General Characteristics of the Motion of Multiple-Pode Joints

1984 ◽  
Vol 51 (1) ◽  
pp. 171-178 ◽  
Author(s):  
T. W. Lee ◽  
E. Akbil
Keyword(s):  
Functional Analysis ◽  
Analytical Method ◽  
Input Output ◽  
Displacement Analysis ◽  
General Displacement ◽  
Motion Parameters ◽  
The Creation ◽  
Motion Characteristics ◽  
And Behavior ◽  
Output Equation

This paper presents an analytical method on the investigation of the motion characteristics of a class of spatial mechanical components involving the ball-and-trunnion type of joint, namely, the multiple-pode joint. Algebraic derivations of the input-output equation and explicit relations for motion parameters are presented for these joints as well as their shaft couplings. From this general displacement analysis, some insights into the basic nature and behavior of the multiple-pode joint are observed and interpreted. The creation of shaft couplings using these joints and their functional analysis are also illustrated in several cases.

On the Motion Characteristics of Tripode Joints. Part 1: General Case

1984 ◽  
Vol 106 (2) ◽  
pp. 228-234 ◽  
Author(s):  
E. Akbil ◽  
T. W. Lee
Keyword(s):  
Constant Velocity ◽  
Analytical Study ◽  
Orbital Motion ◽  
Analytical Investigation ◽  
Rigorous Proof ◽  
Input Output ◽  
Arbitrary Position ◽  
Motion Parameters ◽  
Motion Characteristics ◽  
Output Equation

This paper is concerned with the analytical investigation of the motion characteristics of tripode joints with general proportions and arbitrary position of shafts. It provides a rigorous proof that the tripode joint is not a true constant velocity joint except in ideal cases, and this is due to the inherent orbital motion of the output spider shaft. Algebraic derivations of the input-output equation and explicit relations for motion parameters are presented. From this general analytical study, some insights into the behavior of the tripode joint are observed and interpreted.

Displacement Analysis of a Special Case of the 7R, Single-Loop, Spatial Mechanism

1983 ◽  
Vol 105 (1) ◽  
pp. 78-87
Author(s):  
Hiram Albala ◽  
David Pessen
Keyword(s):  
Input Output ◽  
Fourth Degree ◽  
Displacement Analysis ◽  
Single Loop ◽  
Spatial Mechanism ◽  
Rotation Axes ◽  
Successive Rotation ◽  
Special Case ◽  
Output Equation

Based on the displacement equations for the general n-bar, single-loop spatial linkage, obtained elsewhere, the displacement analysis for a special case of the 7R spatial mechanism is carried out. In this mechanism the successive rotation axes are perpendicular to each other, the distances between axes 3-4, 4-5, 5-6, are equal and the offsets along axes 4 and 5 are zero, when input axis is labeled axis 1. In this fashion, there still remain nine free linkage parameters. Input-output equation is of the eighth-degree in the tangent of half the output angle. A particular case of this one, where all the distances between axes are equal and all the offsets along axes are zero, leads to an input-output equation of the fourth-degree in the same quantity, with a maximum of four closures. This mechanism resulted to be a double-rocker.

Synthesis of Mechanisms Including Circuit Defects, Branch Defects and Input-Crank Rotatability

1992 ◽  
Author(s):  
Jyun-Cheng Cheng ◽  
Dilip Kohli
Keyword(s):  
Mechanism Design ◽  
Analytical Method ◽  
Input Output ◽  
Design Variables ◽  
Synthesis Of Mechanisms ◽  
Circuit Defects ◽  
Novel Concept ◽  
Output Equation

Abstract In this paper, an analytical method is developed for synthesizing linkages (with a quadratic input-output equation) which are free from circuit and branch defects and, in addition, may be required to have fully rotatable cranks. A novel concept called the range defect of the input link is introduced. It is shown that the range defect results in a circuit defect. Further, all circuit defects except those introduced as a result of range defects can be eliminated by eliminating branch defects. The circuit defect introduced by the range defect is eliminated by first eliminating the range defect and then eliminating the branch defect. Inequalities are developed as a function of mechanism design variables which represent the existence of range defects and therefore a possible circuit defect. The circuit defect identifiers are then developed and used in the synthesis of function generating planar four-bar and spatial RSSR linkages. The method developed is general and is applicable to any mechanism with a quadratic input-output equation such as RSSP, spherical 4-bar and 4R3P linkages.

Displacement Analysis of a Spatial 7R Mechanism—A Generalized Lobster’s Arm

1979 ◽  
Vol 101 (2) ◽  
pp. 224-231 ◽  
Author(s):  
J. Duffy ◽  
S. Derby
Keyword(s):  
Mathematical Model ◽  
Kinematic Analysis ◽  
Input Output ◽  
Major Step ◽  
Displacement Analysis ◽  
The Mathematical Model ◽  
Output Equation

An input-output equation of degree 24 is derived for a spatial 7R mechanism with consecutive pair axes intersecting. This mechanism is essentially the mathematical model for the kinematic analysis of a lobster’s arm which is an open 6R chain with mutually perpendicular consecutive pair axes, the geometry of which was first described by Willis [4] in 1841. The analysis of this special 7R mechanism constitutes a major step towards the solution of the general 7R mechanism with seven axes arbitrarily oriented in space.

Displacement Analysis of Spatial Six-Link, 5R-C Mechanisms: A General Solution

1985 ◽  
Vol 107 (3) ◽  
pp. 353-357 ◽  
Author(s):  
Xu Li Ju ◽  
J. Duffy
Keyword(s):  
General Solution ◽  
Angular Displacement ◽  
Problem Formulation ◽  
Input Output ◽  
Displacement Analysis ◽  
Numerical Example ◽  
Single Operation ◽  
Half Angle ◽  
Output Equation

Four angular displacement equations are derived for the spatial 5R-C hexagon from which an input-output equation of 16th degree in the tan-half-angle of the output angular displacement for each of the RCRRRR, RRCRRR mechanisms and the yet unsolved RRRRRC2 mechanism can be obtained by the elimination of two unwanted variables in a single operation. This novel problem formulation is a general solution for all 5R-C mechanisms. Results are verified by a numerical example.

scholarly journals Research on Measurement Method of Parachute Scanning Platform Based on MEMS Device

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 402
Author(s):  
Ning Liu ◽  
Tianqi Tian ◽  
Zhong Su ◽  
Wenhao Qi
Keyword(s):  
Physical Simulation ◽  
Inertial Sensors ◽  
Rotational Velocity ◽  
Attitude Measurement ◽  
Matlab Simulation ◽  
Scanning Angle ◽  
Reduce Development Time ◽  
Motion Parameters ◽  
Motion Characteristics ◽  
Scanning Motion

This paper studies the measurement of motion parameters of a parachute scanning platform. The movement of a parachute scanning platform has fast rotational velocity and a complex attitude. Therefore, traditional measurement methods cannot measure the motion parameters accurately, and thus fail to satisfy the requirements for the measurement of parachute scanning platform motion parameters. In order to solve these problems, a method for measuring the motion parameters of a parachute scanning platform based on a combination of magnetic and inertial sensors is proposed in this paper. First, scanning motion characteristics of a parachute-terminal-sensitive projectile are analyzed. Next, a high-precision parachute scanning platform attitude measurement device is designed to obtain the data of magnetic and inertial sensors. Then the extended Kalman filter is used to filter and observe errors. The scanning angle, the scanning angle velocity, the falling velocity, and the 2D scanning attitude are obtained. Finally, the accuracy and feasibility of the algorithm are analyzed and validated by MATLAB simulation, semi-physical simulation, and airdrop experiments. The presented research results can provide helpful references for the design and analysis of parachute scanning platforms, which can reduce development time and cost.

scholarly journals The Royal Institution in Ancient Iran

2016 ◽  
Vol 12 (10) ◽  
pp. 71
Author(s):  
Jafar Aghazadeh ◽  
Hasan Mohammadi
Keyword(s):  
Analytical Method ◽  
Human Being ◽  
Human Beings ◽  
Main Obstacle ◽  
Ordinary Life ◽  
The Earth ◽  
Royal Institution ◽  
History Of ◽  
The Creation ◽  
The Right

<p>In the thoughts and beliefs of Iranians, kingdom has had a history of the creation of human beings on the earth. Accordingly, Iranians believe that the first creature and human being on the earth was the first king of Iran. Iranians connects the history of their mythical royal dynasties to the creation of humanity. For Iranians, the mythical kings of Iran are the creators of the royal institution and the functions and duties of the royal institution have been established, developed and transferred to next generations by the measures of these kings. The objective of the present study is to investigate the establishment of the royal institution and the development of royal institution in ancient Iran by a descriptive-analytical method. The findings indicate that Iranians had specific sacredness for their kings and called the first creature of Ahura Mazda as the King. In addition, they believed that kings should perform particular tasks whose formation was attributed to the mythical kings of Iran. Further, they believed that only those persons had the right of being a king who were from the race of kings and were approved by Ahura Mazda. to examine Lessing’s elucidation of authentic knowledge in <em>Shikasta</em>. The methodology appropriated in the paper entails depiction of visible world as an illusion of the Real pointed in Plato’s allegory of Cave and Nagarjuna’s Mundane Truth. We clarify emotion as the main motivator of such illusionary status stressed in both Plato and Nagarjuna’s thoughts. We argue that while the importance of reason and eradicating emotion cannot be ignored, what adjoins people to Truth is mindfulness and intuitive knowledge which is close to Nagarjuna’s non-dual patterns. By examining ordinary life as the illusion of Real, and emotion as the main obstacle to achieve the Truth emphasized in both Nagarjuna and Plato’s trends, we depart from other critics who undermine the eminence of essentialist trace in Lessing’s works and examine her approach towards Truth merely under postmodern lens. This departure is significant since we clarify while essentialism has been abandoned to a large extent and supporters of Plato have become scarce, amalgamation of his thoughts with spiritual trends opens a fresh way to earn authenticity in Lessing’s novel. </p><p> </p>

Polynomial Solutions to the Displacement Analysis of 10-Link 1-DOF Mechanisms

1998 ◽  
Author(s):  
A. K. Dhingra ◽  
A. N. Almadi ◽  
D. Kohli
Keyword(s):  
Closed Form ◽  
Solution Process ◽  
Input Output ◽  
Analysis Problem ◽  
Displacement Analysis ◽  
Kinematic Chains ◽  
Polynomial Solutions ◽  
Elimination Procedure ◽  
Half Angle ◽  
Univariate Polynomial

Abstract This paper presents closed-form polynomial solutions to the displacement analysis problem of planar 10-link mechanisms with 1 degree-of-freedom (DOF). Using the successive elimination procedure presented herein, the input-output (I/O) polynomials as well as the number of assembly configurations for five mechanisms resulting from two 10-link kinematic chains are presented. It is shown that the displacement analysis problems for all five mechanisms can be reduced to a univariate polynomial devoid of any extraneous roots. This univariate polynomial corresponds to the I/O polynomial of the mechanism. In addition, one of the examples also illustrates how trigonometric manipulations in conjunction with tangent half-angle substitutions can lead to non-trivial extraneous roots in the solution process. Theoretical conditions for identifying and eliminating these extraneous roots are also presented.

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