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Auswahl der wissenschaftlichen Literatur zum Thema „Mobile vertical turning center“
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Zeitschriftenartikel zum Thema "Mobile vertical turning center"
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Суббота, Анатолий Максимович, und Елена Юрьевна Костерная. „КІНЕМАТИКА РУХУ РОБОТА З ТРЬОМА РОЛИКОНЕСУЧИМИ КОЛЕСАМИ“. Open Information and Computer Integrated Technologies, Nr. 82 (19.12.2018): 60–71. http://dx.doi.org/10.32620/oikit.2018.82.05.
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The article introduction provides an overview of the historical development of mechatronic devices, from ancient times to the present. It is emphasized that the development of modern robotics in relation to work in aggressive environments is a very urgent task. Especially important is the creation of autonomous functioning robots to work in high radiation areas, chemically contaminated areas, demining, fire extinguishing, etc. Then this article presents material on the physics of a mechanical system motion, which is a mobile platform with three roller-bearing wheels, or so-called omni-wheels. This question is revealed on the basis of the derivation of the kinematic equations for the platform motion, based on transformation matrices, which allow to obtain the total dependences of the projections of the linear velocities of the roller-bearing wheels on the axis of the fixed (base) coordinate system. It is indicated that the transition to movement from the position at to the position at can be carried out in two ways. In the first method, the robot turns around on the center of mass by creating a torque about the vertical axis of the robot, followed by movement parallel to the axis . In the second method, by creating such a state of the wheels, i.e. the magnitude of the linear velocity and its direction, which will ensure a linear movement of the center of mass of the robot in a given direction without first rotating the body about the vertical axis. It is noted that the first method in relation to the second has both advantages and disadvantages. The advantages include ease of management and the ability to rigidly fix the camera of the review on the platform body. However, this method is more energy consuming and requires additional time for the implementation of the camera turn to a given direction. The second method is not deprived of these drawbacks, and the overview camera may have a turning mechanism, which ensures its independent functioning from the platform position control system. Given this, the kinematics of the movement of the platform according to the second method are considered. As an example, it is shown that by jointly solving the obtained kinematic equations, for example, for selected mutually perpendicular directions of the platform mass center movement, characterized by angles or , it is easy to explain the physics of platform moving in a given direction from any starting position without first turning to a given direction.
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Strauss, R., S. Schuster und K. G. Götz. „Processing of artificial visual feedback in the walking fruit fly Drosophila melanogaster.“ Journal of Experimental Biology 200, Nr. 9 (01.05.1997): 1281–96. http://dx.doi.org/10.1242/jeb.200.9.1281.
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A computerized 360 degrees panorama allowed us to suppress most of the locomotion-induced visual feedback of a freely walking fly without neutralizing its mechanosensory system ('virtual open-loop' conditions). This novel paradigm achieves control over the fly's visual input by continuously evaluating its actual position and orientation. In experiments with natural visual feedback (closed-loop conditions), the optomotor turning induced by horizontal pattern motion in freely walking Drosophila melanogaster increased with the contrast and brightness of the stimulus. Conspicuously striped patterns were followed with variable speed but often without significant overall slippage. Using standard open-loop conditions in stationary walking flies and virtual open-loop or closed-loop conditions in freely walking flies, we compared horizontal turning induced by either horizontal or vertical motion of appropriately oriented rhombic figures. We found (i) that horizontal displacements and the horizontal-motion illusion induced by vertical displacements of the oblique edges of the rhombic figures elicited equivalent open-loop turning responses; (ii) that locomotion-induced visual feedback from the vertical edges of the rhombic figures in a stationary horizontal position diminished the closed-loop turning elicited by vertical displacements to only one-fifth of the response to horizontal displacements; and (iii) that virtual open-loop responses of mobile flies and open-loop responses of immobilized flies were equivalent in spite of delays of up to 0.1 s in the generation of the virtual stimulus. Horizontal compensatory turning upon vertical displacements of oblique edges is quantitatively consistent with the direction-selective summation of signals from an array of elementary motion detectors for the horizontal stimulus components within their narrow receptive fields. A compensation of the aperture-induced ambiguity can be excluded under these conditions. However, locomotion-induced visual feedback greatly diminished the horizontal-motion illusion in a freely walking fly. The illusion was used to assay the quality of open-loop simulation in the new paradigm.
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Liu, De Ping, Jie Li, Yu Feng Su und Yu Ping Wang. „Temperature Field Modeling and Thermal Deformation Analysis of Turning and Milling Machining Center“. Advanced Materials Research 189-193 (Februar 2011): 1986–90. http://dx.doi.org/10.4028/www.scientific.net/amr.189-193.1986.
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Taking the high-speed CX series vertical milling compound machining center of CX8075 produced by Anyang Xinsheng Machine Tool Co., Ltd. as example, the machine three-dimensional simplified model is established, the source of the heat and the distribution of the important hot-points are analyzed, the machine temperature field distribution is derived which lays a foundation for the thermal error compensation. Taking into account the moving part-saddle of the machining center, its mathematic model is obtained, the important hot-points are studied, the thermodynamic parameters are determined. Based on ANSYS finite element method, the steady-state temperature field and the thermal deformation of saddle are presented, the optimal design of high-speed and high-accuracy machine tool is doned and its thermal deformation analysis is realized.
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Diaconu, E. M. „Smart Lighting System“. Scientific Bulletin of Electrical Engineering Faculty 21, Nr. 1 (01.04.2021): 6–9. http://dx.doi.org/10.2478/sbeef-2021-0002.
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Abstract This paper proposes a system that allows the control of the lights in a house, building/edifice. The system can be controlled by an application that is made in MIT App Inventor for mobile devices that use Android OS(operating system). The application sends data, via Bluetooth, to the control center, the control center powers on the selected light by turning it on and setting its intensity based on the user preferences. The control center is made from an Arduino Nano programing board, the signal used for powering the lights and setting the brightness is a PWM (Pulse Width Modulation) signal. The system contains the Arduino Nano board, Bluetooth HC-05 module for communication with the mobile application and four LED’s that are used to simulate the lights.
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Zhao, Wei, Han Xu Sun, Qing Xuan Jia, Yan Heng Zhang und Tao Yu. „Mechanical Analysis of the Jumping Motion of a Spherical Robot“. Advanced Materials Research 591-593 (November 2012): 1457–60. http://dx.doi.org/10.4028/www.scientific.net/amr.591-593.1457.
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The obstacle surmounting capability of traditional spherical mobile robot is limited, especially when the spherical mobile robot comes across vertical barrier. In this paper we design a new kind of spherical mobile robot with two-mass-one-spring mechanism based on tradition spherical mobile robot. This spherical robot could not only move agility and move with the zero turning radius like traditional spherical mobile robot but also jump in three-dimensional space. In this paper we build the mathematical model of robot jumping with friction. Numeric simulations are carried out for the model using Matlab and ADAMS, we get the similar curve. These simulation results verify the validity of the mechanics model. At last we design an experimental facility, verify the model of robot jumping by experiment. Our work will be the base of model machine designing.
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Jindrich, D. L., und R. J. Full. „Many-legged maneuverability: dynamics of turning in hexapods“. Journal of Experimental Biology 202, Nr. 12 (15.06.1999): 1603–23. http://dx.doi.org/10.1242/jeb.202.12.1603.
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Remarkable similarities in the vertical plane of forward motion exist among diverse legged runners. The effect of differences in posture may be reflected instead in maneuverability occurring in the horizontal plane. The maneuver we selected was turning during rapid running by the cockroach Blaberus discoidalis, a sprawled-postured arthropod. Executing a turn successfully involves at least two requirements. The animal's mean heading (the direction of the mean velocity vector of the center of mass) must be deflected, and the animal's body must rotate to keep the body axis aligned with the heading. We used two-dimensional kinematics to estimate net forces and rotational torques, and a photoelastic technique to estimate single-leg ground-reaction forces during turning. Stride frequencies and duty factors did not differ among legs during turning. The inside legs ended their steps closer to the body than during straight-ahead running, suggesting that they contributed to turning the body. However, the inside legs did not contribute forces or torques to turning the body, but actively pushed against the turn. Legs farther from the center of rotation on the outside of the turn contributed the majority of force and torque impulse which caused the body to turn. The dynamics of turning could not be predicted from kinematic measurements alone. To interpret the single-leg forces observed during turning, we have developed a general model that relates leg force production and leg position to turning performance. The model predicts that all legs could turn the body. Front legs can contribute most effectively to turning by producing forces nearly perpendicular to the heading, whereas middle and hind legs must produce additional force parallel to the heading. The force production necessary to turn required only minor alterations in the force hexapods generate during dynamically stable, straight-ahead locomotion. A consideration of maneuverability in the horizontal plane revealed that a sprawled-postured, hexapodal body design may provide exceptional performance with simplified control.
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Sozzi, Stefania, und Marco Schieppati. „Stepping in Place While Voluntarily Turning Around Produces a Long-Lasting Posteffect Consisting in Inadvertent Turning While Stepping Eyes Closed“. Neural Plasticity 2016 (2016): 1–14. http://dx.doi.org/10.1155/2016/7123609.
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Training subjects to step in place on a rotating platform while maintaining a fixed body orientation in space produces a posteffect consisting in inadvertent turning around while stepping in place eyes closed (podokinetic after-rotation, PKAR). We tested the hypothesis that voluntary turning around while stepping in place also produces a posteffect similar to PKAR. Sixteen subjects performed 12 min of voluntary turning while stepping around their vertical axis eyes closed and 12 min of stepping in place eyes open on the center of a platform rotating at 60°/s (pretests). Then, subjects continued stepping in place eyes closed for at least 10 min (posteffect). We recorded the positions of markers fixed to head, shoulder, and feet. The posteffect of voluntary turning shared all features of PKAR. Time decay of angular velocity, stepping cadence, head acceleration, and ratio of angular velocity after to angular velocity before were similar between both protocols. Both postrotations took place inadvertently. The posteffects are possibly dependent on the repeated voluntary contraction of leg and foot intrarotating pelvic muscles that rotate the trunk over the stance foot, a synergy common to both protocols. We propose that stepping in place and voluntary turning can be a scheme ancillary to the rotating platform for training body segment coordination in patients with impairment of turning synergies of various origin.
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Aragón-Martínez, Aldo, Manuel Arias-Montiel, Esther Lugo-González und Ricardo Tapia-Herrera. „Two-finger exoskeleton with force feedback for a mobile robot teleoperation“. International Journal of Advanced Robotic Systems 17, Nr. 1 (01.01.2020): 172988141989564. http://dx.doi.org/10.1177/1729881419895648.
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In this work, the design, manufacturing, instrumentation, and application of a two-finger exoskeleton with force feedback are presented. The exoskeleton is based on remote center of motion mechanisms in order to avoid mechanical interference with the user’s fingers and is manufactured by three-dimensional printing. The developed exoskeleton is applied in a mobile robot teleoperation by mapping the finger movements in forward and turning commands for the robot. The presence of obstacles detected by the robot is sensed by the user by means of a feedback force. The problem of simultaneously communicating a data acquisition card and the robot hardware by MATLAB ® Simulink® was solved by using an external Wi-Fi module. The result is a lightweight exoskeleton which is able to communicate bidirectionally with a mobile robot by a personal computer for teleoperation tasks. The success of the system implementation is proven by a set of experiments presented in the final part of the article.
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Delgado, Raimarius, und Byoung Choi. „Network-Oriented Real-Time Embedded System Considering Synchronous Joint Space Motion for an Omnidirectional Mobile Robot“. Electronics 8, Nr. 3 (13.03.2019): 317. http://dx.doi.org/10.3390/electronics8030317.
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This paper proposes a real-time embedded system for joint space control of omnidirectional mobile robots. Actuators driving an omnidirectional mobile robot are connected in a line topology which requires synchronization to move simultaneously in translation and rotation. We employ EtherCAT, a real-time Ethernet network, to control servo controllers for the mobile robot. The first part of this study focuses on the design of a low-cost embedded system utilizing an open-source EtherCAT master. Although satisfying real-time constraints is critical, a desired trajectory on the center of the mobile robot should be decomposed into the joint space to drive the servo controllers. For the center of the robot, a convolution-based path planner and a corresponding joint space control algorithm are presented considering its physical limits. To avoid obstacles that introduce geometric constraints on the curved path, a trajectory generation algorithm considering high curvature turning points is adapted for an omnidirectional mobile robot. Tracking a high curvature path increases mathematical complexity, which requires precise synchronization between the actuators of the mobile robot. An improvement of the distributed clock—the synchronization mechanism of EtherCAT for slaves—is presented and applied to the joint controllers of the mobile robot. The local time of the EtherCAT master is dynamically adjusted according to the drift of the reference slave, which minimizes the synchronization error between each joint. Experiments are conducted on our own developed four-wheeled omnidirectional mobile robot. The experiment results confirm that the proposed system is very effective in real-time control applications for precise motion control of the robot even for tracking high curvature paths.
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Horák, Marcel, František Novotný, Michal Starý und Josef Černohorský. „New Generation of Mobile Platform of Service Robot for Motion along Vertical Walls“. Applied Mechanics and Materials 613 (August 2014): 126–31. http://dx.doi.org/10.4028/www.scientific.net/amm.613.126.
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The paper sums up results achieved during in the last few years of the development and research of service robots aiming their use for service applications on vertically oriented walls with predominantly smooth contact surfaces having minimal altitude unevenesses within the range ± 5 mm. Two robot generations are described step by step, and both of them use the same mechanical principle of the patented system of motion. The system uses the intermittent motion when positions of the robot legs and body alternate cyclically, and the appropriate gripping force of a holding-down system is realized by vacuum. As compared with the first version, the current one allows legs to move independent in part. In that way it is possible to compensate better variations of parallelism between a contact plane of the robot holding-down system and a vertical wall. Moreover, the robot is provided with a rotary unit making possible a rotation on the axis going through the robot center and being perpendicular to the contact plane, which guarantees a change in the robot orientation in the plane. As for drives, very compact rotary actuating mechanisms (servo drives) are used, having a high ratio of power parameters in relation to weight and dimensions, combined with a control based on an industrial PC.
Dissertationen zum Thema "Mobile vertical turning center"
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Pomikálek, Adam. „Mobilní soustružnické obráběcí centrum se svislou osou obrobku“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-443775.
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The subject of this diploma thesis is the conceptual design of a mobile lathe centre with a vertical workpiece axis. First, a search in the field of mobile lathes, stationary lathes and methods of their transport is performed. Then, from the described transport machine options, the most suitable transport variant is selected, thanks to which variants of the mobile machine solution are created. Subsequently, the design of the winning variant is fully adapted to the method of transport using containers. Emphasis is placed on simple construction, maximum use of the transport packaging in the machine frame and easy assembly of the machine customer. For these reasons, the machine frame must consist of two containers. Finally, the assembly and adjustment of the machine tool are solved in combination with the verification of the functionality of the proposed concept.
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Krenželok, Andrzej. „Podavač palet svislého obráběcího centra“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-229185.
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The subject of this thesis is the proposal of constructional solution for pallet changer of the vertical machining center. This pallet changer serves for the manipulation with technological pallets between dilatory places of the machining center and charger of pallets. Thanks to this changer the machines share one workpieces´ base. Main accent is not put only on the function but also on the low price of this solution.
Buchteile zum Thema "Mobile vertical turning center"
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Li, Jialin, Yidu Zhang, Qiong Wu und Hanjun Gao. „The Dynamic Characteristics Analysis of the Vertical Milling-Turning Machining Center“. In Lecture Notes in Electrical Engineering, 1143–52. Singapore: Springer Singapore, 2016. http://dx.doi.org/10.1007/978-981-10-2875-5_92.
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Gai, Yuxian, Huiying Liu und Shen Dong. „Vibration Control System for a Sub-Micro Ultra-Precision Turning Machine“. In 2007 First International Conference on Integration and Commercialization of Micro and Nanosystems. ASMEDC, 2007. http://dx.doi.org/10.1115/mnc2007-21040.
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For a sub-micro ultra-precision turning machine using airsprings as vibration isolation elements, a 5 FOG mathematical model is established, activation f acted on the machine bed is as the input, the output are vertical displacement y1, oscillating φ1, ψ1 around the horizontal axle x and z of the machine bed, vertical displacement y2 of the main spindle box, and vertical displacement y3 of the slider. The equations for vibration system of 5 FOG are solved. The results indicate, when actuation force f ≠ 0, the outputs of all 5 FOG are increasing with the increasing of f. when activation f = 0, the outputs of all 5 FOG tend to zero. Assuming f include the vibration of machine base and an external force, when external force is equal to that of the vibration of machine base, then f = 0. The vibration of 5 FOG can be effectively isolated, so electromagnetic actuators as an external force, also as active vibration isolation elements can be used in the isolation system. Three electro-magnetic actuators arranging as triangle act as an external force, the quantity is equal to that of the base vibration, and the phase reverse. In fact ultra-precision turning machine is a complicated mechanism system and in the machining process, the headstock and horizontal-slider are in the movement, that is to say, the center of mass of the ultra-precision machine is changeable. Impossible is f = 0 for a practical control. In order to get a effective vibration isolation, fuzzy controller is used. The synthetic experiments have been done for the 5 FOG vibration system of the ultra-precision turning machine. The result of three actuations experiment that has been done in y direction indicates that the vibration of y direction, and oscillating φ1, ψ2 around the horizontal axle x and z of the machine bed are to be controlled. A work-piece of aluminum alloy has been machined using the sub-micro ultra-precision turning machine with the active vibration isolation elements, and without the active vibration isolation elements, AFM microscope graphs show the surface roughness of the work-piece machined by the former better as by the latter.
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O’Toole, Aaron T., und Stephen L. Canfield. „Developing a Kinematic Estimation Model for a Climbing Mobile Robotic Welding System“. In ASME 2010 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/detc2010-28878.
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Skid steer tracked-based robots are popular due to their mechanical simplicity, zero-turning radius and greater traction. This architecture also has several advantages when employed by mobile platforms designed to climb and navigate ferrous surfaces, such as increased magnet density and low profile (center of gravity). However, creating a kinematic model for localization and motion control of this architecture is complicated due to the fact that tracks necessarily slip and do not roll. Such a model could be based on a heuristic representation, an experimentally-based characterization or a probabilistic form. This paper will extend an experimentally-based kinematic equivalence model to a climbing, track-based robot platform. The model will be adapted to account for the unique mobility characteristics associated with climbing. The accuracy of the model will be evaluated in several representative tasks. Application of this model to a climbing mobile robotic welding system (MRWS) is presented.
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Williams, Kenneth A., Christina N. Yarborough und James E. Smith. „Structural Design Considerations of a Circulation Controlled Vertical Axis Wind Turbine“. In ASME 2009 3rd International Conference on Energy Sustainability collocated with the Heat Transfer and InterPACK09 Conferences. ASMEDC, 2009. http://dx.doi.org/10.1115/es2009-90078.
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In the latter half of the twentieth century extensive research had been performed to improve the efficiency and operational life of Vertical axis wind turbines (VAWTs) in order to make them competitive with the more common horizontal axis wind turbines (HAWTs). Due to the completely random wind conditions and a continuously changing angle of attack of the rotating airfoil, fatigue of the system components was a major contributor to the short operational life of these traditional VAWTs. The fluctuating aerodynamic forces generated by the airfoil during rotation subject the support shaft to a substantial amount of torque ripple. In addition to the varying torque produced by the turbine, the centripetal forces generated by the airfoil’s rotation proved to be extremely large and create problems with deflection and fatigue in the airfoil’s internal support structure and especially at the attachment point of the airfoil to the support arm. One method for improving the efficiency of an aerodynamic system is to reduce the weight of the system. However, because of the forces generated during turbine operation, this proved to be a nontrivial task. West Virginia University’s (WVU) Center for Industrial Research Applications (CIRA) is exploring the implementation of circulation control on a vertical axis wind turbine to increase the lift to drag ratio of the turbine’s airfoils in order to produce a greater turning force and improve the efficiency of the system. While the common structural challenges of vertical axis wind turbines still apply, those implementing circulation control introduce additional design hurdles which must be overcome. These additional design problems concern mainly with the airfoil construction and support shaft in that they must be capable of accommodating the circulation control system components. This paper introduces the geometrical design constraints imposed on a vertical axis wind turbine through the operational requirements and serviceability of the circulation control system in addition to the traditional aerodynamic and centripetal forces generated and how they are resolved onto the individual turbine components.
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Kumar, Padmanabhan, Tristan W. Hill, D. Andrew Bryant und Stephen L. Canfield. „Modeling and Design of a Linkage-Based Suspension for Tracked-Type Climbing Mobile Robotic Systems“. In ASME 2011 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/detc2011-48555.
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Skid steer tracked-based robots are popular due to their mechanical simplicity, zero-turning radius and greater traction. This architecture also has several advantages when employed by mobile platforms designed to climb and navigate ferrous surfaces, such as increased magnet density and low profile (center of gravity). However, the suspension design plays a critical and unique role in track-based climbing systems relative to their traditional counterparts. In particular, the suspension must both accommodate irregularities in the climbing surface as well as transfer forces to the robot chassis required to maintain equilibrium. Furthermore, when properly designed, the suspension will distribute the climbing forces in a prescribed manner over the tractive elements. This paper will present a model for analysis and design of a linkage-type suspension for track-based climbing robot systems. The paper will further propose a set of requirements termed “conditions of climbing” that must be met to ensure stable (no falling) climbing for a given robot design over a range of climbing surface geometries. A recursive strategy is proposed to implement these conditions and yield a factor of safety in the current climbing state. This model will be compared through empirical testing with several prototype climbing robot systems. A method will also be demonstrated to use this model in the design of a preferred suspension system.
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Ramanathan, Vikram, Andy Zelenak und Mitch Pryor. „Instantaneous Center of Rotation-Based Master-Slave Kinematic Modeling and Control“. In ASME 2019 Dynamic Systems and Control Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/dscc2019-9123.
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Abstract This article presents a novel kinematic model and controller design for a mobile robot with four Centered Orientable Conventional (COC) wheels. When compared to non-conventional wheels, COC wheels perform better over rough terrain, are not subject to vertical chatter and offer better braking capability. However, COC wheels are pseudo-omnidirectional and subject to nonholonomic constraints. Several established modeling and control techniques define and control the Instantaneous Center of Rotation (ICR); however, this method involves singular configurations that are not trivial to eliminate. The proposed method uses a novel ICR-based kinematic model to avoid these singularities, and an ICR-based nonlinear controller for one ‘master’ wheel. The other ‘slave’ wheels simply track the resulting kinematic relationships between the ‘master’ wheel and the ICR. Thus, the nonlinear control problem is reduced from 12th to 3rd-order, becoming much more tractable. Simulations with a feedback linearization controller verify the approach.
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Mandala, Mahender, Jonathan Pearlman, Olof Berner, Padmaja Kankipati und Rory Cooper. „Design and Development of the Single Motor Propelled Drive-Train (SiMPl-D)“. In ASME 2013 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/detc2013-13225.
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Mobile robotic devices and other mobility related drive systems are often relegated to one of the two classes of devices available today: wheeled devices or tracked devices. Wheeled systems are more energy efficient and reliable than tracked systems, but existing designs have drawbacks related to rough-terrain driving and maneuvering in tight spaces. In this paper we describe the design and development of a drive system named the Single Motor Propelled Drive-train (SiMPl-D), which can potentially improve maneuvering over rough terrain and in tight spaces compared to traditional wheeled robots. SiMPl-D has two prominent features: a single drive motor, which provides both propulsion and turning, and is suspended under the center of mass of the device on a swingarm, which is linked through a suspension system to caster wheels; and it has reconfigurable drive wheel, which changes the turning radius of the device. Due to these features, SiMPl-D can traverse a wide range of terrain while remaining energy and cost efficient. SiMPl-D has been successfully used in an indoor/outdoor low-cost personal mobility device and is currently being implemented in other robotic mobility applications.
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Kushnir, E. „Effect of Machine Tool Structure Dynamic on Machine Cutting Performances“. In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-79769.
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Quality of machine tool structure is defined by it static and dynamic compliance. The effect of static stiffness at part shape and machine productivity is one of the reasons that structure static stiffness is used as a main criterion in machine design. The machine dynamic stiffness or compliance directly effect roundness (for example, profile of cross section in turning), surface finish, and indirectly tool life and life of machine components. These effects are defined by structure resistance to transmit vibration in cutting zone or other points of interest in machine tool structure. Dynamic compliance defines accuracy of machining, because it stipulates how machine response to any exciting force, occurring inside and outside machine structure. Dynamic compliance limits the productivity of cutting because it defines maximum depth of cut that may be achieved at a machine in particular set up. The goal of dynamic analysis is to find parameters of the structure that have dominant effect at it dynamic compliance and improve structure based at this information. Usually dynamic analyses required more complicated methodological approach because of coupling between different modes of vibration. The methodology of dynamic analysis of machine tool is illustrated by analysis of mobile spindle module and turning center. The obtained theoretical results are compared with actual testing data.
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Ferris, Lauren, Linda Denney und Lorin Maletsky. „A Performance Test to Assess Strategies to Transfer Weight During Knee Flexion and Extension With Rotation for Individuals With a Total Knee Replacement“. In ASME 2012 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/sbc2012-80440.
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Stability has been defined as the ability to transfer the vertical projection of the center of gravity to the supporting base and keep the knee as still as possible1. The transfer of weight (load) to a single limb while still in double-stance is functional and simulates every day activities such as loading the dishwasher, transferring laundry, or reaching to pick up an item. Adding rotation in a transverse plane to this weight shift challenges knee stability, especially those with a total knee replacement (TKR). A clinical sign of laxity in mid-flexion indicates a risk for developing symptomatic instability; a common reason for TKR revision2. Laxity is usually measured clinically in a single plane (anterior-posterior) and functionally with added turning maneuvers. Single-leg weight acceptance has been analyzed during athletic activities such as hopping, landing with cutting as well as in the older population with stair ascent and descent3–5. Although single-leg performance tests are a good indicator of knee stability, weight shift during double-stance may be more functional for individuals with a TKR. A functional double-stance test should include both flexion/extension with rotation and loading. Our study utilizes a novel approach (Target Touch Task) in order to facilitate transfer of load to one extremity during squatting or extending while still in double-stance. The objective of this study was to identify strategies utilized by individuals with a TKR while in double-stance transferring load during rotational activities.
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Haughn, Kevin P. T., Lawren L. Gamble und Daniel J. Inman. „Horizontal Planform Morphing Tail for an Avian Inspired UAV Using Shape Memory Alloys“. In ASME 2018 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/smasis2018-7986.
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Unlike most modern aircraft, which have a vertical tail component, birds fly utilizing a purely horizontal tail. In order to provide control normally associated with a vertical rudder, bird’s tails are incredibly mobile, twisting, pitching, and widening to perform necessary aerial maneuvers. This research primarily focuses on the development and testing of a mechanical planform morphing horizontal control surface, aiming to emulate the tail-spread control action of birds. This horizontal control surface is implemented on a small, tailless, avian inspired unmanned aerial vehicle (UAV). In this research, the horizontal control surface, made entirely of 3D printed material, comprises a rigid overlapping top layer held together by a soft and elastic honeycomb bottom layer, allowing for shape morphing without compromising structural integrity required to withstand aerodynamic forces. Using the relatively large strain and strength offered by shape memory alloy (SMA) springs, the 3D printed horizontal tail undergoes a notable and consistent geometric change. To quantify the system’s performance, the tail width and center was measured while actuating the springs through a range of frequencies from 0.01 to 10 Hz. Preliminary experiments were conducted in a 1ft. × 1 ft. open loop wind tunnel at the University of Michigan at wind speeds of 5, 10 and 15 m/s to quantify the effects of aerodynamic loading on actuation magnitude and speed.
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Musunuri, Naga A., Pushpendra Singh und Ian S. Fischer. „PIV Measurement of the Transient Fluid Flow due to the Adsorption of Particles“. In ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fedsm2014-21854.
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The particle image velocimetry (PIV) technique is used to study the physics of particle adsorption and the spontaneous dispersion of powders that occurs when particles come in contact with a fluid-liquid interface. The dispersion can occur so quickly that it appears explosive, especially for small particles on the surface of mobile liquids like water. The measurements show that the adsorption of a spherical particle causes an axisymmetric streaming flow about the vertical line passing through the center of the particle. The fluid directly below the particle rises upward, and near the surface, it moves away from the particle. The flow, which develops within a fraction of second after the adsorption of the particle, persists for several seconds. The flow strength, and the volume over which it extends, decrease with decreasing particle size. The streaming flow induced by the adsorption of two or more particles is a combination of the flows which they induce individually.