• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.6
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• pp.389-394
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• 2004

This paper proposes a speed estimation method using FLC(Fuzzy Logic Controller) in order to realize the speed control of PMAM(Permanent Magnet AC Motor) with no speed sensor. This method uses FLC as a adaptive laws of MRAS(Model Reference Adaptive System) and estimates the rotor speed of PMAM with a difference between the reference model and the adjustable model. Speed control is performed by PI controller with the estimated speed. The experiment is executed to verify the propriety and the effectiveness of the proposed system.

• Journal of Broadcast Engineering
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• v.14 no.4
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• pp.409-418
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• 2009

This paper proposes a method to estimate the flow speed of pedestrians in surveillance videos. In the proposed method, the average moving speed of pedestrians is measured by estimating the size of real-world motion from the observed motion vectors. For this purpose, a pixel-to-meter conversion factor is introduced which is calculated from camera parameters. Also, the height information, which is missing because of camera projection, is predicted statistically from simulation experiments. Compared to the previous works for flow speed estimation, our method can be applied to various camera views because it separates scene parameters explicitly. Experiments are performed on both simulation image sequences and real video. In the experiments on simulation videos, the proposed method estimated the flow speed with average error of about 0.08m/s. The proposed method also showed promising results for the real video.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.4739-4746
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• 2013

In position detection for super speed maglev propulsion control, the influence of position signal delay and transmit cycle on propulsion power degradation is investigated analytically and validated by test bed experiments. As a solution to the problem caused by signal transmit, position signal compensation and estimation method is proposed and applied to the test bed. Through experiments, it is confirmed that by adapting the proposed method, the propulsion power is increased remarkably, which results in acceleration and velocity performance improvement. This method could be effectively applied to position detection system of Korean super speed maglev which is under development.

• The Journal of Korea Robotics Society
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• v.18 no.2
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• pp.182-188
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• 2023

Due to the acceleration of an aging society, the need for lower limb exoskeletons to assist gait is increasing. And for use in daily life, it is essential to have technology that can accurately estimate gait phase even in the walking environment and walking speed of the wearer that changes frequently. In this paper, we implement an LSTM-based gait phase estimation learning model by collecting gait data according to changes in gait speed in outdoor level ground and stair environments. In addition, the results of the gait phase estimation error for each walking environment were compared after learning for both max hip extension (MHE) and max hip flexion (MHF), which are ground truth criteria in gait phase divided in previous studies. As a result, the average error rate of all walking environments using MHF reference data and MHE reference data was 2.97% and 4.36%, respectively, and the result of using MHF reference data was 1.39% lower than the result of using MHE reference data.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.11
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• pp.126-137
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• 1997

This paper describes the algorithm which can estimate road following direction and deetect obstacle using a monocular vision system. This algorithm can estimate the course of vehicle using the vanishing point properties and detect obstacle by statistical method. The proposed algorithm is composed of four steps, which are lane prediction, lane extraction, road following parameter estimation and obstacle detection. It is designed for high processing speed and high accuracy. The former is achieved by a small area named sub-windown in lane existence area, the later is realized by using connected edge points of lane. We would like to present that the new mehod can detect obstacle using the simple statistical method. The paracticalities of the processing speed, the accuracy of the algorithm and proposing obstacle detection method, have been justified through the experiment applied VTR image of the real road to the algorithm.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.8
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• pp.168-175
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• 1995

A robust speed control algorithm under disturbances and reference change is developed using the self tuning control method in order to control induction motors. The method incorporates the concepts of the well known internal model principle and the annihilator polynomial. The effectiveness of the method is evaluated through the speed control experimental results of an induction motor for refernce change and arbitrary distrbance.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.5
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• pp.677-682
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• 2010

This paper addresses a method of estimating roughly the human pose by comparing Haar-wavelet value which is learned in face detection technology using AdaBoost algorithm. We also presents its application to face recognition. The learned weak classifier is used to a Haar-wavelet robust to each pose's feature by comparing the coefficients during the process of face detection. The Mahalanobis distance is used to measure the matching degree in Haar-wavelet selection. When a facial image is detected using the selected Haar-wavelet, the pose is estimated. The proposed pose estimation can be used to improve face recognition speed. Experiments are conducted to evaluate the performance of the proposed method for pose estimation.

• Journal of Power Electronics
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• v.16 no.4
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• pp.1346-1354
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• 2016

This paper proposes a design guideline for the feedback gain of the adaptive full-order observer in the speed sensorless control of induction machines. The performance of the adaptive full-order observer is dependent on its feedback gain. This paper presents a pole placement method for the observer feedback gain design to improve the estimation performance of the speed adaptive observer. In the proposed method, the observer poles can be chosen independently of the induction motor poles. Instead, they can be positioned according to the operating speed. An analysis and experimental results obtained with the proposed method reveals better performances under general operating conditions.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.52 no.4
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• pp.154-160
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• 2003

This paper is proposed a ANN-based rotor position and speed estimation method for IPMSM by measuring the currents. Because the proposed estimator treats the estimated motor speed as the weights, it is possible to estimate motor speed to adapt back propagation algorithm with 2 layered neural network. The proposed control algorithm is applied to IPMSM drive system. The operating characteristics controlled by neural networks are examined in detail.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.1
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• pp.57-65
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• 2001

The speed control without a speed sensor is expected strongly to progress reliability, simplicity and cost performance of Induction Motor(I.M) systems. Also, it contributes to expansion of I.M systems into various industrial application fields. This paper investigates a novel speed sensorless control method of I.M considering the secondary resistance identification based on the transientless torque control technique. Especially, this paper aimed at the identification of the secondary resistance simultaneously with speed estimation superposing of sinusoidal flux wave to a constant flux value. Furthermore, the secondary flux with some frequency is controlled independently on torque control. The proposed speed estimation method is derived from a motor circuit equation theoretically and also it can be conducted easily by detecting primary motor currents and primary voltage commands at every sampling time. Some numerical simulations with the assumption of using a pulse width modulation(PWM) voltage source inverter are performed to verify the proposed method.