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Ghilardelli, Fabio, Corrado Guarino Lo Bianco, and Marco Locatelli. "Smart Changes of the End-Effector Orientation for the Automatic Handling of Singular Configurations." IEEE/ASME Transactions on Mechatronics 21, no. 4 (August 2016): 2154–64. http://dx.doi.org/10.1109/tmech.2015.2506679.
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Balasubramanian, Sivakumar, Sandeep Guguloth, Javeed Shaikh Mohammed, and S. Sujatha. "A self-aligning end-effector robot for individual joint training of the human arm." Journal of Rehabilitation and Assistive Technologies Engineering 8 (January 2021): 205566832110198. http://dx.doi.org/10.1177/20556683211019866.
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Aim: Intense training of arm movements using robotic devices can help reduce impairments in stroke. Recent evidence indicates that independent training of individual joints of the arm with robots can be as effective as coordinated multi-joint arm training. This makes a case for designing and developing robots made for training individual joints, which can be simpler and more compact than the ones for coordinate multi-joint arm training. The design of such a robot is the aim of the work presented in this paper. Methods: An end-effector robot kinematic design was developed and the optimal robot link lengths were estimated using an optimization procedure. A simple algorithm for automatically detecting human limb parameters is proposed and its performance was evaluated through a simulation study. Results: A six-degrees-of-freedom end-effector robot with three actuated degrees-of-freedom and three non-actuated self-aligning degrees-of-freedom for safe assisted training of the individual joints (shoulder or elbow) of the human arm was conceived. The proposed robot has relaxed constraints on the relative positioning of the human limb with respect to the robot. The optimized link lengths chosen for the robot allow it to cover about 80% of the human limb’s workspace, and possess good overall manipulability. The simple estimation procedure was demonstrated to estimate human limb parameters with low bias and variance. Discussion: The proposed robot with three actuated and three non-actuated degrees-of-freedom has a compact structure suitable for both the left and right arms without any change to its structure. The proposed automatic estimation procedure allows the robot to safely apply forces and impose movements to the human limb, without the need for any manual measurements. Such compact robots have the highest potential for clinical translation
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Jie, Lim Wei, Teoh Poh Sen, Nor Maniha Abdul Ghani, and Mohammad Fadhil Abas. "Automatic Control of Color Sorting and Pick/Place of a 6- DOF Robot Arm." Journal Européen des Systèmes Automatisés 54, no. 3 (June 25, 2021): 435–43. http://dx.doi.org/10.18280/jesa.540306.
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This work focuses on the implementation and design of a six degree of freedom, 6-DOF control of automatic color sorting and pick and place tasks for a robot arm using wireless controlling interface – Blynk apps. Based on the collaboration between the servo motor and input color sensor, this wireless control of automatic color sorting robot arm provides a powerful wireless control GUI (Graphics User Interface) and to enable the method for manual color sorting mode. The color sorting mode is performed once the mode is turned on by the user. The robot arm able to differentiate the colors of the object (input) and categorize or classify the object to the correct places automatically. It provides a stable, efficient, and precision results without any vibration of control as the main target for this project. In this work, six servo motors were used to realize the real robotic arm for industrial use. Five servos were operated to control the entire robot arm motion including the base, shoulder, and elbow as well as one servo is reserved for the positioning of the end effector. Two input variables namely TSC3200 Color Sensors & HC-SR04 Ultrasonic Sensors were employed as the input for the robot arm. The output variable mainly focused on the servo motor as the links for the robot arm to reposition and change the motion for the entire system.
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Prablanc, C., and O. Martin. "Automatic control during hand reaching at undetected two-dimensional target displacements." Journal of Neurophysiology 67, no. 2 (February 1, 1992): 455–69. http://dx.doi.org/10.1152/jn.1992.67.2.455.
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1. The aim of this study was to demonstrate that goal-directed pointing movements, executed at normal speed to a small visual target, but without vision of the movement, do not rely on preprogrammed commands (open-loop process); by contrast these responses are under the control of a feedback loop, which compares the ongoing response and the goal (or its internal representation). When the location of this goal is changed at the onset of the movement, an automatic correction of the path occurs. Modification of the goal was obtained by presenting a target in the peripheral visual field that the subject had to look at and point at as quickly and accurately as possible. When the orienting ocular saccade reached its peak velocity, statistically corresponding to the hand movement onset, the target was suddenly shifted 10 degrees in a random direction. This perturbation was undetected by the subject because of the absence of perception during the saccade. For the compensation to occur, the initial orientation of the movement and also its extent had to be modified. The results revealed 1) a nearly complete compensation of the movement path and a 66- to 80-ms duration lengthening; 2) relatively short reaction times to the perturbations (from 145 to 174 ms, with effective reaction times even 40 ms shorter); 3) nearly identical spatiotemporal movement characteristics to the perturbations, regardless of whether vision of the hand was allowed, suggesting that corrections were subserved by the same mechanisms. 2. The spatiotemporal characteristics of these unconscious corrections were similar to those observed in the classical double-step experiments investigating the intentional modifications of ongoing movements and suggest that they might share some common low-level mechanisms. That is, they could rely on visuokinesthetic feedback loops, which compare the updated information provided by the eye at the end of the saccade and the proprioceptive information of the end point effector (the fingertip here); they could also rely on feed-forward processes detecting the discrepancy between an efference copy of the movement and the new goal; or they could rely on a combination of those two main processes.
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Wang, Zhanxi, Xiansheng Qin, Jing Bai, Xiaoqun Tan, and Jing Li. "Design and Implementation of Multifunctional Automatic Drilling End Effector." IOP Conference Series: Materials Science and Engineering 187 (March 2017): 012032. http://dx.doi.org/10.1088/1757-899x/187/1/012032.
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Zhang, Bin, Chengli Zhang, Fugui Xie, Wangmin Yi, Shaohua Meng, and Wei Wang. "Design of an End-effector for Spacecraft Automatic Assembly Robot." IOP Conference Series: Materials Science and Engineering 616 (October 16, 2019): 012010. http://dx.doi.org/10.1088/1757-899x/616/1/012010.
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Semjon, Ján, and Michal Šulik. "Proposal End-Effectors for Robotic Workplaces with SCARA Robot." Applied Mechanics and Materials 844 (July 2016): 13–18. http://dx.doi.org/10.4028/www.scientific.net/amm.844.13.
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Article deals with the design of the end effector on SCARA robot whose task is to manipulate from three kinds of products.Two types of products have the precisely defined offtake points and are oriented by means of vibrating trays.The third type of product comes undirected by conveyor belt.Position and orientation of the third product is identified by means of a camera system. The role of the article is to suggest such a solution robotic effector that without the use of automatic exchange of effectors was possible to manipulate from all products on the robotized workplace.
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Vassura, G., T. Salmon Cinotti, and S. Caselli. "An end effector for automatic assembly of seals by an industrial robot." International Journal of Advanced Manufacturing Technology 1, no. 3 (May 1986): 43–54. http://dx.doi.org/10.1007/bf02601453.
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Lin, Wei Yang, Yue Du, Xiao Jun Yang, and Bing Li. "Parametric Optimal Design of Robot End-Effector Tool for Robot-Assisted Automatic Polishing System." Key Engineering Materials 450 (November 2010): 333–36. http://dx.doi.org/10.4028/www.scientific.net/kem.450.333.
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In this paper the multi-objective optimization design of a preliminarily designed end-effector tool for robot-assisted automatic polishing system is presented. ADAMS and iSIGHT are integrated for the multi-objective optimization design, the overall procedure of which is shown in this paper. Design of Experiment is arranged before optimization. The global optimization methods provided by iSIGHT software- Exterior Penalty and Multi-Island Genetic are utilized to perform optimizing process. Simulation executed in ADAMS with model updating with optimized structural design parameters verifies the significance of the multi-objective optimization in improving the performance of preliminarily designed end-effector tool.
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Ranky, Paul G. "Reconfigurable robot tool designs and integration applications." Industrial Robot: An International Journal 30, no. 4 (August 1, 2003): 338–44. http://dx.doi.org/10.1108/01439910310479603.
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Robot tools, or in more general terms, end‐of‐arm tools, or robot end‐effectors are general purpose, programmable or task‐oriented devices connected between the robot wrist and the object or load to be manipulated and/or processed by the robot. They can offer and/or limit the versatility of grasping and/or processing of different components, sensing their characteristics and working together with the robot control system to provide a reliable “service” throughout the component manipulation cycle. Reconfigurable robot tooling enables the robot to rapidly change its end‐effectors or fingers of its end‐effectors, typically under programmable software control. The importance of providing lean‐flexibility by means of reconfigurable, automated robot hand changers (ARHC), particularly in small‐batch robotic welding, assembly, machine loading and in other flexible robot cells, is discussed with examples. Some known systems are demonstrated and the “Ranky‐type” ARHC design is illustrated in more detail.
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Huang, Mingsen, Xiaohu Jiang, Long He, Daeun Choi, John Pecchia, and Yaoming Li. "Development of a Robotic Harvesting Mechanism for Button Mushrooms." Transactions of the ASABE 64, no. 2 (2021): 565–75. http://dx.doi.org/10.13031/trans.14194.
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HighlightsA robotic mushroom picking mechanism was developed, including positioning, picking, and stipe trimming.The picking end-effector was designed based on a bending motion around the stipe-substrate joint.The overall success rate of the developed picking mechanism reached 91.4%.Acting time and air pressure for the suction cup were studied in mushroom bruise level tests.Abstract. Button mushroom (Agaricus bisporus) harvesting mainly relies on costly manpower, which is time-consuming and labor-intensive. Robotic harvesting is an alternative method to address this challenge. In this study, a robotic mushroom picking mechanism was designed, including a picking end-effector based on a bending motion, a four degree-of-freedom (DoF) positioning end-effector for moving the picking end-effector, a mushroom stipe trimming end-effector, and an electro-pneumatic control system. A laboratory-scale prototype was fabricated to validate the performance of the mechanism. Bruise tests on the mushroom caps were also conducted to analyze the influence of air pressure and acting time of the suction cup on bruise level. The test results showed that the picking end-effector was successfully positioned to the target locations. The success rate of the picking end-effector was 90% at first pick and increased to 94.2% after second pick. The main reason for the failures was inclined growing condition of those mushrooms, resulting in difficulties in engaging the mushroom cap with the suction cup facing straight downward. The trimming end-effector achieved a success rate of 97% overall. The bruise tests indicated that the air pressure was the main factor affecting the bruise level, compared to the suction cup acting time, and an optimized suction cup may help to alleviate the bruise damage. The laboratory test results indicated that the developed picking mechanism has potential to be implemented in automatic mushroom harvesting. Keywords: Bruise test, End-effector, Mushroom, Robotic harvesting.
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Voellmer, George. "A passive end effector change-out mechanism for on-orbit robotic servicing." Computers in Industry 23, no. 1-2 (November 1993): 65–74. http://dx.doi.org/10.1016/0166-3615(93)90116-i.
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Ma, Yanqin, Kai Du, Dongfeng Zhou, Juan Zhang, Xilong Liu, and De Xu. "Automatic precision robot assembly system with microscopic vision and force sensor." International Journal of Advanced Robotic Systems 16, no. 3 (May 1, 2019): 172988141985161. http://dx.doi.org/10.1177/1729881419851619.
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An automatic precision robot assembly system is established. The robot assembly system mainly consists of an industrial robot, three cameras, a micro force sensor, and a specific gripper. The industrial robot is a six-axis serial manipulator, which is used to conduct grasping and assembly subtasks. Two microscopic cameras are fixed on two high accuracy translational platforms to provide visual information in aligning stage for assembly. While one conventional camera is installed on the robotic end effector to guide the gripper to grasp component. The micro force sensor is installed on the robotic end effector to perceive the contacted forces in inserting stage. According to the characteristics of components, an adsorptive gripper is designed to pick up components. In addition, a three-stage “aligning–approaching–grasping” control strategy for grasping subtask and a two-stage “aligning–inserting” control strategy for assembly subtask are proposed. Position offset compensation is computed and introduced into aligning stage for assembly to make the grasped component in the microscopic cameras’ small field of view. Finally, based on the established robot assembly system and the proposed control strategies, the assembly tasks including grasping and assembly are carried out automatically. With 30 grasping experiments, the success rate is 100%. Besides, the position and orientation alignment errors of pose alignment for assembly are less than 20 μm and 0.1°.
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Chen, Wei, Junjie Liu, Yang Tang, and Huilin Ge. "Automatic Spray Trajectory Optimization on Bézier Surface." Electronics 8, no. 2 (February 1, 2019): 168. http://dx.doi.org/10.3390/electronics8020168.
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The trajectory optimization of automatic spraying robot is still a challenging problem, which is very important in the whole spraying work. Spray trajectory optimization consists of two parts: spray space path and end-effector moving speed. A large number of spraying experiments have proved that it is very important to find the best initial trajectory of spraying. This paper presents an automatic spray trajectory optimization that is based on the Bézier surface. Spray the workpiece for Bezier triangular surface modeling and find the best initial trajectory of the spraying robot, establish the appropriate spraying model, plan the appropriate space path, and finally plan the trajectory optimization along the specified painting path. The validity and practicability of the method presented in this paper are proved by an example. This method can also be extended to other applications.
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Kang, S. Y., K. Chuang, and Y. C. Lee. "Random Change of Vibration Modes in Thermosonic Bonding." Journal of Electronic Packaging 120, no. 3 (September 1, 1998): 253–58. http://dx.doi.org/10.1115/1.2792630.
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Thermosonic bonding is being widely used for wire bonding and tape automated bonding (TAB). It is also being developed for flip-chip assemblies. The bonding process is sensitive to system parameters such as ultrasonic frequency, bonding tool length, and friction. One of the process control challenges is to prevent the random change of vibration modes. The change from an axial to a bending mode excitation may reduce the ultrasonic vibration amplitude at the bonding interface and result in poor bond quality. In this work, we have studied the random mode change effected by tool length, friction, and the frequency window selected for the power generator. In one case, the mode change was not observed when the tool end extended 2.32 cm below the longitudinal axis of the bonding horn. In the other case, however, the resonant frequency switched between 58.4 and 60.0 kHz when the tool moved 0.31 cm downward with all other system parameters held constant. Such a frequency shift resulted in a change of vibration amplitudes between 1.63 and 0.55 μm. Different random mode changes measured were explained by our theoretical models consisting of a modal analysis for the system and a vibration model for the tool. The models generated a guideline to prevent mode change by selecting the right system parameters.
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Khodabandehloo, K. "Robotic handling and packaging of poultry products." Robotica 8, no. 4 (October 1990): 285–97. http://dx.doi.org/10.1017/s0263574700000321.
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SUMMARYThis paper presents the findings of a research programme leading to the development of a robotic system for packaging poultry portions. The results show that an integrated system, incorporating machine vision and robots, can be made feasible for industrial use. The elements of this system, including the end-effector, the vision module, the robot hardware and the system software are presented. Models and algorithms for automatic recognition and handling of poultry portions are discussed.
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Zhu, Weidong, Along Zhang, Biao Mei, and Yinglin Ke. "Automatic stepping for circumferential splice drilling in aircraft fuselage assembly." Industrial Robot: An International Journal 43, no. 2 (March 21, 2016): 144–52. http://dx.doi.org/10.1108/ir-06-2015-0114.
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Purpose – A large number of fastener holes have to be drilled with high quality in the circumferential splice region during the assembly of aircraft fuselage. The purpose of this paper is to design an automatic stepping mechanism for a circumferential splice drilling machine, to meet the requirements of large workspace and high accuracy in drilling at the same time. Design/methodology/approach – A docking position detection method based on magnetic proximity sensors is proposed for the positioning of the arc-shaped rail with respect to the circumferential rails, which significantly improves the accuracy and reliability of automatic stepping. The slipping phenomenon of the end-effector is analyzed, and the optimized counter weights are used to eliminate the slipping and improve the working stability of the stepping mechanism. Findings – An automatic stepping mechanism is developed for the circumferential splice drilling machine, which comprises the docking position detection method and the elimination/suppression method of the end-effector’s slipping. Practical implications – The proposed automatic stepping mechanism has been integrated into the circumferential splice drilling machine for the fuselage assembly in an aircraft company in China. Originality/value – An automatic stepping scheme for the circumferential splice drilling machine is proposed, which enhances the efficiency in circumferential splice drilling in aircraft fuselage assembly.
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Liu, Yu, Zainan Jiang, Hong Liu, and Wenfu Xu. "Geometric Parameter Identification of a 6-DOF Space Robot Using a Laser-Ranger." Journal of Robotics 2012 (2012): 1–11. http://dx.doi.org/10.1155/2012/587407.
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The geometric parameters of a space robot change with the terrible temperature change in orbit, which will cause the end-effector pose (position and orientation) error of a space robot, and so weakens its operability. With this in consideration, a new geometric parameter identification method is presented based on a laser-ranger attached to the end-effector. Then, independence of the geometric parameters is analyzed, and their identification equations are derived. With the derived identification Jacobian matrix, the optimal identification configurations are chosen according to the observability indexO3. Subsequently, through simulation the geometric parameter identification of a 6-DOF space robot is implemented for these identification configurations, and the identified parameters are verified in a set of independent reference configurations. The result shows that in spite of distance measurement alone, pose accuracy of the space robot still has a greater improvement, so the identification method is practical and valid.
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Grishin, Andrey, Maia Cherney, Tara Condos, Kathryn Barber, Deborah Anderson, Sadhna Phanse, Mohan Babu, Gary Shaw, and Miroslaw Cygler. "Bacterial Effector Kinases." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C428. http://dx.doi.org/10.1107/s2053273314095710.
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Protein phosphorylation is one of the main signaling mechanisms in eukaryotic cells. Not surprisingly, pathogenic adopted this mechanism to interfere with signaling processes in the host cell. To this end pathogens evolved kinases that, in addition to other bacterial effector proteins, are injected into the host cell via a syringe-like type 3 (T3SS) or type 4 (T4SS) secretion systems. Kinases NleH1 and NleH2 from pathogenic E. coli, OspG from Shigella, SteC and SboH from Salmonella, LegK1-4 from Legionella and YspK and YpkA from Yersinia represent currently known effector kinases. Some of these kinases were likely derived from eukaryotes via horizontal gene transfer (SteC, LegK1-4, YpkA). Other kinases (NleH, OspG, SboH and YspK) have been so far identified only in the pathogenic bacteria. The structures of NleH and OspG proved that these kinases, which are half the size of an average human kinase, contain only a core kinase fold. These kinases lack the main regulatory element – the activation loop. The structure of NleH suggests that it has no activation mechanism since the apo-kinase domain adopts an active conformation and no change is observed on nucleotide binding. The OspG kinase, which also contains only the core kinase fold, is stimulated by its binding partner, the ubiquitin-conjugating enzyme E2-ubiquitin complex. The structure of OspG:UbcH7-Ub complex shows that OspG binds the E2 and ubiquitin (Ub) at two distinct sites on its surface. In this complex the OspG active site is unobstructed and primed for catalysis. However the mechanism of OspG activation remains presently unknown. Both NleH and OspG were found to inhibit the NF-kB pathway, however the substrates forOspG and NleH kinase activities are not yet known.
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Asakawa, Naoki, Fumitake Saegusa, and Masatoshi Hirao. "Automation of Deburring by a Material-Handling Robot —Generation of a Deburring Path Based on a Characteristic Model—." International Journal of Automation Technology 4, no. 1 (January 5, 2010): 26–32. http://dx.doi.org/10.20965/ijat.2010.p0026.
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This study deals with the automation of deburring in press working using a material-handling robot. The robot simultaneously manipulates and deburrs a workpiece using robot control commands automatically generated. Robot control commands are generated based on environmental information — positioning of carry-in/carry-out table, tool and end effector dimensions — and CAD data using a “characteristic model” to realize robot operation suiting the working environment. The results of experiments confirm the proposal’s effectiveness in automatic deburring and material handling.
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Carpio Alemán, Marco, Roque Saltaren, Alejandro Rodriguez, Gerardo Portilla, and Juan Placencia. "Rotational Workspace Expansion of a Planar CDPR with a Circular End-Effector Mechanism Allowing Passive Reconfiguration." Robotics 8, no. 3 (July 19, 2019): 57. http://dx.doi.org/10.3390/robotics8030057.
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Cable-Driven Parallel Robots (CDPR) operate over a large positional workspace and a relatively large orientation workspace. In the present work, the expansion of the orientation Wrench Feasible Workspace (WFW) in a planar four-cable passive reconfigurable parallel robot with three degrees of freedom was determined. To this end, we proposed a circular-geometry effector mechanism, whose structure allows automatic mobility of the two anchor points of the cables supporting the End Effector (EE). The WFW of the proposed circular structure robot was compared with that of a traditional robot with a rectangular geometry and fixed anchor points. Considering the feasible geometric and tension forces on the cables, the generated workspace volume of the robot was demonstrated in an analysis-by-intervals. The results were validated by simulating the orientation movements of the robot in ADAMS software and a real experimental test was developed for a hypothetical case. The proposed design significantly expanded the orientation workspace of the robot. The remaining limitation is the segment of the travel space in which the mobile connection points can slide. Overcoming this limitation would enable the maximum rotation of the EE.
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Güler, Fatma. "The adjoint trajectory of robot end effector using the curvature theory of ruled surface." Filomat 34, no. 12 (2020): 4061–69. http://dx.doi.org/10.2298/fil2012061g.
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The ruled surface is formed by the movement of a director based on a curve. The point P not on the director vector at fixed frame o-ijk draws a curve. However, each position of this point on the curve always corresponds to position of director on the ruled surface, or this point is adjoint to director vector. Thus, the curve is adjoint to the ruled surface. In this study, we expressed the adjoint trajectory of robot end effector. We can change the trajectory of the robot movement by defining the adjoint trajectory when it may not be physically achievable and not re-computation of the robot trajectory. We investigated the angular acceleration and angular velocity of adjoint trajectory of the robot end effector. Also, we obtained the condition that moving point is a fixed point.
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Aguas, Xavier Iván, Andrés Cuaycal, Israel Paredes, and Marco Herrera. "A Fuzzy Sliding Mode Controller for Planar 4-Cable Direct Driven Robot." Enfoque UTE 9, no. 4 (December 21, 2018): 99–109. http://dx.doi.org/10.29019/enfoqueute.v9n4.403.
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Cable Direct Driven Robots (CDDRs) are a special class of parallel robots but they are formed by replacing all the supporting rigid links with cables. Compare with traditional robots, these robots are good candidates for performing a wide range of potential applications. A Planar CDDR model is considered in this paper since no rotational move and no moment resistance are required on the end-effector, all 4 cables convene in a single point and the end-effector is modeled as a point mass. The main goal of this paper is to present a new approach in control by developing a Sliding Mode Controller (SMC) with a Fuzzy-PI as sliding surface using Fuzzy logic toolbox in Matlab/Simulink. The tests performed were Step change reference test and Tracking trajectory test to observe the behavior of the cables during the trajectory and the end-effector movement. Simulation was carried out on Planar 4-Cable CDDR to prove the effectiveness of the proposed control law and the results were compared with a PI Controller and a conventional SMC in terms of integral square error (ISE) index. Only the kinematic model of Planar 4-Cable CDDR is considered in this paper.
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Friedrich, Christian, and Steffen Ihlenfeldt. "Model Calibration for a Rigid Hexapod-Based End-Effector with Integrated Force Sensors." Sensors 21, no. 10 (May 19, 2021): 3537. http://dx.doi.org/10.3390/s21103537.
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Integrated single-axis force sensors allow an accurate and cost-efficient force measurement in 6 degrees of freedom for hexapod structures and kinematics. Depending on the sensor placement, the measurement is affected by internal forces that need to be compensated for by a measurement model. Since the parameters of the model can change during machine usage, a fast and easy calibration procedure is requested. This work studies parameter identification procedures for force measurement models on the example of a rigid hexapod-based end-effector. First, measurement and identification models are presented and parameter sensitivities are analysed. Next, two excitation strategies are applied and discussed: identification from quasi-static poses and identification from accelerated continuous trajectories. Both poses and trajectories are optimized by different criteria and evaluated in comparison. Finally, the procedures are validated by experimental studies with reference payloads. In conclusion, both strategies allow accurate parameter identification within a fast procedure in an operational machine state.
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Zhang, Juan, Wenrong Wu, and Lie Bi. "An automatic approach and grip method of micro-particle in 3D space." International Journal of Modern Physics B 31, no. 07 (March 19, 2017): 1741013. http://dx.doi.org/10.1142/s0217979217410132.
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Micro-particle is hard to be observed as small scale and hard to be gripped as micro-force from substrate, an automatic approach and grip method of micro-particle in the guide of microscopic vision systems is proposed in the paper to grip micro-particle. First, the micro-gripper driven by electrostatic force is introduced and forces in gripping process are analyzed. Second, a micro-assembly robot composed of two microscopic vision systems is established to monitor micro-operation process and to operate micro-particle. Image features of micro-particle and micro-gripper end-effector are extracted by image feature extraction method to calculate relative position of micro-particle and micro-gripper in image space. Last, a movement control strategy in 3D space based on image Jacobian matrix is studied to control micro-gripper approach and align with micro-particle. Experimental results verified the effectiveness of proposed methods.
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Fairey, Adrian S., Kerry S. Courneya, Catherine J. Field, Gordon J. Bell, Lee W. Jones, and John R. Mackey. "Randomized controlled trial of exercise and blood immune function in postmenopausal breast cancer survivors." Journal of Applied Physiology 98, no. 4 (April 2005): 1534–40. http://dx.doi.org/10.1152/japplphysiol.00566.2004.
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The objective was to determine the effects of exercise training on changes in blood immune function in postmenopausal breast cancer survivors. Fifty-three postmenopausal breast cancer survivors were randomly assigned to an exercise ( n = 25) or control group ( n = 28). The exercise group trained on cycle ergometers three times per week for 15 wk. The control group did not train. The primary end point was change in natural killer cell cytotoxic activity in isolated peripheral blood mononuclear cells. Secondary end points were changes in standard hematological variables, whole blood neutrophil function, the phenotypes of isolated mononuclear cells, estimations of unstimulated and phytohemaglutinin-stimulated mononuclear cell function (rate of [3H]thymidine uptake), and the production of proinflammatory [interleukin (IL)-1α, tumor necrosis factor-α, IL-6] and anti-inflammatory cytokines (IL-4, IL-10, transforming growth factor-β1). Statistical tests were two-sided (α < 0.05). Fifty-two participants completed the trial. Intention-to-treat analyses, which included the baseline value as a covariate, showed significant differences between groups for change in percent specific lysis of a target natural killer cell at all five effector-to-target ratios (adjusted mean between-group change over all 5 effector-to-target ratios = +6.34%; P < 0.05 for all comparisons), the lytic activity per cell (adjusted mean between-group change = −2.72 lytic units; P = 0.035), and unstimulated [3H]thymidine uptake by peripheral blood lymphocytes (adjusted mean between-group change = +218 per dpm × 106cells; P = 0.007). There were no significant differences between groups for change in any other end point. Exercise training increased natural killer cell cytotoxic activity and unstimulated [3H]thymidine uptake by peripheral blood lymphocytes in postmenopausal breast cancer survivors.
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Jackson, Shawn, Victoria Volk, and Jodi Prosise. "Novel Design for a Simple and Affordable End-Effector for an Upper-Limb Prosthesis." International Journal for Service Learning in Engineering, Humanitarian Engineering and Social Entrepreneurship 12, no. 1 (June 2, 2017): 62–73. http://dx.doi.org/10.24908/ijsle.v12i1.6691.
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An affordable prosthetic arm was designed to be used in underprivileged areas to allow more upper-limb amputees to have access to prosthetics that can help them regain their independence. The primary user of the prosthesis will be the amputee(s) who receive the device; beneficiaries include the amputee’s family and the community involved in the manufacturing of future prostheses. The customer requirements include cost-effectiveness, the ability to withstand humidity, cleanability, low maintenance, long life, lightweight, and the ability to perform simple tasks independently. A new end-effector was created that meets the range-of-motion required for the user to perform his/her required tasks. The end-effector is comprised of a PVC cap, PVC coupling, wooden ball holding the tool, and two wooden stop rings. The device screws onto the forearm PVC pipe and locks into place. Four end-effectors were created: toothbrush, fork, spoon, and pen. A change-out station was created to allow the user to independently attach and detach the different end-effectors. The total cost of the device was $20.66.
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Antonov, Anton, Alexey Fomin, Victor Glazunov, Sergey Kiselev, and Giuseppe Carbone. "Inverse and forward kinematics and workspace analysis of a novel 5-DOF (3T2R) parallel–serial (hybrid) manipulator." International Journal of Advanced Robotic Systems 18, no. 2 (March 1, 2021): 172988142199296. http://dx.doi.org/10.1177/1729881421992963.
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The proposed study provides a solution of the inverse and forward kinematic problems and workspace analysis for a five-degree-of-freedom parallel–serial manipulator, in which the parallel kinematic chain is made in the form of a tripod and the serial kinematic chain is made in the form of two carriages displaced in perpendicular directions. The proposed manipulator allows to realize five independent movements—three translations and two rotations motion pattern (3T2R). Analytical relationships between the coordinates of the end-effector and five controlled movements provided by manipulator’s drives (generalized coordinates) were determined. The approach of reachable workspace calculation was defined with respect to available design constraints of the manipulator based on the obtained algorithms of the inverse and forward kinematics. Case studies are considered based on the obtained algorithms of inverse and forward kinematics. For the inverse kinematic problem, the solution is obtained in accordance with the given laws of position and orientation change of the end-effector, corresponding to the motion along a spiral-helical trajectory. For the forward kinematic problem, various assemblies of the manipulator are obtained at the same given values of the generalized coordinates. An example of reachable workspace designing finalizes the proposed study. Dimensions and extreme values of the end-effector orientation angles are calculated.
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Zhao, Dong Hui, Hui Zhang, and Jun Xing Hou. "Design of Fruit Picking Device Based on the Automatic Control Technology." Key Engineering Materials 620 (August 2014): 471–77. http://dx.doi.org/10.4028/www.scientific.net/kem.620.471.
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£oWith our country's labor cost increase and forestry operations to improve the degree of automation, the automatic picking device will be gradually adopted to pick fruit in the future. This paper discusses the design process of intelligent mobile platform, five axis manipulator, end effector, electrical control device which belong to the automatic fruit picking device. The device is installed in the automatic navigation system and visual identity system, can accurately locate the position and pick fruit. The CAD/CAE software device was mainly used to design and analysis model, and design efficiency, feasibility and scientific were improved. According to the current development trend of fruit species gradually increased, the manipulator hand can adjust, which can pick the different shapes of fruits, and is installed with a visual sensor, pressure sensor, position sensor in the manipulator, and the finger stress analysis was made. In addition, the application of S7-200 model of PLC and pneumatic technology is used in the picking device, so that the overall structure is compact, more stable.
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Bi, Yun Bo, Yong Chao Li, Yi Hang Jiang, Jiang Xiong Li, Wei Wang, Mian Gao, and Shuo Li. "An Industrial Robot Based Drilling System for Aircraft Structures." Applied Mechanics and Materials 433-435 (October 2013): 151–57. http://dx.doi.org/10.4028/www.scientific.net/amm.433-435.151.
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In order to realize automatic flexible drilling with high efficiency and good quality, a drilling system was established, which integrates the technology of laser measurement, off-line programming, computer control and robotics. In this system, the key coordinate frames are established by the laser tracker, the drilling programs are generated by the off-line programming and simulation system, the communication between the automatic drilling control system and the robot control system is based on the socket technique. By running drilling program, the moving platform, robot and the end effector can work automatically and harmoniously. In addition, the deviation compensation methods of hole position and its normal vector are proposed. The experimental results show that the efficiency of drilling can achieve 6 holes per minute, the position accuracy can be effectively controlled within 0.3mm, and the normal accuracy is better than 0.5°.
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Wang, Haixia, Xiao Lu, Zhanyi Hu, and Yuxia Li. "A vision-based fully-automatic calibration method for hand-eye serial robot." Industrial Robot: An International Journal 42, no. 1 (January 19, 2015): 64–73. http://dx.doi.org/10.1108/ir-06-2014-0352.
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Purpose – The purpose of this paper is to present a fully automatic calibration method for hand-eye serial robot system is presented in this paper. The so-called “fully automatic” is meant to calibrate the robot body, the hand-eye relation, and the used measuring binocular system at the same time. Design/methodology/approach – The calibration is done by controlling the joints to rotate several times one by one in the reverse order (i.e. from the last one to the first one), and simultaneously take pictures of the checkerboard patterns by the stereo camera system attached on the end-effector, then the whole robot system can be calibrated automatically from these captured images. In addition, a nonlinear optimization step is used to further refine the calibration results. Findings – The proposed method is essentially based on an improved screw axis identification method, and it needs only a mirror and some paper checkerboard patterns without resorting to any additional costly measuring instrument. Originality/value – Simulations and real experiments on MOTOMAN-UP6 robot system demonstrate the feasibility and effectiveness of the proposed method.
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Hashimoto, Hideki, Takashi Kubota, Motoo Sato, and Fumio Harashima. "Visual Control of Robotic Manipulator Based on Artificial Neural Network." Journal of Robotics and Mechatronics 3, no. 5 (October 20, 1991): 394–400. http://dx.doi.org/10.20965/jrm.1991.p0394.
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This paper describes a control scheme for a robotic manipulator system which uses visual information to position and orientate the end-effector. In the scheme the position and the orientation of the target workpiece with respect to the base frame of the robot are assumed to be unknown, but the desired relative position and orientation of the end-effector to the target workpiece are given in advance. The control system directly integrates visual data into the servoing process without subdividing the process into determination of the position, orientation of the workpiece and inverse kinematic calculation. An artificial neural network system is used for determining the change in joint angles required in order to achieve the desired position and orientaion. The proposed system can control the robot so that it approach the desired position and orientaion from arbitary initial ones. Simulation for the robotic manipulator with six degrees of freedom is done. The validity and the effectiveness of the proposed control scheme are varified by computer simulations.
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Wang, Junli, Shitong Wang, and Wenhao Leng. "Vision Positioning-Based Estimation Method and Its Simulation Studies on State of Underwater Manipulator." Mathematical Problems in Engineering 2021 (February 22, 2021): 1–12. http://dx.doi.org/10.1155/2021/6656928.
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Work class remote operated vehicles (ROVs) are generally equipped with underwater manipulators and are widely used in underwater intervention and maintenance tasks. As the load of underwater operation is relatively heavy, most commercial underwater manipulators are hydraulically actuated and are not equipped with any sensor for joint angles to keep their architectures compact. Therefore, the automatic control methods widely used in industrial robots cannot be simply applied to underwater manipulators. In this paper, an estimation method on joint angles of manipulator is presented, in which several markers are arranged on the arm links and positioned from the corresponding cameras; consequently, the joint angles of the manipulator are estimated. The simulation results show that under typical optical vision positioning error (RMS: 5 mm), the positioning error of the end effector can be estimated as about 10 mm (RMS), which means that the proposed estimation method is feasible for the state estimation for automatic control of underwater manipulators.
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Mao, Hanping, Guoxin Ma, Luhua Han, Jianping Hu, Feng Gao, and Yang Liu. "A whole row automatic pick-up device using air force to blow out vegetable plug seedlings." Spanish Journal of Agricultural Research 18, no. 4 (February 9, 2021): e0211. http://dx.doi.org/10.5424/sjar/2020184-17003.
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Aim of study: To develop a whole row automatic pick-up device using air force to blow out plug seedlings, to avoid the damage to seedlings that the current way of seedling picking by needle insertion induces.Area of study: Jiangsu Province, China.Material and methods: We designed a pick-up device which mainly consists of a seedling transporting device, a seedling air loosening device, a seedling clamping device and an automatic control system. The damage rate of seedling was significantly reduced and the success rate of seedling picking was increased by using the new seedling air loosening method and the new designed end-effectors. A prototype of the new pick-up device was produced according to the calculation results, and the performance tests were arranged under actual production conditions in an indoor laboratory.Main results: The calculation showed that when the diameter of the blowhole in air nozzle is 3.5 mm, and the air pressure is between 0.146 MPa and 0.315 MPa, the seedlings can be blown out successfully. Besides, the clamping strain test showed that the new designed end-effector can meet the requirements of seedling picking. The orthogonal test showed that both the air pressure and water content significantly affected the success ratio. The success ratio reached 96.64% when air pressure was 0.4 MPa, water content was 55%-60% and airflow rate was 100%, what meets the current requirements of transplanting.Research highlights: This research can provide some references for the automatic transplanting technology.
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Furlong, Michele, and Tian P. S. Oei. "CHANGES TO AUTOMATIC THOUGHTS AND DYSFUNCTIONAL ATTITUDES IN GROUP CBT FOR DEPRESSION." Behavioural and Cognitive Psychotherapy 30, no. 3 (July 2002): 351–60. http://dx.doi.org/10.1017/s1352465802003107.
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The present study sought to clarify the role of cognitive change in Cognitive Behavioural Therapy (CBT) by examining the relationship between depression outcome and changes to automatic thoughts and dysfunctional attitudes at different points of therapy. Thirty patients suffering from Major Depression (MDD) or Dysthymia attended the 12 sessions of a group CBT program. Multiple regressions found total scores on the Automatic Thoughts Questionnaire (ATQ) and cumulative change scores on the Dysfunctional Attitudes Scale (DAS) to predict scores on the Beck Depression Inventory (BDI) at later stages of therapy, though neither form of cognition was predictive from earlier stages of therapy. Only scores on the ATQ were significantly related to both cognitive and somatic subscales of the BDI, indicating that automatic thoughts are more directly related to cognitive change than dysfunctional attitudes. Overall findings suggest that significant reductions in both automatic thoughts and dysfunctional attitudes are related to non-clinical levels of depressive symptoms at the end of the treatment.
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Wei, Ziying, Huibo Zhang, Baoshan Zhao, Xiaoang Liu, and Rui Ma. "Impact Force Identification of the Variable Pressure Flexible Impact End-Effector in Space Debris Active Detumbling." Applied Sciences 10, no. 9 (April 26, 2020): 3011. http://dx.doi.org/10.3390/app10093011.
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The security of the space environment is under serious threat due to the increase in space debris in orbit. The active removal of space debris could ensure the sustainable use of the space environment; this removal relies on detumbling technology. According to the characteristics of the mechanical impact-type active detumbling method, this paper discusses a method to accurately identify the impact force using a pressure sensor. In this work, the impact force between a flexible impact end-effector and the space debris was analyzed theoretically and experimentally considering the pressure change during impact. Firstly, a nonlinear impact force model was established for the impact between a flexible end-effector and space debris. Secondly, impact experiments were performed and the friction model was modified. Finally, the effect of detumbling was verified through simulation experiments. The results showed that the identification error of normal impact force was less than 6.7% and the identification error of tangential friction force was less than 6.9%. Therefore, this identification method of impact force met the requirements of space debris detumbling, which has important guiding significance for the active removal technology of space debris.
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Khoshzaban, M., F. Sassani, and P. D. Lawrencet. "Kinematic Calibration of Industrial Hydraulic Manipulators." Robotica 14, no. 5 (September 1996): 541–51. http://dx.doi.org/10.1017/s0263574700020026.
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SUMMARYA novel off-line technique for automatic calibration of kinematic parameters for hydraulic manipulators is presented. Hydraulically actuated manipulators have joints which are always powered and, unlike conventional robots, may not have conventional joint sensors to exploit in the calibration procedure. Instead, our approach employs an external three-dimensional linkage, termed “the calibrator”, which has sufficient number of joints with corresponding sensors. One end of the calibrator is grasped by the manipulator's end effector while the other end is attached to a passive spherical joint fixed to the world coordinate system. The mobile closed kinematic chain thus formed has the added advantage of eliminating the explicit measurement of the manipulator's endpoint location. A sequential identification technique that uses a least squares numerical search algorithm has been developed based on link-by-link movement of the manipulator. Simulation and experimental calibration results on a typical mobile hydraulic manipulator are reported in this paper, which show that the proposed technique is globally stable, and potentially fast, inexpensive, and easy to apply on site.
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Kulpate, Chaiyapol, Mehran Mehrandezh, and Raman Paranjape. "An Eye-To-Hand Panoramic Vision System for 3D Positioning of a Robotic Arm." Journal of Robotics and Mechatronics 20, no. 1 (February 20, 2008): 135–50. http://dx.doi.org/10.20965/jrm.2008.p0135.
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A novel visual servoing structure is presented for robot positioning under an eye-to-hand camera configuration using panoramic vision. The proposed algorithm is based upon Image-Based Visual Servoing (IBVS) and uses only one fixed camera in conjunction with a stationary flat mirror. A single landmark mounted on the robot's end-effector along with its mirror reflection provide enough information for 3D reasoning based on a 2D image when viewed by a camera. The equations describing the relationship between the velocity of the coordinate frame attached to the robot's end-effector and rate of change in image features called the image Jacobian are presented. A novel set of image features that yield a full-rank image Jacobian is introduced. The Visual servoing based on an online estimation of the image Jacobian using a Kalman Filter (KF) is also presented. Simulated and experimental results illustrate the robustness of the proposed visual servoing structure. In addition, the accuracy of the proposed visual servoing structure is evaluated with an error analysis and sensitivity tests.
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Mosadeghzad, M., D. Naderi, and S. Ganjefar. "Dynamic modeling and stability optimization of a redundant mobile robot using a genetic algorithm." Robotica 30, no. 3 (July 26, 2011): 505–14. http://dx.doi.org/10.1017/s0263574711000804.
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SUMMARYKinematic reconfigurable mobile robots have the ability to change their structure to increase stability and decrease the probability of tipping over on rough terrain. If stability increases without decreasing center of mass height, the robot can pass more easily through bushes and rocky terrain. In this paper, an improved sample return rover is presented. The vehicle has a redundant rolling degree of freedom. A genetic algorithm utilizes this redundancy to optimize stability. Parametric motion equations of the robot were derived by considering Iterative Kane and Lagrange's dynamic equations. In this research, an optimal reconfiguration strategy for an improved SRR mobile robot in terms of the Force–Angle stability measure was designed using a genetic algorithm. A path-tracking nonlinear controller, which maintains the robot's maximum stability, was designed and simulated in MATLAB. In the simulation, the vehicle and end-effector paths and the terrain are predefined and the vehicle has constant velocity. The controller was found to successfully keep the end-effector to the desired path and maintained optimal stability. The robot was simulated using ADAMS for optimization evaluation.
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Güler, Fatma, and Emin Kasap. "A path planning method for robot end effector motion using the curvature theory of the ruled surfaces." International Journal of Geometric Methods in Modern Physics 15, no. 03 (February 20, 2018): 1850048. http://dx.doi.org/10.1142/s0219887818500482.
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Using the curvature theory for the ruled surfaces a technique for robot trajectory planning is presented. This technique ensures the calculation of robot’s next path. The positional variation of the Tool Center Point (TCP), linear velocity, angular velocity are required in the work area of the robot. In some circumstances, it may not be physically achievable and a re-computation of the robot trajectory might be necessary. This technique is suitable for re-computation of the robot trajectory. We obtain different robot trajectories which change depending on the darboux angle function and define trajectory ruled surface family with a common trajectory curve with the rotation trihedron. Also, the motion of robot end effector is illustrated with examples.
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Cappelluti, G., A. Morea, C. Notarnicola, and F. Posa. "Automatic Detection of Local Cloud Systems from MODIS Data." Journal of Applied Meteorology and Climatology 45, no. 8 (August 1, 2006): 1056–72. http://dx.doi.org/10.1175/jam2393.1.
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Abstract This paper describes an algorithm that is aimed at the identification of cloudy and clear pixels in Moderate-Resolution Imaging Spectroradiometer (MODIS) images to support earth science and nowcasting applications. The process from geolocated and calibrated data allows one to obtain cloud masks with four clear-sky confidence levels for five different cloud system types. The technique has been developed using the MODIS cloud-mask algorithm heritage, but the threshold tests performed have been executed without comparing solar reflectances and thermal brightness temperatures with thresholds determined in advance, but instead with thresholds carried out from classification methods. The main advantage of this technique is that the thresholds are obtained directly from the images. Seventy-five percent of the spectral signatures (known as end members) derived from the winter images in the detection of the various cloud types and 80% of the summer end members can be considered as being well discriminated. Furthermore, it seems that the end members characterizing the different cloud systems are constant throughout the various seasons of the year (they vary with a confidence level of 60%), whereas those describing clear sky change in a notable manner (the associated confidence level is 99%). The algorithm is able to produce cloud masks pertinent to limited regions at a mesoscale level, which may be a key factor for nowcasting purposes. This work shows that the use of end members and spectral angles, as opposed to spectral thresholds, should be carefully examined because of the fact that it might be simpler or that higher performances may be achieved at a regional scale.
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Sosa-Méndez, Deira, Esther Lugo-González, Manuel Arias-Montiel, and Rafael A. García-García. "ADAMS-MATLAB co-simulation for kinematics, dynamics, and control of the Stewart–Gough platform." International Journal of Advanced Robotic Systems 14, no. 4 (July 1, 2017): 172988141771982. http://dx.doi.org/10.1177/1729881417719824.
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The mechanical structure known as Stewart–Gough platform is the most representative parallel robot with a wide variety of applications in many areas. Despite the intensive study on the kinematics, dynamics, and control of the Stewart–Gough platform, many details about these topics are still a challenging problem. In this work, the use of automatic dynamic analysis of multibody systems software for the kinematic and dynamic analysis of the Stewart–Gough platform is proposed. Moreover, a co-simulation automatic dynamic analysis of multibody systems (ADAMS)-MATLAB is developed for motion control of the Stewart–Gough platform end-effector. This computational approach allows the numerical solution for the kinematics, dynamics, and motion control of the Stewart–Gough platform and a considerable reduction on the analytical and programming effort. The obtained results in the three topics (kinematics, dynamics, and control) are validated by comparing them with analytical results reported in the literature. This kind of computational approach allows for the creation of virtual prototypes and saves time and resources in the development of Stewart–Gough platform-based robots applications.
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Bjorck, Johan, Brendan H. Rappazzo, Di Chen, Richard Bernstein, Peter H. Wrege, and Carla P. Gomes. "Automatic Detection and Compression for Passive Acoustic Monitoring of the African Forest Elephant." Proceedings of the AAAI Conference on Artificial Intelligence 33 (July 17, 2019): 476–84. http://dx.doi.org/10.1609/aaai.v33i01.3301476.
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In this work, we consider applying machine learning to the analysis and compression of audio signals in the context of monitoring elephants in sub-Saharan Africa. Earth’s biodiversity is increasingly under threat by sources of anthropogenic change (e.g. resource extraction, land use change, and climate change) and surveying animal populations is critical for developing conservation strategies. However, manually monitoring tropical forests or deep oceans is intractable. For species that communicate acoustically, researchers have argued for placing audio recorders in the habitats as a costeffective and non-invasive method, a strategy known as passive acoustic monitoring (PAM). In collaboration with conservation efforts, we construct a large labeled dataset of passive acoustic recordings of the African Forest Elephant via crowdsourcing, compromising thousands of hours of recordings in the wild. Using state-of-the-art techniques in artificial intelligence we improve upon previously proposed methods for passive acoustic monitoring for classification and segmentation. In real-time detection of elephant calls, network bandwidth quickly becomes a bottleneck and efficient ways to compress the data are needed. Most audio compression schemes are aimed at human listeners and are unsuitable for low-frequency elephant calls. To remedy this, we provide a novel end-to-end differentiable method for compression of audio signals that can be adapted to acoustic monitoring of any species and dramatically improves over naive coding strategies.
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Montalvo, William, Juan Escobar-Naranjo, Carlos A. Garcia, and Marcelo V. Garcia. "Low-Cost Automation for Gravity Compensation of Robotic Arm." Applied Sciences 10, no. 11 (May 31, 2020): 3823. http://dx.doi.org/10.3390/app10113823.
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During the Industry 4.0 era, the open source-based robotic arms control applications have been developed, in which the control algorithms apply for movement precision in the trajectory tracking paths based on direct or reverse kinematics. Therefore, small errors in the joint positions can summarize in large position errors of the end-effector in the industrial activities. Besides the change of the end-effector position for a given variation of the set-point in manipulator joint positions depends on the manipulator configuration. This research proposes a control based on Proportional Derivative (PD) Control with gravity compensation to show the robustness of this control scheme in the robotic arm’s industrial applications. The control algorithm is developed using a low-cost board like Raspberry Pi (RPI) where the Robot Operating System (ROS) is installed. The novelty of this approach is the development of new functions in ROS to make the PD control with gravity compensation in low-cost systems. This platform brings a fast exchange of information between the Kuka™ youBot robotic arm and a graphical user’s interface that allows a transparent interaction between them.
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Rubio-Gómez, Guillermo, Sergio Juárez-Pérez, Antonio Gonzalez-Rodríguez, David Rodríguez-Rosa, Lis Corral-Gómez, Alfonso I. López-Díaz, Ismael Payo, and Fernando J. Castillo-García. "New Sensor Device to Accurately Measure Cable Tension in Cable-Driven Parallel Robots." Sensors 21, no. 11 (May 21, 2021): 3604. http://dx.doi.org/10.3390/s21113604.
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Cable-driven parallel robots are a special type of robot in which an end-effector is attached to a fixed frame by means of several cables. The position and orientation of the end-effector can be controlled by controlling the length of the cables. These robots present a wide range of advantages, and the control algorithms required have greater complexity than those in traditional serial robots. Measuring the cable tension is an important task in this type of robot as many control algorithms rely on this information. There are several well-known approaches to measure cable tension in cable robots, where a trade-off between complexity and accuracy is observed. This work presents a new device based on strain gauges to measure cable tension specially designed to be applied in cable-driven parallel robots. This device can be easily mounted on the cable near the fixed frame, allowing the cable length and orientation to change freely, while the measure is taken before the cable passes through the guiding pulleys for improved accuracy. The results obtained from the device show a strong repeatability and linearity of the measures
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Wang, Hongbo, Peng Chen, Yungui Li, Bowen Sun, Ziyu Liao, Baoshan Niu, and Jianye Niu. "New Rehabilitation Assessment Method of the End-Effector Finger Rehabilitation Robot Based on Multi-Sensor Source." Healthcare 9, no. 10 (September 23, 2021): 1251. http://dx.doi.org/10.3390/healthcare9101251.
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In the process of rehabilitation, the objectivity and the accuracy of rehabilitation assessment have an obvious impact on the follow-up training. To improve this problem, using a multi-sensor source, this paper attempts to establish a comprehensive assessment method of the finger rehabilitation effect, including three indicators of finger muscle strength, muscle fatigue degree, and range of motion. Firstly, on the basis of the fingertip pressure sensor of the End-Effector Finger Rehabilitation Robot, a mathematical model of finger muscle strength estimation was established, and the estimated muscle strength was scored using the entropy weight method. Secondly, using an sEMG signal sensor, a fatigue monitoring system was designed in the training process, and the fatigue degree was determined on the basis of the change trend of the eigenvalues of MAV and RMS. Lastly, a human–machine motion coupling model was established, and the joint range of motion acquisition and scoring model were obtained on the basis of the motor encoder. According to the above three indicators, using the AHP assessment method to establish a comprehensive rehabilitation assessment method, the effectiveness of the method was verified by experiments. This paper provides a potential new idea and method for objective, accurate, and convenient assessment of finger function rehabilitation, which is of positive significance for alleviating the burden on rehabilitation doctors and improving rehabilitation efficiency.
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Hamaguchi, Masafumi, and Takao Taniguchi. "An Obstacle Avoidance Method for Action Support 7-DOF Manipulators Using Impedance Control." Journal of Robotics 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/842717.
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An obstacle avoidance method of action support 7-DOF manipulators is proposed in this paper. The manipulators are controlled with impedance control to follow user's motions. 7-DOF manipulators are able to avoid obstacles without changing the orbit of the end-effector because they have kinematic redundancy. A joint rate vector is used to change angular velocity of an arbitrary joint with kinematic redundancy. The priority of avoidance is introduced into the proposed method, so that avoidance motions precede follow motions when obstacles are close to the manipulators. The usefulness of the proposed method is demonstrated through obstacle avoidance simulations and experiments.
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Kato, Daiki, Kenya Yoshitsugu, Toshiki Hirogaki, Eiichi Aoyama, and Kenichi Takahashi. "Predicting Positioning Error and Finding Features for Large Industrial Robots Based on Deep Learning." International Journal of Automation Technology 15, no. 2 (March 5, 2021): 206–14. http://dx.doi.org/10.20965/ijat.2021.p0206.
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In this study, we evaluated the motion accuracy of a large industrial robot and its compensation method and constructed an off-line teaching operation based on three-dimensional computer aided design data. In this experiment, we used a laser tracker to measure the coordinates of the end effector of the robot. Simultaneously, the end-effector coordinates, each joint angle, the maximum current of the motors attached to each joint, and rotation speed of each joint were measured. This servo information was converted into image data as visible information. For each robot movement path, an image was created; the horizontal axis represented the movement time of the robot and the vertical axis represented the servo information. A convolutional neural network (CNN), a type of deep learning, was used to predict the positioning error with high accuracy. Subsequently, to identify the features of the positioning error, the image was divided into several analysis areas, one of which was filled with various colors and analyzed by the CNN. If the prediction accuracy of the CNN decreased, then the analysis area would be identified as a feature. Thus, the features of the Y-axis positioning error were observed for teaching each joint angle in the opposite direction just after the start of the motion, overshoot of the rotational joint current, and the change in the swivel joint current.
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Azarfar, Azita. "Self-tuning Fuzzy Task Space Controller for Puma 560 Robot." IAES International Journal of Robotics and Automation (IJRA) 7, no. 4 (December 1, 2018): 273. http://dx.doi.org/10.11591/ijra.v7i4.pp273-282.
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Since in most robot applications the desired paths are determined in task space or Cartesian space, it is important to control the robot arm in task space. In this paper a fuzzy controller with modifiable scaling factors is proposed to control the robot end-effector in task space. The controller is a fuzzy system with a mechanism to change the scaling factors when the error is bounded under a predetermined value. The controller is designed in joint space and is developed to work space by using inverse Jacobian strategy. The simulations results on Puma 560 robot manipulator illustrate the high performance of presented control method.
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Krishnan, Megha G., Abhilash T. Vijayan, and Ashok Sankar. "Performance enhancement of two-camera robotic system using adaptive gain approach." Industrial Robot: the international journal of robotics research and application 47, no. 1 (November 4, 2019): 45–56. http://dx.doi.org/10.1108/ir-08-2019-0174.
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Purpose This paper aims to improve the performance of a two-camera robotic feedback system designed for automatic pick and place application by modifying its velocity profile during switching of control. Design/methodology/approach Cooperation of global and local vision sensors ensures visibility of the target for a two-camera robotic system. The master camera, monitoring the workspace, guides the robot such that image-based visual servoing (IBVS) by the eye-in-hand camera transcends its inherent shortcomings. A hybrid control law steers the robot until the system switches to IBVS in a region proven for its asymptotic stability and convergence through a qualitative overview of the scheme. Complementary gain factors can ensure a smooth transition in velocity during switching considering the versatility and range of the workspace. Findings The proposed strategy is verified through simulation studies and implemented on a 6-DOF industrial robot ABB IRB 1200 to validate the practicality of adaptive gain approach while switching in a hybrid visual feedback system. This approach can be extended to any control problem with uneven switching surfaces or coarse/fine controllers which are subjected to discrete time events. Practical implications In complex workspace where robots operate in parallel with other robots/humans and share workspaces, the supervisory control scheme ensures convergence. This study proves that hybrid control laws are more effective than conventional approaches in unstructured environments and visibility constraints can be overcome by the integration of multiple vision sensors. Originality/value The supervisory control is designed to combine the visual feedback data from eye-in-hand and eye-to-hand sensors. A gain adaptive approach smoothens the velocity characteristics of the end-effector while switching the control from master camera to the end-effector camera.