• 전기학회논문지
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• 제65권5호
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• pp.794-803
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• 2016

This paper propose a sensorless control system of IPMSM with a adaptive back-EMF estimator and improved instantaneous reactive power compensator. A saliency-based back-EMF is estimated by using the adaptive algorithm. The estimated back-EMF is inputted to the phase locked loop(PLL) and the improved instantaneous reactive power(IRP) compensator for estimating the position/speed of the rotor and compensating the error components between the estimated and the actual position, respectively. The stability of the proposed system is achieved through Popov's hyper stability criteria. The validity of proposed algorithm is verified by the simulations and experiments.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.192-196
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• 1988

This paper presents a feasibility study related to the design of a linear multivariable compensator for a model of boiler-turbine system. The nonlinear dynamics are linearized at a operating condition. At the operating point an LQG/LTR compensator is designed. Simulations are included to illustrate the usefulness of this linear multivariable control law.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 추계학술대회
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• pp.315-316
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• 2011

This paper presents speed control scheme of the PMSM which has torque compensator to reduce the speed error and ripple. The proposed speed controller is based on the conventional PI control scheme. But the additional torque compensator which is different to the conventional differential controller produces a compensation torque to suppress speed ripple. In order to determine the proper compensation, the activation function which has discrete value is used in the proposed control scheme. With the proposed activation function, the compensation torque acts to suppress the speed error increasing. The proposed speed control scheme is verified by the computer simulation and experiments of 400[W] PMSM. In the simulation and experiments, the proposed control scheme has better control performance compare than the conventional PI and PID control schemes.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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• pp.47-50
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• 1995

This paper concerns an adaptive control scheme which is an extension of the simplified adaptive control. Originally, the SAC approach was developed based on the command generator tracker (CGT) theory for perfect model tracking. An attractive point of the SAC is that a control input can be synthesized without any prior knowledge about plant structure. However, a feedforward dynamic compensator of the CGT is removed from the basic structure of the SAC. This deletion of the compensator makes perfect model tracking difficult against even a step input. In this paper, an adaptive control system is redesigned to achieve perfect model tracking for as long as possible by reviving the dynamic compensator of the CGT. The proposed method is applied to slewing control of a flexible space structure and compared to the SAC responses.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권2호
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• pp.153-160
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• 1999

Dual-stage servo system for super-high density HDD has the chances of being composed of the coarse actuator(VCM) for track-seeking control and the fine actuator(microactuator) for-following control in near future. This paper presents the concept design of dual-stage servo system and the track-following control using an electrostatic microactuator for super-high density HDD. The electrostatic microactuator is designed and fabricated by MEMS(micro-electro-mechanical system) process. Both the nonlinear plant(voltage/displacement-to-electrostatic force) and the linear plant(electrostatic force-to-displacement) of the microactuator are established. Inverse function of the nonlinear plant is employed for a feedforward nonlinear compensator design. And feedforward control effect of this compensator is shown by time-domain experiments. A track-following feedback controller is designed using the feedback nonlinear compensator which is derived from the feedforward nonlinear compensator. The track-following control experiment is done to show the control efficiency of the proposed control system. And, excellent track-following control performance(2.21kHz servo-bandwidth, 7.51dB gain margin, $50.98^{\circ}$phase margin) is achieved by the proposed control system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.220-220
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• 2000

In this paper, some non-interaction problems in tandem cold rolling mill are considered, which are required to control effectively a thickness of the cold .oiled strip. First, Interstand non-interactive compensate. (Interstand NIC) is designed for decoupling the interaction between stands. Next, a L2 optimization based pre-compensator is designed for decoupling the interaction between roll gap and strip tension in the stand. Finally, the effectness of the proposed decoupling methods is demonstrated via simulations.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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• pp.845-848
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• 1993

This paper proposes a design method of fuzzy phase-lead compensator and its self-learning by neural network. The main feature of the fuzzy phase-lead compensator is to have parameters for effectively compensating phase characteristics of control systems. An important theorem which is related to phase-lead compensation is derived by introducing concept of frequency characteristics. We propose a design procedure of fuzzy phase-lead compensators for linear controlled objects. Furthermore, we realize a neuro-fuzzy compensator for unknown or nonlinear controlled objects by using Widrow-Hoff learning rule.

• 제어로봇시스템학회논문지
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• 제3권2호
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• pp.197-203
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• 1997

In this paper, we present a GP-PID(Generalized Predictive PID) controller which has the same structure as a generalized predictive control with steady-state weighting. The proposed controller can perform better than the conventional PID controller because it includes intrinsic delay-time compensator. The PID tuning parameters and delay-time compensator are calculated by equating the two degree of freedom PID to a linear form of GPC. The proposed controller is combined with a supervisor for safe start and self-tuning. GP-PID controller has been tested for various numerical models and an experimental stirred tank heater. As a result, it was observed that the proposed controller shows a satisfactory performance for variable delay as well as stochastic disturbance.

• Transactions on Control, Automation and Systems Engineering
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• 제3권2호
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• pp.111-116
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• 2001

A neural network compensator for stick-slip friction phenomena in meashartonics servo systems is practically proposed to supplement the traditionally available position and velocity control loops for precise motion control. The neural network compensa-tor plays the role of canceling the effect of nonlinear slipping friction force. It works robustly and effectively in a real control system. This enables the mechatronics servo systems to provide more precise control in the digital computer. It was confirmed that the con-trol accuracy is improved near zero velocity and points of changing the moving direction through numerical simulation. However, asymptotic property on the steady state error of the normal operation points is guaranteed by the integral term of traditional velocity loop controller.

• 제어로봇시스템학회논문지
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• 제7권4호
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• pp.351-361
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• 2001

In this paper, a generalized framework called as robust internal-loop compensator(RIC) is presented, and by using this, a structural design method of sliding of sliding mode controller is proposed. First, a general sliding mode controller is derived and a stabilizing control input is designed based on Lyapunov redesign for the system in the presence of uncertainty and disturbance. And adopting the internal model following control, RIC is proposed. Next, using the structural characteristics of the proposed RIC, disturbance attenuation characteristics are analyzed and the performance of the closed-loop system is predicted. Through this analysis, it is shown that if the control gain of RIC is increased by N times, the magnitude of error is reduced to its 1/N. the proposed method is verified through experiments using a high-precision positioning system and the performance is evaluated.