• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.865-870
• /
• 2003

A motion controller has been used variously in industry such as semiconductor manufacture equipment, industrial robot, assembly/conveyor line applications and CNC equipment. There are several types of controller in motion control. One of these is a PC-based motion controller such as PCI or ISA, and another is stand-alone motion controller. The PC bus-based motion controller is popular because of improving bus architectures and GUI (Graphic User Interface) that offer convenience of use to user. There are some problems in this. The PC bus-based solution allows for only one of the form factors, so it has a poor flexibility. The overall system package size is bigger than other motion control system. And also, additional axes of control require additional slot, however the number of slots is limited. Furthermore, unwieldy and many wirings come to connect plants or I/O. The stand-alone motion controller has also this limit of axes of control and wiring problems. To resolve these problems, controller must have capability of operating as stand-alone devices that resides outside the computer and it needs network capability to communicate to each motion device. In this paper, a network-based stand-alone motion system is proposed. This system integrates PC and motion controller into one stand-alone motion system, and uses CAN (Controller Area Network) as network protocol. Single board computer that is type of 3.5" FDD form factor is used to reduce the system size and cost. It works with Windows XP Embedded as operating system. This motion system operates by itself or serves as master motion controller that communicates to slave motion controller. The Slave motion controllers can easily connect to master motion system through CAN-network.

• Journal of Biosystems Engineering
• /
• 제31권6호
• /
• pp.514-523
• /
• 2006

Production of green pepper has been increased due to customer's preference and a projected ten-year boom in the industry in Korea. This study was carried out to develop an automatic grading and sorting system for green pepper using machine vision. The system consisted of a feeding mechanism, segregation section, an image inspection chamber, image processing section, system control section, grading section, and discharging section. Green peppers were separated and transported using a bowl feeder with a vibrator and a belt conveyor, respectively. Images were taken using color CCD cameras and a color frame grabber. An on-line grading algorithm was developed using Visual C/C++. The green peppers could be graded into four classes by activating air nozzles located at the discharging section. Length and curvature of each green pepper were measured while removing a stem of it. The first derivative of thickness profile was used to remove a stem area of segmented image of the pepper. While pepper is moving at 0.45 m/s, the accuracy of grading sorting for large, medium and small pepper are 86.0%, 81.3% and 90.6% respectively. Sorting performance was 121 kg/hour, and about five times better than manual sorting. The developed system was also economically feasible to grade and sort green peppers showing the cost about 40% lower than that of manual operations.

• Journal of Biosystems Engineering
• /
• 제33권5호
• /
• pp.348-354
• /
• 2008

Egg grading is determined by exterior and interior quality. Among the evaluation methods for the egg quality, a candling method is common to identify eggs with cracked shells and interior defects. But this method is time-consuming and laborious. In addition, practically, it is challenging to detect hairline and micro cracks. In this study, an on-line inspection system based on acoustic resonance frequency analysis was developed to detect hairline cracks on eggshells. A roller conveyor was used to transfer eggs along one lane to the impact position where each of eggs rotated by the roller was excited with an impact device at four different locations on the eggshell equator. The impact device was consisted of a plastic hammer and a rotary solenoid. The acoustic response of the egg to the impact was measured with a small condenser microphone at the same position as the impact device was installed. Two acoustic parameters, correlation coefficient for normalized power spectra and standard deviation of peak resonant frequencies, were used to detect cracked eggs. Intact eggs showed relatively high correlations among the four normalized power spectra and low standard deviations of the four peak resonant frequencies. On the other hand, cracked eggs showed low correlations and high standard deviations as compared to the intact. This method allowed a crack detection rate of 97.6%.

• 농업과학연구
• /
• 제48권1호
• /
• pp.141-149
• /
• 2021

The cultivation area for domestic cabbage increased by 26.3% from 10,968 ha in 2019 to 13,854 ha in 2020, and among leafy vegetables, the cabbage cultivation area was 62%, and production was 78.9%. Demand for field crop production of cabbage, which has a relatively high-income level compared to rice farming, is increasing, and mechanization of the field operation is urgently needed due to the insufficient development of related farming machinery. In this study, a prototype fabrication and performance test of a tractor-attached cabbage collector was carried out. The transport section was divided into two parts, one for the feeding and transportation and the other for the screening and packaging to selectively collect cabbages in bulk bags or boxes. The length of the primary collecting conveyor was designed to meet the field conditions of the Korean cabbage cultivation standards so that six cultivation rows could be worked simultaneously. Power was controlled by a hydraulic transmission line of the tractor and was easily mounted onto the 3-point hitch links behind the tractor. When the performance was evaluated, the transfer rate, loss rate, damage rate, and work performance were 100, 0, 1.2%, and 1.9 h·10 a^-1. Final improvement and commercialization of the prototype would considerably contribute to the mechanization of harvesting cabbage, the main ingredient of Kimchi.

• 한국축산시설환경학회지
• /
• 제14권1호
• /
• pp.47-52
• /
• 2008

1. 조사농장의 산란율은 하이라인, 이사브라운 모두 $85{\sim}93%$ 수준 이였으며, 농가자체 파란율은 하이라인 $1.5{\sim}2.2%$, 이사브라운 $1{\sim}1.4%$이었다. 2. 계란 이송단계별 파란발생비율은 집란벨트 4.7%> 엘리베이터 2.5%> 선란기 1.7%> 컨베이어 0.9% 순 이었다. 3. 집란벨트에서 엘리베이터로 이송 중 계란이송가이드를 설치할 경우 약 1%의 파란경감 효과가 있는 것으로 나타났다. 4. 하이라인 브라운은 주령이 높아지면서 파란율은 높아지고, 파각력은 낮아지는 것으로 나타났으며, 회귀계수 분석 유의성은 $R^2=0.7$로 파각력의 변화가 파란율에 영향을 미치는 것으로 분석되었다. 5. 이사브라운에서는 환우 전에 비하여 환우 후 파각력이 높아진 것으로 나타났다. 6. 난각 두께와 파각력, 그리고 접촉 후 파각변위와 파각력과의 관계에서 이들 함수의 변수간에 회귀관계는 유의성이 나타나지 않았다.

• 영어영문학
• /
• 제54권2호
• /
• pp.301-322
• /
• 2008

Pauline Hopkins's Of One Blood; Or, the Hidden Self was published in the Colored American Magazine during 1902-03. As a literary experimentalist and a political protester, Hopkins uses her fiction as a medium to overcome and ameliorate the violently racialized surroundings of the turn-of-the-century America. Having been faced with racist rhetorics and theories growing on biological differences between races, Hopkins must have felt an overwhelming urgency to challenge the heritage of slavery in American history. In order to speak out her political agenda in such a milieu, she needed a new setting as well as new narrative materials for the new era. She had to move the setting from America to Africa, the ancient utopian Ethiopia; her interest in the ancient African civilization reflects both a popular African-American vision of Africa and the movement of "black nationalism" of the time. She also needed materials from nineteenthcentury sciences, the newly evolving theories of psychology and mysticism (spiritualism/mesmerism), to explore the meaning of "the hidden self" which unfolds the complex nature of Hopkin's position on race, "blood," and African-American racial subjectivity. Hopkins in the novel explores not the color line but the bloodline. Tracing the horrific legacy of incest in the history of slavery, she attempts to redefine the true racial identity of African-Americans in America and to reconstruct their past, both family and race history. At the very center of her major tropes in the novel-such as "of one blood," "the hidden self," and incest-exists female body. Black female body, though it represents the violent site of sexual body (rape and incest) in slavery, ultimately becomes a vehicle to convey and preserve the truth of racial memory/past/history for African-Americans. As a conveyor of the past, black women not just connect the past and the present but also reawaken AfricanAmericans with the legacy of the African 'pure' bloodline. Hopkins's vision here necessitates the reevaluation of black women's role in family and history, heralding the 20th-century black feminine writing. With the major tropes, Hopkins clearly suggests that the blood of (African-)Americans is unrecognizably intermixed. Although the novel ends with ambivalence and without resolution on what Africa signifies, those tropes certainly offer her a vehicle for criticizing as well as for challenging the racial reality of America.