• 제목/요약/키워드: gripping

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Development of Oriental Melon Harvesting Robot in Greenhouse Cultivation (시설재배 참외 수확 로봇 개발)

  • Ha, Yu Shin;Kim, Tae Wook
    • 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%.

Experimental Study on GFRP Reinforcing Bars with Hollow Section (중공형 GFRP 보강근의 인장성능 실험연구)

  • You, Young-Jun;Park, Ki-Tae;Seo, Dong-Woo;Hwang, Ji-Hyun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.19 no.1
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    • pp.45-52
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    • 2015
  • Fiber-reinforced polymer (FRP) has been generally accepted by civil engineers as an alternative for steel reinforcing bars (rebar) due to its advantageous specific tensile strength and non-corrosiveness. Even though some glass fiber reinforced polymer (GFRP) rebars are available on a market, GFRP is still somewhat uncompetitive over steel rebar due to their high cost and relatively low elastic modulus, and brittle failure characteristic. If the price of component materials of GFRP rebar is not reduced, it would be another solution to increase the performance of each material to the highest degree. The tensile strength generally decreases with increasing diameter of FRP rebar. One of the reasons is that only fibers except for fibers in center resist the external force due to the lack of force transfer and the deformation of only outer fibers by gripping system. Eliminating fibers in the center, which do not play an aimed role fully, are helpful to reduce the price and finally FRP rebar would be optimized over the price. In this study, the effect of the hollow section in a cross-section of a GFRP rebar was investigated. A GFRP rebar with 19 mm diameter was selected and an analysis was performed for the tensile test results. Parameter was the ratio of hollow section over solid cross-section. Four kinds of hollow sections were planned. A total of 27 specimens, six specimens for each hollow section and three specimens with a solid cross-section were manufactured and tested. The change by the ratio of hollow section over solid cross-section was analyzed and an optimized cross-section design was proposed.

A Study on the Weathering Resistance of Fixatives Used on Conservation of Painting Layer of Korea Wooden Painting (한국 판벽화 채색층 보존처리 고착제의 내후성 연구)

  • Lee, Seul;Han, Kyeong Soon
    • Journal of Conservation Science
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    • v.34 no.5
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    • pp.397-405
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    • 2018
  • Currently, there are very few studies on Korean wall paintings. Therefore, this study discusses the current conditions of wooden paintings and the characteristics of the adhesive agent in the painting layer separation. Korean land pine was chosen as the support, while white oysters shells, orpiment, red ocher, Noerok, and azurite were used as pigments. With four adhesive agents, including animal glue, Gelidium, methyl cellulose, and PVAc (caparol binder), a comparative experiment was conducted, by dividing them into two concentrations, of 0.5% and 1.5%. The temperature, humidity, and ultraviolet rays, which are contributing environmental factors in cultural assets after fixing, were artificially investigated. After deterioration, observed color difference, fixing, and the surface. Results showed that the animal glue strongly fixing all the colored layers compared to the other adhesives; however, azurite had a partial change when used outdoors. With Gelidium, which functioned similar to animal glue, the azurite was affected by the ultraviolet rays; nevertheless, despite the variations in temperature and humidity, it had the best gripping force compared to the other adhesive agents. Methyl cellulose was glossy at a high concentration, and was relatively strong against rapid changes in temperature and humidity. PVAc significantly reduced the binding force, compared to other adhesive agents.

A Study on Applying Guidance Laws in Developing Algorithm which Enables Robot Arm to Trace 3D Coordinates Derived from Brain Signal (로봇 팔의 뇌 신호로부터 유도된 3D 좌표 추적을 위한 Guidance Law 적용에 관한 연구)

  • Kim, Y.J.;Park, S.W.;Kim, W.S.;Yeom, H.G.;Seo, H.G.;Lee, Y.W.;Bang, M.S.;Chung, C.K.;Oh, B.M.;Kim, J.S.;Kim, Y.;Kim, S.
    • Journal of Biomedical Engineering Research
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    • v.35 no.3
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    • pp.50-54
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    • 2014
  • It is being tried to control robot arm using brain signal in the field of brain-machine interface (BMI). This study is focused on applying guidance laws for efficient robot arm control using 3D coordinates obtained from Magnetoencephalography (MEG) signal which represents movement of upper limb. The 3D coordinates obtained from brain signal is inappropriate to be used directly because of the spatial difference between human upper limb and robot arm's end-effector. The spatial difference makes the robot arm to be controlled from a third-person point of view with assist of visual feedback. To resolve this inconvenience, guidance laws which are frequently used for tactical ballistic missile are applied. It could be applied for the users to control robot arm from a first-person point of view which is expected to be more comfortable. The algorithm which enables robot arm to trace MEG signal is provided in this study. The algorithm is simulated and applied to 6-DOF robot arm for verification. The result was satisfactory and demonstrated a possibility in decreasing the training period and increasing the rate of success for certain tasks such as gripping object.

Brake Module Assembly Using a Redundant Robot Having an 1 DOF End Effector (1 자유도 엔드 이펙터를 갖는 여유 자유도 로봇을 사용한 브레이크 모듈 조립)

  • Jeong, Jae Ung;Sung, Young-Whee;Chu, Baek-Suk;Kwon, Soon-Jae
    • Journal of the Institute of Convergence Signal Processing
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    • v.15 no.3
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    • pp.104-111
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    • 2014
  • In this paper, we deal with robotic automation for assembling car brake modules. A car brake module is comprises of a torque member, two brake pads, and two pad liners. In the assembly process, brake pads and pad liners are needed to be inserted in a torque member. If we use a typical robotic hand for the assembly, task time takes too long. So, we propose two methods. The first method is to use an end effector that has five grippers capable of gripping five assembly parts. In the first method we attached the implemented end effector to a conventional 6 degrees of freedom industrial manipulator and performed the bake module assembly task. Experimental results show that the task time is remarkably reduced. The brake module assembly task needs the robot to change its orientation frequently, so, in the second method, we added one degree of freedom to the end effector that is used in the first method. By attaching it to a conventional 6 degrees of freedom industrial manipulator, we composed a 7 degrees of freedom redundant manipulator. A redundant manipulator has the advantage of flexible manipulation so the robot can change its orientation easily and can perform assembly task very fast. Experimental results show that the second method dramatically reduce whole task time for brake module assembly.

Development of Variable Stiffness Soft Robot Hand for Improving Gripping Performance (그리핑 성능 향상을 위한 가변강성 소프트 로봇 핸드 개발)

  • Ham, KiBeom;Jeon, JongKyun;Park, Yong-Jai
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.12
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    • pp.47-53
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    • 2018
  • Various types of robotic arms are being used for industrial purposes, particularly with the small production of multi-products, and the importance of the gripper, which can be used in industrial fields, is increasing. This study evaluated a variable stiffness mechanism gripper that can change the stiffness using the nonlinearity of a flexible material. A prototype of the gripper was fabricated and examined to confirm the change in stiffness. The previous gripper was unable to grip objects in some situations with three variable stiffness mechanism. In addition, these mechanisms were not balanced and rarely rotated when the object was gripped. Therefore, a new type of gripper was needed to solve this problem. Inspired by the movements of the human palm and Venus Flytrap, a new type of a variable stiffness soft robot hand was designed. The possibility of grasping could be increased by interlocking the palm folding mechanism by pulling the tendon attached to the variable stiffness mechanism. The soft robotic hand was used to grasp objects of various shapes and weights more stably than the previous variable stiffness mechanism gripper. This new variable stiffness soft robot hand can be used selectively depending on the application and environment to be used.

Biometric analysis hand parameters in young adults for prosthetic hand and ergonomic product applications

  • Gkionoul Nteli Chatzioglou;Yelda Pinar;Figen Govsa
    • Anatomy and Cell Biology
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    • v.57 no.2
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    • pp.172-182
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    • 2024
  • This study aimed to evaluate the superficial anatomy, kinesiology, and functions of the hand to reveal its morphometry and apply the findings in various fields such as prosthetic hand and protective hand support product design. We examined 51 young adults (32 females, 19 males) aged between 18-30. Hand photographs were taken, and measurements were conducted using ImageJ software. Pearson correlation analysis was performed to determine the relationship between personal information and the parameters. The results of the measurements showed the average lengths of finger segments: thumb (49.5±5.5 mm), index finger (63.9±4.1 mm), middle finger (70.7±5.2 mm), ring finger (65.5±4.8 mm), and little finger (53.3±4.3 mm). Both females and males, the left index finger was measured longer than the right index finger. The right ring finger was found to be longer than the left in both sexes. Additionally, length differences between fingers in extended and maximally adducted positions were determined: thumb-index finger (56.1±6.2 mm), index-middle finger (10.7±4.1 mm), middle-ring finger (10.8±1.4 mm), and ring-little finger (25.6±2.7 mm). Other findings included the average radial natural angle (56.4°±10.5°), ulnar natural angle (23.4°±7.1°), radial deviation angle (65.2°±8.2°), ulnar deviation angle (51.2°±9.6°), and grasping/gripping angle (49.1°±5.8°). The average angles between fingers in maximum abduction positions were also measured: thumb-index finger (53.4°±6.5°), index-middle finger (17.2°±2.6°), middle-ring finger (14.3°±2.3°), and ring-little finger (32.1°±7.0°). The study examined the variability in the positioning of proximal interphalangeal joints during maximum metacarpophalangeal and proximal interphalangeal flexion, coinciding with maximum distal interphalangeal extension movements. The focal points of our observations were the asymmetrical and symmetrical arches formed by these joints. This study provides valuable hand parameters in young adults, which can be utilized in various applications such as prosthetic design, ergonomic product development, and hand-related research. The results highlight the significance of considering individual factors when assessing hand morphology and function.

An Experimental Study on Establishing Criteria of Gripping Work in Construction Site (건설 현장 악력 작업안전 기준 설정에 관한 실험적 연구)

  • 손기상;이인홍;최만진;안병준
    • Journal of the Korean Society of Safety
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    • v.10 no.3
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    • pp.81-95
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    • 1995
  • Now, safety assurance in construction sites should be accomplished by its own organization rather than control of the code or government. It is believed that the safety assurance can be considerably improved by a lecture or an education using the existing theories or literatures up to now, but it is thought that fundamental safety assurance we not able to be accomplished without developing safety devices '||'&'||' equipment or taking fundamental measures, based on the result analyzed from workers behaviors. There are various behaviors of the workers showed in construction site, but only tests for hammerusing works such as form, re-bar, stone workers directly related to the grip strength are mainly performed, investigated and measured here for the study. The above works are similar to power grip, 7th picture on seven items which are categorized for hand grip types(Ammermin 1956 ; Jones ; Kobrick 1958). Measurements of grip strength are commonly taken in anthropometric surveys. They are easy to administer but unfortunately it is rather dubious whether they yield any data that are of interest to the engineer. Very fewer controls of tools are grasped and squeesed studies showed very little overall correlation between grip strength and other measures of bodily strength (Laubach, Kromer, and Thordsen 1972), but hammer-using work which is practically progressed in construction site are mainly influenced with grip strength. According to the investigation on work measurement, it is shown that 77% of form worker are using hammer to be related to grip strength. In this study, it is particularly noticed that wearing safety gloves in construction site is required for workers safety but 20% difference between grip strength with safety gloves and without ones are commonly neglected in the site(Fig. 1). Nevertheless, safety operation with consideration of the above 20% difference is not considered in the construction site. Factors of age, kinds of work, working time, with or without safety gloves are in vestigated '||'&'||' collected at the sites for this study. Test, not at each working hour but at 14 : 00 when the almost all of the workers think the most tired, resulting from the questionaires, also when it is shown on the research report has been performed and compared for main kinds of works : form '||'&'||' re-bar work. Tests were performed with both left SE rightand of the workers simultaneously in construction site using Rand Dynamometer(Model 78010, Lafayette Instrument Co., Indiana, U.S.A) by reading grip strength on the gauge while they are pulling, and then by interviewing on their ages, works, experiences and etc., directly. The above tests have been performed for the dates of 15th march-26th May '95 with consideration of site condition. And even if various factors of ambient temperature on the testing date, working condition, individual worker's habit and worker's condition of the previous ate are concerned with the study. Those are considered as constants in this study. Samples are formwork 53, rebar 62, electrician 5, plumber 4, welding 1 from D construction Co., Ltd, ; formwork 12, re-bar 5, electrician 2, from S construction Co., Ltd, , formwork 78, re-bar 18, plumber 31, electrician 13, labor 48, plumber 31, plasterer 15, concrete placer 6, water proof worker 3, maisony 5 from B construction Co., Ltd. As In the previously mentioned, main aspect to be investigated in this study will be from '||'&'||' re-bar work because grip strength will be directly applied to these two kinds of works ; form '||'&'||' re-bar work, eventhough there are total 405 samples taken. It is thought that a frequency of accident occurrence will be mainly two work postures "looking up '||'&'||' looking down" to be mainly sorted, but this factor is not clarified in this study because It will be needed a lot of work more. Tests has been done at possible large scale of horizontally work-extended sites within one hour in order to prevent or decrease errors '||'&'||' discrepancies from time lag of the test. Additionally, the statistical package computer program SPSS PC+has been used for the study.

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The Differentiation Process of the Soul and the Opposites in God in The Red Book (『레드 북』에 나타나는 심혼의 분화 과정과 신의 대극성의 문제)

  • Ki-Hwan Kim
    • Sim-seong Yeon-gu
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    • v.36 no.2
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    • pp.105-159
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    • 2021
  • The Red Book is a personal record that contains Jung's psychological self-experiment and describes his own experiences of the individuation process. Throughout The Red Book, Jung describes how he got caught by the spirit of the depths and dethroned the spirit of this time, how he regained his lost soul by getting to the bottom of inner processes, how he differentiated the soul upon encountering the various aspects of his soul, and finally how he confronted God approaching Jung in the form of the divine opposites. The spirit of the depths as a personification of the collective unconscious caught up with Jung and launched him into the individuation process. The spirit of the depths was "the God yet to come". Jung realized that he had been driven by the collective spirit of his time and then set off on a journey into a new territory of life under the guidance of the spirit of the depths. Jung first encountered his lost soul, afterwards experiencing various aspects of the soul-spirit duo such as Salome-Elijah, Helena-Simon, and Baucis-Philemon. In the process of individuation, the initial experience of the soul can appear to the ego as a Satanic force which darkens the consciousness. The Red Book describes how Jung consciously integrated the Satanic force and came to realize the meaning of it. Jung's experience of emotionally gripping aspects of the soul led him to the awareness of the dark side of God, Satan, while the insights he gained from that Satanic emotionality led him to the awareness of the bright side of God, Christ. Through this process, he finally encountered the opposites in God. Jung also referred to the Self as an image of God which manifests itself in the psyche. Jung later discovered God as a phenomenal psychic reality which incarnates itself from the unconscious into the conscious. He did it in terms of strict empirical science. Although the incarnation process of the deity is the main cause of psychological conflict and distress of a human being, if accepted consciously, we come to realize that the incarnation process of the deity in the psyche is the ultimate teleology and meaning of our life as well.