The Development of an Atlas of the Kinematic Structures of Mechanisms

1984 ◽  
Vol 106 (4) ◽  
pp. 458-461 ◽  
Author(s):  
M. Mayourian ◽  
F. Freudenstein
Keyword(s):  
Wide Class ◽  
Mechanical Design ◽  
Three Dimensional ◽  
Kinematic Structure ◽  
Kinematic Chains ◽  
The Creation ◽  
Partial Automation

Based on the restrictions governing the admissible graphs of the kinematic chains of mechanisms, an atlas or listing of 35 graphs has been developed which defines the kinematic structure of a wide class of plane and three-dimensional mechanisms with up to six links. Such an atlas can serve as the basis for the creation of mechanisms in the conceptual stage of mechanical design and permits the partial automation of this process. The same procedure would also be applicable to the development of a similar atlas for mechanisms with more than six links and a greater variety of joints.

Determining the Presence of Rigid Sub-Frames in Kinematic Chains

1988 ◽  
Author(s):  
R. Bhasin ◽  
J. E. Beard ◽  
J. A. Brewer
Keyword(s):  
Kinematic Structure ◽  
Planar Mechanisms ◽  
Kinematic Chains ◽  
Automated Process ◽  
The Creation

Abstract Applying the concepts of the instant centers (IC’s) to the kinematic structure of a mechanism, a powerful new tool has been developed to detect the presence of a rigid sub-frame (RSF) in it’s configuration. The presence of an over-defined IC indicates the presence of an over-constrained sub-chain in the configuration. A ‘trace’ (T) of all the instant center, obtained at any stage of the analysis, is required to be maintained and compared, in order to develop a generalized method that applies only to the topology of the configuration. The compact, efficient and completely automated process of RSF checking allows a purely arbitrary approach to the creation of the kinematic structure of planar mechanisms of unlimited size.

The Creation of a Multi-Link Load Balancing Mechanism for Planetary Gearing: Part 1 — Type Synthesis

1992 ◽  
Author(s):  
Zhang Hong ◽  
Ting Li Yang ◽  
Jin Kui Chu ◽  
Wei-qing Cao
Keyword(s):  
Load Balancing ◽  
Arbitrary Number ◽  
Degrees Of Freedom ◽  
Kinematic Structure ◽  
Type Synthesis ◽  
Kinematic Chains ◽  
Topological Parameters ◽  
Topological Characteristics ◽  
The Creation

Abstract This series of papers design a multi-link load balancing mechanism for the Planetary Gearings with arbitrary number of planet gears. Based on the study of SGP load balancing mechanisms, this paper analyzed the relations between the function and kinematic structure of the multilink load balancing mechanism, and presented the topological characteristics and parameters of the kinematic chains suited for load balancing mechanism. Those topological parameters depend on the number of planet gears. In the type synthesis for the case of six planet gears, the kinematic chains with five degrees of freedom and eighteen links were enumerated according to the topological characteristics. The resulting mechanisms were 15 candidate multi-link load balancing mechanism.

Atlas Database of 2-DOF Kinematic Chains and Its Application to the Creative Design of Mechanisms

2011 ◽  
Author(s):  
Huafeng Ding ◽  
Andre´s Kecskeme´thy ◽  
Zhen Huang
Keyword(s):  
Graph Representation ◽  
Creative Design ◽  
The Novel ◽  
Kinematic Structure ◽  
Performance Indices ◽  
Topological Graphs ◽  
Systematic Method ◽  
Kinematic Chains ◽  
Challenging Issue ◽  
The Creation

Creation of novel kinematic structures of mechanisms has been a challenging issue which is usually conducted on experience and intuition. This paper, however, proposes a systematic method for the creative design of mechanism-based products and equipments on the basis of corresponding atlas database, and the creative design of an 11-link 2-DOF rode tractor is provided as an example. First, the transformation of the kinematic structure of mechanisms into graph representation is addressed. Then, the complete atlas database of 11-link 2-DOF kinematic chains is established by obtaining all the non-fractionated topological graphs through their contracted graphs and all the fractionated topological graphs through the combination of 1-DOF kinematic chains. Finally, based on the established atlas database, the creation design for the novel mechanisms of 11-link 2-DOF rode tractors is implemented, and all the nine novel feasible mechanisms (including the widely used one reported in literature) which satisfy the proposed performance indices are obtained.

Design of a Human Knee Reeducation Mechanism

2019 ◽  
Vol 11 (1) ◽  
pp. 42-53
Author(s):  
Allaoua Brahmia ◽  
Ridha Kelaiaia
Keyword(s):  
Lower Limb ◽  
Mechanical Design ◽  
Kinematic Chain ◽  
Lower Limbs ◽  
Kinematic Structure ◽  
Robotic Device ◽  
Human Knee ◽  
Kinematic Study ◽  
Rehabilitation Exercise ◽  
New Machine

Abstract To establish an exercise in open muscular chain rehabilitation (OMC), it is necessary to choose the type of kinematic chain of the mechanical / biomechanical system that constitutes the lower limbs in interaction with the robotic device. Indeed, it’s accepted in biomechanics that a rehabilitation exercise in OMC of the lower limb is performed with a fixed hip and a free foot. Based on these findings, a kinematic structure of a new machine, named Reeduc-Knee, is proposed, and a mechanical design is carried out. The contribution of this work is not limited to the mechanical design of the Reeduc-Knee system. Indeed, to define the minimum parameterizing defining the configuration of the device relative to an absolute reference, a geometric and kinematic study is presented.

CREATING AN OVER PRESSURE SENSOR METRAN-43 DI WITH THE KOMPAS-3D PROGRAM

2019 ◽  
Author(s):  
Roman Grishin ◽  
Dmitriy Nesnov
Keyword(s):  
Pressure Sensor ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Graphic Editor ◽  
The Creation ◽  
Photorealistic Images

This article describes the creation of a three-dimensional model of the overpressure sensor Metran-43 using the graphic editor COMPASS-v17, as well as photorealistic images in the program Artisan Rendering and created animation disassembly-Assembly of the device, allowing you to see the internal components of the product.

Design and operation of a tripod walking robot via dynamics simulation

Robotica ◽  
2010 ◽  
Vol 29 (5) ◽  
pp. 733-743 ◽  
Author(s):  
Conghui Liang ◽  
Hao Gu ◽  
Marco Ceccarelli ◽  
Giuseppe Carbone
Keyword(s):  
Mechanical Design ◽  
Low Cost ◽  
Three Dimensional ◽  
The Body ◽  
Dynamics Simulation ◽  
Walking Ability ◽  
Walking Robot ◽  
Three Dimensional Model ◽  
Software Environment ◽  
Leg Mechanisms

SUMMARYA mechanical design and dynamics walking simulation of a novel tripod walking robot are presented in this paper. The tripod walking robot consists of three 1-degree-of-freedom (DOF) Chebyshev–Pantograph leg mechanisms with linkage architecture. A balancing mechanism is mounted on the body of the tripod walking robot to adjust its center of gravity (COG) during walking for balancing purpose. A statically stable tripod walking gait is performed by synchronizing the motions of the three leg mechanisms and the balancing mechanism. A three-dimensional model has been elaborated in SolidWorks® engineering software environment for a characterization of a feasible mechanical design. Dynamics simulation has been carried out in the MSC.ADAMS® environment with the aim to characterize and to evaluate the dynamic walking performances of the proposed design with low-cost easy-operation features. Simulation results show that the proposed tripod walking robot with proper input torques, gives limited reaction forces at the linkage joints, and a practical feasible walking ability on a flatten ground.

Influence of Different Parametrizations on the Optimum Design of a High Pressure Turbine Blade Firtree

2016 ◽  
Author(s):  
Frank Wagner ◽  
Arnold Kühhorn ◽  
Thomas Weiss ◽  
Dierk Otto
Keyword(s):  
High Pressure ◽  
Turbine Blade ◽  
Complex Geometry ◽  
Three Dimensional ◽  
Parametric Models ◽  
Limiting Factor ◽  
High Pressure Turbine ◽  
The Creation ◽  
High Flexibility ◽  
Critical Regions

Today the design processes in the aero industry face many challenges. Apart from automation itself, a suitable parametric geometry setup plays a significant role in making workflows usable for optimization. At the same time there are tough requirements against the parametric model. For the lowest number of possible parameters, which should be intuitively ascertainable, a high flexibility has to be ensured. Within the parameter range an acceptable stability is necessary. Under these constraints the creation of such parametric models is a challenge, which should not be underestimated especially for a complex geometry. In this work different kinds of parametrization with different levels of complexity will be introduced and compared. Thereby several geometry elements will be used to handle the critical regions of the geometry. In the simplest case a combination of lines and arcs will be applied. These will be replaced by superior elements like a double arc construct or different formulations of b-splines. There will be an additional focus on the variation of spline degree and control points. To guarantee consistency a set of general parameters will be used next to the specific ones at the critical regions. The different parameter boundaries have a influence on the possible geometries and should therefore be tested separately before an optimization run. The analysis of the particular parametrization should be compared against the following points: • effort for the creation of the parametrization in theory • required time for the implementation in the CAD software • error-proneness/robustness of the parametrization • flexibility of the possible geometries • accuracy of the results • influence of the number of runs on the optimization • comparison of the best results Even though this assessment matrix is only valid for the considered case, it should show the general trend for the creation of these kinds of parametric models. This case takes a look at a firtree of a high pressure turbine blade, which is a scaled version of the first row from a small to medium aero engine. The failure of such a component can lead to a critical engine failure. For that reason, the modeling/meshing must be done very carefully and the contact between the blade and the disc is of crucial importance. It is possible to use scaling factors for three dimensional effects to reduce the problem to a two dimensional problem. Therefore the contact description is shortened from face-to-line to line-to-point. The main aim of the optimization is the minimization of the tension (notch stress) at the inner bends of the blade respectively at the outer bends of the disc. This has been the limiting factor in previous investigations. At this part of the geometry the biggest improvement are expected from a superior parametrization. Another important constraint in the optimization is the pressure contact (crushing stress) between blade and disc. Additionally the geometry is restricted with measurements of the lowest diameter at specific fillets to fulfill manufacturing requirements.

Entrepreneurs’ network evolution – the relevance of cognitive social capital

2015 ◽  
Vol 21 (2) ◽  
pp. 197-223 ◽  
Author(s):  
Sara Jonsson
Keyword(s):  
Social Capital ◽  
Private Information ◽  
Three Dimensional ◽  
Network Evolution ◽  
Fashion Industry ◽  
Cognitive Dimension ◽  
Content Type ◽  
Start Up ◽  
The Creation ◽  
Cognitive Social Capital

Purpose – The purpose of this paper is to investigate entrepreneurs’ network evolution in the start-up phase. Design/methodology/approach – Based on the case studies of six fashion start-up firms, this study uses a three-dimensional perspective on social capital (structural, relational, cognitive) to investigate entrepreneurs’ network evolution (i.e. initiation of new relationships) in the start-up phase so as to acquire resources and support for firms’ goals. The study focuses particularly on the understudied cognitive dimension of social capital. The fashion industry provides a relevant research setting because it is characterised by changes in demand, which generate opportunities for entrepreneurship. Findings – The findings show that the display of cognitive attributes is important for the creation of structural social capital (the establishment of new relationships). The findings also indicate that relationships initiated based on the cognitive dimension have a high probability of developing into embedded relationships, thereby becoming high in the relational dimension and providing access to private information containing referrals to other actors. Thus, these relationships also promote the continued development of the structural dimension. Originality/value – The findings imply that the entrepreneurs’ sets of cognitive attributes constitute an important asset in the creation of social capital. They also point to the importance of signalling these values to potential resource holders. Relationships initiated through the display of cognitive attributes can provide resources without requiring immediate economic remuneration.

scholarly journals Mechanical design and analysis of a gripper for non-cooperative target capture in space

2018 ◽  
Vol 10 (11) ◽  
pp. 168781401881064 ◽  
Author(s):  
Yili Zheng ◽  
Guannan Lei ◽  
Mingwei Zhang ◽  
Qianbo Che
Keyword(s):  
Mechanical Design ◽  
Three Dimensional ◽  
Simulation Software ◽  
Microgravity Environment ◽  
Three Dimensional Modeling ◽  
Target Capture ◽  
Model Collision ◽  
Rigid Connection ◽  
Aluminum Honeycomb ◽  
Ground Test

Space grippers are the key devices for accomplishing space non-cooperative target capture, which has a great significance for satellite services and space debris removal. This article proposes a novel mechanical gripper device for the capture of aluminum honeycomb panels of non-cooperative satellites. The gripper was modeled and assembled in the three-dimensional modeling platform UGNX. The model was imported into the simulation software ADAMS. ADAMS is capable of analyzing the kinematic feasibility of the gripper model. Collision and penetrating power analysis of the mechanical claws into an aluminum honeycomb plate were carried out in LS-DYNA. Through non-vertical piercing experiment, the maximum approaching angle tolerance is 10°. The established rigid connection can withstand a destructive force greater than 1000 N. A prototype of the mechanical gripper is built. A ground test was carried out with this prototype, in which a test-platform simulated the space microgravity environment. The results certified that the prototype could reach the target at a relative speed of 0.5 m/s and then quickly complete the grabbing motion and establish a rigid connection. The experiment shows that this mechanical gripper can accomplish the task of repeatedly capturing the surface of non-cooperative space satellites.

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