• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.1
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• pp.70-79
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• 2005

In this paper, improvement method of control performance by a full-order observer using reduced-order state equation is proposed in the low speed range. Full-order observer using reduced-order state equation is the motor speed and the disturbance torque observer. The proposed algorithm is very stable in the low speed range about 1.9[rpm]. The disturbance torque in the motor drive system degrades speed control performance in the low speed range. The proposed algorithm estimated both motor speed and disturbance torque. The estimated disturbance torque is used as a feedforward value in output of the speed controller, As a result, it improves the response of load torque in the low speed range(1.9rpm).

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.1
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• pp.89-99
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• 2014

This paper presents the experimental torque disturbance analysis of a missile hatch system by spline backlash. The missile hatch system uses a spline and gear train for vertical elevation of the heavy hatch. The spline used for the rotation shaft of the hatch is generally used for automotive driving parts that transmit high amounts of power. It has an angular backlash, which results in jerks. Backlash of the hatch spline influences hatch swinging. The spline backlash and hatch swing are experimentally analyzed by measuring the hatch's rotation angle and acceleration. Hatch swing is visually observable for a short period, and it is measured by measuring the rotation angle variation and hatch acceleration. The shape of fluctuation and duration time of hatch angle variation are similar to those of torque. This shows that the hatch swing due to spline backlash generates torque disturbances.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.3
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• pp.511-518
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• 2021

In order to obtain a good tracking performance of the motor, it is necessary to design a controller that can respond to a disturbance by including a disturbance observer. The disturbance observer of the motor is designed to estimate the load torque and the back electromotive voltage based on the first-order low-pass filter. A PI controller and an IP controller were designed to compare the correlation between the disturbance observer and the controller and to obtain improved control performance. To check the performance of the designed observer and the controller, it was applied to a 120 [W] class BLDC motor. As a result, overshoot is reduced, and it can be seen that the steady-state error converges to zero.

• Journal of Astronomy and Space Sciences
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• v.16 no.2
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• pp.265-272
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• 1999

A thrusters modulation method is suggested for spacecraft attitude control with asymmetric configured thrusters during orbit adjustment maneuvers. Attitude is controlled by thrusters off-modulation during orbit maneuvers. Usual control method for symmetric configured thrusters cam not be applied for asymmetric configured thrusters. Disturbance induced from thrusters asymmetricity shall be compensated during pulsing. In this paper, a thrusters control method using null solution is suggested, which is shown working well without inducing disturbance.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.1
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• pp.1-8
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• 2016

In this study, we propose a control algorithm for Inertially Stabilized Platforms (ISP), which combines Disturbance Observer (DOB) with conventional proportional integral derivative (PID) control algorithm. A single axis ISP system was constructed using a direct drive motor. The joint friction was modeled as a nonlinear function of joint speed while the accuracy of the model was verified through experiments and simulation. In addition, various Q-filters, which have different orders and relative degrees of freedom (DOF), were implemented. The stability and performance of the ISP were compared through experimental study. The performance of the proposed PID-plus-DOB algorithm was compared with the experimental results of the conventional double loop PID control under artificial vehicle motion provided motion simulator with six DOF.

• Journal of the Institute of Convergence Signal Processing
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• v.8 no.2
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• pp.119-123
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• 2007

This paper investigates a speed sensorless control of induction motor. The control strategy is based on MRAS(Model Reference Adaptive System) using load-torque observer as a reference model for flux estimation. The speed response of conventional MRAS controller characteristics is affected by variations of load torque disturbance. In the proposed system, the speed control characteristics using a load-torque observer control isn't affected by a load torque disturbance. Control algorithm that propose whole system through MATLAB SIMULINK because do modelling simulation result are presented to prove the effectiveness of the adaptive sliding mode controller for the drive variable load of induction motor. Therefore we hope to be extended in industrial application.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.408-409
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• 2018

본 논문에서는 BLDC와 PI 제어기를 사용하여 전동기의 속도를 제어할 때 전차원 관측기를 적용하여 부하 토크를 추정 및 보상함으로써 속도 리플을 줄일 수 있는지를 검증하고자 하였다. 모터 구동 시에는 필연적으로 부하 토크가 외란으로 포함되며 그로 인해 제어대상인 속도에 리플을 야기하게 된다. 따라서 보다 안정적인 제어를 위해서는 이 외란을 보상해주는 것이 필요한데, 관측기를 이용하면 별도의 장비나 센서 없이 이 부하 토크를 효과적으로 보상해 줄 수 있다.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.4
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• pp.839-848
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• 2012

In this paper, we propose a robust control scheme of AC servo motors to suppress disturbance torques effectively. The proposed controller consists of both a model based feed-forward controller and a stabilizing feedback controller. The feed-forward controller is designed such that the output of the nominal plant tracks perfectly the reference velocity command with desired dynamic characteristics. The feedback controller stabilizes the overall closed loop system. Furthermore, the feedback controller contains a free function that can be chosen arbitrarily. The free function can be designed so as to achieve both suppression of disturbances and robustness to model uncertainties. In order to illuminate the superior performance of the proposed control scheme to the conventional ones, we present some simulation results.

• 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.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.6
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• pp.635-642
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• 2004

In electric motor coaches. the rolling stocks move by the adhesive effort between rail and driving wheel. Generally, the adhesive effort is defined by the function of both the weight of electric motor coach and the adhesive effort between rails and driving wheel. The characteristics of adhesive effort is strongly affected by the conditions between rails and driving wheel. When the adhesive effort decreases suddenly, the electric motor coach has slip phenomena. This paper proposes a re-adhesion control based on disturbance observer and sensor-less vector control. The numerical simulation and experimental results point out that the proposed readhesion control system has the desired driving wheel torque response for the tested bogie system of electric coach. Based on this estimated adhesive effort, the re-adhesion control is performed to obtain the maximum transfer of the tractive effort.