• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2007.11a
• /
• pp.296-299
• /
• 2007

본 논문에서는 전기로 합금철 투입 중량을 보다 정밀하게 제어하기 위하여 퍼지 함수를 사용한 제어 기법을 적용하였다. 합금철 중량 제어에 사용된 퍼지 제어는 기존 단순 패턴 제어에 비하여 합금철 계량 정밀도를 높였으며, 합금철 계량 시간을 크게 단축시켰다. 한편 퍼지 제어 함수는 제어수식을 일반화시켜서 Programmable Logic Controller (PLC)의 래더 프로그램으로 구현하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.46 no.6
• /
• pp.487-495
• /
• 2018

Experimental analysis of the spray characteristics of the movable sleeve injector, which can simultaneously control the area of the annular gap and the pintle gap, has been studied and a method for controlling the uniform performance over a wide thrust range has been studied. It is confirmed that the design flow rate is not satisfied when the constant pressure difference is set regardless of the opening distance of the sleeve. In order to improve this, the differential pressure in the annular gap and the pintle gap was applied differently according to the opening distance. It was confirmed that the design flow rate was satisfied within the operating range and thrust control was linear from 25% to 100% in linear sleeve area.

• 제어로봇시스템학회:학술대회논문집
• /
• 2002.10a
• /
• pp.120.5-120
• /
• 2002

1. Introduction 2. Property of FPGA 3. Evolvable Hardware (EHW) 4. Genetic Algorithm Processor (GAP) 5. State Machine 6. Conclusion

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.52 no.6
• /
• pp.342-350
• /
• 2003

In this paper, a levitation controller for a magnetic levitation(MagLev) system is designed and implemented. The target to be controlled is PEM(permanent and electromagnet) type with 4-corners levitation which is open-loop unstable, highly non-linear and time-varying system. The digital control system consists of a VME-based CPU board, AD board, PU board, 4-Quadrant chopper, and gap sensor, accelerometer as feedback sensors. In order to estimate the velocity of the magnet, we used 2nd-order state observer with acceleration and gap signal as input and output, respectively. Using the estimated states, a state feedback control law for the plant is designed and the feedback gains are selected by using the pole-placement method. The designed controller is experimentally validated by step-type gap reference change and force disturbance test.

• 제어로봇시스템학회:학술대회논문집
• /
• 1995.10a
• /
• pp.154-157
• /
• 1995

A magnetic levitation control system is nonlinear and very unstable. Thus there should be a stabilizing compensation network and a feedback path. Due to the levitation control a noncontact photoresistor sensor is generally used. One photocell provides a certain amount of variation in length by the ball shadow casted on the cell surface. Furthermore at the boundary of the cell, the linearity of sensitivity deteriorates severely. To overcome the constraints of the length and linearity, an efficient sensor array is deviced and applied in the feedback path of a large-gap magnetic levitation control system. A number of CdS photocells and a summing circuit of the sensor output signals are used for a sensor array. The levitation length of a ball and the transient performances are main objectives of the large-gap suspension system using the sensor array.

• Journal of Advanced Marine Engineering and Technology
• /
• v.22 no.6
• /
• pp.888-893
• /
• 1998

In this paper, we present a magnetic levitation system which has not a gap sensor with sensor-less realization and stabilizing controller design. For measuring gap between magnet and levitated object we propose a gap sensorless method and adop two-degree-of-freedom controller for robust-ness and performence of the magnetic levitation system. From time responeses we confirm that the proposed sensorless method which can be applied to magnetic levitation system. Also the designed stabilizing controller has good disturbance rejection and reference tracking performance.

• Transactions of the Society of Information Storage Systems
• /
• v.5 no.1
• /
• pp.41-46
• /
• 2009

In SIL-based NFR servo systems, the residual error and the overshoot that are occurred in the process of the modes-witching servo which consists of approach, gap-control modes, and safety mode are reduced by using PID controller. However, the design method of conventional PID controller is not sufficient for the stable air gap control system. Therefore, the optimal PID controller using LQR manner is more useful to find the designed parameters of PID controller. In this paper, we show that the performance of the optimal PID controller is better than that of the lead-lag controller.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2003.05a
• /
• pp.1004-1008
• /
• 2003

Near-filed optical storage using cantilever aperture tip is a promising way fer next generation optical data storage. To enhance the speed of reading and writing data, gap between tip and media should be controlled fast and precisely within near field region. In this paper, several PZT actuators are analyzed far constructing dual servo control algorithm: coarse actuators(stact. PZT, bimorph PZI) for media surface inclination and One actuator(film PZT) for media surface roughness. Dynamic analysis of stack PZT, bimorph PZT, and film PZT are performed through the frequency response. Based on the frequency response and mathematical model, fast analog controller is designed.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.52 no.11
• /
• pp.535-540
• /
• 2003

Since axial flux motor has an advantage over more conventional radial flux type motor such as high power density, it can be used as a power train for hybrid electric vehicle and electric vehicle. Also operating range can be extended and efficiency can be improved by changing air gap. Optimal operating air gap is estimated based on the measured efficiency at different air gap. Motor model is developed based on estimated optimal air gap and efficiency. Motor/controller performance is analyzed through simulation. Possible application area of axial flux motor was explored through simulation.

• Journal of the Korean Society of Industry Convergence
• /
• v.26 no.6_2
• /
• pp.1127-1134
• /
• 2023

In this paper, we proposes a study on air gap control for magnetic levitation of transverse flux permanent magnet electromagnets. In general, mechanical systems have a high failure rate of bearings. Bearings in particular are problematic because they have high surface wear rate and degradations. To solve this problem, replacing the bearing with a magnetic levitation electromagnet system can provide lightweight and efficiency improvements. However, precise air gap control is essential to control the magnetic levitation electromagnet system. Therefore, in this paper, we identify the instable cause of gap control through a mathematical modeling and verify through experiment a control algorithm that can use compensation.