• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.206-211
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• 1993

This paper presents a new identification method which utilizes fuzzy inference in parameter identification. The proposed system has an additional control loop where a real plant is replaced by a plant model. The control system to be designed is to satisfy the following specifications: 1) It has zero steady-state error. 2) It has adequate damping characteristics. 3) 1),2) satisfied, it has a shortest rise-time. Fuzzy rules describe the relationship between comparison results of the features and magnitude of modification in the model parameter values. This method is effective in auto-tuning because the response of the closed loop is verified. The proposed method is tested in simulation for several plants with high-order lags and dead-times.

• 한국정보시스템학회지:정보시스템연구
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• 제19권4호
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• pp.233-252
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• 2010

Due to its capabilities, RFID (Radio Frequency IDentification) has shown its applicability in various areas of business operations. This study describes the successful RFID system implemented in the auto parts manufacturing company called "E" to improve the efficiency of auto parts painting process management. The findings of this study show that an RFID system could help companies reduce manufacturing cost, inventory, and error rate in the auto-parts painting process. The RFID system descried in this study also demonstrates that an RFID system could make production data available real time to the company's ERP system and thus, managers and supervisors on the shop floor are able to make more informed business decisions. The findings of this study imply that RFID systems can be used to improve the efficiency of various manufacturing operations in companies. This study also provides IT professionals with practical guidelines for an effective implementation of RFID systems. In other words, it provides IT practitioners with the information on the success factors for implementing RFID systems as well as potential problems and solutions to them when implementing RFID systems.

• Journal of Biosystems Engineering
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• 제27권5호
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• pp.451-458
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• 2002

This paper introduces that livestock can be effectively managed by an individual electronic identification system. The proposed system was composed of the original code transmitter, receiver, personal computer, micro-processor, and RS485 telecommunications module. In the individual electronic identification system, the signal including encoded information of a milk-cow was transmitted from an original code transmitter to a micro-processor through RS485 telecommunications module. The transmitted signal can be successfully displayed in a personal computer. This system can be managed by 9999 individuals with a original code transmitter. The recognition rate of an individual electronic identification system was 98.5% and also auto-feeder operates very well. an individual electronic identification system was developed for automation of stockbreeding management. To automate the breeding management, it is necessary to obtain and analyze the individual information distinguished from others preferentially.

• 자동차안전학회지
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• 제12권2호
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• pp.27-32
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• 2020

This paper presents steering system requirements to ensure the stabilized lateral control of autonomous driving vehicles. The two main objectives of a lateral controller in autonomous vehicles are maintenance of vehicle stability and tracking of the desired path. Even if the desired steering angle is immediately determined by the upper level controller, the overall controller performance is greatly influenced by the specification of steering system actuators. Since one of the major inescapable traits that affects controller performance is the time delay of the steering actuator, our work is mainly focused on finding adequate parameters of high level control algorithm to compensate these response characteristics and guarantee vehicle stability. Actual vehicle steering angle response was obtained with Electric Power Steering (EPS) actuator test subject to various longitudinal velocity. Steering input and output response analysis was performed via MATLAB system identification toolbox. The use of system identification is advantageous since the transfer function of the system is conveniently obtained compared with methods that require actual mathematical modeling of the system. Simulation results of full vehicle model suggest that the obtained tuning parameter yields reduced oscillation and lateral error compared with other cases, thus enhancing path tracking performance.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 춘계학술대회
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• pp.502-504
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• 2021

UAV(Unmanned Aerial Vehicle)에 대한 활용영역은 시간이 갈수록 꾸준히 확대되고 있다. 특히 네 개 이상의 수평적인 프로펠러로 구성된 VTOL(Vertical Take-Off and Landing) 기능이 가능한 UAV는 시스템 안정성 및 비교적 단순한 항공역학적 설계 및 구조에 따라 다양한 플랫폼이 등장하고 있으며 비교적 저렴한 가격으로 응용제품들이 시중에 유통이 되고 있다. 대부분의 UAV는 GCS(Ground Control System, 지상시스템)를 통해 임무가 수행된다. 지상시스템은 주로 인터넷에 연결되어있기 때문에, 전자 지도 및 기타 최적의 비행조건(온도, 습도, 풍향 등)을 위한 환경정보를 또한 얻을 수 있다. 본 논문은 AIS(Auto Identification System)를 통해 얻은 정보를 기반으로 식별된 선박으로의 접근 및 감시(monitoring)하기 위한 UAV의 운영기법을 설계한다.

• 소음진동
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• 제8권3호
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• pp.533-541
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• 1998

Recently, optical disk drives are increasingly demanded to have higher speed as well as high information density, especially for applications like CD ROM drives. To this end, improvement of their optical pickup structure and control is recognized the very challenging issue. In this paper, the pickup is first analytically modelled in a plane to describe its coupled auto-focusing and auto-tracking motions. Subsequently, the model is linearized and combined with actuator dynamics for the auto-focusing system. With its unmeasurable parameters being estimated based on experimental data, an approximate I-DOF linear model is obtained neglecting the coupling term. To design the high speed and robust positional servo controller realistic design specifications are addressed, and H control method is employed based on the approximate model. Finally, taking the pickup in a commerical high speed CD ROM drive as an example performance of the designed controller is verified through realtime experiments.

• 소음진동
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• 제10권3호
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• pp.451-456
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• 2000

In this paper a discrete time model for the identification of nonlinear vibration system with stick-slip friction is proposed. The proposed model can handle the highly nonlinear behavior of the friction such as stick-slip phenomenon and Stribeck effect. The basic idea of the proposed model is as follows : If the nonlinearity of the system can be predicted as a simple function then this nonlinear function term cab be directly used in the discrete time model. By doing this the number of nonlinear terms in the model can be much less than those of NARMAX model which is widely used nonlinear discrete model. The simulation result shows that the proposed model can estimate the response of the nonlinear vibration system with stick-slip friction very well with less computational effort.

• 제어로봇시스템학회논문지
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• 제10권6호
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• pp.545-550
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• 2004

Recent natural disasters like flooding and slope collapse have shown the need for natural risk management system, as they endanger directly public health and cause severe damages on the national economy. In order to improve the efficiency of risk management systems, this management system based on AANN(Auto-Associative Neural Network)is proposed in this paper. AANN can be effectively used for identification of abnormal data and data compression. The proposed AANN-based risk management system collects and stores measurement data from sensors and transmits them to remote server for web-monitoring. Generally, it is desirable to transmit the compressed data instead of raw data in normal state. However, if dangerous situation happens, rapid tramission of measurement data should be required. These requirements are easily satisfied by using AANN. In order to verify the feasibilities of the proposed system, The AANN-based risk management system is applied to slope collapse monitoring system.

• Structural Engineering and Mechanics
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• 제46권3호
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• pp.433-445
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• 2013

Vibration-based structural identification has become an important tool for structural health monitoring and safety evaluation. However, various kinds of uncertainties (e.g., observation noise) involved in the field test data obstruct automation system identification for accurate and fast structural safety evaluation. A practical way including a data preprocessing procedure and a vector backward auto-regressive (VBAR) method has been investigated for practical bridge identification. The data preprocessing procedure serves to improve the data quality, which consists of multi-level uncertainty mitigation techniques. The VBAR method provides a determinative way to automatically distinguish structural modes from extraneous modes arising from uncertainty. Ambient test data of a cantilever beam is investigated to demonstrate how the proposed method automatically interprets vibration data for structural modal estimation. Especially, structural identification of a truss bridge using field test data is also performed to study the effectiveness of the proposed method for real bridge identification.

• Journal of Power Electronics
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• 제5권3호
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• pp.198-205
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• 2005

The mechanical system of a drive can often be modeled as a two- or three-mass-system. The load is coupled to the driving motor by a shaft able to perform torsion oscillations. For the automatic tuning of the control, it is necessary to know the mathematical description of the system and the corresponding parameters. As the manpower and setup-time necessary during the commissioning of electrical drives are major cost factors, the development of self-operating identification strategies is a task worth pursuing. This paper presents an identification method which can be utilized for the assisted commissioning of electrical drives. The shaft assembly can be approximated as a two-mass non-rigid mechanical system with four parameters that have to be identified. The mathematical background for an identification procedure is developed and some important implementation issues are addressed. In order to avoid the excitation of the system with its natural resonance frequency, the frequency response can be obtained by exciting the system with a Pseudo Random Binary Signal (PRBS) and using the cross correlation function (CCF) and the auto correlation function (ACF). The reference torque is used as stimulation and the response is the mechanical speed. To determine the parameters, especially in advanced control schemes, a numerical algorithm with excellent convergence characteristics has also been used that can be implemented together with the proposed measurement procedure in order to assist the drive commissioning or to achieve an automatic setting of the control parameters. Simulations and experiments validate the efficiency and reliability of the identification procedure.