Study on synthesis method of λ-formed 4-bar linkages approximating a straight line

2009 ◽  
Vol 44 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Han Jianyou ◽  
Qian Weixiang ◽  
Zhao Huishe
Keyword(s):  
Synthesis Method ◽  
Straight Line

Synthesis method based on solution regions for planar four-bar straight-line linkages

2012 ◽  
Vol 26 (10) ◽  
pp. 3159-3167 ◽  
Author(s):  
Yin Lairong ◽  
Han Jianyou ◽  
Mao Cong ◽  
Huang Juan ◽  
Yang Tong
Keyword(s):  
Synthesis Method ◽  
Straight Line

Synthesis of Rectilinear Motion Generating Spatial Mechanism With Application to Automotive Suspension

2008 ◽  
Vol 130 (6) ◽  
Author(s):  
Jing-Shan Zhao ◽  
Fulei Chu ◽  
Zhi-Jing Feng
Keyword(s):  
Synthesis Method ◽  
Rectilinear Motion ◽  
End Effector ◽  
Kinematic Chains ◽  
Spatial Mechanism ◽  
Straight Line ◽  
Automotive Suspension ◽  
Generic Process ◽  
Wheel Track

This paper proposes a synthesis method for rectilinear motion generating spatial mechanism with application to automotive suspension. First, it presents a generic process to synthesize the kinematic chains of a mechanism with the prescribed mobility, and then it deduces the construction criteria of feasible kinematic chains for such a mechanism. The most outstanding advantages of the rectilinear motion generating spatial mechanism used as the independent automotive suspension are that the orientation and position parameters such as kingpin, caster, camber, axis distance, and wheel track are always maintained constant during jounce and rebound. These ideal characteristics are guaranteed by the particular rigid guidance mechanism whose end effector only has one translation along an exact straight line.

A GRAPHICAL-ANALYTICAL TECHNIQUE FOR THE SYNTHESIS OF NON-CIRCULAR GEARS IN PATH-GENERATING GEARED FIVE-BAR MECHANISMS

2008 ◽  
Vol 32 (3-4) ◽  
pp. 487-498 ◽  
Author(s):  
D. Mundo ◽  
G. Gatti
Keyword(s):  
Synthesis Method ◽  
Inverse Kinematic ◽  
Polynomial Functions ◽  
Line Segments ◽  
Analytical Technique ◽  
Straight Line ◽  
Planar Trajectory ◽  
Inverse Kinematic Analysis ◽  
Actual Configuration ◽  
Two Degree Of Freedom

The paper presents a graphical-analytical technique for the synthesis of non-circular gears in path-generating geared five-bar mechanisms. In such mechanisms, a two degree-of-freedom (dof) five-bar linkage is integrated by a pair of non-circular gears to precisely guide a coupler point along a prescribed planar trajectory. The synthesis method proposed here considers the most general case, where the prescribed trajectory consists of a series of open curves. Each segment of the prescribed path identifies a phase of the mechanism motion that is referred to as requested motion branch. In each of these phases, for any prescribed position of the coupler point, the inverse kinematic analysis of the linkage and the Aronhold-Kennedy theorem are used to identify the actual configuration of the system and locate the instantaneous centre of the relative motion between the two cranks of the linkage. The regions of the gear’s centrodes, corresponding to the requested motion branches, are thus synthesized. These regions are connected to each other by using proper polynomial functions, as to guarantee a continuous and cyclic motion of the mechanism. An example is illustrated where the requested coupler point trajectory consists of a series of straight line segments.

scholarly journals Synthesis Theory and Optimum Design of Four-bar Linkage with Given Angle Parameters

2019 ◽  
Vol 10 (2) ◽  
pp. 545-552 ◽  
Author(s):  
Lairong Yin ◽  
Long Huang ◽  
Juan Huang ◽  
Peng Xu ◽  
Xuejun Peng ◽  
...  
Keyword(s):  
High Efficiency ◽  
Synthesis Method ◽  
Point Contact ◽  
Straight Line ◽  
Synthesis Of Mechanisms ◽  
Solution Region ◽  
Straight Line Mechanism ◽  
Four Bar Linkage ◽  
The Given ◽  
Ball Point

Abstract. In this paper, a synthesis method is proposed for the 5-point-contact four-bar linkage that approximates a straight line with given angle parameters. The given parameters were the angles and the location of the Ball point. Synthesis equations were derived for a general Ball–Burmester point case, the Ball–Burmester point at an inflection pole, and the Ball point that coincided with two Burmester points, resulting in three respective groups of bar linkages. Next, taking Ball–Burmester point as the coupler point, two out of the three bar-linkage combinations were used to generate three four-bar mechanisms that shared the same portion of a rectilinear trajectory. Computation examples were presented, and nine cognate straight-line mechanisms were obtained based on the Roberts-Chebyshev theory. Considering that the given parameters were angles which was arbitrarily chosen, with the other two serving as the horizontal and vertical axes, so the solution region graphs of the solutions for three mechanism configurations were plotted. Based on these graphs, the distribution of the mechanism attributes was obtained with high efficiency. By imposing constraints, the optimum mechanism solution was straightforwardly identified by the designers. For the angular parameters prescribed in this paper, the solutions for three straight-line mechanism configurations were obtained, along with nine cognate straight-line mechanisms that shared the same portion of the rectilinear trajectory. All the fixed pivot installation locations and motion performances differed, thus providing multiple solutions to the trajectory of the synthesis of mechanisms.

Microdensitometer—computer correlation analysis of ultrastructural periodicity

1978 ◽  
Vol 36 (2) ◽  
pp. 32-33
Author(s):  
D.R. Ensor ◽  
C.G. Jensen ◽  
J.A. Fillery ◽  
R.J.K. Baker
Keyword(s):  
Correlation Analysis ◽  
Background Noise ◽  
Computer Control ◽  
Optical Diffraction ◽  
Screw Thread ◽  
Straight Line ◽  
Computer Storage ◽  
Correlation Process ◽  
Electron Microscope Image ◽  
Fixed Beam

Because periodicity is a major indicator of structural organisation numerous methods have been devised to demonstrate periodicity masked by background “noise” in the electron microscope image (e.g. photographic image reinforcement, Markham et al, 1964; optical diffraction techniques, Horne, 1977; McIntosh,1974). Computer correlation analysis of a densitometer tracing provides another means of minimising "noise". The correlation process uncovers periodic information by cancelling random elements. The technique is easily executed, the results are readily interpreted and the computer removes tedium, lends accuracy and assists in impartiality.A scanning densitometer was adapted to allow computer control of the scan and to give direct computer storage of the data. A photographic transparency of the image to be scanned is mounted on a stage coupled directly to an accurate screw thread driven by a stepping motor. The stage is moved so that the fixed beam of the densitometer (which is directed normal to the transparency) traces a straight line along the structure of interest in the image.

Freeze fracture imaging and computer simulation of liposome structure: Membrane geometry and defects

1983 ◽  
Vol 41 ◽  
pp. 646-647
Author(s):  
Joseph A. Zasadzinski
Keyword(s):  
Liquid Crystalline ◽  
Freeze Fracture ◽  
Continuum Theory ◽  
Closed Surfaces ◽  
Straight Line ◽  
Low Weight ◽  
Concentric Spheres ◽  
Membrane Geometry ◽  
Dupin Cyclides ◽  
Limiting Case

At low weight fractions, many surfactant and biological amphiphiles form dispersions of lamellar liquid crystalline liposomes in water. Amphiphile molecules tend to align themselves in parallel bilayers which are free to bend. Bilayers must form closed surfaces to separate hydrophobic and hydrophilic domains completely. Continuum theory of liquid crystals requires that the constant spacing of bilayer surfaces be maintained except at singularities of no more than line extent. Maxwell demonstrated that only two types of closed surfaces can satisfy this constraint: concentric spheres and Dupin cyclides. Dupin cyclides (Figure 1) are parallel closed surfaces which have a conjugate ellipse (r1) and hyperbola (r2) as singularities in the bilayer spacing. Any straight line drawn from a point on the ellipse to a point on the hyperbola is normal to every surface it intersects (broken lines in Figure 1). A simple example, and limiting case, is a family of concentric tori (Figure 1b).To distinguish between the allowable arrangements, freeze fracture TEM micrographs of representative biological (L-α phosphotidylcholine: L-α PC) and surfactant (sodium heptylnonyl benzenesulfonate: SHBS)liposomes are compared to mathematically derived sections of Dupin cyclides and concentric spheres.

Human Enamel Replication

1976 ◽  
Vol 34 ◽  
pp. 180-181
Author(s):  
Norman L. Dockum ◽  
John G. Dockum
Keyword(s):  
Organic Matrix ◽  
Human Teeth ◽  
Human Enamel ◽  
Straight Line ◽  
Ultrastructural Characteristics

Ultrastructural characteristics of fractured human enamel and acid-etched enamel were compared using acetate replicas shadowed with platinum and palladium. Shadowed replications of acid-etched surfaces were also obtained by the same method.Enamel from human teeth has a rod structure within which there are crystals of hydroxyapatite contained within a structureless organic matrix composed of keratin. The rods which run at right angles from the dentino-enamel junction are considered to run in a straight line perpendicular to the perimeter of the enamel, however, in many areas these enamel rods overlap, interlacing and intertwining with one another.

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