• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.10
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• pp.1303-1307
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• 2018

A improving sensorless compensator for the IPMSM(Interior Permanent Magnet Synchronous Motor) drive system is proposed. Generally, the motor drive system is required the robust parameter variation and disturbance. The speed estimation methods of the conventional IRP(Instantaneous Reactive Power) compensator is improved by the speed estimation techniques of the current model observer with the proposed instantaneous reactive power compensator. Performance evaluations of the novel speed error compensator and sensorless control system are carried out by the experiments.

• Proceedings of the KIPE Conference
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• 2007.11a
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• pp.7-10
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• 2007

The current model based sensorless method has many benefits that it can be robust control for large load torque. However, this method should determine a coefficient of back electro motive force(back-emf). This coefficient is varied by load torque and speed. Also, the coefficient determining equation is not exist, so it is determined only by experiment. On the other hands, using only back-emf estimatior method can not drive in low speed area and it has weakness in load variation. For these problems, this paper suggests the hybrid sensorless method that mixes the back-emf estimator regarding saliency and the current based sensorless model. This estimator offers not only non-necessary coefficient for current sensorless model, but also wide speed area operating in no specific transition method.

• 전기의세계
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• v.30 no.8
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• pp.501-508
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• 1981

A novel and simple method of designing the current feedback loop for the velocity controller of an armature controlled dc servo motor is presented. Instead of constructing the usual tight current feedback loop, a loose current feedback loop is suggested in this paper. More specifically, the armature current is not limited to a fixed constant value, but instead the upper bound value is allowed to be variable along with the present motor speed. The control system designed in this manner shows that the motor under control is robust to a wide range of loading conditions and yields a more rapid transient characteristics which is verified experimentally by applying the method in the design of the controller for an Industrial robot.

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.2
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• pp.159-166
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• 2010

For a grid-connected inverter in distributed generation systems, the current control is essential, and recently, the predictive current control based on a high performance digital signal processors (DSP) to satisfy a fast dynamic response has been widely investigated. However, the performance of predictive current control is degraded by the time delay due to digital implementation, the parameter and measured value errors and the interference of noise, and also theses make system even unstable. Therefore, this paper proposes the predictive current control using grid voltage observer for grid-connected inverter applications. To determine the relevant voltage observer gain, the low-order harmonics of grid voltage are considered, and the effect of filter parameter errors is analyzed. The proposed method has a fast current response capability, the robustness to noise and simple implementation due to voltage sensorless control and the robust current control performance to low-order grid harmonics. The feasibility of the proposed method is verified by simulation and experimental results.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.1
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• pp.42-53
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• 1996

The paper presents a speed control system of vector controlled induct- ion motor using neural networks. The main feature of proposed speed control system is a Neural Network Controller(NNC) which supplies torque current to induction motor and Neural Network Emulator(NNE) which captures the forward dynamics of induction motor. A back propagation training algorithm is employed to train the NNE and NNC. In order to determine the NNC output error, plant(induction motor) output error can be back propagated through the NNE. The NNC and NNE for speed control of vector controlled induction motor is carried out by TMS320C30 DSP and IGBT current regulated PWM inverter. Through computer simulation and experimental results, it is verified that proposed speed control system is robust to the load variation. (author). refs., figs.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.67-69
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• 2007

PMSM (Permanent Magnet Synchronous Motor) current control is a most inner loop of electromechanical driving systems and it plays a foundation role in the hierarchy's control loop of several mechanical machine systems. In this paper, a simple RMRAC control scheme for the PMSM is proposed in the synchronous frame. In the synchronous current model, the input signal is composed of as a calculated voltage by adaptive laws and system disturbances. The gains of feed-forward and feed-back controller are estimated by the proposed e-modification methods respectively, where the disturbances are assumed as filtered current tracking errors. After the estimation of the disturbances from the tracking errors, the corresponding voltage is fed forward to control input to compensate for the disturbances. The proposed method is robust to high frequency disturbances and has a fast dynamic response to time varying reference current trajectory. It also shows a good real-time performance duo to it's simplicity of control structure. Through the simulations considering several cases of external disturbances and experimental results, efficiency of the proposed method is verified

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.3
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• pp.203-209
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• 2014

The rear center-hinge bracket is designed for supporting and folding the rear-seat backrest. This bracket needs to be strong enough to be able to rigidly hold the rear-seat backrest and to withstand luggage loads from the car trunk that are generated when a vehicle is driving on the roads. Particularly, current accident studies report that many serious occupant injuries occurred when the rear-seat back easily folded inward toward the car interior, driven by the luggage loads in the trunk. Given this fact, the robust design of the rear center-hinge bracket that mainly supports the rear backrest has become more important for providing customer safety and preventing high warranty and durability problems. However, none of the studies have emphasized its significant role and considered its robust optimization. Therefore, this paper presents how the hinge-bracket design is optimized based on an application of the finite-element method coupled with the parameter design using Taguchi's design experiment. Finally, Taguchi method's application optimizes a robust center-hinge bracket that shows more rigid performance although it has lighter weight and thinner thickness.

• Journal of Korean Society for Quality Management
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• v.30 no.1
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• pp.133-143
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• 2002

We propose an optimal design to improve the muffler's capacity by reducing the noise of the intake system by adapting kriging method with the robust design. For the first stage of a design, the length and radius of each component of the current muffler system are selected as control factors. Then, the $L_18$ table of orthogonal arrays is adapted to extract the effective main factors. As the second stage, the $L_18$ table of orthogonal arrays using kriging method is adapted to take the significant factors into consideration. As an optimal design, the $L_18$ table of orthogonal arrays with main effects is proposed and the kriging method is adapted for more efficient design. The kriging method improves the performance of intake system.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.11
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• pp.93-101
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• 1993

The transfer function of vector-controlled induction motor is represented along with both unstructured and structured uncertainty such as the error of rotor time constant and current ripple. The low-pass-filter behavior of a magnetizing inductance gets rid of unstructured uncertainty in the transfer function. The robust controller to compensate variation of the transfer function is designed using simple P-I linear controllers. The coefficients of speed PI controller are determined from an overshoot and a rising time of system and the coefficients of model-following PI controller are obtained using the solution of Riccati equation of LQR control in the state space equation of the error system. Experimental results with the DSP-based model-following robust controller are shown a good robustness against the structured uncertainty of the motor.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.328-333
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• 1996

In this paper, we propose a new method to estimate robot position without landmark. At first, it is studied to estimate robot state using Markov decision rule. And, a matching method is discussed for estimating current position more accurately under the estimated current state. At second, we combine or fuse the matching method with the POMDP method in order to estimate the position under a dynamically changing environment. Finally we will show that our method can estimate the position precisely and robustly of which error are not cumulated through simulation results.