• Title/Summary/Keyword: Formation control

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Formation Control for Swarm Robots Using Artificial Potential Field (인공 포텐셜 장을 이용한 군집 로봇의 대형 제어)

  • Kim, Han-Sol;Joo, Young-Hoon;Park, Jin-Bae
    • Journal of the Korean Institute of Intelligent Systems
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    • v.22 no.4
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    • pp.476-480
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    • 2012
  • In this paper, artificial potential field(APF) is applied to formation control for the leader-following swarm robot. Furthermore, APF is constructed by applying the electrical field model. Moreover, to model the obstacle effectively, each obstacle has different form due to the electrical field equation. The proposed method is formed as two sub-objective: path planning for the leader-robot and following-robots following the leader-robot. Finally, simulation example is given to prove the validity of proposed method.

Three-Dimensional Pose Estimation of Neighbor Mobile Robots in Formation System Based on the Vision System (비전시스템 기반 군집주행 이동로봇들의 삼차원 위치 및 자세 추정)

  • Kwon, Ji-Wook;Park, Mun-Soo;Chwa, Dong-Kyoung;Hong, Suk-Kyo
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.12
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    • pp.1223-1231
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    • 2009
  • We derive a systematic and iterative calibration algorithm, and position and pose estimation algorithm for the mobile robots in formation system based on the vision system. In addition, we develop a coordinate matching algorithm which calculates matched sequence of order in both extracted image coordinates and object coordinates for non interactive calibration and pose estimation. Based on the results of calibration, we also develop a camera simulator to confirm the results of calibration and compare the results of simulations with those of experiments in position and pose estimation.

Novel Biocide Controls Biofilm Formation without Adversely Affecting the Papermaking Process

  • Bharti, Shashank;Kim, Hyung-Ju;Kim, Ik-Dong
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2006.06a
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    • pp.67-71
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    • 2006
  • Strong oxidizing biocides are commonly used to control biofilm formation in alkaline papermaking systems. However, paper streams contain many substances that react with or consume oxidizers (e.g., fiber and starch, Therefore, to achieve effective microbiological control, the oxidizer must be overfed to overcome the effect of these substances. When dosed in this manner, the oxidizer can cause many unwanted reactions and adverse side effects, including the consumption of costly papermaking additives increased corrosion rates, and reduced felt life. Some oxidizers also contribute to the formation of halogenated organic compounds. When used for biofilm control, strong oxidizers can cause more problems than they remedy. A patented biocide that effectively controls biofilm without the adverse side effects associated with strong oxidizing biocides is available from Hercules. $Spectrum^{(R)}$ XD3899 Ammonium Bromide Technology, which can be described as a mild oxidizer, is currently used on more than 300 machines globally and has resulted in numerous production and/or machine efficiency records since its introduction in 2001.

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A Study on Obstacle Avoid Method and Synchronization of multi chaotic robot for Robot Formation Control based on Chaotic Theory (카오스 이론에 기반한 포메이션 제어를 위한 다중 카오스 로봇의 장해물 회피 및 동기화에 관한 연구)

  • Bae, Young-Chul;Park, Jong-Kyu
    • The Journal of the Korea institute of electronic communication sciences
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    • v.5 no.5
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    • pp.534-540
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    • 2010
  • In this paper, we propose the mathematical algorithm for collision avoidance between the robots and for the obstacle avoidance during the operation of the several chaotic robotics. For the useful formation control and as one of the method to provide command structure of communication between the robots, we also propose the synchronization method between the robotic system and confirmed the result with the computer simulation.

A Characteristics Study on the Visualization and Heat Transfer of the Frost Formation Structure Variation by Control Plate Surface Temperature (표면온도 제어에 의한 착상층 구조변화의 가시화 및 열전달 특성 연구)

  • Kim Kyung-Chun;Ko Choon-Sik;Jeong Jae-Hong;Ko Young-Hwan;Shin Jong-min
    • 한국가시화정보학회:학술대회논문집
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    • 2002.11a
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    • pp.55-58
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    • 2002
  • To control the frost formation, a temperature variation of the cooling plate and characteristics on hydrophilic and hydrophobic surfaces was attempted. As a temperature variation of the cooling plate, being closely related to the frost layer density of frost layer is found to be affected by the melting process inside the frost layer during the heating period. At characteristics on surface, completely different structures of frost are appeared in the initial stage of frost formation due to the difference in surface conditions, while those effects are vanished with time. It is found that the frost thickness, density and heat flux characteristics are closely associated with the frost structure.

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Study on Adhesion Formation by Artificial Injuries in Rats (쥐에서 인공창상에 의한 유착형성에 관한 연구)

  • Kang Tae-Young;Choi Min-Cheol;Lee Hyo-Jong
    • Journal of Veterinary Clinics
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    • v.9 no.2
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    • pp.483-488
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    • 1992
  • This experiment was carried out to establish the grade of adhesion formation and changes of blood following artificial injuries such as abrasion, incision and electrocautery on colon and uterine horns in rats. 36 rats (abrasion-, incision-, electrocautery-treated groups) had laparotomy and abdominal injuries, twelve rats( control group) had only laparotomy, Ten days fellowing abdominal injuries, the score of adhesion formation and changes of blood were noted 1. Electrocautery-treated group was significant evident in adhesion formation in colon(p<0.01) and electrocautery and incision-treated groups were more evident than abrasion and control group in uterine horns(p<0.01) 2. Changes of erythrocytes number and PCV were tended to decrease during 5 days after operation, but recover normal level 10 days after operation. 3. Changes of leucocytes number were showed to significantly increase in electrocautery and incision-treated groups 5 days after operation. 4. The electrocautery-treated group was showed to significantly decrease in plasma protein and increase in plasma fibrinogen concentration.

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Sliding Mode Control for the Configuration of Satellite Formation Flying using Potential Functions

  • Lim, Hyung-Chul;Bang, Hyo-Choong;Kim, Hae-Dong
    • International Journal of Aeronautical and Space Sciences
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    • v.6 no.2
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    • pp.56-63
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    • 2005
  • Some methods have been presented to avoid collisions among satellites for satellite formation flying mission. The potential function method based on Lyapunov's theory is known as a powerful tool for collision avoidance in the robotic system because of its robustness and flexibility. During the last decade, a potential function has also been applied to UAV's and spacecraft operations, which consists of repulsive and attractive potential. In this study, the controller is designed using a potential function via sliding mode technique for the configuration of satellite formation flying. The strategy is based on enforcing the satellite to move along the gradient of a given potential function. The new scalar velocity function is introduced such that all satellites reach the goal points simultaneously. Simulation results show that the controller drives the satellite toward the desired point along the gradient of the potential function and is robust against external disturbances.

Effects of Electrical Stimulation on Edema Formation in Frog Hind Limbs (전기자극이 개구리 뒷다리 부종형성에 미치는 영향)

  • Park Rae-Joon
    • The Journal of Korean Physical Therapy
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    • v.7 no.1
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    • pp.1-8
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    • 1995
  • The purpose of this study was to determine the effects of high voltage pulsed current(HVPC) and low voltage pulsed current(LVPC) on posttraumatic edema formation in frog hind limbs In this study, 16 bullfrogs(Rana Catesbeiana), weighting 189g to 340g were used. Limb 16 anesthetized bullfrogs were systemically injuried by weight drop. One hind limb of each frogs was randomly selected to receive continuous 120 pps HVPC and 100 pps LVPC at $90\%$ of motor threshold(HVPC : 33.3v, LVPC : 0.2-1mA). The opposite hind was remained as a control. A series of six 30-minute treatment(interrupted by 30-minute rest) was begun minutes after injury. The results were as follows. 1. Cathodal HVPC has heed shown to be effective in curbing posttraumatic edema formation in frogs, but anodal HVPC did not effect. 2. Volumes of hind limbs treated with LVPC were not significantly different over time from those of untreated hind limbs. 3. Therefore, waveform(HVPC versus LVPC) seems to influence the efficacy of electrotherapy for edema control. 4. Electrical stimulation were not increased edema formation on frog hind limbs.

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A STUDY OF ROOT RESORPTION AND ALVEOLAR BONE CHANCES DURING TOOTH MOVEMENT AFTER TREATMENT WITH ETIDRONATE DISODIUM (Biphosphonate (Etidronate disodium) 투여 후 치아이동에 따른 치근흡수 및 치조골 변화에 관한 연구)

  • Hwang, Chung-Ju;Sohn, Byung-Hwa
    • The korean journal of orthodontics
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    • v.21 no.1 s.33
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    • pp.77-96
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    • 1991
  • Many studies has been conducted concerning prevention of unnecessary complications such as root resorption during orthodontic too th movement under various mechanical forces. Nowadays, the cause of the root resorption is not thought to be confined only to mechanical forces. But the factor that affects bone metabolism are thought to be major one of the predisposing factors. The light microscope and scanning electron microscope were used to the effects of 60 gm, and 100 gm of tipping force on root resorption of cats, which were treated with Etidronate disodium. The results were as follows: 1. In the 60gm control group, hyalinization on the compression site of periodontal ligament appeared after first week and second week. In the 60gm experimental group, it appeared after first week with low frequency. In the 100gm control group it appeared with high frequency by first and second week while in 100gm experimental group, it appeared with low frequency. 2 In the 100gm control group, resorption of the cementum and the alveolar bone rapidly increased after second week. In the 60gm experimental group, resorption or formation of alveolar bone and cementum didn't appear all through the experimental period. 3. In the 100gm control group, formation of cementum and alveolar bone appeared after first week while in the 100gm experimental group, formation of cementum and alveolar bone appeared after second week and fourth week respectively. In the 60gm control group, formation of the cementum didn't appear all through the experimental period. 4. In the control group, the root resolution of 100gm group was higher than that of 60gm group after second week, while in experimental group, root resorption didn't appear regardless of the forces.

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Evaluation of bone formation and membrane degradation in guided bone regeneration using a 4-hexylresorcinol-incorporated silk fabric membrane

  • Lee, Sang-Woon;Um, In Chul;Kim, Seong-Gon;Cha, Min-Sang
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.37
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    • pp.32.1-32.5
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    • 2015
  • Background: The aims of present study were (1) to evaluate new bone formation among the 4-hexylresorcinol (4HR)-incorporated silk fabric membrane (SFM), conventional SFM, and uncovered control groups and (2) to compare the amount of residual membrane between the 4HR-incorporated SFM and conventional SFM in a rabbit parietal defect model. Methods: Nine New Zealand white rabbits were used for this animal study. After the formation of a bilateral parietal bone defect (diameter 8.0 mm), either 4HR-incorporated SFM or conventional SFM was grafted into the defect. The defect in the control was left uncovered. New bone formation and the amount of residual membrane were evaluated by histomorphometry at 8 weeks after the operation. Results: The total amount of new bone was $37.84{\pm}8.30%$ in the control, $56.64{\pm}15.74%$ in the 4HR-incorporated SFM group, and $53.35{\pm}10.52%$ in the conventional SFM group 8 weeks after the operation. The differences were significant between the control and 4HR-incorporated SFM group (P = 0.016) and between the control and conventional SFM group (P = 0.040). The residual membrane was $75.08{\pm}10.52%$ in the 4HR-incorporated SFM group and $92.23{\pm}5.46%$ in the conventional SFM group 8 weeks after the operation. The difference was significant (P = 0.039). Conclusions: The 4HR-incorporated SFM and conventional SFM groups showed more bone regeneration than the control group. The incorporated 4HR accelerated the partial degradation of the silk fabric membrane in a rabbit parietal defect model 8 weeks after the operation.