• 전자공학회논문지S
• /
• 제34S권11호
• /
• pp.80-92
• /
• 1997

This research focuses onan efficient control method of temperature for multiple points using only one processor. For a yarn production system, the surface temperature control of heaters are very important for quality control. Therefore, we designed a temperature controller for a draw and twist machine and applied Fuzzy-PWM algorithm to the controller. If we use a processor for the temperature control of multiple points with the conventional ON/OFF control, the control performance of the system becomes poor. To overcome these problems, we developed a new Fuzzy-PWM algorithm for the adjustment of power rate to the heaters in the conventional ON/OFF control. It is shown that this algorithm has the same effects as the PID algorithm for the temperature control of each point. The proposed algorithm is robust against the production condition and environment such as the reference temperature and the thickness of yarn, since the power rate to the heater is adjusted by Fuzzy Rules derived from the values of the reference termperatureand the thickness of yarn. To obtain optimal Fuzzy rulees, the control simulations are perfodrmed through the modelling of the heater and simulation of Fuzzy rules. This algorithm is applied for the multiple pont temperature controller and showed satisfactory performance.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1994년도 추계학술대회 논문집
• /
• pp.748-754
• /
• 1994

This paper deals with a geometric error simulator, measurement and inspection of workpiece errors on the machine tools, and identification and compensation methodology of thermal errors in machining centers. In order to raise the machining accuracy of workpieces a measurement and inspection system on the machine tool is developed. By using MPPGT module Manual and CNC type CMMs are realized on the machining centers. To compensate for geometric and thermal deformation errors of machining centers, a real time and an off line geometric adaptive control system were developed on the machining centers. A vertical and a horizontal machining center equipped with FANUC 0MC were used for experiments. Performance of the systems were confirmed with a large amount of experiment.

• KIEE International Transactions on Power Engineering
• /
• 제4A권4호
• /
• pp.207-213
• /
• 2004

In this paper, the on-line volt/var control algorithms of the Load Tap Changer (LTC) transformer and Shunt Capacitor (SC) are proposed for distribution volt/var compensation. In the existing volt/var control of the distribution substation, the feeder voltage and reactive power demand of the distribution are mainly controlled by the LTC transformer tap position and on/off operation of the Sc. It is very difficult to maintain volt/var at the distribution networks within the satisfactory levels due to the discrete operation characteristics of the LTC and SC. In addition, there is the limitation of the LTC and SC operation times, which affects their functional lifetimes. The proposed volt/var control algorithm determines an optimal tap position of the LTC and on/off status of the SC at a distribution substation with multiple connected feeders. The mathematical equations of the proposed method are introduced. A simple case study is performed to verify the effectiveness of the proposed method.

• 한국컴퓨터정보학회지
• /
• 제2권1호
• /
• pp.35-44
• /
• 1995

• 식물병연구
• /
• 제24권4호
• /
• pp.353-358
• /
• 2018

본 연구팀에서 개발한 키틴분해미생물 대량배양 bioformulated product는 다양한 작물의 병과 선충의 생물적 방제에 성공적으로 이용되어 왔다. 이 연구에서는 개발된 키틴분해미생물 대량배양 기술을 활용하여 인삼 모잘록병의 생물적 방제법을 확립하고자 수행하였다. 인삼 잘록병 오염 토양을 이용한 포트에서 키틴최소배지에서 배양한 키틴분해미생물 Chrobacterium sp.와 L. enzymogenes 혼합배양액 처리구에는 인삼의 출아율과 인삼 잘록병율이 통계적으로 유의하게 감소하였다. 개발된 키틴분해미생물 배양액의 생물적 방제 능력은 희석여부와 처리시기에 따라 차이를 보였다. 인삼 포장에서 혼합배양액을 파종 전 종자침지하고 출아기에는 토양관주하였을 때, 본포의 2년생 인삼에서 배양원액은 2회 토양관주, 10배 희석액은 3회 토양관주에서 높은 방제효과를 나타냈다. 토직 본포의 경우 배양 원액의 종자 침지에 의한 방제효과는 낮았지만, 종자침지 후 1회 또는 2회 토양관주는 살균제인 톨클로로포스메틸수화제의 종자분의소독과 비슷한 수준의 방제효과를 보였다. 이러한 결과는 Chromobacterium sp. C-61와 L. enzymogenes C-3의 혼합배양액을 이용하여 인삼 잘록병 방제에 화학적 살균제를 대신할 수 있을 효과적인 대안이 될 수 있을 것이다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
• /
• pp.547-549
• /
• 1987

The purpose of this paper is to present an efficient and practical method for a Hissle autopilot design problem. The method emphasizes on the use of a modern design technique to classical flight control specifications and the trade-off between dynamic performance and robustness of the Missle autopilot control system.

• The Journal of Korean Physical Therapy
• /
• 제26권5호
• /
• pp.280-289
• /
• 2014

Purpose: This study was conducted in order to determine the stimulation variables which should be considered when neuromuscular electrical stimulation (NMES) is applied for a muscle under the normal innervation to minimize muscle fatigue and increase force-generating ability. Methods: A total of 23 healthy men participated in the study and all subjects were randomly assigned to the 1:1 group, 1:3 group, 1:5 group, and control group with on-off ratio of NMES. The subjects performed a fatigue task, consisting of 10 times of isometric contraction sustained by NMES. NMES using Russian current stimulation was applied to muscle fatigue and divided into three sessions by pulse frequency (10 bps, 30 bps, 90 bps). The EMG was recorded using an MP 100 system from the quadriceps femoris muscle in four groups. Results: The differences of delta MdF and delta MF of between on-off ratio groups of 10 bps, 30 bps, and 90 bps pulse frequencies were very significant (p<0.05). According to the results of post hoc of 10, 90 bps, it was greater in the 1:1 group and the 1:3 group compared with the 1:5 group, and no fatigue was observed in the control group. In 30 bps, it was greater in the 1:1 group compared with 1:3, 1:5, and control group (p<.05). Conclusion: Among NMES variables to minimize muscle fatigue, the larger on-off ratio by pulse frequency showed the lower muscle fatigue. Therefore, on-off ratio needs to be great enough, and will be more efficient with the frequency 30 bps rather than of 10 bps and 90 bps.

• 한국생산제조학회지
• /
• 제9권5호
• /
• pp.87-95
• /
• 2000

The numerical analysis and the experiments are carried out to develop the design program for the flow control valve attached to the vane pump for power steering. The factors affecting the flow rate characteristics are analyzed by the experiments and the numerical analysis. The results are summarized as follows; (1) the main factors affecting to the first and second control flow rate are the diameter of big and small rod of the spool. (2) the cut off is mainly affected by the main spring constant, the initial displacement of main spring and the small diameter of the spool. (3) the dropping slope characteristics are decided by the chamfer of spool and the dynamic characteristics of the spool.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2000년도 전력전자학술대회 논문집
• /
• pp.701-704
• /
• 2000

A SRG(Switched Reluctance Generator) has many advantages such as efficiency simple controllability low cost and robustness compared with outer machines. But the theories that have been adopted as SRG control methods up to the present are complicated. This paper proposes a simple control methods using PID which controls only a turn-off angle while making turn-on angle signals of SRG constant. controlling the voltage differences between the reference and the real value and calculating the proper turn-off angle of the load variations can implement to keep the output voltage constant. the control method suggested in this paper enhances the efficiency of this system and simplifies the hardware and software by using only the voltage and speed sensors. The proposed method is verified by experiment

• International Journal of Aeronautical and Space Sciences
• /
• 제17권1호
• /
• pp.120-131
• /
• 2016

The full results of troubleshooting process related to the flight control system of a tilt-rotor type UAV in the flight tests are described. Flight tests were conducted in helicopter, conversion, and airplane modes. The vehicle was flown using automatic functions, which include speed-hold, altitude-hold, heading-hold, guidance modes, as well as automatic take-off and landing. Many unexpected problems occurred during the envelope expansion tests which were mostly under those automatic functions. The anomalies in helicopter mode include vortex ring state (VRS), long delay in the automatic take-off, and the initial overshoot in the automatic landing. In contrast, the anomalies in conversion mode are untrimmed AOS oscillation and the calibration errors of the air data sensors. The problems of low damping in rotor speed and roll rate responses are found in airplane mode. Once all of the known problems had been solved, the vehicle in airplane mode gradually reached the maximum design speed of 440km/h at the operation altitude of 3km. This paper also presents a comprehensive detailing of the control systems of the tilt-rotor unmanned air vehicle (UAV).