Mechanism Link Rotatability and Limit Position Analysis Using Polynomial Discriminants

1987 ◽  
Vol 109 (2) ◽  
pp. 178-182 ◽  
Author(s):  
R. L. Williams ◽  
C. F. Reinholtz
Keyword(s):  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Position Analysis ◽  
Numerical Example ◽  
Single Degree ◽  
Spatial Mechanisms ◽  
Limit Position

A theory is proposed for algebraically determining the limit positions of single-degree-of-freedom mechanisms. The absence of limit positions indicates that the link being considered is a fully rotating crank. This theory is applied in the present paper to the RSSR and RRSS spatial mechanisms. Conditions for spatial mechanisms analogous to Grashof’s law should be attainable using this theory. A numerical example is given to illustrate the theory.

Four-Position Synthesis for Spatial Mechanisms With Two Independent Loops

1992 ◽  
Author(s):  
Chien H. Chiang ◽  
Wei Hua Chieng ◽  
David A. Hoeltzel
Keyword(s):  
Rigid Body ◽  
Mathematical Models ◽  
Analytical Methods ◽  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Practical Applications ◽  
Single Degree ◽  
Spatial Mechanisms ◽  
Position Synthesis ◽  
Independent Loops

Abstract Mathematical models that have been employed to synthesize spatial mechanisms for rigid body guidance have been found to be too complicated to implement in practical applications, especially for four-position guidance synthesis. This paper describes simple analytical methods for synthesizing single degree-of-freedom spatial mechanisms having two independent loops for four precision positions. In addition, prescribed timing has been simultaneously considered for several spatial mechanisms.

A Machine Learning Approach to Solving the Alt-Burmester Problem for Synthesis of Defect-free Spatial Mechanisms

2021 ◽  
pp. 1-14
Author(s):  
Shashank Sharma ◽  
Anurag Purwar
Keyword(s):  
Machine Learning ◽  
Learning Algorithm ◽  
Degree Of Freedom ◽  
Synthesis Problem ◽  
Machine Learning Algorithm ◽  
Motion Synthesis ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Spatial Mechanisms ◽  
Machine Learning Approach

Abstract In this paper, we present a machine-learning algorithm to synthesize defect-free single degree of freedom spatial mechanisms for the Alt-Burmester problem. The Alt-Burmester problem is a generalization of a pure motion synthesis problem to include via path-points with missing orientations. While much work has been done towards the synthesis of planar and, to some extent, spherical mechanisms, the generation of mechanisms that are free of circuit, branch, and order defects has proven to be a difficult task. This is even more challenging for spatial mechanisms, which can consist of a large number of circuits and branches. Moreover, the Alt-Burmester problem makes solving such problems using an analytical approach further demanding. In this paper, we present a novel machine-learning algorithm for solving the Alt-Burmester problem for spatial 5-SS platform mechanism using a Variational Auto-Encoder (VAE) architecture. The VAE helps capture the relationship between path and orientation properties of the motion of the 5-SS mechanisms, which enables reformulating the Alt-Burmester problem into a pure motion synthesis problem. The end goal is to produce defect-free spatial mechanism design solutions. While our focus in this paper is on the 5-SS mechanisms, this approach can be scaled to any single-degree-of-freedom spatial mechanisms.

Cylindrical Single-Degree-of-Freedom Spatial Mechanisms for Cell Restraint

2012 ◽  
Vol 4 (2) ◽  
Author(s):  
Gregory H. Teichert ◽  
Quentin T. Aten ◽  
Sandra H. Burnett ◽  
Larry L. Howell ◽  
Brian D. Jensen
Keyword(s):  
Transgenic Animal ◽  
Degree Of Freedom ◽  
Surface Micromachining ◽  
Electromechanical Systems ◽  
Single Degree Of Freedom ◽  
Spatial Mechanism ◽  
Single Degree ◽  
Spatial Mechanisms ◽  
Production Techniques ◽  
Cell Support

Many transgenic animal production techniques require egg cells to be held in place during injection of the transgene. This paper presents a micro-electromechanical systems (MEMS) mechanism that provides cell support, self-centers the cell, and requires a single linear input for actuation. This restraint device uses an innovative spatial mechanism, termed a cylindrical mechanism. The kinematics and design of the restraint are discussed. The MEMS cell restraints were fabricated using a surface micromachining process, after which the mechanism’s cell support, self-centering of the cell, and motion were verified.

Kinematic comparison of single degree-of-freedom robotic gait trainers

2021 ◽  
Vol 159 ◽  
pp. 104258
Author(s):  
Jeonghwan Lee ◽  
Lailu Li ◽  
Sung Yul Shin ◽  
Ashish D. Deshpande ◽  
James Sulzer
Keyword(s):  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Robotic Gait
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