The purpose of this study is to design and control position and torque based on the steering controller of power tiller simulator developed by the National Institute of Agricultural Sciences. The tiller simulator selects sensors and motors to detect the motion of the mechanism required for steering, and controls the tiller's steering controller through the PID control method and the PWM control method which can control simultaneously the position and torque. Simulation tests are carried out under various conditions to verify the efficiency of the proposed controller. The power tiller training simulator can be used as a means to prevent agricultural machinery accidents caused by human factors. Through the simulator, the driver can experience a variety of tasks without any risk of collision, the results of his actions, and learn the cause and effect concepts, which can be used for safety education and accident experience.
The two-spotted spider mite, Tetranychus urticae, is one of the most important pests of crops. However, chemical acaricides are not always effective and their continuous use has resulted in resistance among two-spotted spider mite populations. To reduce or replace use of chemical acaricides, the entomopathogenic fungi having acaricidal activity were investigated. As results, 12 isolates could be selected from 342 isolates of fungi against two-spotted spider mite. To show the multiple roles of entomopathogenic fungi against plant pathogen, the antimicrobial activity of selected 12 isolates were evaluated to plant pathogenic bacterium Ralstonia solanacearum and fungus Botrytis cinerea. Various antimicrobial activities were observed against these plant pathogens. Consequently, these entomopathogenic fungi would be offered an alternative for dual control agents against the two-spotted spider mite and plant diseases.
A multi-input single-output (MISO) semi-active control systems were studied by many researchers. For more improved vibration control performance, a structure requires more than one control device. In this paper, multi-input multi-output (MIMO) semi-active fuzzy controller has been proposed for vibration control of seismically excited small-scale buildings. The MIMO fuzzy controller was optimized by multi-objective genetic algorithm. For numerical simulation, five-story example building structure is used and two MR dampers are employed. For comparison purpose, a clipped-optimal control strategy based on acceleration feedback is employed for controlling MR dampers to reduce structural responses due to seismic loads. Numerical simulation results show that the MIMO fuzzy control algorithm can provide superior control performance to the clipped-optimal control algorithm.
복합구조제어시스템의 동시최적설계방법에 관하여 연구하였다. 여기에서는 수동제어장치 뿐만 아니라 능동제어장치의 배치와 용량, 제어기 등이 설계변수가 되며 설계인자들의 만족도를 나타내는 선호도함수를 정의하여 이를 이용하여 최적화문제를 정식화한다. 또한 수동 및 능동제어장치의 설계변수로부터 동시에 최적해를 찾아내기 의한 수치적 방법으로 유전자알고리즘을 사용하였다. 지진하중을 받는 다자유도 구조물의 설계에 및 수치모사를 통하여 제안한 방법의 타당성을 검증하고자 하였다.
본 시험은 유기인계 살충제인 Terracur P입제 및 Lebaycid 입제와 유기염소계 살충제인 상감마입제를 수면시용 하였을때 수도요해충인 이화명충, 끝 동매미충, 애멸구 및 흰둥멸구에 대한 동시방제가능성과 방제적기를 구명하고 약제간의 방제효과를 비교코저 실시하였다. 얻어진 시험결과는 다음과 같다. 1) 약제처리후 부화직후 이화명충 접종 시험에 있어서 상감마와 Terracur P는 높은 살충율을 보였으나 Lebaycid의 살충율은 낮았다. 約 살충력 잔효일수에 있어서 상감마는 8-14日이었고 Terracur P는 6일간이었다. 2) 당초 계획된 방제적기에 관한 정보는 얻을 수 없었다. 즉 주어진 일간격이 좁아 유의한 차를 얻을 수 없었다. 3) 1,2화기 이화명충에 대한 방제효과는 Terracur P=상감마>Lebaycid의 순이었다. 4) Terracur P와 Lebaycid 입제의 처리는 끝동매미충의 방제효과가 좋았으나 상감마의 방제효과는 기대할 수 없었다. 끝동매미충에 대한 Terracur P와 Lebaycid입제의 잔효력은 30일 이상이었다. 5) 애멸구와 흰등별구에 대한 시험은 충의 서식밀도가 낮기 때문에 약제간 방제효과를 얻을 수 없었다. 6) 공시약제중 Terracur P와 Lebaycidd입제는 이화명충과 끌동매미충의 동시방제제로서 사용할 수 있을 것 같다
Conventional path tracking methods designed for two-wheeled differential drive robots are not suitable for omni-directional robots. In this study, we present a controller which can accomplish more accurate path tracking and orientation correction by exploiting the unconstrained movement capability of omni-directional robots. The proposed controller is proven to be stable using a Lyapunov stability criterion. Various experiments in real environments show that performance of path tracking and orientation correction has improved in the proposed controller.
This paper presents a frequency-response test performed on an antagonistic actuation system consisting of two Mckibben pneumatic artificial muscles and a pneumatic circuit. A linear model, capable of estimating the dynamic characteristics of the antagonistic system in the operating range of pneumatic artificial muscles, was optimally calculated based on frequency-response results and applied to a multiple simultaneous specification control scheme. Trajectory tracking results showed that the presented multiple simultaneous specification controller, built experimentally by three PD typed sample controllers, satisfied successfully all required control specifications; rising time, maximum overshoot, steady-state error.