We study the transmission by two consecutive four-bar linkages with aligned frame links. The paper focusses on so-called "reducible" examples on the sphere where the 4-4-correspondance between the input angl...
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ISBN:
(纸本)9789048196883
We study the transmission by two consecutive four-bar linkages with aligned frame links. The paper focusses on so-called "reducible" examples on the sphere where the 4-4-correspondance between the input angle of the first four-bar and the output-angle of the second one splits. Also the question is discussed whether the components can equal the transmission of a single four-bar. A new family of reducible compositions is the spherical analogue of compositions involved at Burmester's focal mechanism.
The main direction in the use of solar energy conversion systems is to improve their efficiency by using dual axial tracking systems. The energy required for positioning the photovoltaic platforms is significant due t...
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ISBN:
(纸本)9789048196883
The main direction in the use of solar energy conversion systems is to improve their efficiency by using dual axial tracking systems. The energy required for positioning the photovoltaic platforms is significant due to the complexity of constructive solutions of dual axial tracking systems, which incorporate one driving source for each axis, and of the control systems. Thus, the interest in research, innovation, production and implementation of tracking systems increased. This paper presents a new tracking system for photovoltaic platforms actuated by a single rotary electric motor and the tracking method used in order to maximize the energy production.
We present the overall design of ANG, a new walking aid for the elderly. The objectives of this walking aid is to provide a low-cost and low-intrusivity aid for the elderly. ANG is based on a classical 4-wheel Rollato...
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ISBN:
(纸本)9789048196883
We present the overall design of ANG, a new walking aid for the elderly. The objectives of this walking aid is to provide a low-cost and low-intrusivity aid for the elderly. ANG is based on a classical 4-wheel Rollator, the two rear wheels being fixed while the two front are caster wheels. The rear wheels have been motorized, a bistable clutching mechanism allowing to clutch and unclutch the motors at will. ANG will provide fall prevention, navigation assistance, walking aid and may also be used as a rehabilitation tool. We present in this paper the mechanical design of ANG and some of the modes in which it may be used.
A very tempting and demanding application within the robotic field concerns the flight simulators. The definition of a flight simulator given by Collins Dictionary is: "A ground-training device that reproduces ex...
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ISBN:
(纸本)9789048196883
A very tempting and demanding application within the robotic field concerns the flight simulators. The definition of a flight simulator given by Collins Dictionary is: "A ground-training device that reproduces exactly the conditions experienced on the flight deck of an aircraft" [1]. The computer based flight simulators still take advantage of the human organ illusion. When the pilots turn any direction in flight simulator, the motion base supports the real bank to some extent. The dynamic analysis of the flight and the dynamic behavior of the simulator are crucial for identifying the differences between fly and simulation stress imposed on the structure and to determine the adequate generalized force value in the control. Therefore in this paper the generalized forces to induce a controlled acceleration in the cockpit frame are determined and the fitting diagrams are depicted.
This article presents a systematic investigation of the dynamic balancing of a single crank-double slider mechanism of which the coupler links have symmetric motion. From the equations of the linear momentum and angul...
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ISBN:
(纸本)9789048196883
This article presents a systematic investigation of the dynamic balancing of a single crank-double slider mechanism of which the coupler links have symmetric motion. From the equations of the linear momentum and angular momentum the force balance conditions and moment balance conditions are derived. Both general and specific force balanced and moment balanced configurations are obtained step by step, are put in perspective, and are illustrated to gain a systematic overview of the balancing possibilities of this type of mechanism. Also the addition of a counter-rotating element is considered.
During technical diagnosis it is often needed to determine object dimensions remotely by results of some optical data. The digital photography is the perspective method for non-invasive measurement of industrial machi...
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ISBN:
(纸本)9789048196883
During technical diagnosis it is often needed to determine object dimensions remotely by results of some optical data. The digital photography is the perspective method for non-invasive measurement of industrial machinery objects. But the peculiarities of equipment and digital photo process bring some important restrictions and constraints to measurement process. We tried to explain the peculiarities and unite the advantages of different methods of photographical non-invasive measurement for easy flat cam mechanism to recover the cam profile and estimate precision of measurements.
In this paper a 2-DOF parallel mechanism used for orientation is presented. This mechanism could be applied for orientation of the TV satellite antennas, sun trackers etc. Based on the kinematic scheme of the mechanis...
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ISBN:
(纸本)9789048196883
In this paper a 2-DOF parallel mechanism used for orientation is presented. This mechanism could be applied for orientation of the TV satellite antennas, sun trackers etc. Based on the kinematic scheme of the mechanism, the algorithms for the kinematic models are solved, the workspace and singularities are described and analyzed. An optimal design of the mechanism is performed. Finally, the design of the mechanism is also described.
This paper focuses on the study of static and dynamic stiffness (normal modes and natural frequencies) by a method which enables to evaluate the vibration behaviour of low mobility parallel manipulators, i.e., less th...
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ISBN:
(纸本)9789048196883
This paper focuses on the study of static and dynamic stiffness (normal modes and natural frequencies) by a method which enables to evaluate the vibration behaviour of low mobility parallel manipulators, i.e., less than 6 degrees-of-freedom. The purpose of this study is to improve the structural behaviour of this type of manipulators under the effect of static and dynamic external loads. As a starting point, we use a previously developed methodology for static rigidity obtaining for the aforementioned manipulators characteristics, using as case study DAEDALUS I parallel robot. The method is applied to a simplified model to analyze the evolution of the static stiffness, the frequencies and normal modes in the whole workspace. The method involves the use of one analytical model, other numerical, based on finite elements and a comparison with an experimental campaign on a prototype. From this study, the results of the natural frequencies trends of the manipulator are represented in tridimensional maps.
The paper presents an analytical and computer-aided procedure for the prediction of the dynamic transmission error of helical gear pairs by using variable mesh stiffness. An improved model of the mesh stiffness is dev...
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ISBN:
(纸本)9789048196883
The paper presents an analytical and computer-aided procedure for the prediction of the dynamic transmission error of helical gear pairs by using variable mesh stiffness. An improved model of the mesh stiffness is developed by including specific meshing characteristics of helical gear pairs. The effects of addendum modification coefficients and face-width of gear pairs on the time varying mesh stiffness are investigated. A comparative study has been performed to analyze the effect of the total contact ratio and its components on the dynamic transmission error of helical gear pairs.
Considering the latest results in robotic assisted surgery it is obvious that robots became useful tools in minimally invasive surgery (MIS), providing benefits such as reduction in hand tremor, the possibility of rea...
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ISBN:
(纸本)9789048196883
Considering the latest results in robotic assisted surgery it is obvious that robots became useful tools in minimally invasive surgery (MIS), providing benefits such as reduction in hand tremor, the possibility of reaching positions and places that could prove difficulty in reaching using classical instruments, navigation and workspace scaling. In this paper the inverse dynamic model for a parallel robot conceived for MIS using virtual work principle is presented. The results of the analytic dynamic model have been validated by means of a Multi-Body simulation.
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