• Journal of Institute of Control, Robotics and Systems
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• v.7 no.1
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• pp.1205-1210
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• 2001

This paper describes a methodology using neural network to compensate the nonlinear error of deriving speed for electric differential system included in electric vehicle. An electric differential system which drives each of the left and right wheels of the electric vehicle independently. The electric vehicle driven by induction motor has the nonlinear speed error which depends on a steering angle and speed command. When a vehicle drives along a curved road lane, the speed unblance of inner and outer wheels makes vehicles vibration and speed reduction. To compensate for the speed error, we collected the speed data of the inner wheel and outer wheel in various speed and the steering angle data by using an manufactured electric vehicle and the real system. According to the analysis of the acquisited data, we designed the differential speed control system based on a speed error compensator using neural network.

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.164-167
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• 2001

In resent years, electric power quality has become an important issue in power system. Voltage variation and compensation countermeasures of KEPCO system in west Gyeongnam have been simulated using PSS/E. In this paper, in the abnormal power system, the adaption of SVC, high speed and continuous control are simulated for voltage compensation. It is shown that the SVC is the optimal voltage compensation method in loop power system or 2 lines radial system.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.12
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• pp.1610-1617
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• 1988

In this paper, a robust discrete-time adaptive control with compensation is proposed for single-input single-output discrete-time plants which have unmodeled dynamics. The stability of the overall system is studied using the conic sector stability theorems when a normalized constant gain parameter adaptation algorithm and a properly chosen compensation are used. An illustrative exmple shows that this compensation can also increase the parameter adaptation speed. And a method of compensation using the adaptive observation is also discussed.

• Journal of Industrial Technology
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• v.28 no.B
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• pp.199-207
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• 2008

A linear wind prediction program, WAsP, was employed to predict wind speed at two different sites located in complex terrain in South Korea. The reference data obtained at locations more than 7 kilometers away from the prediction sites were used for prediction. The predictions from the linear model were compared with the measured data at the two prediction sites. Two compensation methods such as a self-prediction error method and a delta ruggedness index (RIX) method were used to improve the wind speed prediction from WAsP and showed a good possibility. The wind speed prediction errors reached within 3.5 % with the self prediction error method, and within 10% with the delta RIX method. The self prediction error method can be used as a compensation method to reduce the wind speed prediction error in WAsP.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.10
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• pp.894-902
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• 2000

This paper proposes a force reflection control method with a speed saturation compensation scheme for the slave manipulators having a speed saturation due to the high reduction ratio joints. When speed saturation is generated, the proposed force reflection control method not only shows an anti-windup feature in controlling the slave manipulator but also makes the master manipulator move slowly using the force reflection caused by saturation. In this way, the position of the slave manipulator tracks the reference position regardless of speed saturation. The experimental results show that the proposed control method provides excellent performance.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.268-273
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• 2008

A linear wind prediction program, WAsP, was employed to predict wind speed at two different sites located in complex terrain in South Korea. The reference data obtained at locations more than 7 kilometers away from the prediction sites were used for prediction. The predictions from the linear model were compared with the measured data at the two prediction sites. Two compensation methods such as a self-prediction error method and a delta ruggedness index (RIX) method were used to improve the wind speed prediction from WAsP and showed a good possibility. The wind speed prediction errors reached within 3.5 % with the self prediction error method, and within 10% with the delta RIX method. The self prediction error method can be used as a compensation method to reduce the wind speed prediction error in WAsP.

• Journal of the Korean Vacuum Society
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• v.20 no.6
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• pp.387-394
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• 2011

Standard devices and procedures for measuring the pumping speed, one of the most important parameters indicating the operation performance of the vacuum pump, have been developed and widely utilized. Though the standard system has a firm theoretical basis, it is, sometimes, inevitable to alter something in the system for a practical purpose compared with ideal conditions, which may lead to a large measurement error. In this paper, characteristics and systematic errors of various ideal or practical schemes for measuring the pumping speed are analyzed, and compensation terms are proposed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.68 no.3
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• pp.430-438
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• 2019

For a pump or a compressor motor, a high periodic load torque variation is induced by the mechanical works, and it causes system vibration and noise. To minimize these problems, load torque compensation method, injecting periodic torque current, could be utilized. However, with the sensorless control method, which is usually utilized in the pump and compressor for low cost, the periodic torque current degrades the accuracy of the rotor position estimation owing to the inductance variation. This paper analyzes the rotor position and speed estimation error of sensorless control method with constant motor parameters under period loading. Assuming the constant speed by the accurate load torque compensation, the speed error equation is derived in frequency domain with inductance depending on the stator current. Further, it is also shown that the rotor position error could be minimized by compensating the inductance variation. The simulation and experimental results verify that the derived speed error model and the validity of the inductance compensation method.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1233-1239
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• 2004

This study analysis the current level of the Korea High Speed Line by mathematical model of the rail and compensation capacitors. The rail and compensation capacitors are represented by transmission parameters and the analysis is processed by computer simulation.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.6
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• pp.612-619
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• 2004

Servo motor systems with ball-screw and timing-belt are widely used in NC, robot, FA and industrial applications. However, the nonlinear friction torque and damping effect in machine elements reduce the control performance. Especially tracking errors in trajectory control and very low velocity control range are serious due to the break-away friction and Stribeck effects. In this paper, a new double speed controller is proposed for compensation of the nonlinear friction torque. The proposed double speed controller has outer speed controller and inner friction torque compensator. The proposed friction torque compensator compensates the nonlinear friction torque with actual speed and speed error information. Due to the actual information for friction torque compensator without parameters and mathematical model of motor, proposed compensator is very simple structure and the stability is very high. The proposed compensator is verified by simulation and experimental results.