• 제어로봇시스템학회:학술대회논문집
• /
• 1988.10b
• /
• pp.1018-1021
• /
• 1988

This study is concerned with modeling an elastomer constitutive relation by utilizing the truncated Volterra series. Actual experimental data from the Instron Tester are obtained for combined input, i.e. constant strain rate followed by a constant strain input. These data are then estimated for step inputs and utilized for the truncated Volterra series models. One second order and one third order truncated Volterra series models have been employed to estimated the force-displacement relation which is one of the prominent properities to characterize the viscoelastic material. The third order Volterra series model has better results, compared with those of the second order Volterra series model.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.25 no.2
• /
• pp.119-124
• /
• 1988

Real-time adaptive lattice predictor was implemented on the TMS32020 DSP chip for digital signal processing. The implemented system was composed of Input-Output units and centrla processing-control unit and its supporting assembly soft ware. The performance of hardware realization was verified by comparing input signal and one-step prediction signal which are calcualted by the real-time adaptive lattice predictor. As a result, for 4 stage lattice structure, the maximum running frequency was obtained as 6.41 KHz in this experiment.

• Journal of Electrical Engineering and information Science
• /
• v.2 no.4
• /
• pp.53-58
• /
• 1997

In this paper, the power system stabilizer(PSS) using the sliding mode observer-model following(SMO-MF) with closed-loop feedback (CLF) for single machine system is extended to multimachine system. This a multimachine SMO-MF PSS for unmeasureable plant state variable is obtained by combining the sliding mode-model following(SM-MF) including closed-loop feedback(CLF) with the full-order observer(FOO). And the estimated control input for unmeasurable plant sate variables is derived by Lyapunov's second method to determine a control input that keeps the system stable. Time domain simulation results for the torque angle and for the angular velocity show that the proposed multimachine SMO-MF PSS including CLF for unmeasurable plant sate variables is able to damp out the low frequency oscillation and to achieve asymptotic tracking error between the reference model state at different initial conditions and at step input.

• Journal of Institute of Control, Robotics and Systems
• /
• v.19 no.3
• /
• pp.190-194
• /
• 2013

This paper presents experimental results of the attitude control for a two-rotor system with 3-DOF(degree-of-freedom). Two DC motors are equipped at the two ends of a rectangular beam to generate lift force and the relation between motor voltage and lift force is found experimentally. And inertial sensors are mounted at the center of the beam to measure the roll angle and a complementary filter is designed to get the angle during DC motors driving. A controller with nonlinear compensation, integrator and state feedback to achieve asymptotic tracking for a step input and reject input disturbance is designed and experimented.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.9 no.5
• /
• pp.65-72
• /
• 2000

This paper presents the study of the tension control in a web transfer system. In this study the sliding mode controller is applied to a time-varying nonlinear mathematical model. The model was derived to consider the effects of changing the roll radius in tension variation during winding and unwinding. The uncertainty in modeling may be due to unmodelled dynamics, on variations in system model. Designed sliding mode controller made the system error always staying in the suggested surface from the beginning. Through this, system is maintained to be robust against a disturbance and uncertainty. To verify the designed controller has a good performance, various inputs such as desired velocity, step input, and trapezoidal input are applied. When the sliding mode controller was used, the system(the tension control) performance was improved comparing to the PID controller. The robustness of the controller with respect to an estimation error was verified through simulations.

• International Journal of Aeronautical and Space Sciences
• /
• v.12 no.1
• /
• pp.16-23
• /
• 2011

In this paper, nonlinear model predictive control (NMPC) is addressed to develop formation guidance for multiple unmanned aerial vehicles. An NMPC algorithm predicts the behavior of a system over a receding time horizon, and the NMPC generates the optimal control commands for the horizon. The first input command is, then, applied to the system and this procedure repeats at each time step. The input constraint and state constraint for formation flight and inter-collision avoidance are considered in the proposed NMPC framework. The performance of NMPC for formation guidance critically degrades when there exists a communication failure. In order to address this problem, the modified optimal guidance law using only line-of-sight, relative distance, and own motion information is presented. If this information can be measured or estimated, the proposed formation guidance is sustainable with the communication failure. The performance of this approach is validated by numerical simulations.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.1668-1671
• /
• 2003

A novel dual-frequency microstrip printed-dipole antenna operating at 5 GHz and 10 GHz is presented. This antenna is designed for wireless and mobile communication. The balance step coplanar strip is used to be a transmission line at the center of dipole with matching impedance at 50 ohm. Using the conductor strip align on the other side of antenna and adjust the width of step coplanar strip line to improved input impedance matching. By modification for matching impedance of dual frequency antenna are not affected to the radiation patterns. The Finite Difference Time Domain (FDTD) technique is applying to analyze the basic characteristic properties such as $S_{11}$ , input impedance , VSWR and radiation patterns. And these parameters are discussed. The analyze problem space are $51{\times}197{\times}175$ cells and cell dimension are ${\Delta}x=0.3\;mm$ and ${\Delta}y={\Delta}z=0.15\;mm$.

• 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.

• Proceedings of the KIPE Conference
• /
• 2001.07a
• /
• pp.189-192
• /
• 2001

A new phase-shifted parallel-input/series-output dual converter for high-power step-up applications has been proposed. It features a high efficiency due to the low switch turn-off voltage, low device stresses, low ripple contents, and a fast control-to-output dynamics compared to its PWM counterpart. To confirm the validity of the proposed converter, experimental results from an 800W, 350Vdc prototype are presented.

• Journal of Magnetics
• /
• v.21 no.4
• /
• pp.491-495
• /
• 2016

We developed an embedded Object-Oriented Micromagnetic Frame (OOMMF) script schemes for more flexible simulations for complex and dynamic mircomagnetic behaviors. The OOMMF can be called from any kind of softwares by system calls, and we can interact with OOMMF by updating the input files for next step from the output files of the previous step of OOMMF. In our scheme, we set initial inputs for OOMMF simulation first, and run OOMMF for ${\Delta}t$ by system calls from any kind of control programs. After executing the OOMMF during ${\Delta}t$, we can obtain magnetization configuration file, and we adjust input parameters, and call OOMMF again for another ${\Delta}t$ running. We showed one example by using scripting embedded OOMMF scheme, tunneling magneto-resistance dependent switching time. We showed the simulation of tunneling magneto-resistance dependent switching process with non-uniform current density using the proposed framework as an example.