• 음성과학
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• 제15권1호
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• pp.75-83
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• 2008

The interior of an automobile is a very noisy environment with both stationary cruising noise and the reverberated music or speech coming out from the audio system. For robust speech recognition in a car environment, it is necessary to extract a driver's voice command well by removing those background noises. Since we can handle the music and speech signals from an audio system in a car, the reverberated music and speech sounds can be removed using an acoustic echo canceller. In this paper, we implement an acoustic echo canceller with robust double-talk detection algorithm using TMS-320C6711 DSK. First we developed the echo canceller on the PC for verifying the performance of echo cancellation, then implemented it on the TMS320C6711 DSK. For processing of one speech sample with 8kHz sampling rate and 256 filter taps of the echo canceller, the implemented system used only 0.035ms and achieved the ERLE of 20.73dB.

• 제어로봇시스템학회논문지
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• 제6권12호
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• pp.1045-1052
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• 2000

In this paper, we propose a method to apply the Input Shaping Technique (IST) to multi-input multi-output (MIMO) systems. In MIMO systems, there is a high possibility of multi-mode residual vibration. The IST filter designed for this multi mode may need a longer time to suppress the residual vibration. Previous works prove that we can shorten the time lag by using negative sequence. This negative sequence, however, causes another problem - it requires excessive control input. In this paper, we provide a remedy to reduce the size of control input by limiting the reference input by limiting the reference input and its derivative. The result of simulations and experiments on a 2 link flexible arm confirmed the effectiveness of the proposed method.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.155-158
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• 2000

A new control method for single-phase shunt active power line conditioners(APLC's) operated under zero average power consumption is proposed in this paper. The amplitude of the sinusoidal source current which is in-phase with the source voltage can be determined from the average value of the instantaneous load power. Then the command current for the shunt APLC is obtained by subtraction the source current from the load current. Neither bulky filter nor time-consuming computation is required. The shunt power compensator supplies all the harmonics of he load current and the source only supplies the fundamental component,. Experimental results on a prototype verify the feasibility of the presented scheme,

• 로봇학회논문지
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• 제4권4호
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• pp.289-297
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• 2009

This paper presents the development and control of a two wheeled car-like mobile robot using balancing mechanism whose heading control is done by turning the handle. The mobile inverted pendulum is a combined system of a mobile robot and an inverted pendulum system. A sensor fusion technique of low cost sensors such as a gyro sensor and a tilt sensor to measure the balancing angle of the inverted pendulum robot system accurately is implemented. Experimental studies of the trajectory following control task has been conducted by command of steering wheel while balancing.

• 제어로봇시스템학회논문지
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• 제9권12호
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• pp.1001-1008
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• 2003

A time-delay compensation method for vector control system is proposed that can compensate for voltage and current distortions resulting from a time delay in the overall system due to the low pass filter, hysteresis control inverter, microprocessor program computation time, and so on. The proposed scheme estimates the time delay using the difference between the Q-axis stator current command and the time-delayed actual Q-axis stator current in a synchronous reference frame, then compensates the time delay in the voltage and current using the angular displacement of a DQ transformation. Accordingly, the proposed scheme can accurately compensate for the time delay related to the overall system, thereby significantly improving the performance of the vector control system, as verified by simulation and experiment.

• 대한임베디드공학회논문지
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• 제7권1호
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• pp.33-39
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• 2012

In this paper, we propose robot control interface using gaze recognition which is not limited by head motion. Most of the existing gaze recognition methods are working well only if the head is fixed. Furthermore the methods require a correction process per each person. The interface in this paper uses a camera with built-in infrared filter and 2 LED light sources to see what direction the pupils turn to and can send command codes to control the system, thus it doesn't need any correction process per each person. The experimental results showed that the proposed interface can control the system exactly by recognizing user's gaze direction.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1779-1780
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• 2008

This paper presents a switching system of speed controller between PI (Proportional_Integrator) and P_LPF (Proportional_Low pass filter) to improve overshoot and slow settling time in DC motor. When the integrator is saturated in the PI controller, the error signal is integrated continuously. For preventing the state, the Anti-windup scheme is proposed. But the Anti-windup scheme dose not show stable characteristics in the whole speed command section after tuned a gain. By using P_LPF switching system these problems are improved and there is no need to tune of user hereafter, when the integrator is saturated. The proposed method is verified by the simulation results using MATLAB SIMULINK.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.281-281
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• 2000

This paper presents an implementation of speech recognition system for teaching an autonomous mobile robot. The use of human speech as the teaching method provides more convenient user-interface for the mobile robot. In this study, for easily teaching the mobile robot, a study on the autonomous mobile robot with the function of speech recognition is tried. In speech recognition system, a speech recognition algorithm using HMM(Hidden Markov Model) is presented to recognize Korean word. Filter-bank analysis model is used to extract of features as the spectral analysis method. A recognized word is converted to command for the control of robot navigation.

• 한국산업융합학회 논문집
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• 제23권1호
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• pp.49-55
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• 2020

This paper presents the system modeling, analysis, and controller design and implementation with a inverted pendulum system in order to test Linear Quadratic control based robust algorithm for inverted pendulum robot. The balancing of an inverted pendulum robot by moving pendulum robot like as 'segway' along a horizontal track is a classic problem in the area of control. This paper will describe two methods to swing a pendulum attached to a cart from an initial downwards position to an upright position and maintain that state. The results of real experiment show that the proposed control system has superior performance for following a reference command at certain initial conditions.

• 한국산학기술학회논문지
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• 제15권8호
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• pp.5219-5226
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• 2014

본 논문에서는 확률신경망 이론을 적용하여 GPS 단절구간에서 보행자의 위치정보의 정확도를 향상시키는 기법을 제안한다. 일반적인 보행 외 옆으로 걷기, 오리걸기, 기어가기 등 여러 보행 형태에 대한 보행 패턴을 학습하고 이에 대한 이동거리를 구하여 관성항법의 적분오차를 최소화하도록 한다. 제안 시스템은 보행자가 휴대할 수 있는 소형/경량화/저전력 설계된 H/W 모듈 형태로 구현을 하였으며, 건물 내에서의 보행자 이동 실험을 통해 제안 시스템의 성능을 검증하였다.