• 한국기후변화학회지
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• 제9권4호
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• pp.377-384
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• 2018

The chamber method is widely used for measuring methane emission from paddy rice fields. The closed static chamber has advantages of easy installation and removal in the field and low manufacturing cost. However, the manual chamber method requires a lot of labor and has a limited sampling time and frequency. To overcome the disadvantages of the manual chamber, the auto-chamber system is used for measuring methane emission. We compared the differences in methane flux between the auto-chamber and manual chamber. To investigate methane emissions by the two methods, a chamber was installed for each of the following treatments : control without rice straw (NA), spring plowing after autumn rice straw application (SPRA) and autumn plowing after autumn rice straw application (APRA). The total methane emission was lowest in the control and highest in APRA with both methods. There was no significant difference in total methane emission between the methods, but dynamic fluctuation in methane with temperature change was accurately measured in the auto-chamber. Measuring methane emission with an auto-chamber system is expected to reduce uncertainty and increase accuracy, accompanied by labor reduction.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.769-770
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• 2012

• 자동차안전학회지
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• 제12권1호
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• pp.15-25
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• 2020

This paper presents a longitudinal control algorithm for ensuring takeover time of autonomous vehicle using V2V communication. In the autonomous driving of more than level 3, autonomous systems should control the vehicles by itself partially. However if the driver's intervention is required for functional safety, the driver should take over the control reasonably. Autonomous driving system has to be designed so that drivers can take over the control from autonomous vehicle reasonably for driving safety. In this study, control algorithm considering takeover time has been developed based on computation method of takeover time. Takeover time is analysed by conditions of longitudinal velocity of preceding vehicle in time-velocity plane. In addition, desired clearance is derived based on takeover time. The performance evaluation of the proposed algorithm in this study was conducted using 3D vehicle model with actual driving data in Matlab/Simulink environment. The results of the performance evaluation show that the longitudinal control algorithm can control while securing takeover time reasonably.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.769-772
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• 2003

Middleware enables different networking devices and protocols to inter-operate in ubiquitous home network environments. The UPnP(Universal Plug and Play) middleware, which runs on a PC and is based on the IPv4 protocol, has attracted much interest in the field of home network research since it has versatility. The UPnP, however, cannot be easily accessed via the public Internet since the UPnP devices that provide services and the Control Points that control the devices are configured with non-routable local private or Auto IP networks. The critical question is how to access UPnP network via the public Internet. The purpose of this study is to deal with the non-routability problem in local private and Auto IP networks by improving the conventional Control Point used in UPnP middleware-based home networks. For this purpose, this paper proposes an improved Control Point for accessing and controlling the home network from remote sites via the public Internet, by adding a web server to the conventional Control Point. The improved Control Point is implemented in an embedded GNU/Linux system running on an ARM9 platform.

• 한국항공우주학회지
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• 제42권12호
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• pp.997-1003
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• 2014

무인항공기의 자동이착륙을 성공적으로 수행하기 위해서는 자동 지상활주 제어는 반드시 설계되어야 하는 중요한 부분이다. 이러한 지상활주 제어기를 설계하기 위해서는 정확하고 신뢰도 높은 착륙장치 모델은 반드시 필요하다. 본 연구에서는 착륙장치 모델링을 완성하기 위해서 특별히 착륙장치 측력 모델링을 수행하였다. 조향각 명령을 포함한 Cornering Angle을 계산하여 측력을 모델링하였다. 그리고 모델링된 착륙장치 모델을 포함한 비선형 6자유도 시뮬레이션 환경을 이용하여, 항공기의 바람벡터 방향인 Course Angle 오차를 해소하기 위한 전륜 조향(Nose Wheel Steering)과 러더 조향(Rudder Steering)을 동시에 이용하는 자동 지상활주 제어기를 설계하였다. 설계된 지상활주 제어기를 동일하게 적용하여, 착륙장치 모델을 포함한 시뮬레이션 결과와 실제 무인기를 이용한 자동 지상활주 시험 결과를 비교하였고, 이로써 착륙장치 측력 모델링과 지상활주 제어기의 정확성을 입증하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.111-112
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• 2006

A new MR cylinder with built-in valves using Magneto - Rheological fluid (MR valve) is proposed for fluid power control systems. The MR fluid is a newly developed functional fluid whose obvious viscosity is controlled by the applied magnetic field intensity. This MR cylinder, which is composed of cylinder with small clearance and piston with electromagnet, has the characteristics of simple, compact and reliable structure. This paper presents a method to control the pressure of MR cylinder by using Generalized Predictive Control (GPC) algorithm. The differential pressure is controlled by applying magnetic field intensity to MR fluid. The use of GPC controller is to generate a control sequence by minimizing a cost function in such a way that the future system output is driven close to reference over finite prediction horizons. Experimental results from real time control using GPC method compared with conventional PID control method are also shown in this paper.

• 전기전자학회논문지
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• 제26권2호
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• pp.280-286
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• 2022

본 논문에서는 Digital Signal Processor(DSP)와 PLECS 소프트웨어를 사용하여 영구자석동기전동기(Permanent Magnet Synchronous Machine, PMSM)를 위한 Rapid Control Prototyping (RCP)를 구현하였다. PLECS의 Auto-code generation(ACG) 기능을 활용하여 제어 프로세서를 DSP로 사용하는 PMSM 구동 시스템에 대한 현재 벡터 제어 알고리즘을 보다 상대적으로 간단하고 효율적으로 개발할 수 있다. 본 논문에서는 모델 기반 설계(Model Based Design, MBD)와 real time control(실시간 제어) 배경을 살펴본다. 또한, DSP 보드와 호환되는 상용 RCP 제품 및 실험을 통한 PMSM 드라이브 제어를 구현하였다.

• 제어로봇시스템학회논문지
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• 제7권12호
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• pp.973-979
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• 2001

Sliding mode control guarantees robustness in the presence of modeling uncertainties and external disturbances. However, this can be obtained at the cost of high control activity that may lead to chattering As one way to alleviate this problem a boundary layer around sliding surface is typically used. In this case the selection of controller gain, control ban width and boundary layer thickness is a crucial problem for the trade-off between tracking error and chattering. The parameter tuning is usually done by trail-and-error in practice causing significant effort and time. An auto tuning method based on fuzzy rules is proposed in the paper in this method tracking error and chattering are monitored by performance indices and the controller tunes the design parameters intelligently in order to compromise both indices. To demonstrate the efficiency of the propose method a mass-spring translation system and a roboic control system are simulated and tested It is shown that the proposed algorithm is effective to facilitae the parameter tuning for sliding mode controllers.

• 제어로봇시스템학회논문지
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• 제13권11호
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• pp.1112-1118
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• 2007

We propose a new-focusing method for test handlers of compact camera module (CCM), The MMD (max-min difference) method is applied to calculate the focus value quickly considering the noisy output of CCM. Also, the fuzzy search method is applied to find the maximum focus value effectively. We design a fuzzy processor to control the lens position by focus values and brightness values, which improves the focusing performance in the sense of speed and processor memory. The proposed method is implemented by computer program and installed at the CCM test handler machines. The simulation results are presented to verify the usefulness of the proposed method.

• 자동차안전학회지
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• 제4권2호
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• pp.5-10
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• 2012

Whiplash is the most frequent injury among occupants in low speed rear-end car collision. The aim of this paper is to analyze thecorrelation between influence parameters of head restraints and whiplash injury criteria.In this paper, DFSS (Design for Six Sigma) method is used for optimum design of head restrains. Four control factors of head restraints have selected by function matrix method. The effects of the control factors have been experimentally evaluated by using a sled pulse from 16km/h relative velocity which is suggested by KNCAP (Korean New Car Assessment Program). In order to reduce the noise factors of dynamic tests, whiplash tests were repeated twice. By using DFSS, the correlation between control factors and injury criteria has been comprehended.