• Journal of Biosystems Engineering
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• 제37권3호
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• pp.201-208
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• 2012

Purpose: This study was conducted to develop a vegetable transplanting robot which transplants seedlings from a nursery tray to a plant pot using its four fingers. Method: The robot consists of the transplanting part, nursery tray moving part, plant pot moving part, main frame and controller. Two moving parts are controlled by the photo sensor and servo motor. The transplanting part was composed with two components; transporting device using E-MY2H(SMC Corp., Japan) for controlling finger position accurately and finger for transplanting the seedling. Results: Head lettuce using the transplanting robot was transplanted in 21 days after sowing based upon the seed shape measurement and removing examination. The optimal finger shape was thin pin type because it caused minimum damage to the roots of seedlings. Conclusions: The four inclined pin type was applied to remove the seedlings from the nursery tray. In addition, the transplanting capacity of the developed robot was 2800 pots per hour and the rate of success was 99% and above.

• 전기학회논문지
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• 제56권1호
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• pp.71-80
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• 2007

A control approach for the sensorless speed control of interior permanent magnet synchronous motor(IPMSM) based on adaptive integral the binary is proposed. With a main loop regulator and an auxiliary loop regulator, the binary observer has a property of the chattering alleviation in the constant boundary layer. However, the width of the constant boundary limits the steady state estimation accuracy and robustness. In order to improve the steady state performance of the binary observer, the binary observer is formed by adding extra integral augmented switching the hyperplane equation. By mean of integral characteristics, the rotor speed can be finely estimated and utilized for a sensorless speed controller for IPMSM. The proposed adaptive integral binary observer applies an adaptive scheme, because the parameters of the dynamic equations such as the machine inertia or the viscosity friction coefficient is not well known and these values can be easily changed generally during normal operation. Therefore, the observer can overcome the problem caused by using the dynamic equations, and the rotor speed estimation is constructed by using the Lyapunov function. The experimental results of the proposed algorithm are presented to demonstrate the effectiveness of the approach.

• 한국산업융합학회 논문집
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• 제19권1호
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• pp.42-49
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• 2016

This study proposes a non-contact inspective technology based robot vision system for Faulty Inspection of welding States and Parts Shape. The maine focus is real time implementation of the machining parts' automatic inspection by the robotic moving. For this purpose, the automatic test instrument inspects the precision components designator the vision system. pattern Recognition Technologies and Precision Components for vision inspection technology and precision machining of precision parts including the status and appearance distinguish between good and bad. To perform a realization of a real-time automation integration system for the precision parts of manufacturing process, it is designed a robot vision system for the integrated system controller and verified the reliability through experiments. The main contents of this paper, the robot vision technology for noncontact inspection of precision components and machinery parts is useful technology for FA.

• 한국산업융합학회 논문집
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• 제17권2호
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• pp.42-53
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• 2014

Robust voice recognition (RVR) is essential for a robot to communicate with people. One of the main problems with RVR for robots is that robots inevitably real environment noises. The noise is captured with strong power by the microphones, because the noise sources are closed to the microphones. The signal-to-noise ratio of input voice becomes quite low. However, it is possible to estimate the noise by using information on the robot's own motions and postures, because a type of motion/gesture produces almost the same pattern of noise every time it is performed. In this paper, we propose an RVR system which can robustly recognize voice by adults and children in noisy environments. We evaluate the RVR system in a communication robot placed in a real noisy environment. Voice is captured using a wireless microphone. Navigation Strategy is shown Obstacle detection and local map, Design of Goal-seeking Behavior and Avoidance Behavior, Fuzzy Decision Maker and Lower level controller. The final hypothesis is selected based on posterior probability. We then select the task in the motion task library. In the motion control, we also integrate the obstacle avoidance control using ultrasonic sensors. Those are powerful for detecting obstacle with simple algorithm.

• Journal of Biosystems Engineering
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• 제18권3호
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• pp.199-208
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• 1993

This study was attempted to develop the eletronic-hydraulic hitch system for controlling the attitude of tractor implements and to investigate control performance of the system through experiments. Main components of the system developed in this study were reference inputs panel, inclination angle detecter, electronic controller consisted of IBM-AT PC and interfaces, electro-hydraulic directional valves and other hydraulic components and three-point hitch linkage. Experiments were carried out to investigate the response of the system to the step and sine inputs. The effects of hydraulic flow rate and dead band on control performance were analized. Attitude of the implement was controlled within 2.4-5.1 degrees to the setting attitude when the hydraulic flow rate was in the range of $0.25-1.5{\ell}/min$. And implement was controlled without rapid amplitude attenuation and phase angle change in the frequency range of 0.02-0.2Hz when the hydraulic flow rate was in the range of $0.25-1.5{\ell}/min$. Control performance of the system can be expected to be improved if the inclination angle detecter show rapid and stable output as the implement moves.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2008년도 한국우주과학회보 제17권2호
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• pp.35.3-36
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• 2008

The ground-based spacecraft simulator is a useful tool to realize various space missions and satellite formation flying in the future. Also, the spacecraft simulator can be used to develop and verify new control laws required by modern spacecraft applications. In this research, therefore, Hardware-in-the-loop (HIL) simulator which can be demonstrated the experimental validation of the theoretical results is designed and developed. The main components of the HIL simulator which we focused on are the thruster system to attitude control and automatic mass-balancing for elimination of gravity torques. To control the attitude of the spacecraft simulator, 8 thrusters which using the cold gas (N2) are aligned with roll, pitch and yaw axis. Also Linear actuators are applied to the HIL simulator for automatic mass balancing system to compensate for the center of mass offset from the center of rotation. Addition to the thruster control system and Linear actuators, the HIL simulator for spacecraft attitude control includes an embedded computer (Onboard PC) for simulator system control, Host PC for simulator health monitoring, command and post analysis, wireless adapter for wireless network, rate gyro sensor to measure 3-axis attitude of the simulator, inclinometer to measure horizontality and battery sets to independently supply power only for the simulator. Finally, we present some experimental results from the application of the controller on the spacecraft simulator.

• 한국멀티미디어학회논문지
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• 제5권6호
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• pp.753-758
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• 2002

본 논문에서는 ADSL용 아날로그 Front- end의 수신단과 송신단에 활용하기 위한 저전압 특성의 3V CMOS 프로그램머블 증폭기(PGA)를 설계하였다. 설계된 수신단의 PGA는 1.1MHz로 연속시간 저역통과 필터와 연결하여 0db에서 30db까지 이득을 조정해주며, 송신단의 PGA는 138MHz의 저역필터와 연결하여 15db에서 0db까지의 이득을 조정할 수 있다. 모든 PGA의 이득은 디지털 로직과 메인 컨트롤러에 의해서 프로그램 될 수 있도록 설계하였다. 설계된 PGA는 $0.35\mu{m}$ COMS 파라미터를 이용하여 Hspice시뮬레이션으로 그 특성을 확인하였다.

• 한국산학기술학회논문지
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• 제10권1호
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• pp.67-74
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• 2009

본 연구에서는 임베디드 시스템과 지그비(Zigbee) 무선통신을 기반으로 지능형 자동차를 위한 모니터링 및 제어가 가능한 임베디드 웹서버를 구축하였다. 자동차의 모든 정보를 담고있는 ECU(Electronic Control Unit)에 주제어기와 임베디드 시스템을 인터페이스 시켜 자동차의 운행정보를 모니터링하고, 자동차의 내, 외부에 추가된 센서신호는 지그비 통신을 이용해 임베디드 시스템에 전달하도록 하였다. 임베디드 시스템을 이용해 웹서버를 구축했기 때문에 개인용 컴퓨터 및 모바일 기기를 이용하여 차량에 접속할 수 있으며, 자동차의 상태를 실시간 감지하고 제어할 수 있다.

• Journal of Power Electronics
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• 제14권6호
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• pp.1109-1118
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• 2014

A Fundamental Frequency Sorting Algorithm (FFSA) is proposed in this paper to balance the voltages of floating dc capacitors for Modular Multilevel Converters (MMCs). The main idea is to change the sequences of the CPS-PWM carriers according to the capacitor voltage increments during the previous fundamental period. Excessive frequent sorting is avoided and many calculating resources are saved for the controller. As a result, more sub-modules can be dealt with. Furthermore, it does not need to measure the arm currents. Therefore, the communication between the controllers can be simplified and the number of current sensors can be reduced. Moreover, the proposed balancing method guarantees that all of the switching frequencies of the sub-modules are equal to each other. This is quite beneficial for the thermal design of the sub-modules and the lifetime of the power switches. Simulation and experimental results acquired from a 9-level prototype verify the viability of the proposed balancing method.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 추계학술대회 논문집
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• pp.31-32
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• 2012

This paper presents a new design of magnetic bearing structure for application in Nuclear Power Plant (NPP). The proposed design includes so-called saturated coils which is used to generate the bias flux for bearing almost the whole mass of the rotor, and so-called linear auxiliary coil controlled to stabilize the suspension. The saturated coil is considered as an special electromagnet which is controlled to operate in the region of magnetic saturation in order to minimize the bias current as well as to enhance the magnetic flux density. This strategy will result in a very compact size of magnetic bearing as well as increasing the speed of the response of the current controller. The novel structure is expected to be applied to design very high power gas turbine generator of next generation of fast reactor in which the mass of rotor can reach 50 tons. The total power of the NPP can reach 2,000 MW. Moreover, the issue of arc occurrence between coils is also discussed and two solutions are proposed.