• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.10
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• pp.151-157
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• 2006

As people's living standard is being improved, human works are being replaced by robots. However, because most robots are used in process industry, fixed on the ground, we need to develop human robots that have wide applications. Currently many researches are being conducted on human robots with the object of replacing human works, but because of lack of relevant hardware, such robots are being applied limitedly to very simple tasks. To overcome the limitation, the present study developed a kinematical mechanism and a controller. Based on human kinematics, the shoulders and the arms were composed of master arms with 3 degree of freedom, and we reproduced motions similar to human ones through the characteristics of joint variables and experiment on the trajectory of the end effector.

• Journal of the Korean Society for Precision Engineering
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• v.34 no.4
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• pp.243-246
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• 2017

In this study, flexible fixtures and end effectors are conceptually designed for the holding of thin-walled carbon-fiber reinforced-plastic (CFRP) workpieces in machining processes. Firstly, the fixture scenarios and system requirements for the conceptual designs of flexible-fixture and core units are proposed, including the propounding of the workpiece-holding mechanism and the core-unit requirements. A ball-joint pneumatic system is determined as a locking mechanism of the flexible-fixture system for the machining of thin-walled components. Secondly, conceptual designs of the core units are suggested with the driven requirements from the fixture scenarios. A self-tilting mechanism and an end-effector return mechanism are also proposed. Finally, the prototypes of the core units are manufactured, and the workpiece-holding capacity of each prototype is measured.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.4
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• pp.411-417
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• 2004

Recently, instruments and systems related on biological technology have been enormously developed. Particularly, many researches for biological cell injection have been carried out. Usually, excessive contact force occurring when the end-effector and a biological cell contact might make a damage on the cell. Unfortunately, the excessive force could easily destroy the membrane and tissue of the cell. In order to overcome the problem, we proposed a new injection system for biological cell manipulation. The proposed injection system can measure the contact force between a pipette and a cell by using a force sensor. Also, we used vision technology to correctly guide the tip of the pipette to the cell. Consequently, the proposed injection system could safely manipulate the biological cells without any damage. This paper presents the introduction of our new injection system and design concepts of the new micro end-effector. Through a series of experiments the proposed injection system shows the possibility of application for precision biological cell manipulation such as DNA operation.

• Journal of Bio-Environment Control
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• v.23 no.2
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• pp.123-130
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• 2014

Oriental melon (Cucumis melo var. makuwa) should be cultivated on the soil and be harvested. It is difficult to find because it is covered with leaves, and furthermore, it is very hard to grip it due to its climbing stems. This study developed and tested oriental melon harvesting robots such as an end-effector, manipulator and identification device. The end effector is divided into a gripper for harvest and a cutter for stems. In addition, it was designed to control the gripping and cutting forces so that the gripper could move four fingers at the same time and the cutter could move back and forth. The manipulator was designed to realize a 4-axis manipulator structure to combine orthogonal coordinate-type and shuttle-type manipulators with L-R type model to rotate based on the central axis. With regard to the identification device, oriental melon was identified using the primary identification global view camera device and secondary identification local view camera device and selected in the prediction of the sugar content or maturity. As a result of the performance test using this device, the average harvest time was 18.2 sec/ea, average pick-up rate was 91.4%, average damage rate was 8.2% and average sorting rate was 72.6%.

• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.284-290
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• 2013

This study analyzed the geometric, compressive, cutting and friction properties of oriental melons in order to design a gripper capable of soft handling and a cutter for cutting oriental melon vine among the end effector of oriental melon as a preliminary step for developing the end effector of the robot capable of harvesting oriental melons in protected cultivation. As a result, the average length, diameter at the midpoint, weight, volume and roundness of the oriental melons were 108 mm, 70 mm, 188 g, 333 mL and 3.8 mm. Nonlinear regression analysis was performed on the equation $W=L^a{\times}D_2^b$ with variation of the length (L) and diameter (D2) of the weight (W) of the oriental melons. As a result, it was shown that there was a correlation between a of 2.0279 and b of -0.9998 as a constant value. The average diameter of the oriental melon vine was 3.8 mm, and most vines were distributed within a radius of 5 mm from the center. The average yield value, compressive strength and hardness of the oriental melons were $36.5N/cm^2$, $185.7N/cm^2$ and $636.7N/cm^2$, respectively. The average cutting force and shear strength of the oriental melon vines were $2.87{\times}10^{-2}\;N$ and $5.60N/cm^2$, respectively. The maximum friction coefficient of the oriental melons was rubber of 0.609, followed by aluminium of 0.393, stainless steel of 0.177 and teflon of 0.079. It was considered possible to apply it to the size of the gripper and cutter, turning radius, dynamics of drive motor and selection of materials and their quality in light of the position error and safety factor according to the movement when designing end effector based on the analyzed data.

• The Journal of Korea Robotics Society
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• v.15 no.2
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• pp.91-99
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• 2020

Fruit and vegetable harvesting robots have been widely studied and developed in recent years to reduce the cost of harvesting tasks such as labor and time. However, harvesting robots have many challenges due to the difficulty and uncertainty of task. In this paper, we characterize the crop environment related to the harvesting robot and analyzes state-of-the-art of the harvesting robot especially, in the viewpoint of robotic end-effector. The end-effector, an one of most important element of the harvesting robot, was classified into gripper and harvesting module, which were reviewed in more detail. Performance measures for the evaluation of harvesting robot such as test, detachment success, harvest success, and cycle time were also introduced. Furthermore, we discuss the current limitations of the harvesting robot and challenges and directions for future research.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2000.10b
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• pp.31-35
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• 2000

현재 대부분의 작물수확에 있어, 노지 재배를 탈피하여 시설재배면적이 증가하고 있다. 현재 원예산업에서 전체 농가 생산액 대비를 보면 95년 기준으로 38.9%를 점하고 있다. 이는 80년대 이후 해마다 증가하였고, WTO시대에 도래하여 세계 속에서 우리 농산물은 경쟁을 해야 할 때다. 원예산업 비중에서, 채소가 25.2%, 과수가 11.2%, 화훼가 2%를 차지하고 있다. 이중 시설채소 재배도 8.5%의 비중을 차지하고 있고, 통계청 자료에 의하면 오이의 재배면적이 97년에 268ha에서 98년에 420ha로 증가하였다. (중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2000.10b
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• pp.98-103
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• 2000

포도 생과의 수입 개방으로 1996년에 2,400톤, 1997년에 3,500톤을 수입한 바 있다. 현재까지는 칠레산 포도가 3월부터 5월 사이에 수입되어 그 동안 안정적으로 발전해 오던 시설포도의 수익성이 크게 떨어진 바 있으나 수입종 과실의 품질, 기호성, 신선도, 잔류 농약의 문제 등으로 소비자들이 국산 포도를 선호하고 있어 크게 문제되지 않고 있다. 그러나 앞으로의 포도의 지속적인 수입 개방으로 인하여 좋은 품질의 포도가 수입될 것으로 예상된다. (중략)

• Journal of Biosystems Engineering
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• v.29 no.3
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• pp.281-286
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• 2004

The end-effector is the one of the important factors on development of the cucumber robot to harvester a cucumber. Three end-effectors were designed the single blade end-effector with one blade, the double blade end-effector with two blades and the triple blade end-effector with three blades. Performance tests of the end-effector, the fully integrated system, were conducted to determine the cutting rate by using two different kinds of cucumber. The success rates of cucumber cutting ratio of single end-effector, double end-effector and triple end-effector in laboratory. were 61.7%, 95%, 86.7%, respectively. The cutting rate of single blade or double blade was a little difference with respect to the different diameters of cucumber stem. However, the success cutting rate of the end-effector with triple blade was 61.7% under 29mm diameter of a grabbing stem section. The triple end-effector was not suitable for harvesting a cucumber, but was considered to be suitable for harvesting a grape, an apple and a tomato. The success rate of cucumber cutting ratio of triple end-effectors in greenhouse was 84%. The failure cutting rate was 16% which are due to abnormal shape of cucumber fruit.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.6
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• pp.104-110
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• 2014

This paper presents a non-contact inspection system for automatically measuring the thickness of an aircraft wing rip product. In order to conduct the inspection of the wing rib thickness automatically, a non-contact laser displacement sensor, end-effector, and a robot were selected for use. The non-contact type inspection system was evaluated by measuring the measurement deviation of the rotation direction of a C-type yoke end-effector and the transfer direction of a V-slim end-effector. In addition, the non-contact inspection system for wing rib thickness measurements was validated through thickness measurements of a web, flange, and stiffener.