Development of a Novel Coupling Mechanism for Modular Self-Reconfigurable Mobile Robots

2015 ◽  
Author(s):  
Wael Saab ◽  
Pinhas Ben-Tzvi
Keyword(s):  
Mobile Robots ◽  
Scale Up ◽  
High Strength ◽  
Design Parameters ◽  
Coupling Mechanism ◽  
Dynamic Simulations ◽  
Challenging Tasks ◽  
Application Requirements ◽  
Fail Safe ◽  
Coupling Mechanisms

This paper presents the development of a novel coupling mechanism for modular self-reconfigurable mobile robots. Modular self-reconfigurable mobile robotic systems consist of a large number of self-sufficient modules that can transform into various configurations. One of the most challenging tasks in this field is designing a reliable and flexible coupling mechanism that physically connects modules to form larger and more articulated structures to scale up locomotion and manipulation functions. In this research we propose GHEFT: a Genderless, High strength, Efficient, Fail-safe, and high misalignment Tolerant coupling mechanism that aids the process of self-reconfiguration, and self-repair. Many existing coupling mechanisms fail to possess these crucial design features. The proposed mechanism ensures an efficient and high strength connection due to non-back drivable actuation and specially designed clamping profiles that enables modules to tolerate large misalignments and engage/disengage without gender restrictions in the presence of one-sided malfunction; thus, increasing both the versatility and robustness of the entire robotic system. In this paper, misalignment analysis is performed to formulate simple relations based on clamping profile design parameters to achieve specific misalignment tolerances based on application requirements. These formulations are used to compute maximum misalignment tolerances. Dynamic simulations are then performed to determine maximum misalignment tolerance capabilities and verify computed tolerances.

A Genderless Coupling Mechanism With Six-Degrees-of-Freedom Misalignment Capability for Modular Self-Reconfigurable Robots

2016 ◽  
Vol 8 (6) ◽  
Author(s):  
Wael Saab ◽  
Pinhas Ben-Tzvi
Keyword(s):  
Degrees Of Freedom ◽  
High Strength ◽  
Robotic Systems ◽  
Critical Element ◽  
Coupling Mechanism ◽  
Six Degrees Of Freedom ◽  
Reconfigurable Robots ◽  
Docking Mechanism ◽  
Fail Safe ◽  
Coupling Mechanisms

Abstract This paper presents the design and integration of a genderless coupling mechanism for modular self-reconfigurable mobile robots. Modular self-reconfigurable mobile robotic systems consist of a number of self-sufficient modules that interconnect via coupling mechanisms and adopt different configurations to modify locomotion and/or manipulation capabilities. Coupling mechanisms are a critical element of these robotic systems. This paper focuses on a docking mechanism called GHEFT: a Genderless, High-strength, Efficient, Fail-safe, and high misalignment Tolerant coupling mechanism that aids self-reconfiguration. GHEFT provides a high strength and energy efficient connection using nonback drivable actuation with optimized clamping profiles that tolerate translational and angular misalignments. It also enables engagement/disengagement without gender restrictions in the presence of one-sided malfunction. The detailed design of the proposed mechanism is presented, including optimization of the clamping profile geometries. Experimental validation of misalignment tolerances and achievable clamping forces and torques is performed to demonstrate the strength, efficiency, and fail-safe capabilities of the proposed mechanism, and these results are compared to reported results of some of the existing coupling mechanisms.

Design of a continuous flow immobilized-cell reactor for biosynthetical production of L-aspartic acid

1985 ◽  
Vol 50 (10) ◽  
pp. 2122-2133 ◽  
Author(s):  
Jindřich Zahradník ◽  
Marie Fialová ◽  
Jan Škoda ◽  
Helena Škodová
Keyword(s):  
Aspartic Acid ◽  
Continuous Flow ◽  
Immobilized Cells ◽  
Scale Up ◽  
Fixed Bed ◽  
Packed Bed ◽  
Fixed Bed Reactor ◽  
Experimental Program ◽  
Design Parameters ◽  
Immobilized Cell

An experimental study was carried out aimed at establishing a data base for an optimum design of a continuous flow fixed-bed reactor for biotransformation of ammonium fumarate to L-aspartic acid catalyzed by immobilized cells of the strain Escherichia alcalescens dispar group. The experimental program included studies of the effect of reactor geometry, catalytic particle size, and packed bed arrangement on reactor hydrodynamics and on the rate of substrate conversion. An expression for the effective reaction rate was derived including the effect of mass transfer and conditions of the safe conversion-data scale-up were defined. Suggestions for the design of a pilot plant reactor (100 t/year) were formulated and decisive design parameters of such reactor were estimated for several variants of problem formulation.

scholarly journals Ultrahigh Ballistic Resistance of Twisted Bilayer Graphene

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 206
Author(s):  
Qing Peng ◽  
Sheng Peng ◽  
Qiang Cao
Keyword(s):  
Weight Ratio ◽  
High Strength ◽  
Bilayer Graphene ◽  
Energy Propagation ◽  
Dynamic Simulations ◽  
Protective Material ◽  
Impact Performance ◽  
Ballistic Resistance ◽  
Twisted Bilayer Graphene ◽  
The Impact

Graphene is a good candidate for protective material owing to its extremely high stiffness and high strength-to-weight ratio. However, the impact performance of twisted bilayer graphene is still obscure. Herein we have investigated the ballistic resistance capacity of twisted bilayer graphene compared to that of AA-stacked bilayer graphene using molecular dynamic simulations. The energy propagation processes are identical, while the ballistic resistance capacity of the twisted bilayer graphene is almost two times larger than the AA-bilayer graphene. The enhanced capacity of the twisted bilayer graphene is assumed to be caused by the mismatch between the two sheets of graphene, which results in earlier fracture of the first graphene layer and reduces the possibility of penetration.

Type Synthesis of a 1T Symmetric Coupling Mechanism with the Method of Separation and Merger

2014 ◽  
Vol 635-637 ◽  
pp. 1290-1293
Author(s):  
Shou Li Zhang ◽  
Jing Fang Liu ◽  
Yue Qing Yu
Keyword(s):  
Linear Combination ◽  
Parallel Mechanism ◽  
Creative Design ◽  
Coupling Mechanism ◽  
Type Synthesis ◽  
Structural Synthesis ◽  
Hybrid Mechanism ◽  
Coupled Structures ◽  
Coupling Mechanisms

The structural synthesis is the primary and the most important issue in the process of mechanism creative design. In the paper, Firstly, select a 1T symmetric parallel mechanism, and the constraint and mobility of the branches can be analyzed. With the method of linear combination of the screws, the new branches are constructed. Then, using the measure of separation and merger, parts of the limbs of the parallel mechanism can be replaced by equivalent coupled structures, so corresponding symmetric coupling mechanisms with equal mobility are synthesized. Finally, solving the constraint screws of the branch of the coupling mechanism, in order to prove the hybrid mechanism is full-cycle or not.

DESIGN PARAMETERS SELECTION OF SPRINGBACK EFFECT IN AIR-V BENDING USING TAGUCHI APPROACH ON ADVANCE HIGH STRENGTH STEEL-DP590

2015 ◽  
Vol 76 (3) ◽  
Author(s):  
Shahrul Azam Abdullah ◽  
Muhamad Sani Buang ◽  
Juri Saedon ◽  
Hashim Abdullah
Keyword(s):  
Plate Thickness ◽  
High Strength Steels ◽  
High Strength ◽  
Design Parameters ◽  
Optimum Level ◽  
Advanced High Strength Steels ◽  
Parameters Selection ◽  
Bending Process ◽  
Punch Radius ◽  
Evaluation Problem

Advanced High Strength Steels (AHSS) are increasingly utilized especially in automotive industry. However, forming of AHSS is challenging particularly in prediction of springback effect caused by material properties, tools and dies parameters, work material and bending technique factors. An air V-bending process was chosen as an evaluation problem because it showed larger springback effect. This paper presents an optimization to predict the influence of various parameters on springback of sheet metal in air V-bending process using Taguchi method (TM). The experimental study was conducted on DP590 sheets with plate thickness of 1 and 2 mm under different process parameters such as punch radius, die radius, die gap and punch travel. A significant level of springback parameters was further described by using the analysis of variance (ANOVA). It showed that the contribution percentage of each factor to springback was calculated to optimum level and the significant levels of entire factor were observed. The thickness of material, die width, punch travel and punch radius were found to be the most significant factor affecting springback while die radius is insignificant. 

scholarly journals Active Vibration Control of Launch Vehicle on Satellite Using Piezoelectric Stack Actuator

2018 ◽  
Author(s):  
Mehran Makhtoumi
Keyword(s):  
Vibration Control ◽  
Vibration Suppression ◽  
Virtual Work ◽  
Active Vibration Control ◽  
High Strength ◽  
Launch Vehicle ◽  
Design Parameters ◽  
Control Analysis ◽  
Active Vibration ◽  
Piezoelectric Stack Actuator

Satellites are subject to various severe vibration during different phases of flight. The concept of satellite smart adapter is proposed in this study to achieve active vibration control of launch vehicle on satellite. The satellite smart adapter has 18 active struts in which the middle section of each strut is made of piezoelectric stack actuator. Comprehensive conceptual design of the satellite smart adapter is presented to indicate the design parameters, requirements and philosophy applied which are based on the reliability and durability criterions to ensure successful functionality of the proposed system. The coupled electromechanical virtual work equation for the piezoelectric stack actuator in each active strut is drived by applying D'Alembert's principle. Modal analysis is performed to characterize the inherent properties of the smart adapter and extraction of a mathematical model of the system. Active vibration control analysis was conducted using fuzzy logic control with triangular membership functions and acceleration feedback. The control results conclude that the proposed satellite smart adapter configuration which benefits from piezoelectric stack actuator as elements of its 18 active struts has high strength and shows excellent robustness and effectiveness in vibration suppression of launch vehicle on satellite.

The Effect of a Fractal Profile Tolerance on the Dynamic Performance of Cams

1996 ◽  
Author(s):  
Daniel A. McAdams ◽  
Kristin L. Wood
Keyword(s):  
Fractal Geometry ◽  
Surface Characterization ◽  
Dynamic Performance ◽  
Design Parameters ◽  
Fractal Surface ◽  
Profile Error ◽  
Dynamic Simulations ◽  
Profile Tolerance ◽  
Cam Follower ◽  
Successful Design

Abstract To ensure a successful design, it is important to understand the effect that design parameters have on design performance. Tolerances are an important subset of design parameters. In this paper, the relevance of fractal surface characterization for profile tolerances is investigated. The notion of fractal geometry is discussed. The validity of a fractal characterization on a cam surface is determined. Dynamic simulations of a cam-follower system are used to qualify the effect of a fractal profile error on system performance.

Fixed-Bed Adsorption Column Studies for the Removal of Methyl Orange from Water Using Polyethyleneimine-Graphene Oxide Polymer Nanocomposite Beads

2021 ◽  
Vol 891 ◽  
pp. 31-36
Author(s):  
Jirah Emmanuel T. Nolasco ◽  
Camille Margaret S. Alvarillo ◽  
Joshua L. Chua ◽  
Ysabel Marie C. Gonzales ◽  
Jem Valerie D. Perez
Keyword(s):  
Graphene Oxide ◽  
Methyl Orange ◽  
Large Scale ◽  
Scale Up ◽  
Fixed Bed ◽  
Breakthrough Curves ◽  
Design Parameters ◽  
Column Studies ◽  
Fixed Bed Column ◽  
Adsorption Column

Continuous fixed-bed column studies were performed using nanocomposite beads made up of chitosan, polyethyleneimine, and graphene oxide as adsorbents for the removal of methyl orange (MO) in water. The effects of different operating parameters such as initial MO concentration (5, 10, and 15 ppm), bed height (10, 17.5, and 25 cm), and flow rate (27, 43, and 58 mL/min) were investigated using an upward-flow fixed-bed column set-up. The breakthrough curves generated were fitted with Adams-Bohart, Thomas, Yoon-Nelson, and Yan et al. models. The results showed that Yan et al. model agreed best with the breakthrough curves having an R2 as high as 0.9917. Lastly, design parameters for a large-scale adsorption column were determined via scale-up approach using the parameters obtained from column runs.

Mobile Worm-Like Robots for Pipe Inspection

2015 ◽  
pp. 168-218 ◽  
Author(s):  
Sergey Fedorovich Jatsun ◽  
Andrei Vasilevich Malchikov
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Mobile Robots ◽  
Experimental Studies ◽  
Design Parameters ◽  
Robot Motion ◽  
Robot Dynamics ◽  
Confined Space ◽  
Pipe Inspection ◽  
The Mathematical Model

This chapter describes various designs of multilink mobile robots intended to move inside the confined space of pipelines. The mathematical model that describes robot dynamics and controlled motion, which allows simulating different regimes of robot motion and determining design parameters of the device and its control system, is presented. The chapter contains the results of numerical simulations for different types of worm-like mobile robots. The experimental studies of the in-pipe robots prototypes and their analyses are presented in this chapter.

A Unified Classification Ecosystem for Auctions

2010 ◽  
Vol 1 (3) ◽  
pp. 53-74 ◽  
Author(s):  
Dimitrios M. Emiris ◽  
Charis A. Marentakis
Keyword(s):  
Recent Literature ◽  
Price Formation ◽  
Design Parameters ◽  
Systematic Research ◽  
Relevant Research ◽  
Continuous Growth ◽  
Seminal Paper ◽  
New Developments ◽  
Application Requirements ◽  
Games Theory

Auctions have known considerable and continuous growth during the last decades due to their interesting properties in price formation when the value of goods traded is not known or varies. The systematic research in the area of auctions has advanced considerably since William Vickrey’s seminal paper on 1961. Although earlier research has been based mainly on Microeconomics and Games Theory, recent advances extended relevant research in Operational Research and Information Technology. Today, auctions and their applications form a challenging topic not only for economists but for operational researchers, marketers, logisticians and management engineers as well. This paper provides an overview of recent literature in auction theory, focusing on contemporary auction techniques and proposes an Auctions Classification Ecosystem (ACE) that encompasses previous works and new developments in the area. The proposed unified classification approach encompasses auction features and mechanism design parameters in a single scheme. This scheme facilitates the understanding of auction characteristics and supports auction practitioners in designing the appropriate format depending on the application requirements.

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