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.

On the Motion of Lineal Bodies Subject to Linear Damping

1997 ◽  
Vol 64 (1) ◽  
pp. 227-229 ◽  
Author(s):  
M. F. Beatty
Keyword(s):  
Differential Equation ◽  
Dynamical Systems ◽  
Rigid Body ◽  
General Class ◽  
Plane Motion ◽  
Rigid Bodies ◽  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Linear Damping

Wilms (1995) has considered the plane motion of three lineal rigid bodies subject to linear damping over their length. He shows that these plane single-degree-of-freedom systems are governed by precisely the same fundamental differential equation. It is not unusual that several dynamical systems may be formally characterized by the same differential equation, but the universal differential equation for these systems is unusual because it is exactly the same equation for the three very different systems. It is shown here that these problems belong to a more general class of problems for which the differential equation is exactly the same for every lineal rigid body regardless of its geometry.

ON MOTION GENERATION OF WATT I MECHANISMS FOR MECHANICAL FINGER DESIGN

2008 ◽  
Vol 32 (3-4) ◽  
pp. 411-422 ◽  
Author(s):  
QIONG SHEN ◽  
WEN-TZONG LEE ◽  
KEVIN RUSSELL ◽  
RAJ S. SODHI
Keyword(s):  
Rigid Body ◽  
Relative Motion ◽  
Degree Of Freedom ◽  
Planar Motion ◽  
Motion Generation ◽  
Single Degree Of Freedom ◽  
Closed Loops ◽  
Single Degree ◽  
Mechanical Finger

This work formulates and demonstrates a motion generation method for the synthesis of a particular type of planar six-bar mechanism-the Watt I mechanism. The Watt I mechanism is essentially a “stacked” four-bar mechanism (having two closed loops and a single degree of freedom). Extending the planar motion generation method of Suh and Radcliffe [11] to incorporate relative motion between moving pivots, Watt I mechanisms are synthesized to simultaneously approximate two groups of prescribed rigid-body poses for simultaneous dual motion generation capability. The example included demonstrates the synthesis of a finger mechanism to achieve a prescribed grasping pose sequence.

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.

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.

General Order Criteria for the Precision Position Synthesis of Single Degree-of-Freedom Planar Linkages

1994 ◽  
Author(s):  
John A. Mirth
Keyword(s):  
Order Conditions ◽  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Complete Order ◽  
Continuous Rotation ◽  
General Order ◽  
Planar Linkages ◽  
Position Synthesis

Abstract The order in which a single degree-of-freedom planar linkage passes through a series of design positions depends on both the relative orientations of a designated input link and the branch characteristics of that same link. The input link must have a continuous rotation as it passes through all design positions that lie on the same branch. The continuous rotation criteria does not apply to design positions on different branches of the linkage. Complete order conditions are presented for linkages with four design positions that lie on one to four separate branches.

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.

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