Representation of the Variable Chain Mechanisms With Sequential Movement

2006 ◽  
Author(s):  
Hsing-Hui Huang
Keyword(s):  
Topological Structure ◽  
Parallel System ◽  
Degree Of Freedom ◽  
Composite Function ◽  
Sequential System ◽  
Sequential Movement ◽  
Parallel Movement ◽  
One Step ◽  
System Movement

A mechanism that encounters a certain change in the number of links or degree of freedom during operation will also result the variation of the topological structure in every stage. Since the mechanisms with variable chain in different stages during operation have different topologies, but the applications of this kind of mechanisms are very extensively. And this also result the complications of representation of the topology thoroughly. Mechanisms with variable chain now always been represented by graph according to the topology of each stage, but hardly represent by using a formula. We would like to propose an approach to develop the function for representing the mechanism with variable chain that focus on the sequential movement, and help the representation of the operation not only by the graph but also by the function. According to the operation of the mechanisms with variable chain, the movement of the mechanisms can be classified into parallel system movement and sequential system movement. Parallel movement mechanisms are the mechanisms operate more than one links in the same time when giving an input; and when we give an input that can operate just only one link and effect and transfer the movement of the next one step by step, we can call this kind of mechanisms as sequential mechanisms. In this work we apply composite function for represent the movement of each stage, and also verified the representation by applying it on the existed examples.

Coordinated Visual and Kinematic Servoing for Positioning Manipulating UAV End-Effectors

2014 ◽  
Author(s):  
Todd W. Danko ◽  
Paul Y. Oh
Keyword(s):  
Disaster Response ◽  
Degrees Of Freedom ◽  
Joint Space ◽  
Degree Of Freedom ◽  
Ground Vehicles ◽  
Manipulator Arm ◽  
One Step ◽  
Infrastructure Repair ◽  
End Effectors ◽  
Six Degree Of Freedom

Manipulating objects using arms mounted to unmanned aerial vehicles (UAVs) is attractive because UAVs may access many locations that are otherwise inaccessible to traditional mobile manipulation platforms such as ground vehicles. However, the constantly moving UAV platform and compliance of manipulator arms make it difficult to position the UAV and end-effector relative to an object of interest precisely enough for reliable manipulation. Solving this challenge will bring UAVs one step closer to being able to perform meaningful tasks such as infrastructure repair, disaster response, law enforcement, and personal assistance. Toward a solution to this challenge, this paper describes an approach to coordinate the redundant degrees of freedom of a six degree of freedom gantry with those of a six degree of freedom manipulator arm. The manipulator’s degrees of freedom are visually servoed to a specified pose relative to a target while treating motions of the host platform as perturbations. Simultaneously, the host platform’s degrees of freedom are servoed using kinematic information from the manipulator. This drives the base of the manipulator to a position that allows it to assume a joint-space configuration that maximizes reachability while minimizing static torque transmitted from the arm to the host.

Fabrication of a Robotic Hand Using Rapid Prototyping

2000 ◽  
Author(s):  
Jey Won ◽  
Kathryn J. DeLaurentis ◽  
Constantinos Mavroidis
Keyword(s):  
Rapid Prototyping ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Degree Of Freedom ◽  
Robotic Hand ◽  
Mechanical Joints ◽  
One Step

Abstract In this paper, the application of Rapid Prototyping in the fabrication of a robotic hand is presented. Using the Selective Laser Sintering Sinterstation 2000 of DTM Corporation of Austin, TX, prototypes of mechanical joints were fabricated experimentally. The designs of these component joints were then used to fabricate the articulated structure of one four degree of freedom finger of a five-fingered robotic hand. This robotic finger and joints have been fabricated in one step, without requiring assembly while maintaining their desired mobility.

scholarly journals Synthesis and Macrocyclization-Induced Emission Enhancement of Benzothiadiazole-based Macrocycle

2021 ◽  
Author(s):  
Chunju Li ◽  
Yue-Ling Bai ◽  
Lei Cui ◽  
Shuo Li
Keyword(s):  
Solid State ◽  
Topological Structure ◽  
Concentration Quenching ◽  
Device Performance ◽  
Dilute Solution ◽  
Strong Emission ◽  
Emission Enhancement ◽  
Intramolecular Motion ◽  
One Step ◽  
Novel Strategy

Abstract We presented a novel strategy for the improvement of luminophore’s solid-state emission, i.e., macrocyclization-induced emission enhancement (MIEE), by linking luminophores through C(sp3) bridges to give a macrocycle. Benzothiadiazole-based macrocycle (BT-LC) has been synthesized by a one-step condensation of the monomer 4,7-bis(2,4-dimethoxyphenyl)-2,1,3-benzothiadiazole (BT-M) with paraformaldehyde, catalyzed by Lewis acid. BT-LC shows strong emission in both dilute solution and aggregated state. Moreover, in comparison with the monomer, macrocycle BT-LC produces much more intense fluorescence in the solid state (ΦPL=99%) and exhibits better device performance in the application of OLEDs. The MIEE can be ascribed to the restriction of intramolecular motion and the alleviation of the concentration quenching by the macrocyclic topological structure.

Fabrication of Non-Assembly Mechanisms and Robotic Systems Using Rapid Prototyping

2000 ◽  
Vol 123 (4) ◽  
pp. 516-524 ◽  
Author(s):  
Constantinos Mavroidis ◽  
Kathryn J. DeLaurentis ◽  
Jey Won ◽  
Munshi Alam
Keyword(s):  
Rapid Prototyping ◽  
Parallel Manipulator ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Degree Of Freedom ◽  
Robotic Systems ◽  
Robotic Hand ◽  
One Step

In this paper, the application of Rapid Prototyping in fabricating non-assembly robotic systems and mechanisms is presented. Using two Rapid Prototyping techniques, Stereolithography and Selective Laser Sintering, prototypes of mechanical mobile joints were fabricated. The designs of these component joints were then used to fabricate the articulated structure of experimental prototypes for two robotic systems: (1) a three-legged parallel manipulator, (2) a four degree-of-freedom finger of a five-fingered robotic hand. These complex multi-articulated, multi-link, multi-loop systems have been fabricated in one step, without requiring assembly while maintaining their desired mobility. The feasibility and usefulness of Rapid Prototyping as a method for the fabrication of these non-assembly type mechanisms and robotic systems is the focus of this work.

scholarly journals On the Estimation of the Moving Mass of a TMD Installed on a Lively Structure

2021 ◽  
Vol 11 (10) ◽  
pp. 4712
Author(s):  
Alvaro Magdaleno ◽  
Cesar Pelaez ◽  
Alvaro Iglesias-Pordomingo ◽  
Antolin Lorenzana
Keyword(s):  
Natural Frequency ◽  
Damping Ratio ◽  
Structural Response ◽  
Degree Of Freedom ◽  
Moving Mass ◽  
Tuned Mass Dampers ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Modification Technique ◽  
One Step

Tuned Mass Dampers are devices which can be assimilated to single-degree-of-freedom systems with a certain amount of moving mass, a natural frequency and a damping ratio intended to be installed on lively structures to reduce the contribution of a certain mode to their response. Once placed on the structure, the movement of the mass damper couples to the structural response and determines its properties as an isolated system becomes challenging. The authors have previously presented a methodology to estimate the natural frequency and damping ratio of an SDOF system installed on a structure and not necessarily tuned to a certain mode. It was based on a transmissibility function and, thus, the moving mass could not be estimated. With this work, the authors go one step further and present a novel procedure to estimate the moving mass value by means of the same transmissibility function and two well selected frequency response functions. The methodology is applied to estimate the properties of a real single-degree-of-freedom system placed on a lively timber platform. The results are compared with the mass modification technique to show that the proposed methodology provides better estimations in a more efficient way.

On bonded sequential and parallel insertion systems

2018 ◽  
Vol 52 (2-3-4) ◽  
pp. 127-151
Author(s):  
Markus Holzer ◽  
Bianca Truthe ◽  
Ahmad Firdaus Yosman
Keyword(s):  
Parallel System ◽  
Lindenmayer Systems ◽  
Generative Capacity ◽  
Closure Properties ◽  
Time Step ◽  
Chomsky Hierarchy ◽  
Sequential System ◽  
New Variant

We introduce a new variant of insertion systems, namely bonded insertion systems. In such systems, words are not only formed by usual letters but also by bonds between letters. Words which can be inserted, have “free” bonds at their ends which control at which positions in a word they can be inserted (namely only there, where the bonds “fit”). Two kinds of bonded insertion systems are defined in this paper: so-called bonded sequential insertion systems and bonded parallel insertion systems. In a sequential system, there is only one word inserted at a time. In a parallel system, there is a word inserted at every possible position in parallel in one time step. We investigate the generative capacity of those two kinds and relate the families of generated languages to some families of the Chomsky hierarchy and to families of languages generated by Lindenmayer systems. Additionally, we investigate some closure properties.

Synthesis and Analysis of a Group of 3-Degree-of-Freedom Partially Decoupled Parallel Manipulators

2004 ◽  
Vol 126 (2) ◽  
pp. 301-306 ◽  
Author(s):  
Qiong Jin ◽  
Ting-Li Yang
Keyword(s):  
Topological Structure ◽  
Parallel Manipulators ◽  
Degree Of Freedom ◽  
Parallel Mechanisms ◽  
Kinematics Analysis ◽  
Structural Synthesis ◽  
Real Time Control ◽  
Structure Characteristics ◽  
Time Control ◽  
Internal Relationship

The kinematics decoupling for parallel manipulators is studied in this paper. Based on the topological structure characteristics of parallel mechanisms, the internal relationship between kinematics decoupling and basic kinematics chains is revealed, and the basic principle for structural synthesis of topologically decoupled mechanisms is put forward. Using this theory, a group of 3 degree-of-freedom (DOF) partially decoupled manipulators are synthesized. The expected kinematic outputs of these manipulators are 1-DOF translation and 2-DOF rotation, and motions along or about undesired directions do not exist. The kinematics analysis of a newly synthesized manipulator is discussed and the results indicate that the decoupling property of these architectures makes possible reaching real time control and path planning of parallel manipulators.

An Interactive Minicomputer Program for the Indexing and Simulation of Electron Diffraction Patterns

1976 ◽  
Vol 34 ◽  
pp. 542-543
Author(s):  
R.P. Goehner ◽  
W.T. Hatfield ◽  
Prakash Rao
Keyword(s):  
Electron Diffraction ◽  
Real Time ◽  
Pattern Analysis ◽  
Flow Diagram ◽  
Hard Copy ◽  
Time Analysis ◽  
Real Time Analysis ◽  
Transmission Electron ◽  
One Step ◽  
Diffraction Patterns

Computer programs are now available in various laboratories for the indexing and simulation of transmission electron diffraction patterns. Although these programs address themselves to the solution of various aspects of the indexing and simulation process, the ultimate goal is to perform real time diffraction pattern analysis directly off of the imaging screen of the transmission electron microscope. The program to be described in this paper represents one step prior to real time analysis. It involves the combination of two programs, described in an earlier paper(l), into a single program for use on an interactive basis with a minicomputer. In our case, the minicomputer is an INTERDATA 70 equipped with a Tektronix 4010-1 graphical display terminal and hard copy unit.A simplified flow diagram of the combined program, written in Fortran IV, is shown in Figure 1. It consists of two programs INDEX and TEDP which index and simulate electron diffraction patterns respectively. The user has the option of choosing either the indexing or simulating aspects of the combined program.

Nutrient-regulated gene expression in eukaryotes

2006 ◽  
Vol 73 ◽  
pp. 85-96 ◽  
Author(s):  
Richard J. Reece ◽  
Laila Beynon ◽  
Stacey Holden ◽  
Amanda D. Hughes ◽  
Karine Rébora ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Transcriptional Control ◽  
Direct Interaction ◽  
Signalling Pathways ◽  
A Cell ◽  
One Step ◽  
Higher Eukaryotes ◽  
Regulated Gene Expression

The recognition of changes in environmental conditions, and the ability to adapt to these changes, is essential for the viability of cells. There are numerous well characterized systems by which the presence or absence of an individual metabolite may be recognized by a cell. However, the recognition of a metabolite is just one step in a process that often results in changes in the expression of whole sets of genes required to respond to that metabolite. In higher eukaryotes, the signalling pathway between metabolite recognition and transcriptional control can be complex. Recent evidence from the relatively simple eukaryote yeast suggests that complex signalling pathways may be circumvented through the direct interaction between individual metabolites and regulators of RNA polymerase II-mediated transcription. Biochemical and structural analyses are beginning to unravel these elegant genetic control elements.

CAD: One Step Forward, One Step Back

2010 ◽  
Vol 43 (18) ◽  
pp. 16
Author(s):  
MATTHEW R.G. TAYLOR
Keyword(s):  
One Step
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