• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.230-230
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• 2000

This paper describes a model reference adaptive system(MRAS) for speed control of vector-controlled induction motor without a speed sensor. The proposed approach is based on observing the instantaneous torque. The real torque is calculated by sensing stator current and estimated torque is calculated by stator current that is calculated by using estimated rotor speed. The speed estimation error is linearly proportional to error between real torque and estimated torque. The proposed feedback loop has linear component. Furthermore proposed method is robust to parameters variation. The effectiveness is verified by equation and simulation

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.68-70
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• 1995

The controller for magnetically suspended vehicles considering the speed characteristics is presented. Generally, the attraction force of magnet is determined by input current and air gap. However, when MAGLEV runs at high speed, induced eddy currents in the rail decrease the attraction force. Thus control characteristics of MAGLEV become deteriorated. Therefore, the variation of attraction force according to speed must be considered. Thus we analyzed the speed characteristics of the magnet by FEM. Also, we study on the control characteristics according to speeds, and design the controller considering the decline of levitation force using Neural Network.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.10
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• pp.83-88
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• 2015

Due to low cost and high reliability, Brushless DC (BLDC) motors have been widely used in control applications such as robotics, aerospace and automobile. In the high performance control systems, it is very important to maintain the desired speed even in the face of parameter uncertainties, modeling errors, and disturbance signals. In this paper, we present an $H_{\infty}$ controller for the speed control of BLDC motors to achieve better performance of disturbance rejection. In particular, we discuss how to reduce an initial peaks of control input in the proposed $H_{\infty}$ controller. Some experimental results are provided to establish the effectiveness of the proposed method.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.331-333
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• 1995

A high performance motor drive system must have a good speed command tracking, a insensitivity to a parameter variation and sampling time. In this paper, a robust speed controller for an induction motor is proposed. The speed controller is fuzzy-sliding adaptive controller and its system continuously is varied. That is, only P gain act in dynamic state, I gain in steady-state. Because this system is a sort of adaptive control system, global stability analysis is used to Lyapunov function. Consequently, in this paper application of fuzzy sliding adaptive controller to induction motor controlled by vecter control is presented and the control system is digitally implemented within DSP.

• Journal of Advanced Marine Engineering and Technology
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• v.21 no.2
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• pp.186-194
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• 1997

In this thesis, a new speed control algorithm based on the load torque observer theory is pro¬posed for the high performance speed control of a voltage source inverter to drive a 3 - phase induction motor. The proposed system becomes robust against disturbances using a feed -- for¬ward control of the load torque estimated at load torque observer. Computer simulation and experimental works using the proposed control confirm that transient response for the varia¬tion ofload torque becomes improved, compared with the conventional PI control method.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1024-1026
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• 2006

This paper designed a robust control of an induction motor using a disturbance cancellation observer of a feedforward control. The speed response of conventional PI controller characteristic is affected by variations of load torque disturbance. In the proposed system, the speed control characteristic using a feedforward control isn't affected by a load torque disturbance. High speed calculation and processing for vector control is carried out by ADMC300 digital signal processor. Validity of the proposed control method is verified through simulation and experimental result.

• Journal of Electrical Engineering and information Science
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• v.1 no.2
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• pp.101-108
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• 1996

A new speed controller based on the fuzzy algorithm with hierarchical structure is presented. The input variables of the controller are speed error and its derivative(change of error), where the output variable is the change of torque current command. Several comparisons were performed with conventional PI (proportional plus integral) controller and proposed controller. These controllers are applied to the laboratory model drive system with 2.2kW induction motor. Some simulation and experimental results show that the speed controller using fuzzy algorithm is more robust than the conventional PI controller.

• 제어로봇시스템학회:학술대회논문집
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• 1999.10a
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• pp.302-305
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• 1999

Twin-servo mechanism is used to increase the payload capacity and speed of high precision motion control system. In this paper, we propose a robust synchronizing motion control algorithm to cancel out the skew motion of twin-servo system caused by different dynamic characteristics of two driving systems and the vibration generated by high accelerating and decelerating motions. This proposed control algorithm consists of separate feedback motion control algorithm of each driving system and skew motion compensation algorithm between two systems. Robust model reference tracking controller is proposed as a separate motion controller and its disturbance attenuation property is shown. For the synchronizing motion, skew motion compensation algorithm is designed, and the stability of whole Closed loop system is proved based on passivity theory.

• Proceedings of the KAIS Fall Conference
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• 2008.05a
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• pp.192-195
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• 2008

Robust control for DC motor is needed according to the highest precision of industrial automation. However, when a motor control system with PID controller has an effect of load disturbance, it is very difficult to guarantee the robustness of control system. In this paper, PID-Expert hybrid control method for motor control system as a compensation method solving this problem is presented. If PID control system is stable, the Expert controller is idle. if the error hits the boundary of the constraint, the Expert controller begins operation to force the error back to the constraint set. The disturbance effect decrease remarkably, robust speed control of DC motor using PID-Expert Hybrid controller is demonstrated by the simulation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.11
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• pp.1311-1318
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• 2012

Vehicle systems are frequently exposed to parameter uncertainties such as vehicle speed and height of center of gravity. If a controller is designed to be robust against these parameter uncertainties, the rollover prevention capability can be considerably enhanced. In this study, robust controllers $H_2$ and $H_{\infty}$ are designed by using LMI for vehicle rollover prevention control in the discrete time domain. Some simulations using CarSim, a reliable simulation tool, are performed to validate the proposed controllers.