Linkage Design for Gravity Balancing by Means of Non-zero Length Springs

Author(s):  
Yang Zhang ◽  
Vigen Arakelian ◽  
Jean-Paul Le Baron
Keyword(s):  
1961 ◽  
Vol 28 (4) ◽  
pp. 639-639 ◽  
Author(s):  
A. S. Hall ◽  
T. P. Goodman
Keyword(s):  

Author(s):  
Brian Stokes ◽  
Matthew Jose ◽  
Nadine Wiggins ◽  
Tim Albion

Background with rationaleThe burden of chronic kidney disease (CKD) has increased rapidly in Australia over recent years. The financial cost of treating people with end-stage kidney failure by conventional models of dialysis or transplantation represents a substantial healthcare cost and is likely to continue to increase in coming years. Tasmania, the smallest state of Australia and its only island state, has the highest burden of chronic disease nationally, including kidney disease. The aim of this study was to use data-linkage to develop a state-wide dataset to quantify the burden and distribution of CKD, including identifying barriers to dialysis treatment services. Methods/ApproachThe Tasmanian Data Linkage Unit (TDLU) used a complex data linkage design comprising seven disparate datasets representing public and private pathology, public hospital admitted patient and emergency department data, cancer records, dialysis and transplant records and death notifications. A cohort was selected from public and private providers of pathology services in the state to support the establishment of a comprehensive researchable dataset. The datasets spanned the period 2004-2017 and included linkage of both state and national data. ResultsThe study cohort comprised just under 490,000 individuals in the Tasmanian population from the two pathology datasets, with a combined total of 1,347,00 total links made across all datasets. Individual unit records were geocoded according to the Australian Statistical Geographic Standard (2011) with over 92% of the 374,000 unique addresses identified in the public pathology dataset geocoded to address level. ConclusionThe final researchable dataset compiled by the research team following linkage is providing an enormously powerful asset to help answer questions specific to CKD in Tasmania, and that in turn is anticipated to result in greater access to services, improved care and better patient outcomes.


2004 ◽  
Vol 127 (5) ◽  
pp. 931-940 ◽  
Author(s):  
Alba Perez ◽  
J. Michael McCarthy

This paper uses the exponential defined on a Clifford algebra of planar projective space to show that the “standard-form” design equations used for planar linkage synthesis are obtained directly from the relative kinematics equations of the chain. The relative kinematics equations of a serial chain appear in the matrix exponential formulation of the kinematics equations for a robot. We show that formulating these same equations using a Clifford algebra yields design equations that include the joint variables in a way that is convenient for algebraic manipulation. The result is a single formulation that yields the design equations for planar 2R dyads, 3R triads, and nR single degree-of-freedom coupled serial chains and facilitates the algebraic solution of these equations including the inverse kinematics of the chain. These results link the basic equations of planar linkage design to standard techniques in robotics.


1997 ◽  
Vol 11 (2) ◽  
pp. 107-119 ◽  
Author(s):  
Ashim Bose ◽  
Maria Gini ◽  
Donald Riley
Keyword(s):  

1995 ◽  
Vol 117 (B) ◽  
pp. 93-100 ◽  
Author(s):  
A. G. Erdman

The current status of computer-aided design of mechanisms is reviewed. The available software is described and several industrial examples are presented to illustrate current trends in the field of linkage design and analysis. Future strategies and CAD environments are also discussed.


Author(s):  
A. P. Murray ◽  
J. M. McCarthy

Abstract This paper formulates the design theory of planar four-bar linkages using the planar form of dual quaternions known as planar quaternions. The set of positions reachable by the floating link of a dyad is a quadratic algebraic surface called a constraint manifold. Determining the coefficients of the quadratic form defining this manifold is equivalent to setting the design parameters of the linkage. If the task of the linkage is specified as geometric constraints on the location of the floating link, then algebraic constraints are obtained on the quaternion components. We seek the coefficients of the constraint manifold that satisfies these constraints. The result is an algebraic formulation that is symmetric in its characterization of the linkage and task, and provides a versatile tool for the formulation and solution of linkage design problems.


Author(s):  
J. Keith Nisbett ◽  
Sanjay K. Gupta

Abstract Keller’s sketching rules for Burmester curves are implemented on the computer for automatic generation of valid and invalid regions for the existence of the curves. The rules are based on the poles of the coupler motion, which in turn are directly related to the precision positions. All six possible unique arrangements of poles are used in the sketching rules. The sketching rules provide a useful heuristic and geometric approach to relating the sensitivity of the curves to small changes in the pole locations. The regions and the curves are dynamically updated as the poles of the specified motion are moved by the user. The new curve obtained is checked to verify satisfaction of original tolerance specification on the precision positions. The procedure shows promise for artificially intelligent approaches to linkage design.


Author(s):  
Andrew Porter ◽  
Jassim Alhamid ◽  
Changki Mo ◽  
John Miller ◽  
Joseph Iannelli ◽  
...  

Abstract The newly designed 3-dimensional catching robot consists of three revolute joints where the forward linkage is a parallelogram mechanism for keeping the catching end-effector parallel to the picking manipulator’s base. A virtual apple field of 505 apples, designed to test the picking abilities of 7 DOF arm, was used to determine the capabilities of this new catching arm design. The target catching efficiency was 90% for the provided virtual apple field with a maximum drop height of 30 cm. The target coordinates for each virtual apple were found by computer simulation in MATLAB. Geometric parameters were selected such that the catching manipulator could reach every possible drop position in the picking manipulator’s workspace. The design was completed, fabricated, and validated, utilizing the elegant mechanical linkage design. The workspace analysis showed that it had an acceptable 93% catching efficiency, and as the drop height increased, the efficiency approaches 100%. Definitive inverse-kinematics provided exact joint angles required to catch all catchable apples inside of the workspace. Using these angles, the general equation of motion, using Lagrangian mechanics, yielded the required torque outputs of each of the three motors on the arm. Validation of these torques through laboratory experimentation was considered adequate.


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