Design and demonstration of insect mimicking foldable artificial wing using four-bar linkage systems

2014 ◽  
Vol 11 (3) ◽  
pp. 449-458 ◽  
Author(s):  
Quang-Tri Truong ◽  
Byoma Wing Argyoganendro ◽  
Hoon Cheol Park
Author(s):  
J E Baker

A prompt contributor to discussion of Bricard's marvellous revelation of deformable octahedra was Bennett, who related the findings to planar, spherical, and skew assemblages, the last-named consisting of a network formed by his own remarkable four-bar linkage. Since that time, many investigations have been directed to each of Bricard's and Bennett's linkages, but rarely to the notion of a connection between them. The present article draws upon recent discoveries of six-bar linkages synthesized from Bennett isograms to establish a surprising integration of three different families of six-bars and the skew network engendered by the doubly collapsible octahedron.


1995 ◽  
Vol 117 (4) ◽  
pp. 597-600 ◽  
Author(s):  
K. C. Gupta ◽  
R. Ma

The necessary and sufficient conditions for the full input rotatability in a spherical four-bar linkage are proved. The direct criterion is: for all twist angles α in the range [0, π], the excess (deficit) of the sum of the frame and input twist angles over (from) π should, in absolute value, be greater than that for the coupler and follower twist angles; the difference between the follower and input twist angles, in absolute value, should be greater than that for the coupler and follower twist angles. Application of the direct criterion to full rotatability of other links are discussed and some variations in the form of the criterion are developed.


Author(s):  
P. Pracht ◽  
P. Minotti ◽  
M. Dahan

Abstract Linkages are inherently light, inexpensive, strong, adaptable to high speeds and have little friction. Moreover the class of functions suitable for linkage representation is large. For all these reasons numerous recent works deal with the problem of design mechanisms for robotic applications, but very often in terms of components such as gripper, transmission, balancing. We investigate a new application for linkages, using them to design industrial manipulator. The selected mechanism for this application is a four bar linkage with an adjustable lengh for exact path generation. This adjustment is performed by a track or cam which is substituted to a bar. By this mean, we define a cam-modulated linkage which possess superior accuracy potential and is capable of accomodating of industrial design restrictions. Such a kinematic chain is free from structural error for path generation and the presence of the track introduces the flexibility and versality in the usefull four bar chain. The synthesis technique of cam modulated linkage utilizes loop closure equations, envelop theory to find the centerline and the profile of the track. These techniques provide a systematic approach to the design of mechanism for path generation when extreme accuracy is required. In order to complete an contribution, we take in consideration the static balancing of the synthesized manipulator. To achieve static mass balancing we use the potential energy storage capabilities of linear springs, and integrated it with the non-linear motion of mechanism to provide an exact value of the desired counter loading functions. Examples are worked to demonstrate applications of these procedures and to illustrate the industrial potential of spring balancing and cam-modulated linkage.


2021 ◽  
pp. 1-20
Author(s):  
Gui Shun

Abstract Exploring the locomotion of creatures is a challenging task in bionic robots, and the existing iterative design methods are mainly based on one or two characteristics to optimize robots. However, it is hard to obtain other features. Here, we introduced the thinking of system identification theory to the bionic robots, averting the exploration of the dynamics and reducing the difficulty of design greatly. A one-DOF six-bar mechanism (Watt I) was designated as the model to be identified, and it was divided into two parts, i.e. a one-DOF four-bar linkage and a three-DOF series arm. Then we formed constraints and a loss function. The parameters of the model were identified based on the kinematic data of a marmoset jumping. As a result, we obtained the desired model. Then, a prototype derived from the model was fabricated, and the experiments verified the effectiveness of the method. Our method also can be applied to other motion simulation scenarios.


Author(s):  
R. Ma ◽  
K. C. Gupta

Abstract The necessary and sufficient conditions for the full input rotatability in a spherical four bar linkage are proved. The direct criterion is: for all twist angles α in the range [0, π], the excess (deficit) of the sum of the frame and input twist angles over (from) π should, in absolute value, be greater than that for the coupler and follower twist angles; the difference between the follower and input twist angles, in absolute value, should be greater than that for the coupler and follower twist angles. Application of the direct criterion to full rotatability of other links are discussed and some variations in the form of the criterion are developed.


Author(s):  
Y. C. Pao

Abstract A software package MenuCAD has been developed for the general need of designing menu-driven, user-friendly CAD computer programs. The main menu is formatted similar to the major contents in the final report of the design project including Contents, Analysis, Sample Design Cases, Illustrations and Tables, References, and Program Listings. Sub-menus are further divided into items delineating the steps involved in the design. Screen help messages are provided for design of the main menu and sub-menus interactively and for applying the arrow keys on the keyboard to select a sub-menus and a particular item in the sub-menu in order to execute a desired design step. MenuCAD builds the framework, its user has to supplement with a subroutine ExecItem for describing the special features and for directing how each design step should be executed in the project. A CAD design of four-bar linkage project is presented as a sample application of this package.


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