A Novel Continuum Robot Using Twin-Pivot Compliant Joints: Design, Modeling, and Validation

2015 ◽  
Vol 8 (2) ◽  
Author(s):  
Xin Dong ◽  
Mark Raffles ◽  
Salvador Cobos-Guzman ◽  
Dragos Axinte ◽  
James Kell
Keyword(s):  
Kinematic Analysis ◽  
Joint Construction ◽  
Wide Range ◽  
Continuum Robot ◽  
Adequate Accuracy ◽  
Compliant Joint ◽  
Section Design ◽  
Twisting Angle ◽  
Accuracy And Repeatability ◽  
Novel Design

A twisting problem is identified from the central located flexible backbone continuum robot. Regarding this problem, a design solution is required to mechanically minimize this twisting angle along the backbone. Further, the error caused by the kinematic assumption of previous works is identified as well, which requires a kinematic solution to minimize. The scope of this paper is to introduce, describe and teste a novel design of continuum robot which has a twin-pivot compliant joint construction that minimizes the twisting around its axis. A kinematics model is introduced which can be applied to a wide range of twin-pivot construction with two pairs of cables per section design. And according to this model, the approach for minimising the kinematic error is developed. Furthermore, based on the geometry and material property of compliant joint, the work volumes for single/three-section continuum robot are presented, respectively. The kinematic analysis has been verified by a three-section prototype of continuum robot and adequate accuracy and repeatability tests carried out. And in the test, the system generates relatively small twisting angles when a range of end loads is applied at the end of the arm. Utilising the concept presented in this paper, it is possible to develop a continuum robot which can minimize the twisting angle and be accurately controlled. In this paper, a novel design of continuum robot which has a twin-pivot compliant joint construction that minimizes the twisting around its axis is introduced, described and tested. A kinematics model is introduced which can be applied to a wide range of twin-pivot construction with two pairs of cables per section design. Furthermore, based on the geometry and material property of compliant joint, the work volumes for single/three-section continuum robot are presented, respectively. Finally, the kinematic analysis has been verified by a three-section prototype of continuum and adequate accuracy and repeatability tests carried out.

NUMERICAL ANALYSIS OF FLOW BEHAVIOR IN GAS-LIQUID CYLINDRICAL CYCLONE (GLCC©*) SEPARATORS WITH INLET DESIGN MODIFICATIONS

2021 ◽  
pp. 1-27
Author(s):  
Srinivas Swaroop Kolla ◽  
Ram S. Mohan ◽  
Ovadia Shoham
Keyword(s):  
Numerical Study ◽  
Flow Behavior ◽  
Low Cost ◽  
Field Application ◽  
Attractive Alternative ◽  
Inlet Section ◽  
Wide Range ◽  
Cylindrical Cyclone ◽  
Light Oil ◽  
Section Design

Abstract The Gas-Liquid Cylindrical Cyclone (GLCC©*) is a simple, compact and low-cost separator, which provides an economically attractive alternative to conventional gravity-based separators over a wide range of applications. More than 6,500 GLCC©'s have been installed in the field to date around the world over the past 2 decades. The GLCC© inlet section design is a key parameter, which is crucial for its performance and proper operation. The flow behavior in the GLCC© body is highly dependent on the fluid velocities generated at the reduced area nozzle inlet. An earlier study (Kolla et al. [1]) recommended design modifications to the inlet section, based on safety and structural robustness. It is important to ensure that these proposed configuration modifications do not adversely affect the flow behavior at the inlet and the overall performance of the GLCC©. This paper presents a numerical study utilizing specific GLCC© field application working under 3 different case studies representing the flow entering the GLCC, separating light oil, steam flooded wells in Minas, Indonesia. Commercially available Computational Fluid Dynamics (CFD) software is utilized to analyze the hydrodynamics of flow with the proposed modifications of the inlet section for GLCC© field applications.

scholarly journals Two-Side Laser Processing Method for Producing High Aspect Ratio Microholes

2017 ◽  
Vol 5 (4) ◽  
Author(s):  
Vahid Nasrollahi ◽  
Pavel Penchev ◽  
Stefan Dimov ◽  
Lars Korner ◽  
Richard Leach ◽  
...  
Keyword(s):  
Cross Sections ◽  
Laser Processing ◽  
Industrial Applications ◽  
Laser Drilling ◽  
Special Focus ◽  
Geometrical Accuracy ◽  
Aspect Ratios ◽  
Wide Range ◽  
High Flexibility ◽  
Accuracy And Repeatability

Laser microprocessing is a very attractive option for a growing number of industrial applications due to its intrinsic characteristics, such as high flexibility and process control and also capabilities for noncontact processing of a wide range of materials. However, there are some constrains that limit the applications of this technology, i.e., taper angles on sidewalls, edge quality, geometrical accuracy, and achievable aspect ratios of produced structures. To address these process limitations, a new method for two-side laser processing is proposed in this research. The method is described with a special focus on key enabling technologies for achieving high accuracy and repeatability in two-side laser drilling. The pilot implementation of the proposed processing configuration and technologies is discussed together with an in situ, on-machine inspection procedure to verify the achievable positional and geometrical accuracy. It is demonstrated that alignment accuracy better than 10 μm is achievable using this pilot two-side laser processing platform. In addition, the morphology of holes with circular and square cross sections produced with one-side laser drilling and the proposed method was compared in regard to achievable aspect ratios and holes' dimensional and geometrical accuracy and thus to make conclusions about its capabilities.

scholarly journals Obtaining Various Shapes of Machined Surface Using a Tool with a Multi-Insert Cutting Edge

2019 ◽  
Vol 9 (5) ◽  
pp. 880 ◽  
Author(s):  
Tadeusz Mikolajczyk ◽  
Danil Pimenov ◽  
Catalin Pruncu ◽  
Karali Patra ◽  
Hubert Latos ◽  
...  
Keyword(s):  
Cutting Edge ◽  
Machined Surface ◽  
Wide Range ◽  
Complex Shapes ◽  
Functional Features ◽  
Tool Set ◽  
The Individual ◽  
Milling Tools ◽  
Novel Design ◽  
Positive Results

A novel design of a universal form tool is presented for machining complex planar and axisymmetric surfaces. The geometric and kinematic flexibility (GKF) of this tool type means that it can machine a wide range of profiles using a single setup. The operating principle of this multi-insert tool is its combination of single cutting edges, each of which form the individual details of the machined surface. The structure and application of both turning and milling multi-insert tools with combinations of single edges are described in the paper. Complex shapes and forms can be machined by changing the cutting-edge positions. The number of combinations of a given tool set can be determined by using the relations detailed in this study. Both turning and milling tools are utilized in a unique tool holder that clamps the inserts into position and allows their adjustment that is facilitated by special prepared analytical software to the desired object profiles. It is possible to use these tools in machining both wood and aluminum alloys. Finally, the design of the multi-insert tools for turning and milling and its functional features were experimentally verified with positive results.

scholarly journals Experimental methodology and procedure for SAPPHIRE:a Semi-automatic APParatus for High-voltage Ice nucleation REsearch

2020 ◽  
Author(s):  
Jens-Michael Löwe ◽  
Markus Schremb ◽  
Volker Hinrichsen ◽  
Cameron Tropea
Keyword(s):  
Electric Field ◽  
High Voltage ◽  
Surface Defects ◽  
Ice Nucleation ◽  
Experimental Methodology ◽  
Cloud Formation ◽  
Crystal Formation ◽  
Strong Impact ◽  
Wide Range ◽  
Accuracy And Repeatability

Abstract. Ice nucleation is of great interest for various processes such as cloud formation in the scope of atmospheric research, and icing of airplanes, ships or structures. Ice nucleation research aims to improve the knowledge about the physical mechanisms and, therefore improve the safety and reliability of the applications affected by ice nucleation. Several influencing factors like liquid supercooling or contamination with nucleants, as well as external disturbances such as an electric field or surface defects affect ice nucleation. Especially for ice crystal formation in clouds and icing of high-voltage equipment, an external electric field may have a strong impact on ice nucleation. Although ice nucleation has been widely investigated for numerous conditions, the effect of an electric field on nucleation is not yet completely understood; results reported in literature are even contradictory. In the present study, an advanced experimental approach for the examination of ice nucleation in water droplets exposed to an electric field is demonstrated. It comprises a method for droplet ensemble preparation and an experimental setup, which allows observation of the droplet ensemble during its exposure to well-defined thermal and electric fields, which are both variable over a wide range. The entire approach aims at maximizing the accuracy and repeatability of the experiments in order to enable examination of even the most minor influences on ice nucleation. For that purpose, the boundary conditions the droplet sample is exposed to during the experiment are examined in particular detail using experimental and numerical methods. The methodological capabilities and accuracy have been demonstrated based on several test nucleation experiments without an electric field, indicating almost perfect repeatability.

scholarly journals Novel Design of a Soft Lightweight Pneumatic Continuum Robot Arm with Decoupled Variable Stiffness and Positioning

Soft Robotics ◽  
2018 ◽  
Vol 5 (1) ◽  
pp. 54-70 ◽  
Author(s):  
Maria Elena Giannaccini ◽  
Chaoqun Xiang ◽  
Adham Atyabi ◽  
Theo Theodoridis ◽  
Samia Nefti-Meziani ◽  
...  
Keyword(s):  
Variable Stiffness ◽  
Robot Arm ◽  
Continuum Robot ◽  
Novel Design

Novel design and kinematic analysis of a 5-DOFs robotic arm with three-fingered gripper for physical therapy

2020 ◽  
Vol 28 ◽  
pp. 2121-2132 ◽  
Author(s):  
Jyotindra Narayan ◽  
Shivansh Mishra ◽  
Gaurav Jaiswal ◽  
Santosha K. Dwivedy
Keyword(s):  
Physical Therapy ◽  
Kinematic Analysis ◽  
Robotic Arm ◽  
Novel Design

A Generalized Approach for the Kinematic Analysis of Planar Mechanisms

1995 ◽  
Vol 209 (4) ◽  
pp. 237-244
Author(s):  
D J A Simpson ◽  
J E L Simmons ◽  
G Moldovean
Keyword(s):  
Computer Program ◽  
Analytical Method ◽  
Building Block ◽  
Kinematic Analysis ◽  
Displacement Velocity ◽  
Planar Mechanisms ◽  
New Approach ◽  
Wide Range ◽  
Complex Mechanisms

This paper describes a new approach to the kinematic analysis of planar mechanisms. The basis of the analytical method is a generic four-bar sub-mechanism which is used as the single building block from which other composite mechanisms may be created. A computer program has been written embodying this method and has been demonstrated to operate successfully providing animated displays of displacement, velocity and acceleration diagrams for a wide range of complex mechanisms.

scholarly journals Novel Design Approaches in the Fabrication of Polymeric Microarray Patches via Micromoulding

Micromachines ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 554 ◽  
Author(s):  
Inken Ramöller ◽  
Emma McAlister ◽  
Abigail Bogan ◽  
Ana Cordeiro ◽  
Ryan Donnelly
Keyword(s):  
Skin Barrier ◽  
Systemic Delivery ◽  
Porcine Skin ◽  
Density Maps ◽  
In Vitro Permeation ◽  
Wide Range ◽  
Significant Difference ◽  
Permeation Studies ◽  
Novel Design

The focus on novel systems for transdermal delivery of therapeutic agents has increased considerably over recent years, as this administration route comes with many advantages. Polymeric microarray patches (MAPs) are minimally invasive devices that enable systemic delivery of a wide range of drugs by overcoming the outer skin barrier. Conventionally, MAPs fabricated by micromoulding have a low needle density. In this study, the performance of hydrogel-forming MAPs cast using novel industrially manufactured micromoulds with a high needle density (600 needles/0.75 cm2) was compared to that of MAPs obtained using conventional moulds with a lower density (196 needles/0.89 cm2). Surrounding holders for micromoulds were designed for time-efficient fabrication of MAPs. The influence of needle densities on mechanical strength, insertion efficiency and in vitro permeation of ibuprofen sodium (IBU) was analysed. Insertion of both MAPs into an artificial skin model and neonatal porcine skin was comparable. No significant difference was observed in permeation studies of IBU (p > 0.05), with a delivery of 8.7 ± 1.7 mg for low-density and 9.5 ± 0.1 mg for high-density MAPs within 24 h. This highlights the potential of these novel micromoulds for manufacturing polymeric MAPs with a higher needle density for future applications.

scholarly journals Crack Protective Layered Architecture of Lead-Free Piezoelectric Energy Harvester in Bistable Configuration

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5808
Author(s):  
Ondrej Rubes ◽  
Zdenek Machu ◽  
Oldrich Sevecek ◽  
Zdenek Hadas
Keyword(s):  
Energy Harvester ◽  
Lead Free ◽  
Vibration Energy Harvester ◽  
Ultra Low Power ◽  
Energy Harvesters ◽  
Layered Architecture ◽  
Piezoelectric Energy ◽  
Wide Range ◽  
Ultra Low Power Devices ◽  
Novel Design

Kinetic piezoelectric energy harvesters are used to power up ultra-low power devices without batteries as an alternative and eco-friendly source of energy. This paper deals with a novel design of a lead-free multilayer energy harvester based on BaTiO3 ceramics. This material is very brittle and might be cracked in small amplitudes of oscillations. However, the main aim of our development is the design of a crack protective layered architecture that protects an energy harvesting device in very high amplitudes of oscillations. This architecture is described and optimized for chosen geometry and the resulted one degree of freedom coupled electromechanical model is derived. This model could be used in bistable configuration and the model is extended about the nonlinear stiffness produced by auxiliary magnets. The complex bistable vibration energy harvester is simulated to predict operation in a wide range of frequency excitation. It should demonstrate typical operation of designed beam and a stress intensity factor was calculated for layers. The whole system, without presence of cracks, was simulated with an excitation acceleration of amplitude up to 1g. The maximal obtained power was around 2 mW at the frequency around 40 Hz with a maximal tip displacement 7.5 mm. The maximal operating amplitude of this novel design was calculated around 10 mm which is 10-times higher than without protective layers.

Sign in / Sign up

Export Citation Format

Share Document