Статті в журналах з теми "Vertical displacement robots"
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1
Alexandrescu, Nicolae, Constantin Udrea, Despina Duminică, and Tudor Cătălin Apostolescu. "Research on the Vacuum Attachment System of a Cleaning Robot with Vertical Displacement." Advanced Materials Research 463-464 (February 2012): 1673–77. http://dx.doi.org/10.4028/www.scientific.net/amr.463-464.1673.
Повний текст джерелаАнотація:
Autonomous mobile robots for vertical surface cleaning have to support their own weight, fixing elements most frequently used being vacuum cups. An original construction of a cleaning robot with displacements in a vertical plane and vacuum attachment system was developed by the authors. The paper presents the most important results of the research performed in order to establish the behavior of vacuum cups used for coupling to the supporting surface in the presence of external loads.
2
Meng, Qingguo, Xuefeng Yang, Wei Li, En Lu, and Lianchao Sheng. "Research and Analysis of Quasi-Zero-Stiffness Isolator with Geometric Nonlinear Damping." Shock and Vibration 2017 (2017): 1–9. http://dx.doi.org/10.1155/2017/6719054.
Повний текст джерелаАнотація:
This paper presents a novel quasi-zero-stiffness (QZS) isolator designed by combining a tension spring with a vertical linear spring. In order to improve the performance of low-frequency vibration isolation, geometric nonlinear damping is proposed and applied to a quasi-zero-stiffness (QZS) vibration isolator. Through the study of static characteristics first, the relationship between force displacement and stiffness displacement of the vibration isolation mechanism is established; it is concluded that the parameters of the mechanism have the characteristics of quasi-zero stiffness at the equilibrium position. The solutions of the QZS system are obtained based on the harmonic balance method (HBM). Then, the force transmissibility of the QZS vibration isolator is analyzed. And the results indicate that increasing the nonlinear damping can effectively suppress the transmissibility compared with the nonlinear damping system. Finally, this system is innovative for low-frequency vibration isolation of rehabilitation robots and other applications.
3
Pritykin, Fedor Nikolaevich, and Valeriy Ivanovich Nebritov. "Graphic optimization model of the process of welding products by a robot based on Radishchev blueprint." Программные системы и вычислительные методы, no. 2 (February 2021): 63–73. http://dx.doi.org/10.7256/2454-0714.2021.2.35507.
Повний текст джерелаАнотація:
This article reviews the example of using a geometric model of a hypersurface in multidimensional space on the Radishchev blueprint, which reflects interconnection between the four variables in solution of one of the tasks associated with structuring the technological process fulfilled by a welding robot. In structuring technological processes related to welding, it is necessary to solve the optimization task of determining the position of the foundation of welding robot relative to the welded brackets and the axis of the container of cylindrical shape. The welding process requires finding the most optimal welding robot, the geometric model of the kinematic chain of which would move the output link and welding head across all sections of welding seams. As an example, the author reviews the case when the robot is outside the cylindrical container, and welding objects inside and outside. For carrying out the optimization task, the author examines the correlation between the parameters that determine the position of the robot relative to the container, and the minimum possible vertical displacement of the center of the output link based on the graphic optimization model. The multicomponent system comprised of the four parameters is studied based on the Radishchev blueprint. The author drew the combinations of curves that set the framework of curve lines of the dual level of the hypersurface in the four-dimensional space. For determination of the curves, the author found the combinations of projections of the dots on the Radishchev blueprint. The use of dual level lines on the Radishchev blueprint allowed determining most optimal position of the manipulator mechanism with regards to the cylindrical surface in welding the items for various industrial robots described in this article.
4
Ho, Thanhtam, and Li Li Xin. "Design of a Piezoelectrically Actuated Jumping Robot." Advanced Materials Research 311-313 (August 2011): 2211–14. http://dx.doi.org/10.4028/www.scientific.net/amr.311-313.2211.
Повний текст джерелаАнотація:
This paper presents the design and simulation of a mesoscale robot that can jump vertically. The robot uses the vibration of a piezocomposite actuator named LIPCA. A ratchet mechanism is designed to convert the vertical vibration to angular displacement. Then the displacement is transferred to a pair of links such that a spring is compressed. The elastic energy of spring is used to make the robot jump vertically. Simulation results verify that the robot can jump as high as about three times its body height.
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Fu, Yu, Tien-Ruey Hsiang, and Sheng-Luen Chung. "Multi-waypoint visual homing in piecewise linear trajectory." Robotica 31, no. 3 (August 16, 2012): 479–91. http://dx.doi.org/10.1017/s0263574712000434.
Повний текст джерелаАнотація:
SUMMARYThis paper proposes an image sequence-based navigation method under the teaching-replay framework for robots in piecewise linear routes. Waypoints used by the robot contain either the positions with large heading changes or selected midway positions between junctions. The robot applies local visual homing to move between consecutive waypoints. The arrival at a waypoint is determined by minimizing the average vertical displacements of feature correspondences. The performance of the proposed approach is supported by extensive experiments in hallway and office environments. While the homing speed of robots using other approaches is constrained by the speed in the teaching phase, our robot is not bounded by such limit and can travel much faster without compromising the homing accuracy.
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Rachkov, M. Y. "The transport robot with reconfigurable structure." Izvestiya MGTU MAMI 10, no. 2 (June 15, 2016): 39–45. http://dx.doi.org/10.17816/2074-0530-66921.
Повний текст джерелаАнотація:
The paper discusses research results of transport robot new design for automation of different kinds of work in emergency situations. The purpose of research is to expand the robot's functional properties due to the possibility of overcoming the various obstacles, as well as high-speed movement on flat surfaces by reconfiguring its structure to the type of surface displacement. The robot has two caterpillar tracks located on each side of the platform for process equipment and two wheeled driving machines mounted on the front and rear of platform between caterpillar track groups. A feature of the design is that the wheel axis of wheeled driving machines is connected with the platform through levers, which drive is located on platform with the possibility of wheeled driving machines movement vertically relative to platform. Lever length could vary that allows to transform robot for different obstacles. A kinematic model of the robot in SolidWorks was developed to study different traffic modes. An experimental sample remote-controlled robot on the basis of standard components nodes was made. Its laboratory tests confirmed the ability to overcome different types of obstacles. The simulation of control system for levers extension in Matlab Simulink was made. It showed the stability of the system at the given parameters. The results can be used to create full-scale robots.
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Cruz Ulloa, Christyan, Silvia Terrile, and Antonio Barrientos. "Soft Underwater Robot Actuated by Shape-Memory Alloys “JellyRobcib” for Path Tracking through Fuzzy Visual Control." Applied Sciences 10, no. 20 (October 14, 2020): 7160. http://dx.doi.org/10.3390/app10207160.
Повний текст джерелаАнотація:
Recent developments in bioinspired technologies combined with the advance of intelligent and soft materials have allowed soft robots to replicate the behavior of different animal species. These devices can perform complicated tasks such as reaching or adapting in constrained and unstructured environments. This article proposes a methodology to develop a soft robot called “JellyRobcib” inspired in morphology and behavior by jellyfish, using shape-memory alloy springs as actuators (as bio-muscles). Such actuators can move the jellyfish both vertically and laterally by applying closed-loop fuzzy and visual controls. Additionally, Computer-Assisted Designs and Computational Fluid Dynamics simulations have been carried out to validate the soft robot model. The results show that the robot movements are very close to the morphological behavior of a real jellyfish regarding the curves of displacements, speeds and accelerations, after performing several experiments for autonomous movement: vertical ascent, lateral movements and trajectory tracking, obtaining an accuracy of ±1479 cm and repeatability of 0.944 for lateral movements for fuzzy visual control. Furthermore, thermal measurements were taken throughout a given path, allowing the generation of temperature gradients within the underwater environment for monitoring purposes.
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Tătar, Mihai Olimpiu, Florin Haiduc, and Dan Mândru. "Design of a Synchro-Drive Omnidirectional Mini-Robot." Solid State Phenomena 220-221 (January 2015): 161–67. http://dx.doi.org/10.4028/www.scientific.net/ssp.220-221.161.
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Using the synchro-drive principle, the paper presents a new omnidirectional mini-robot with conventional wheels. The synchro-drive principle is achieved applying geared mechanisms: three for steering and another three for displacement. The mini-robot uses two DC motors and three pairs of conventional wheels. The first DC motor controls the rotation of three pairs of the wheels around the horizontal axis thus generating the driving force (traction) to the mini-robot. The second motor controls the rotation of three pairs of the wheels around the vertical axis hence generating their orientation.
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Yeom, Seong Won, and Il Kwon Oh. "Fabrication and Evaluation of Biomimetic Jellyfish Robot Using IPMC." Advances in Science and Technology 58 (September 2008): 171–76. http://dx.doi.org/10.4028/www.scientific.net/ast.58.171.
Повний текст джерелаАнотація:
In this study, fabrication and evaluation of a biomimetic jellyfish robot by using IPMC actuators were performed. Application fields of the existing IPMC actuators are limited due to the flat shape which is a serious weakness for such actuation material. A new curved IPMC actuator with an intended initial deformation was newly developed to overcome the weakness of the flat IPMC actuator and to mimic the jellyfish. The thermal treatment was applied to obtain the intended initial deformation. The bio-inspired input signal was generated with mimicking real motion of the jellyfish. The vertical floating displacement and force of the biomimetic jellyfish robot under various driving signals were measured and compared vertical floating forces and motion of jellyfish robot. Unlike sinusoidal excitation, the bio-inspired input signals make position. Although there are still certain problems to be resolved in the power system and buoyancy, the curved IPMC actuators may possibly be a promising candidate that can materialize the biomimetic fish robot.
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Efremova, K. D., and V. N. Pil'gunov. "Linear positioner based on pneumatic muscle." Izvestiya MGTU MAMI 12, no. 2 (June 15, 2018): 16–29. http://dx.doi.org/10.17816/2074-0530-66825.
Повний текст джерелаАнотація:
The main goal of the work is to investigate the technical possibilities of creating a linear positioner on the basis of pneumatic muscle with acceptable characteristics for positioning. The experimental study of the power characteristics of the pneumatic muscle of the MAS 10-300 series of “FESTO” company is carried out. The physical essence of the cylindrical membrane operation is considered, on the basis of which the pneumatic muscle is constructed and a method for calculating the parameters of the positioning spring has been developed. It is shown that if the positional component is present in the load of pneumatic muscle then its rigidity (the dependence of the force on displacement) allows solving the task of positioning by controlling the pressure in the internal cavity of pneumatic muscle. If there is no positional component in the load or it is too small, then a positioning spring is needed to solve the positioning problem. Methods for determining the parameters of the positioning spring for positioners created on the basis of MAS pneumatic muscles of “FESTO” company are given. It has been established that the pneumatic muscle, which is used as a linear pneumatic motor, generates a pulling force which, with zero reduction of the pneumatic muscle, is 12 ... 14 times greater than the force developed on the return stroke by a pneumatic cylinder of equal working area of the piston and the specific force (force referred to the mass of the pneumatic motor) of pneumatic muscle is 100 times larger. This makes it possible to use pneumatic muscle as a loading device for brake, clamping and tensioning devices of transport systems and mobile units. To use the positioner in the tracking position control system, it must be provided with an analog feedback sensor. The static characteristic of the created physical layout of the positioner, obtained experimentally, has a quasilinear section in the range of the control pressure change of 2.5 ... 5 bar and agrees well with the calculation results. The nature of the transient process with respect to the input effect makes it possible to treat the positioner as an aperiodic link of the first order with a time constant T = 2 ... 5 s. As an example, the possibility of using a positioner in solving problems related to the need to stabilize a cargo platform in a horizontal position, in the case of a shift of the center of gravity of the cargo relative to the vertical axis of the platform, was investigated. The results of the work can be used and implemented in solving problems of linear and angular positioning of the load in flexible production systems, in executive devices of industrial robots, etc.
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Daachi, B., A. Benallegue, T. Madani, and M. E. Daachi. "Neural Networks for Redundant Robot Manipulators Control with Obstacles Avoidance." Journal of Robotics and Mechatronics 16, no. 1 (February 20, 2004): 90–96. http://dx.doi.org/10.20965/jrm.2004.p0090.
Повний текст джерелаАнотація:
In this paper, neural networks of MLP type are used to control constrained redundant robot manipulators with obstacles. The proposed controller is determined using extended Cartesian space to minimise the joint displacements and to avoid obstacles. The neural networks have been used to approximate separately, the functions of the dynamic model of the robot manipulator expressed in the Cartesian space. The adaptation laws weights of each neural network, are obtained via stability study in Lyapunov sense of the system in closed loop. The performances of the proposed control approach are tested on a 3-degree of freedom robot manipulators involving in the vertical space.
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Sui, Tingting, Jinhao Liu, Jianli Wang, and Jianting Zhang. "A Barycenter Control Method for the Bioinspired Forest Chassis Robot on Slope." Journal of Robotics 2021 (April 30, 2021): 1–15. http://dx.doi.org/10.1155/2021/5528746.
Повний текст джерелаАнотація:
To improve the stability of forestry chassis on the slope, a chassis-installed barycenter adjustable mechanism (BAM) is designed, and the control method of the counterweight is proposed to make the chassis barycenter move suitably to achieve the design purpose. The kinematic analysis of BAM is carried out, and the relationship between the translation, rotation, and vertical displacement of counterweight and the chassis barycenter is calculated. Furthermore, the variation curves obtained in Matlab show the barycenter can translate 100 mm, rotate from 0 to 360 degrees, and lower about 180 mm in the vertical direction. Adams is adopted to complete the kinematics simulation of the chassis, indicating that the control method can effectively adjust the barycenter position. Finally, experiments are carried out under slope conditions to analyze chassis stability by testing plantar pressure. The results show that forest chassis using the barycenter control method helps keep stable on the slope of 15 degrees, much better than standard normal chassis.
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Guodong, Zhai, Gao Peiyuan, and Meng Lili. "The kinematics modeling and parameter optimization of six-wheel lunar exploration robot." International Journal of Advanced Robotic Systems 15, no. 3 (May 1, 2018): 172988141877000. http://dx.doi.org/10.1177/1729881418770005.
Повний текст джерелаАнотація:
This article proposes a six-wheel lunar exploration robot which will move on the lunar surface. It is known that lunar surface is mostly rugged. When the six-wheel lunar exploration robot moves on the rugged surface, its centroid position will change, which has an impact on the vehicle obstacle performance and anti-overturning performance, and so on. Therefore, it is very important to analyze the centroid domain of the robot. In order to get the relation between centroid domain and position as well as the posture equation during the motion process, the kinematics model of the robot is built based on the coordinate transforming relations. So the calculation formula of centroid domain and body posture equation at any movement position are obtained. The mathematical model of detection robot is analyzed by entity analysis. So the centroid vector model of radial angle change curve and the changing rule of both sides of the rocker arm angle and centroid vector mode are given. MATLAB [version 6.0] is used to optimize the parameters of the robot and ADAMS is used to simulate the process when the robot moving on the rugged lunar surface. The results show that the centroid domain is a flat area. Based on the calculations and simulations, the vertical displacement and the pitch angle of the robot are decreased with different degrees after the optimization of the rocker arm suspension and the integrated moving stable performance of the lunar exploration robot is obviously enhanced.
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Adamiec-Wójcik, I., Ł. Drąg, S. Wojciech, and M. Metelski. "Application of the Rigid Finite Element Method to Static Analysis of Lattice-Boom Cranes." International Journal of Applied Mechanics and Engineering 23, no. 3 (August 1, 2018): 803–11. http://dx.doi.org/10.2478/ijame-2018-0044.
Повний текст джерелаАнотація:
Abstract In the paper a nonlinear model of a lattice-boom crane with lifting capacity up to 700mT for static analysis is presented. The rigid finite element method is used for discretisation of the lattice-boom and the mast. Flexibility of rope systems for vertical movement and for lifting a load is also taken into account. The computer programme developed enables forces and stress as well as displacements of the boom to be calculated. The model is validated by comparison of the authors’ own results with those obtained using professional ROBOT software. Good compatibility of results has been obtained.
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Ren, Tongqun, Xin Li, Xiaodong Wang, Zheng Xu, Yugang Liu, Jin Yang, and Jiang Guo. "Automatic Sorting System for Rigid Piezoelectric Transducer Wafers Used in Displacement Adjustment." Micromachines 11, no. 10 (September 30, 2020): 915. http://dx.doi.org/10.3390/mi11100915.
Повний текст джерелаАнотація:
Piezoelectric transducer wafers are usually used in pairs to adjust the resonant cavity length of the ring laser gyro. In practice, the paired wafers are required to have similar piezoelectric charge coefficient d31. To handle the pairing operation in-batch, an automatic sorting system was developed on the basis of deformation measurement, which adopted a frame of a Cartesian-coordinate robot. The wafers were self-aligned in the vertical direction, and a vacuum holder was used to pick up, transfer, and then place them on thee testing desk one by one. The excitation voltage was loaded on the wafer by a specifically designed electrode, and the resulting micro deformation was measured by dual opposite inductive micrometers using the relative measurement principle. This particular electrode has the function of attitude self-adjustment and vacuum adsorption, which is conducive to loading the voltage reliably and protecting the wafer from undesired damage. Finally, the wafers were transported to different stock bins based on the measuring results. This system is suited to handle a mass of wafers by continuous processing on site for its high reliability and measurement consistency. The measurement accuracy, validated by laser interferometry, was better than 0.5 μm and the repeatability was superior to 0.1 μm.
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Wang, Binrui, Yixuan Liu, Zhongwen Li, Dijian Chen, Ruizi Ma, and Ling Wang. "Parallel Spine Design and CPG Motion Test of Quadruped Robot." International Journal of Pattern Recognition and Artificial Intelligence 34, no. 05 (August 26, 2019): 2059013. http://dx.doi.org/10.1142/s0218001420590132.
Повний текст джерелаАнотація:
The spine of mammals aids in the stability of locomotion. Central Pattern Generators (CPGs) located in spinal cord can rapidly provide a rhythmic output signal during loss of sensory feedback on the basis of a simulated quadruped agent. In this paper, active spine of quadruped robot is shown to be extremely effective in motion. An active spine model based on the Parallel Kinematic Mechanism (PKM) system and biological phenomena is described. The general principles involved in constructing a neural network coupled with limbs and spine to solve specific problems are discussed. A CPG mathematical model based on Hopf nonlinear oscillators produces rhythmic signal during locomotion is described, where many parameters to be solved must be formulated in terms of desired stability, often subject to vertical stability analysis. Our simulations demonstrate that active spine with setting reasonable CPG parameters can reduce unnecessary lateral displacement during trot gait, improving the stability of quadruped robot. In addition, we demonstrate that physical prototype mechanism provides a framework which shows correctness of simulation, and stability can thus be easily embodied within locomotion.
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Wang, Yang Wei, Zhen Long Wang, Jian Li, and Fei Gao. "Novel Design for a Biomimetic Water-Jetting Propulsion Vehicle Actuated by SMA Wires." Applied Mechanics and Materials 50-51 (February 2011): 73–77. http://dx.doi.org/10.4028/www.scientific.net/amm.50-51.73.
Повний текст джерелаАнотація:
An experimental biomimetic water-jetting propulsion vehicle for robot cuttlefish is presented. Firstly the cuttlefish swimming mode and mantle muscle structure is analyzed as the theory basis. Secondly the vehicle is designed and manufactured. The vehicle is actuated by SMA wires. Through rational structural design, it can achieve flexible water-jetting propulsion like cuttlefish mantle. Thirdly the geometrical model of the biomimetic mantle cross section is built. At last, the performance of the propulsion machine is tested by experiment. The experimental results are mainly about the response curves of the mantle outside diameter, the strain of SMA wire and the swimming displacement with time. The maximum contractive distance of the biomimetic mantle along the vertical direction is 6 mm, the maximum strain of SMA wire is -1.8 %. The maximum swimming speed is 45 mm/s.
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Parkhomey, Igor, Juliy Boiko, and Oleksander Eromenko. "Identification information sensors of robot systems." Indonesian Journal of Electrical Engineering and Computer Science 14, no. 3 (June 1, 2019): 1235. http://dx.doi.org/10.11591/ijeecs.v14.i3.pp1235-1243.
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<span lang="IN">At the present time, the complexity of identification is to find such a description, in which the image (information) of each class would have identified similar properties. The task is to make the transformed description includes the whole set of input images, united by the similarity class by the given ratio.</span><span lang="IN">Using the ordinates of an autocorrelation function is an inseparable shift in the center of gravity of an image, which leads to a change of such description.</span><span lang="IN">Nicest, the concept of an invariant description of information arises, this is an autocorrelation function, which is invariant to the description of any displacements of the image in the vertical and horizontal directions.</span><span lang="IN">The problem of finding an optimal decision rule arises, which, in a number of cases, can be constructed on the basis of a method, based on the definition of the maximum incomplete coefficient of similarity.</span><span lang="IN">Using this method, the solutions, that are almost unintelligible to the errors that arise due to the effects of interference, are found. Therefore, in increments</span><span lang="EN-US"> k</span><span lang="IN">, this rule passes into the Bayes’ rule.</span>
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Ge, Zhen Yang, Wang Wang Wu, Ying Jie Yu, and Rui Qing Zhang. "Design of Mechanical Arm for Laser Weeding Robot." Applied Mechanics and Materials 347-350 (August 2013): 834–38. http://dx.doi.org/10.4028/www.scientific.net/amm.347-350.834.
Повний текст джерелаАнотація:
A design of mechanical arm for laser weeding robot is described. The long term objective of the project is the replacement of chemical weeding by laser weeding. The distinguishing feature of this design is the use of a mechanical arm, which is equipped with a laser generator and a control center consisted of a single chip microcomputer and two driver hybrid ICs. The mechanical arm comprises two stepping motors vertically linked together. The robot moves ahead one step, the working area of laser generator is divided into 10×10 grids. Through the inverse operation of mechanical arm, the motor displacement angle of each grid is calculated. Mechanical arm turns to designated position if single chip gets weeds position information. The result of the design is a key executive mechanism of laser weeding. The operation error of mechanical arm is analyzed. The arm can point the laser beam towards the target weeds with small error. After the order of the execution areas is optimized, the length of arm moving path is shorter. Analysis of the running track shows that the sequence of execution area is feasible and reasonable.
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Huang, Yi-Cheng, Zi-Sheng Yang, and Hsien-Shu Liao. "Labeling Confidence Values for Wafer-Handling Robot Arm Performance Using a Feature-Based General Regression Neural Network and Genetic Algorithm." Applied Sciences 9, no. 20 (October 11, 2019): 4241. http://dx.doi.org/10.3390/app9204241.
Повний текст джерелаАнотація:
The prognosis and management of machine health statuses are emerging research topics. In this study, the performance degradation of a wafer-handling robot arm (WHRA) was predicted using the proposed machine-learning approach. This method considers the eccentric vertical and planar position deviations from a wafer mark using a charge-coupled device (CCD) camera. Synthesized position signals were defined using the square root of x- and y-axes deviations in the horizontal view and the square of the wafer mark diameter in the vertical view. A feature extraction method was used to determine the position status on the basis of these displacements and the area of a wafer mark in a CCD image. The root mean square error and mean, maximum, and minimum of the synthesized position signals were extracted through feature extraction and used for data mining by a general regression neural network (GRNN) and logistic regression (LR) models. The lifetime assessment by confidence value of the WHRA’s remaining useful life (RUL) by the genetic algorithm/GRNN exhibited nearly the same trend as that predicted through a run-to-failure LR model. The experimental results indicated that the proposed methodology can be used for proactive assessments of the RUL of WHRAs.
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Aksungur, Serhat, Muhammet Aydin, and Oğuz Yakut. "Real-time PID control of a novel RCM mechanism designed and manufactured for use in laparoscopic surgery." Industrial Robot: the international journal of robotics research and application 47, no. 2 (November 3, 2019): 153–66. http://dx.doi.org/10.1108/ir-09-2019-0179.
Повний текст джерелаАнотація:
Purpose The purpose of this study is to design and manufacture a new remote center of motion (RCM) mechanism for use in laparoscopic surgical operations. In addition, obtaining the forward and inverse kinematic equations of the RCM mechanism and performing real-time position control with the Proportional–Integral–Derivative (PID) control method. Design/methodology/approach At the design stage, it is benefited from similar triangle rule. To obtain the kinematic equations in a simple way and facilitate control, two-fold displacement ratio is provided between the limbs where linear motion occurs. The rotation and displacement amounts required to move at the RCM point have been calculated by using the kinematic equations of the mechanism. Limb dimensions and motion limits are determined in the manner to avoid singularities and collisions. The x, y and z coordinates of the end effector have been defined as the reference point. Control of the mechanism was provided by PID control. To generate the user interface and control algorithm, MATLAB/Simulink real-time toolbox has been used. Four reference points were determined, control was performed and position error values were examined. MF634 Humusoft data acquisition card has been preferred to collect data from encoders. Findings A novel RCM mechanism has been designed and manufactured. Kinematic equations of this mechanism have been obtained. Position control of the cannula tip has been performed using PID control method for four different reference points. After settlement, maximum position error has been observed as 0.45 mm. Practical implications Structure of the designed mechanism is quite simple. Thus, costs are quite low. The operation area of the operator is widened by hanging the mechanism from the ceiling, so operational capability of health personnel is increasing. It helps to decrease the operation time and increase the success of the operation. Originality/value With this study, it is aimed to contribute to the literature by designing a new RCM mechanism. The rotation of the mechanism around the RCM point is provided by only one rotary motor, and the displacement of the RCM point in the vertical axis is provided by only one linear motor. The mechanism is also a surgical robot. The designed system is suitable for use in robot-assisted laparoscopic surgery in terms of maneuverability.
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Wang, L., J. P. Sadler, L. C. Breeding, and D. L. Dixon. "An In Vitro Study of Implant-Tooth-Supported Connections Using a Robot Test System." Journal of Biomechanical Engineering 121, no. 3 (June 1, 1999): 290–97. http://dx.doi.org/10.1115/1.2798322.
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Many unsolved problems in dental implant research concern the interfacial stress distributions between the implant components, as well as between the implant surface and contacting bone. To obtain a mechanical understanding of how vertical and horizontal occlusal forces are distributed in this context, it is crucial to develop in vitro testing systems to measure the force transmission between dental implants and attached prostheses. A new approach to such testing, involving a robotic system, is described in this investigation. The system has been designed to produce simulated mandibular movements and occlusal contact forces so that various implant designs and procedures can be thoroughly tested and evaluated before animal testing or human clinical trials. Two commonly used fixed prosthesis designs used to connect an implant and a tooth, a rigid connection and a nonrigid connection, were fabricated and used for experimental verification. The displacement and force distributions generated during simulated chewing activities were measured in vitro. Force levels, potentially harmful to human bone surrounding the connected dental implant and tooth, were analyzed. These results are useful in the design of prostheses and connecting components that will reduce failures and limit stress transfer to the implant/bone interface.
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Park, Sang-Eun, Ye-Ji Ho, Min Ho Chun, Jaesoon Choi, and Youngjin Moon. "Measurement and Analysis of Gait Pattern during Stair Walk for Improvement of Robotic Locomotion Rehabilitation System." Applied Bionics and Biomechanics 2019 (October 14, 2019): 1–12. http://dx.doi.org/10.1155/2019/1495289.
Повний текст джерелаАнотація:
Background. Robotic locomotion rehabilitation systems have been used for gait training in patients who have had a stroke. Most commercialized systems allow patients to perform simple exercises such as balancing or level walking, but an additional function such as stair-walk training is required to provide a wide range of recovery cycle rehabilitation. In this study, we analyzed stair-gait patterns and applied the result to a robotic rehabilitation system that can provide a vertical motion of footplates. Methods. To obtain applicable data for the robotic system with vertically movable footplates, stair-walk action was measured using an optical marker-based motion capture system. The spatial position data of joints during stair walking was obtained from six healthy adults who participated in the experiment. The measured marker data were converted into joint kinematic data by using an algorithm that included resampling and normalization. The spatial position data are represented as angular trajectories and the relative displacement of each joint on the anatomical sagittal plane and movements of hip joints on the anatomical transverse plane. Results. The average range of motion (ROM) of each joint was estimated as (−6.75°,48.69°) at the hip, 8.20°,93.78° at the knee, and −17.78°,11.75° at the ankle during ascent and as 6.41°,31.67° at the hip, 7.38°,91.93° at the knee, and −24.89°,24.18° at the ankle during descent. Additionally, we attempted to create a more natural stair-gait pattern by analyzing the movement of the hip on the anatomical transverse plane. The hip movements were estimated to within ±1.57 cm and ±2.00 cm for hip translation and to within ±2.52° and ±2.70° for hip rotation during stair ascent and stair descent, respectively. Conclusions. Based on the results, standard patterns of stair ascent and stair descent were derived and applied to a lower-limb rehabilitation robot with vertically movable footplates. The relative trajectory from the experiment ascertained that the function of stair walking in the robotic system properly worked within a normal ROM.
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Khouadjia, Mohamed Lyes Kamel, Oussama Temami, Oussama Kessal, and Ahmed Abderraouf Belkadi. "Measures of Agreement Between Computation Programs and Experiment: The Case of Beams with Circular Cuts in their Webs." Civil and Environmental Engineering Reports 32, no. 1 (March 1, 2022): 74–87. http://dx.doi.org/10.2478/ceer-2022-0005.
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Abstract In the field of metal construction, cellular beams represent an attractive solution to meeting the various technical and economic constraints, especially for large-span buildings. In particular, they allow components linked to the construction to pass through their openings (ventilation ducts, electrical threads, etc.) and thus contribute to significantly reducing the thickness of the floors. However, the use of such beams requires special attention to comply with the regulations in force, in order to guarantee stability and behavior in line with the challenge of preserving the structures. This article focuses on the analysis of the measures of agreement between experiment and computation programs (strength of materials, Robot structures, and Inflexion-EF) results of the beams with circular cuts in their webs (IPE A 100), supported simply and subjected to a concentrated load. The experimental results show that the vertical displacement resulting from transverse compression is induced by various factors: length, cuts in their webs, location of the load, and stiffening of the beams. The comparison of experimental and theoretical results demonstrates the importance of experimental tests in validating theoretical results.
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Yao, Daojin, Siyu He, Yao Wu, Xiaohui Xiao, and Yang Wang. "Feedforward control for underactuated bipedal walking on varying compliant slopes." Transactions of the Canadian Society for Mechanical Engineering 42, no. 2 (June 1, 2018): 90–104. http://dx.doi.org/10.1139/tcsme-2017-0020.
Повний текст джерелаАнотація:
In this paper, a feedforward control strategy is proposed to enable stable underactuated bipedal walking on varying compliant slopes with a known inclination angle, to handle the variation in natural environments. First, spring–damper units were employed in the horizontal and vertical directions to model the compliant ground, which is described as a rigid kinematic chain coupled with a spring–damper system. Second, a new definition of stable underactuated bipedal walking, based on walking speed, was proposed. Stable walking is achieved by adjusting the velocity of the biped’s center of mass (CoM) within limits that have been proven to allow at least one walking cycle. The proposed feedforward control strategy was based on the motion state of a robot’s CoM, using the new definition of stability and inspired by the gait characteristics of human walking on varying slopes. Speed control is realized by adjusting the displacement of the CoM with the change of slope to achieve stable walking. Finally, simulations were conducted to validate the proposed controller. The simulation results demonstrate that stable walking is achieved on varying compliant slopes by implementing the proposed control strategy.
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AbuZaiter, Alaa, Ee Leen Ng, Suhail Kazi, and Mohamed Sultan Mohamed Ali. "Development of Miniature Stewart Platform Using TiNiCu Shape-Memory-Alloy Actuators." Advances in Materials Science and Engineering 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/928139.
Повний текст джерелаАнотація:
A Stewart platform is a parallel manipulator robot that is able to perform three linear movements, lateral, longitudinal, and vertical, and three rotations, pitch, yaw, and roll. This paper reports a 30 mm × 30 mm × 34 mm miniscale Stewart platform using TiNiCu shape-memory-alloy (SMA) actuators. The proposed Stewart platform possesses various advantages, such as large actuation force and high robustness with a simple mechanical structure. This Stewart platform uses four SMA actuators and four bias springs and performs a linearz-axis movement and tilting motions. The SMA actuators are activated by passing a current through the SMA wires using a heating circuit that generates a pulse width modulation (PWM) signal. This signal is varied to control the level of the displacement and tilting angle of the platform. The tilting direction depends on the SMA actuator that is activated, while all four SMA actuators are activated to achieve the linearz-axis movement. Each SMA actuator exerts a maximum force of 0.6 N at PWM duty cycle of 100%. The fabricated miniature Stewart platform yields a full actuation of 12 mm in thez-axis at 55°C, with a maximum tilting angle of 30° in 4 s.
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Zhang, Leiyu, Jianfeng Li, Shuting Ji, Peng Su, Chunjing Tao, and Run Ji. "Design and human–machine compatibility analysis of Co-Exos II for upper-limb rehabilitation." Assembly Automation 39, no. 4 (September 2, 2019): 715–26. http://dx.doi.org/10.1108/aa-09-2018-0127.
Повний текст джерелаАнотація:
Purpose Upper-limb joint kinematics are highly complex and the kinematics of rehabilitation exoskeletons fail to reproduce them, resulting in hyperstaticity and human–machine incompatibility. The purpose of this paper is to design and develop a compatible exoskeleton robot (Co-Exos II) to address these problems. Design/methodology/approach The configuration synthesis of Co-Exos II is completed using advanced mechanism theory. A compatible configuration is selected and four passive joints are introduced into the connecting interfaces based on optimal configuration principles. A Co-Exos II prototype with nine degrees of freedom (DOFs) is developed and still owns a compact structure and volume. A new approach is presented to compensate the vertical glenohumeral (GH) movements. Co-Exos II and the upper arm are simplified as a guide-bar mechanism at the elevating plane. The theoretical displacements of passive joints are calculated by the kinematic model of the shoulder loop. The compatible experiments are completed to measure the kinematics of passive joints. Findings The compatible configuration of the passive joints can effectively reduce the gravity influences of the exoskeleton device and the upper extremities. The passive joints exhibit excellent compensation effect for the GH joint movements by comparing the theoretical and measured results. Passive joints can compensate for most GH movements, especially vertical movements. Originality/value Co-Exos II possesses good human–machine compatibility and wearable comfort for the affected upper limbs. The proposed compensation method is convenient to therapists and stroke patients during the rehabilitation trainings.
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Virbule, Inese, Dmitrijs Serdjuks, and Karina Buka-Vaivade. "BEHAVIOUR'S ANALYSIS OF LOAD-CARRYING MEMBERS FOR TIMBER FRAMEWORK BUILDING." ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference 1 (June 20, 2019): 330. http://dx.doi.org/10.17770/etr2019vol1.4068.
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The problem of limited raw material and energy resources can be solved by the replacement of non-renewable structural materials by renewable ones. Using of timber structures enables to decrease impact on the planet. It will also help to reverse some of the effects of industrialization. Structural members from solid and glued laminated timber, cross-laminated timber and other timber-based materials are widely used for one-storey and multi-storey buildings. Three-storey timber framework building was considered as an object of investigations. The considered three-storey building has length and width equal to 28 and 13 m, correspondingly. The using of software Autodesk Robot Structural developed FEM model of three-storey platfom framed framework building. Load-carrying structures of considered framework building consist from the load-carrying walls, floors and roofs structures, which develop horizontal and vertical diaphragms providing strength and rigidity of the framework. The rational bay of the light framework structures changes within the limits from 300 to 600 mm. The rational span of beams and purlins does not exceed 4 m. Solid timber with the strength class C24 was assumed as a structural material for timber frameworks members. The OSB sheets were considered as a material of the cladding for external structures. Behaviour of the load-carrying shear walls were analysed by the using of FEM models developed by the software Autodesk Robot Structural and ANSYS 15 so as methods explained in EN 1995-1-1. The software ANSYS 15 was used for the development of separate model of load-carrying shear walls. Initial unit of shear wall – a panel with the dimensions 1.2X2.7 m was considered for the purpose. The bar sub-members of the panel were modelled by the BEAM 188 finite element type. The SHELL 181 and COMBIN 14 finite element types modelled the cladding sub-members and mechanical fasteners. The dependence between the horizontal displacements of the load-carrying wall, intensity of the applied load, area of the openings so as thickness of the wall was obtained as a second power polynomial equation. It was stated, that the obtained FEM models enables to describe the behaviours of the load-carrying shear walls with enough precision.
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Juozapaitis, Algirdas, Donatas Jatulis, and Antanas Šapalas. "DESIGN AND ANALYSIS OF COMBINED PLANE STEEL GUYED TOWER-MAST." Engineering Structures and Technologies 1, no. 4 (December 31, 2009): 157–65. http://dx.doi.org/10.3846/skt.2009.19.
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One of the most effective and widely used high-rise telecommunication structures are steel towers and guyed masts. The behaviour, analysis and application fields are exhaustively discussed in a number of scientific publications. The main advantages of tower structures are low building area, however, from the point of view of steel consumptions, such structures are not effective enough. For technical-economic efficiency not only the rational types of cross sections for typical mast elements are selected, but also various combined structural systems are developed and implemented. Flat tower-masts are also known. They are combined from a single plain truss supported out of its plane by guys. In this case, such mixed system is able to carry acting loads and actions in one direction like a tower and in other direction – like a mast. From a technicaleconomic point of view, such system stands in the intermediate position between the guyed mast and the tower. The major weakness of such framework is relatively great depth and the cross sectional area of the chords of the tower truss which is caused by the relatively high values of the bending moment in the chord acting in the plane of guys and the large buckling length of the chord out of truss plane. It must be stressed that wind action on the investigated structure directly depends on the dimensions of the chord cross section. This paper deals with the new combined plain tower-mast structure the chords of which out of plane are stiffened by and inserted between the guys connecting joints and the double-sided strut members. These members are pre-stressed to avoid compression induced by transverse loading. The analysis of the behavior of a separate strut system under transversal loading is performed and analytical expressions for determining internal forces and displacements in its members with and without pre-stressing are provided. The minimum values of the required pre-stressing in ties of the strut system are described. It is proved that a proper choice of the parameters of structural components gives a possibility of obtaining a favorable distribution of bending moments in the chord. On the basis of numerical experiments, a comparison between the results defined analytically and ones determined by the means of the Autodesk Robot Structural Analysis program is performed. The accuracy of the proposed analytical method is discussed. For defining the behaviour peculiarities of the new combined structural system and for estimating its technical-economic efficiency, the numerical experiment by the means of FEM program (Autodesk Robot Structural Analysis) was carried out. Analysis was performed using 98 meter high ordinary and new guyed tower-mast structures with guys fixed at four levels. The member sections of the analyzed structures designed according to the values of the defined acting internal forces are presented. It is estimated that using strut members helps in considerably reducing (about 4,8 times) the maximum values of bending moments in the chords of tower truss. It was estimated that depth between the chords in a new combined system was 2 times lesser than that in the ordinary tower – mast system. It is shown that in case of the same cross section and value of the pre-stressing force, the value of the vertical reaction of the new strutted tower-mast system on foundation was 1,65 time lesser than that in the ordinary system. Conclusions and recommendations are provided.
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Caresta, Mauro. "Drillstring Torsional Vibrations Cancelation during Off-Bottom Operations." SPE Drilling & Completion, January 1, 2022, 1–10. http://dx.doi.org/10.2118/209196-pa.
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Summary This work presents a method to move a vertical drillstring off-bottom in a given time without exciting the torsional vibrations. The control algorithm was originally developed for robots with flexible arms, and it is here applied to a long drillstring. The control strategy consists of calculating a feedforward torque based on the modal characteristics of the drillstring. The approach presented can be used to change the downhole orientation or to bring the drillstring to a stable rotational speed without residual vibrations before drilling is started. Numerical examples are presented for both displacement and velocity control strategies.
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Li, Jianfeng, Yuan Kong, Mingjie Dong, and Ran Jiao. "Development of a linear-parallel and self-adaptive under-actuated hand compensated for the four-link and sliding base mechanism." Robotica, October 22, 2021, 1–18. http://dx.doi.org/10.1017/s026357472100151x.
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Abstract When the under-actuated hand pinches the object on the worktable, the trajectory of the end of the finger is not a straight line, which makes it difficult for the hand to grasp the object from its both sides. In order to overcome this shortcoming, this paper proposes a new configuration of the linear-parallel and self-adaptive under-actuated hand which uses the four-link and sliding base mechanism to compensate for the vertical displacement of the end of the finger. Based on this new configuration, the mechanical structure of the under-actuated hand is designed, which has five degrees of freedom (DOFs), and is mainly composed of two fingers, a sliding base, four link compensation mechanisms and an outer base. These two fingers have exactly the same structure and size, where each finger uses only one motor to control two joints of the finger which realizes the under-actuated function. Through the cooperation of the four-link and sliding base mechanism, the under-actuated hand can realize the linear-parallel and self-adaptive hybrid grasping mode. Kinematics analysis and contact force analysis of the under-actuated hand are discussed, and the prototype of the under-actuated hand is developed to carry out the grasping experiments. The results of the simulation and experiment all show that the under-actuated hand has good motion performance and grasping stability and can be used as an end effector for intelligent robots.
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Richter, Hanz, and Dan Simon. "Robust Tracking Control of a Prosthesis Test Robot." Journal of Dynamic Systems, Measurement, and Control 136, no. 3 (February 19, 2014). http://dx.doi.org/10.1115/1.4026342.
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This paper develops a passivity-based robust motion controller for a robot used in prosthetic leg performance studies. The mathematical model of the robot and passive prosthesis corresponds to a three degree-of-freedom, underactuated rigid manipulator. A form of robotic testing of prostheses involves tracking reference trajectories obtained from human gait studies. The robot presented in this paper emulates hip vertical displacement and thigh swing, and we consider a prosthesis with a passive knee for control development. The control objectives are to track commanded hip displacements and thigh angles accurately, even in the presence of parametric uncertainties and large disturbance forces arising from ground contact during the stance phase. We develop a passivity-based controller suitable for an underactuated system and compare it with a simple independent-joint sliding mode controller (IJ-SMC). This paper describes the mathematical model and nominal parameters, derives the passivity-based controller using Lyapunov techniques and reports success in real-time implementation of both controllers, whose advantages and drawbacks are compared.
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Guo, Zhao, Haoyong Yu, and Yue H. Yin. "Developing a Mobile Lower Limb Robotic Exoskeleton for Gait Rehabilitation." Journal of Medical Devices 8, no. 4 (August 19, 2014). http://dx.doi.org/10.1115/1.4026900.
Повний текст джерелаАнотація:
A new compact mobile lower limb robotic exoskeleton (MLLRE) has been developed for gait rehabilitation for neurologically impaired patients. This robotic exoskeleton is composed of two exoskeletal orthoses, an active body weight support (BWS) system attached to a motorized mobile base, allowing over-ground walking. The exoskeletal orthosis is optimized to implement the extension and flexion of human hip and knee joints in the sagittal plane. The motor-driven BWS system can actively unload human body weight and track the vertical displacement of the center of mass (COM). This system is compact and easy for therapist to help patient with different weight (up to 100 kg) and height (150–190 cm). Experiments were conducted to evaluate the performance of the robot with a healthy subject. The results show that MLLRE is a useful device for patient to achieve normal over-ground gait patterns.