• Journal of The Korean Society For Urban Railway
• /
• v.6 no.4
• /
• pp.363-372
• /
• 2018

Simulator is used to verifying the function and performance of train control system before verifying with actual train. In this case, it is important that the simulation result should be coincide with the result with actual train. In this paper, the process of the development of automatic train operation (ATO) is described. ATO is in charge of automatic train control such as speed regulation and precision stop control. Identical interfaces from the ATO to the actual train was made in the simulator. Therefore ATO communicates to the simulator in the same way to the actual train. Futhermore, the train dynamic properties was measured by experiments and these were applied to the train model. Hence the response of the train in the simulator to the acceleration command is similar to that of the actual train. The simulation result of precision stop control is compared with the result in the actual train test to show the fidelity of the train model derived in the study and the superiority of this simulator.

• Journal of Power Electronics
• /
• v.11 no.4
• /
• pp.583-590
• /
• 2011

Three-level NPC inverters have been put into practical use for years especially in high voltage high power grids. This paper researches three-level active power filters (APFs). In this paper a mathematical model in the d-q coordinates is presented for 3-phase 3-wire NPC APFs. The deadbeat control scheme is obtained by using state equations. Canceling the delay of one sampling period and providing the predictive value of the harmonic current is a key problem of the deadbeat control. Based on this deadbeat control, the predictive output current value is obtained by the state observer. The delay of one sampling period is remedied in this digital control system by the state observer. The predictive harmonic command current value is obtained by the repetitive predictor synchronously. The repetitive predictor can achieve a better prediction of the harmonic current with the same sampling frequency, thus improving the overall performance of the system. The experiment results indicate that the steady-state accuracy and the dynamic response are both satisfying when the proposed control scheme is implemented.

• Asia pacific journal of information systems
• /
• v.12 no.2
• /
• pp.197-216
• /
• 2002

Cooperativeness within an organization can be conceptualized as the degree of members' willingness to work with others. The simulation study investigates the relationships of cooperativeness with team performance at different levels of information redundancy by using a multi-agents model called Team-Soar. The model consists of a group of four individual Al agents situated in a network, which models a naval command and control team consisting of four members. The study used a $9{\times}3$ design in which agent cooperativeness was manipulated at nine levels by gradually replacing selfish team members with increasing numbers of neutral and cooperative members, while information redundancy was controlled at three different levels(i.e., low, medium, and high). Results of the Team-Soar simulation show that cooperation has positive impacts on team performance. Further, the results reveal that the impact of agent cooperativeness on team performance depends on the amount of information needed to be processed during the decision making process.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1915-1919
• /
• 2004

In this paper, we propose a new discrete-time predictive current controller for a PMSM(Permanent Magnet Synchronous Motor). The main objectives of the current controllers are to ensure that the measured stator currents tract the command values accurately and to shorten the transient interval as much as possible, in order to obtain high-performance of ac drive system. The conventional predictive current controller is hard to implement in full digital current controller since a finite calculation time causes a delay between the current sensing time and the time that it takes to apply the voltage to motor. A new control strategy in this paper is seen the scheme that gets the fast adaptation of transient current change, the fast transient response tracking and is proposed simplified calculation. Moreover, the validity of the proposed method is demonstrated by numerical simulations and the simulation results will be verified the improvements of predictive controller and accuracy of the current controller.

• Proceedings of the KIEE Conference
• /
• 1991.11a
• /
• pp.397-400
• /
• 1991

This paper presents a cartesian space decentralized adaptive controller design for the end effector of the robot manipulator to track the given desired trajectory in the cartesian coordinate. By the cartesian based control scheme, the task related high level motion command is directly executed without solving the complex inverse kinematic equations. The controller does not require the complex manipulator dynamic model, and hence it is computationally very efficient. Each degree of freedom of the end effector on the cartesian space is controlled by a PID feedback controller and a velocity acceleration feed forward conpensation part. Simulation results for a two-link direct drive manipulator conform that the present cartesian based decentralized scheme is feasible.

• Proceedings of the KSME Conference
• /
• 2000.04a
• /
• pp.446-451
• /
• 2000

In this paper, a new adaptive cross-coupling control (CCC) algorithm with an improved contour error model is proposed to maintain contouring precision in high-speed nonlinear contour machining. The proposed method utilizes variable controller gains based on the instantaneous curvature of a contour and the feedrate command. The proposed method is evaluated and compared with the conventional CCC for nonlinear contouring motion through computer simulations. The simulation results show that the proposed CCC improves the contouring accuracy more effectively than the existing method.

• Journal of the Korean Society for Precision Engineering
• /
• v.17 no.11
• /
• pp.108-114
• /
• 2000

In this paper, a new adaptive cross-coupling control(CCC) method with an improved contour error model is proposed to maintain contouring precision in high-speed nonlinear contour machining. The proposed method utilizes variable controller gains based on the instantaneous curvature of a contour and the feedrate command. The proposed method is evaluated and compared with the conventional CCC for nonlinear contouring motion through computer simulations. The simulation results show that the proposed CCC improves the contouring accuracy more effectively than the existing method.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.12 no.1
• /
• pp.45-50
• /
• 1998

In recent year, inverters and cycloconverters system are widely used for fed induction motor drives. Motor drives by cycloconverter is possible to frequency have been directly changed without AC/DC converter, so that circuits is simpler than inverter. A aims of this paper is the control strategy and hardware design for vector control system by cycloconverter fed induction motor drives. In this paper, Algorithm of vector control is derivlid from the model of controlled current source-fed induction motor. Vector control system is implemented using these algorithm and a pulse width controled cycloconverter using a SCR. Cycloconverter of vector control system is controlled by pulse width of SCR's trigger signal. pulse width is controlled primary command current $li_1l$ and frequency TEX>$\omega_1$..

• Information Systems Review
• /
• v.19 no.3
• /
• pp.23-45
• /
• 2017

The ROK military is making a great effort and investment in establishing network-centric warfare, a future battlefield concept, as a major step in the establishment of a basic plan for military innovation. In the military organization level, an advanced process is introduced to shorten the command control time of the military and the business process is improved to shorten the decision time. In the information system dimension, an efficient resource management is achieved by establishing an automated command control system and a resource management information system by using the battle management information system. However, despite these efforts, we must evaluate the present level of informatization in an objective manner and assess the current progress toward the future goal of the military by using objective indicators. In promoting informatization, we must systematically identify the correct areas of improvement and identify policy directions to supplement in the future. Therefore, by analyzing preliminary research, workshops, and expert discussions on the major informatization level evaluation models at home and abroad, this study develops an evaluation model and several indicators that systematically reflect the characteristics of military organizations. The developed informatization level evaluation model is verified by conducting a feasibility test for the troops of the operation class or higher. We expect that this model will be able to objectively diagnose the level of informatization of the ROK military by putting budget and resources into the right place at the right time and to rapidly improve the vulnerability of the information sector.

• Journal of Aerospace System Engineering
• /
• v.11 no.5
• /
• pp.28-35
• /
• 2017

Magnetic Suspension and Balance System (MSBS) demonstrates the capacity to levitate an experimental model absent any mechanical contact using magnetic forces and moments. It allows precise control of position and attitude of the model, and measures external forces and moments acting on the model. For the purpose of acquisition of reliable experimental results under stable and safe conditions, the performance and robustness of the position and attitude control system of MSBS needs to be improved. To this end, Iterative Feedback Tuning (IFT) and L1 adaptive output feedback algorithm were employed to automatically increase command following performance and to ensure robust operation of MSBS with failure of electric power supply. The applicability was validated using computational simulation.