The Intersections of Solids Shown by Electronic Analog for Mechanism Simulation

1971 ◽  
Vol 93 (1) ◽  
pp. 17-26 ◽  
Author(s):  
L. E. Torfason ◽  
F. R. E. Crossley
Keyword(s):  
Three Dimensional ◽  
Analog Computer ◽  
Spatial Mechanisms

The motion of certain spatial mechanisms with up to five links and containing at least one ball-and-socket joint can be visualized and analyzed by considering the intersections of three-dimensional surfaces generated by the mechanism. In this paper these solids and their intersections are represented by electronic analog computer, which can fully simulate in this way the motion capabilities of each link of the mechanism, and plot their relative displacements.

Stereoscopic Drawings Made by Analog Computer of Three-Dimensional Surfaces Generated by Spatial Mechanism

1971 ◽  
Vol 93 (1) ◽  
pp. 239-250
Author(s):  
L. E. Torfason ◽  
F. R. E. Crossley
Keyword(s):  
Three Dimensional ◽  
Analog Computer ◽  
Ball Joint ◽  
Spatial Mechanism ◽  
Transmission Properties ◽  
Spatial Mechanisms ◽  
As If

Spatial mechanisms with up to five links and containing at least one ball joint can be solved by considering the intersection of the three dimensional surfaces which can be generated by portions of the mechanism. This paper presents a method whereby stereoscopic pairs of the surfaces can be drawn using an electronic analog computer and the figures viewed as if they were three dimensional. This results in a far better visualization of the surfaces. In many cases it can be seen what the type of intersection between surfaces is. This determines the gross motion of the mechanism, the limits of its motion, and an estimate of its transmission properties.

The Influence of Internal Friction on the Stability of High Speed Rotors With Anisotropic Supports

1969 ◽  
Vol 91 (4) ◽  
pp. 1105-1113 ◽  
Author(s):  
E. J. Gunter ◽  
P. R. Trumpler
Keyword(s):  
Internal Friction ◽  
High Speed ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Analog Computer ◽  
Three Dimensional Model ◽  
Stiffness Properties ◽  
Stiffness Characteristics ◽  
The Stability ◽  
Internal Rotor

This paper evaluates the stability of the single mass rotor with internal friction on damped, anisotropic supports. The paper shows under what conditions the rotor stability may be improved by an undamped support with anisotropic stiffness properties. A three dimensional model is presented to show the influence of rotor and support stiffness characteristics on stability. Curves are also presented on how support damping may also improve or even reduce rotor stability. An analog computer solution of the governing equations of motion is presented showing the shaft transient motion for various speed ranges, and also plots of the rotor steady state motion are given for various speeds up to and including the stability threshold. The analysis is used to explain many of the experimental observations of B. L. Newkirk concerning stability due to internal rotor friction.

scholarly journals Kinematic Synthesis of Mechanism for System with a Technical Vision

2018 ◽  
Vol 237 ◽  
pp. 03009
Author(s):  
Baurzhan Tultayev ◽  
Gani Balbayev ◽  
Algazy Zhauyt ◽  
Aidos Sultan ◽  
Aigerim Mussina
Keyword(s):  
Design Process ◽  
Three Dimensional ◽  
Kinematic Chain ◽  
Kinematic Synthesis ◽  
New Approach ◽  
Kinematic Chains ◽  
Spatial Mechanisms ◽  
Input And Output ◽  
Technical Vision ◽  
Synthesis Of Mechanism

A solution to the problem of synthesizing an initial three-dimensional kinematic chain with spherical and rotary kinematic pairs is presented. It is shown that this chain can be used as a structural module for structural-kinematic synthesis of three-dimensional four-link motion generating lever mechanisms by the preset positions of the in-and output links. This paper affects the actual today’s problem of optimal synthesis of spatial link mechanisms. In this regard, the task of developing methods for the synthesis of complex spatial link mechanisms with the desired laws of motion of the input and output elements allowing automatizing the implementation of all design phases with the use of computer is quite relevant. The authors develop machine-oriented method of structural and kinematic synthesis of spatial link mechanisms based on the use of spatial initial kinematic chains (IKC) realizing prescribed motions. A new approach to the design of spatial mechanisms is suggested, according to which the design process is based on the kinematic synthesis of four-link initial kinematic chain (IKC) and associable kinematic chains (AKC).

The Study of Spatial Mechanisms by Electronic Analog Computer

1966 ◽  
Vol 88 (3) ◽  
pp. 301-310
Author(s):  
R. E. Keller
Keyword(s):  
Feedback Control ◽  
Control Systems ◽  
Analog Computer ◽  
Simulation Technique ◽  
Spatial Mechanism ◽  
Spatial Mechanisms ◽  
Feedback Control Systems ◽  
Geometrical Relationships

A simulation technique, applicable to any spatial mechanism having lower pairs, is presented. A detailed description of the required electronic analog-computer circuitry is given. The geometrical relationships imposed by a mechanism are satisfied in the simulation by contactor feedback-control systems, thereby minimizing the need for nonlinear computing components such as squarers and multipliers. Several example simulations are presented.

Instantaneous Invariants in Three-Dimensional Kinematics

1978 ◽  
Vol 45 (2) ◽  
pp. 409-414 ◽  
Author(s):  
Y. Kirson ◽  
A. T. Yang
Keyword(s):  
Rigid Body ◽  
Rational Design ◽  
Three Dimensional ◽  
Higher Order ◽  
Surface Generation ◽  
Intrinsic Properties ◽  
Canonical Systems ◽  
Spatial Mechanisms ◽  
Arbitrary Line

The paper generalizes the concepts of canonical systems and instantaneous invariants from planar to three-dimensional kinematics. It presents a systematic procedure to determine the instantaneous invariants. An example is included for illustration. The instantaneous invariants are derived on the basis of line coordinates, therefore they are useful for the characterization of higher-order intrinsic properties of a ruled surface—the path trajectory of an arbitrary line embedded in a rigid body in three-dimensional motion. It is hoped that this study may be useful for the rational design of spatial mechanisms for surface generation.

Experimental and Analytical Study of the Combined Geometric Analog Computer

1968 ◽  
Vol 90 (3) ◽  
pp. 291-302 ◽  
Author(s):  
P. Razelos ◽  
H. G. Elrod ◽  
V. Paschkis
Keyword(s):  
Heat Conduction ◽  
Steady State ◽  
Analytical Study ◽  
Three Dimensional ◽  
Approximate Solutions ◽  
Fundamental Solutions ◽  
Analog Computer ◽  
Infinite Medium ◽  
Diameter Ratio

A method for obtaining approximate solutions of transient three-dimensional heat-conduction problems has been investigated here analytically and experimentally. The method is based on the well-known principle of analogy between flow of heat and electricity and comprises a continuous resistance medium of resistivity ρe but discrete capacitances, which are introduced into the resistance medium through spherical electrodes. It has been shown that the internal behavior of the system is influenced only by the pitch diameter ratio λ of the spheres. Fundamental solutions for the infinite medium have been obtained and the analysis has shown that the system behaves like one having a resistivity ρe* which can be calculated from the actual resistivity of the liquid and the steady-state Green’s function of the fluid-sphere system. Experiments for the determination of the steady-state and transient Green’s functions are described. The accuracy of the method has also been investigated, and an illustrative example is given.

Combined Geometric and Network Analog Computer for Transient Heat Flow

1959 ◽  
Vol 81 (2) ◽  
pp. 144-149 ◽  
Author(s):  
Victor Paschkis
Keyword(s):  
Heat Flow ◽  
Three Dimensional ◽  
Analog Computer ◽  
Transient Heat Flow

A method to analyze three-dimensional transient heat flow is described, which comprises a continuous resistance medium but discrete capacitances. After describing the principles of the technique, the several components and their criteria are discussed, and the accuracy is illustrated by comparing the results of several simple problems with analytically determined values.

On the Intrinsic Properties of Point Trajectories in Three-Dimensional Kinematics

1985 ◽  
Vol 107 (3) ◽  
pp. 401-405 ◽  
Author(s):  
L. M. Hsia ◽  
A. T. Yang
Keyword(s):  
Control Systems ◽  
Rational Design ◽  
Robot Manipulators ◽  
Three Dimensional ◽  
Intrinsic Properties ◽  
Spatial Mechanisms ◽  
Point Trajectories ◽  
Straight Lines ◽  
And Control ◽  
Analytical Expressions

In this paper we derive analytical expressions for curvature, torsion, and radius of osculating sphere of the point trajectory in three-dimensional kinematics. Corresponding to a design position we obtain equations of loci of points tracing straight lines, helical curves, and spherical curves. It is hoped that the result of this study will provide another step toward rational design of spatial mechanisms and control systems for robot manipulators.

The orbit of Pluto over a long interval of time

1966 ◽  
Vol 25 ◽  
pp. 227-229 ◽  
Author(s):  
D. Brouwer
Keyword(s):  
Periodic Orbit ◽  
Numerical Integration ◽  
Restricted Problem ◽  
Three Dimensional ◽  
The Third ◽  
Circular Restricted Problem ◽  
Resonance Relation

The paper presents a summary of the results obtained by C. J. Cohen and E. C. Hubbard, who established by numerical integration that a resonance relation exists between the orbits of Neptune and Pluto. The problem may be explored further by approximating the motion of Pluto by that of a particle with negligible mass in the three-dimensional (circular) restricted problem. The mass of Pluto and the eccentricity of Neptune's orbit are ignored in this approximation. Significant features of the problem appear to be the presence of two critical arguments and the possibility that the orbit may be related to a periodic orbit of the third kind.

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