• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.628-631
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• 2000

A new control method for precision robust speed control of a PMSM(Permanent Magnet Synchronous Motor) using load torque observer is presented. With this system we can obtain more reliable eye moving singal(nystagmus) Until now rotating chair system which is called 2D-optokinetic stimulator is used to make dizzincess. However an inclined rotating chair system witch is 3D-optokinetic stimulator is needed to obtain the precise dizziness data. This 3D-optokinetic sitimulator include unbalanced load aused by unbalanced center of mass. For this case new compensation method is considered to obtain robust speed control using load torque observer. To reduce the effect of this disturbance we can use dead-beat observer which has high gain. The application of the load torque observer is published in [1] for position control. A problem of using speed information such as amplifying effect of noise is reduce by moving average process. The experimental results are depicted in this paper to show the effect of this proposed algorithm.

• Journal of Power Electronics
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• v.18 no.3
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• pp.736-745
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• 2018

This paper presents an extended state observer (ESO) based direct torque control (DTC) for use in induction motor systems to handle the issues of time delays, load torque disturbances and parameter uncertainties. Direct torque control offers an excellent torque response and it does not require a proportion integration (PI) controller in the current loop. However, a PI controller is still adopted in the outer speed loop to generate the torque reference value, which is a slow method. An ESO based compound control scheme is proposed to improve the response rate and accuracy of the torque reference signal, especially when load torque is injected. In addition, the time delay problem is analyzed and compensated for in this paper to reduce torque ripples. The proposed disturbance compensation technique based direct control scheme is shown to have good performance both in the transient and stable states via simulations and experimental results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.11
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• pp.1423-1433
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• 2018

Recently, a permanent magnet synchronous motor of middle and small-capacity has high torque, high precision control and acceleration / deceleration characteristics. But existing control has several problems that include unpredictable disturbances and parameter changes in the high accuracy and rigidity control industry or nonlinear dynamic characteristics not considered in the driving part. In addition, in the drive method for the control of low-vibration and high-precision, the process of connecting the permanent magnet synchronous motor and the load may cause the response characteristic of the system to become very unstable, to cause vibration, and to overload the system. In order to solve these problems, various studies such as adaptive control, optimal control, robust control and artificial neural network have been actively conducted. In this paper, an incremental encoder of the permanent magnet synchronous motor is used to detect the position of the rotor. And the position of the detected rotor is used for low vibration and high precision position control. As the controller, we propose augmented state feedback control with a speed observer and first order deadbeat disturbance observer. The augmented state feedback controller performs control that the position of the rotor reaches the reference position quickly and precisely. The addition of the speed observer to this augmented state feedback controller compensates for the drop in speed response characteristics by using the previously calculated speed value for the control. The first order deadbeat disturbance observer performs control to reduce the vibration of the motor by compensating for the vibrating component or disturbance that the mechanism has. Since the deadbeat disturbance observer has a characteristic of being vulnerable to noise, it is supplemented by moving average filter method to reduce the influence of the noise. Thus, the new controller with the first order deadbeat disturbance observer can perform more robustness and precise the position control for the influence of large inertial load and natural frequency. The simulation stability and efficiency has been obtained through C language and Matlab Simulink. In addition, the experiment of actual 2.5[kW] permanent magnet synchronous motor was verified.

• Proceedings of the KIEE Conference
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• 2005.10a
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• pp.180-183
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• 2005

A programmable dynamometer is the proposed system improved the problem of the torque measuring delay with torque transducer, and the load torque is estimated by the minimal order state observer based on the torque component of the vector control induction moter. Therefore, the torque controller is not affected by a load torque disturbance. To verify a superiority of the proposed control algorithm, the analysis for a root locus of a conventional control method and the proposed one, and simulation and experiment is performed. Therefore we hope to be extended in industrial application.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.1
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• pp.42-49
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• 2004

This paper presents a new method of external load disturbance compensation using deadbeat load torque observer and gain compensation by parameter estimator. The response of the permanent magnet synchronous motor(PMSM) follows the nominal plant. The load torque compensation method is composed of a deadbeat observer. To reduce the noise effect, the post-filter implemented by moving average(MA) process is adopted. The parameter compensator with recursive least square method(RLSM) parameter estimator is suggested to make the new system work as same as the name plate system which in used to take gains. The proposed estimator is combined with a high performance load torque observer to resolve the problems. As a result, the proposed control system has a robust and precise system against the load torque and the parameter variation. A stability and usefulness are verified by computer simulation and experiment.

• Proceedings of the KIPE Conference
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• 2003.07b
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• pp.663-666
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• 2003

This paper presents a speed controller method based on the disturbance torque observer of high performance brushless DC (BLDC) motor drives. In case of the speed control of robot arms and tracking applications with lower stiffness, we cannot design the speed controller gain to be very large from tile viewpoint of the system stability. Thus, the feedforward compensator using disturbance torque observer was proposed. This method can improve the speed characteristic without increasing the speed controller gain. The enhanced speed control performance can be achieved and the speed response against the disturbance torque can be Improved for high-performance BLDC motor drive systems in which the bandwidth of tile speed controller cannot be made large enough. Consequently, speed control for high-performance BLDC motor drives become improved. The simulation results for BLDC motor drive systems confirm the validity of the proposed method.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.4
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• pp.243-250
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• 2003

In this paper, the speed controller of permanent-magnet synchronous motor (PMSM) using the RBF neural (NN) disturbance observer is proposed. The suggested controller is designed using the input-output feedback linearization technique for the nominal model of PMSM and incorporates the RBF NN disturbance observer to compensate for the system uncertainties. Because the RBF NN disturbance observer which estimates the variation of a system parameter and a load torque is employed, the proposed algorithm is robust against the uncertainties of the system. Finally, the computer simulation is carried out to verify the effectiveness of the proposed method.

• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.50-52
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• 2004

Mobility of an indoor wheeled robot is affected by adhesion force that is related to various floor conditions. When the adhesion force between driving wheels and the floor decreases suddenly, the robot has slip state. First of all, this paper models adhesion characteristics and slip in wheeled robot. Secondly, the paper proposes estimation method of adhesion force coefficient according to slip velocity. In oder to overcome this slip problem, optimal slip velocity must be decided for stable movement of wheeled robot. The paper proposes an anti-slip control system based on an ordinary disturbance observer, that is, the anti-slip control is achieved by reducing the driving torque enough to give maximum adhesion force coefficient. These procedure is implemented using a Pioneer 2-DXE parameter.

• Journal of Power Electronics
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• v.14 no.1
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• pp.105-114
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• 2014

The sliding mode control (SMC) strategy is applied to a permanent magnet synchronous machine vector control system in this study to improve system robustness amid parameter changes and disturbances. In view of the intrinsic chattering of SMC, a current sliding mode control method with a load sliding mode observer is proposed. In this method, a current sliding mode control law based on variable exponent reaching law is deduced to overcome the disadvantage of the regular exponent reaching law being incapable of approaching the origin. A load torque-sliding mode observer with an adaptive switching gain is introduced to observe load disturbance and increase the minimum switching gain with the increase in the range of load disturbance, which intensifies system chattering. The load disturbance observed value is then applied to the output side of the current sliding mode controller as feed-forward compensation. Simulation and experimental results show that the designed method enhances system robustness amid load disturbance and effectively alleviates system chattering.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.6
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• pp.531-536
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• 2002

This paper investigates the problem of the speed controller of conventional speed sensorless stator flux-oriented(SFO) induction motor drive, and proposes a robust speed controller to solve the conventional problem. In the proposed method, a robust speed controller for speed sensorless SFO system Is designed by taking advantage of disturbance torque observer and using feedforward.