, brief introductions on the design theory of transceiving part and some results from the field which have been operated recently will be introduced.

• Journal of the Institute of Electronics Engineers of Korea TE
• /
• v.37 no.3
• /
• pp.60-65
• /
• 2000

We propose a new method to deal with the optimal gain self-tuning of the PID controller which is used to industrial process control in various fields. First of all, in this method, first order delay system which was modeled from the unit step response of the system is Pade-approximated, then initial values are determined by the Ziegler-Nickels method. Finally, we can find the parameters of Pm controller so as to maximize the fuzzy inferencl function which includes the maximum overshoot, damping ratio, rising time and settling time. The proposed method also shows good adaptability for variations in characteristics and dead time of the system.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2000.10a
• /
• pp.222-227
• /
• 2000

"Side scan sonar" using acoustic signal has been developed to survey cable laying, sunken bodie\ulcorner bottom and so on. It use the acoustic signals, which are emitted from two transducer arrays, to get gemetri\ulcorner target area. This system consists of transceiver board, towed body, and deck unit. The transceiver board, w\ulcorner watertight canister of the towed body, controls the transmitting and receiving of 400kHz acoustic signals from \ulcorner After receiving the scattered signals, it processes the filtering, AGF(Automatic Gain Control), TVG(Time Heterodyne. The deck unit is composed of the signal processing part, A/D converter, power supplier, and real\ulcorner And the towed body has been designed to satisfy the optimal hydrodynamic behavior during towing. The de\ulcorner theory of transceiving part and some results from field-experiments will be introduced here.

• Journal of the Korean Society for Precision Engineering
• /
• v.8 no.3
• /
• pp.64-72
• /
• 1991

This paper deals with the state estimator and controller. All state variables' feedback in the system were used to improve electro hydraulic servo sysem were used to improve electro hydraulic servo system's responese charact- eristics. Many gains of the state variables'and estimator's are produced by the algebraic Riccati equation, and every state variables'optimal gain and estimator gain is selected by trial and error method. For the designed estimator performance's examination, this paper simulate the time response for the step input, the reduced velocity output in subjected to load torque, and the time response for the step input in changing the inertiamoment.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.23 no.1
• /
• pp.65-75
• /
• 2005

An accurate characterization of the display device is essential for better color matching. The calibration and characterization process in display device is needed to transform the device dependent color to the device independent color. The process of characterization performs a linearization and transforms the linearized values into the CIE XYZ tristimulus values. The purposes of this paper is to propose optimal color transformation method for accurate reproduction of original copy in display device and to explain the propriety of transformation method using specific variable for the power of gradation expression.

• The Journal of the Acoustical Society of Korea
• /
• v.41 no.2
• /
• pp.218-226
• /
• 2022

The main characteristics of the underwater acoustic channel have varying multipath and fast fading. Especially, Frequency Shift Keying (FSK) signals with multiple frequency bands caused loss of information bits allocated on the specific frequencies due to selective fading phenomenon. Therefore, this paper proposes frequency gain control algorithm based on preamble error rates. The proposed algorithm estimates optimal gain value in the range of preamble error rate with less than 10 % for specific faded frequency. By employing turbo equalized FSK signals with rate of 1/3, the experiment was conducted on a lake in Munkyeong city with distance of 300 m to 500 m. The result confirms that packets are decoded successfully by applying proposed algorithm as increasing number of iterations.