• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.10
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• pp.863-871
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• 2017

LMS (least mean square) algorithm widely used in the AVCS (active vibration control system) of helicopters calculates control input using the forward path transfer function and error signal. If the error signal is sinusoidal, it can be represented as the combination of cosine and sine functions with frequency and phase synchronized with the reference signal. The control input also has the same frequency, therefore control algorithm can be simply implemented if the cosine and the sine amplitudes of the control input are calculated and the frequency and phase of the reference signal are used. Calculation of the control input is implemented as simple matrix operation and the change of the control command is slower than the frequency of the error signal, consequently control algorithm can be operated at lower frequency. The signal processing algorithm extracting cosine and sine components of the error signals are modeled using Simulink and PIL (processor-in-the-loop) mode simulation was executed for real-time performance evaluation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.7
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• pp.986-992
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• 2021

To stabilize closed-loop wireless control systems, the state-of-the-art approach receives the individual sensor measurements at the controller and then sends the computed control signal to the actuators. We propose an over-the-air controller scheme where all sensors attached to the plant transmit scaled sensing signals simultaneously to the actuator, and the actuator then computes the feedback control signal by scaling the received signal. The over-the-air controller essentially adopts the over-the-air computation concept to compute the control signal for closed-loop wireless control systems. In contrast to the state-of-the-art sensor-to-controller and controller-to-actuator communication approach, the over-the-air controller exploits the superposition properties of multiple-access wireless channels to complete the communication and computation of a large number of sensing signals in a single communication resource unit. Therefore, the proposed scheme can obtain significant benefits in terms of low actuation delay and low resource utilization with a simple network architecture that does not require a dedicated controller.

• Proceedings of the KOR-KST Conference
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• 1998.10a
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• pp.139-148
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• 1998

과학의 발달과 인간의 편리성 추구 성향에 따라 다양한 분야에서 소리를 이용한 기계·전자 시스템에 대한 연구 개발이 진행 중이다. 아마도 소리를 감지할 수 있는 센서 가격의 저렴함과 인간에게 있어서는 가장 편리한 방법이기 때문일 것이다. 이러한 생각을 바탕으로 소리라는 변수를 교통분야에 응용할 수 있는 분야를 생각해 볼 때 본 연구는 검지기를 이용한 교통 신호제어 분야를 제안하고자 한다. 검지기를 중심으로 한 교통 제어 시스템은 교통관리 측면에서 매우 중요한 분야를 차지하고 있다. 기존 고비용의 검지기 시스템들은 실제 상황에서는 그 투자 비용의 가치만큼 역할을 수행하지 못하고 있으며, 주요 교차로나 고속도로만을 교통변수 측정 및 교통제어의 대상으로 삼고 이들에 대해서만 검지 시스템을 운용하는 등 실용화측면에서 많은 문제점을 가지고 있다. 따라서 저렴하면서도 주요 교차로를 제외한 여타의 비주요 교차로 등과 같은 어떠한 교통 여건에도 적용할 수 있는 소음검지기법의 개발은 실로 높은 연구 가치가 있다고 사료된다. 소음검지시스템은 교통상황변수중 가장 주용한 교통량과 도로 소음과의 상관 관계를 이용하여 신호제어를 하는 원리로 구성된다. 본 연구에서는 이러한 시스템의 제안을 위해 교통소음과 교통량이 어떠한 상관관계를 형성하는 가를 분석하였으며 이를 바탕으로 응용할 수 있는 신호제어 시스템의 일부 교통관련 분야를 제안하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.606-608
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• 2021

Humans and various devices are interconnected using the Internet of Things and are used in various ways. In this study, a synchronization control system with remote locations was constructed using ICT, and a signal system for pedestrians was implemented using the system. PLC circuits were used to implement controllers, through which wireless control signal transmission and reception, LED lamp emission control, and power control were performed. It was confirmed that signal synchronization from the main controller to the remote sub-controller was possible by establishing a controller and pedestrian traffic light system, and lamp signal synchronization of the pedestrian traffic light system installed on both sides of the road was implemented. As a result, it was confirmed that 1:1 remote control or 1:N remote group control was possible, and this result can be used in various fields.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.143-144
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• 2022

자율운항선박의 원격제어를 위해 선박으로부터 다양한 종류와 포맷의 데이터를 전송받아야 한다. 선체 주변환경을 파악하기 위해 CCTV 영상을, 선박의 운항상 태를 파악하기 위해 각종 센서 메시지를, 레이더신호를 전시하기 위한 레이더 신호 혹은 이미지 등의 데이터를 받아 육상제어 시스템에 전시하고, 사용자의 제어명령을 선박에 전달하기 위한 메시지 교환시스템을 개발하였다.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.6
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• pp.738-743
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• 2007

In this paper, a muscle motion sensing system and an artificial arm control system are studied. The artificial arm is for the people who lost one's forearm. The muscle motion sensing system detect the intention of motion from the upper arm's muscle. In sensing system we use flex sensors which is electrical resistance type sensor. The sensor is attached on the biceps brachii muscle and coracobrachialis muscle of the upper arm. We propose an algorithm to classify the one's intention of motions from the sensor signal. Using this algorithm, we extract the 4 motions which are flexion and extension of the forearm, pronation and supination of the arm. To verify the validity of the proposed algorithms we made experiments with two d.o.f. artificial arm. To reduce the control errors of the artificial arm we also proposed a fuzzy PID control algorithm which based on the errors and error rate.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.6 no.2
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• pp.34-44
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• 2007

Many urban cities deployed ITS technologies to improve the efficiency of traffic operation and management including a real-time franc control system (i.e., COSMOS). The system adopted loop detector system to collect traffic information such as volume, occupancy time, degree of saturation, and queue length. This paper investigated the applicability of detector information within COSMOS to represent the congestion level of the links. Initially, link travel times obtained from the field study were related with each of detector information. Results showed that queue length was highly correlated with link travel time, and direct link travel time estimation using the spot speed data produced high estimation error rates. From this analysis, a procedure was proposed to estimate congestion level of the links using both degree of saturation and queue length information.

• Journal of the Korea Society of Computer and Information
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• v.11 no.2 s.40
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• pp.121-129
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• 2006

Rule-based Expert system using Fuzzy technique inferences various rules by user's input condition and the most proper control signal. This system can lose objectivity by input condition which depends on user's decision. This paper can solve those problems by adding case-based system's technique. The traffic signal control expert system is proposed to store the cases based on the statistics, days, seasons and various circumstances and use them.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.2
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• pp.220-223
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• 2006

In this paper, we studied about the level controller of optical signal with 40 channels by 4 VOA(Variable Optical Attenuator) with 12 channels. Total 8 microprocessors control 40 chamois for control of optical signal level so that a microprocessor controls 5 channels each. Moreover a microprocessor was added to communicate with outside and transfer instruction to each microprocessor. The output optical signal is measured and VOA is controlled as a result of it. The VOA outputs is inputted into PD(Photo Detector) at once. We could control multi-channel optical signals simply like this.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.01a
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• pp.169-170
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• 2021

기존 신호등은 보행자를 위한 별도의 안전장치가 없다. 이는 어린아이는 물론 성인들까지 차량의 위협으로부터 안전을 보장받을 수 없다. 본 연구에서는 어린이보호구역에서 사고 발생률을 감소시키는 것을 전제로 아두이노 액추에이터와 스위치를 이용한 전자제어 신호등을 적용하고자 한다. 현재의 신호등 시스템은 단순히 시간의 흐름에 따라 보행자 신호등과 차량용 신호등의 led가 자동으로 변화하여 차량과 보행자를 통제한다. 이러한 시스템은 어린아이들의 돌발행동과 운전자의 미숙한 작동으로 인한 사고를 방지하지 못한다. 본 논문은 이러한 문제점들을 개선하기 위해 기존의 신호등 시스템 대신 스위치와 액추에이터, 초음파 센서, 블루투스 모듈을 적용한 어린이용 보호 전자제어 신호등 기술을 제안한다. 기존의 신호등 시스템과는 다르게 보행자의 직접적인 개입을 통해 시스템을 제어하고, 원활한 교통환경을 만들 수 있다.