A C-Legged Monopedal Robot and Its Transition From Multiple Locomotion Modes

2020 ◽  
Vol 12 (4) ◽  
Author(s):  
Guochao Bai ◽  
Bernhard Thomaszewski
Keyword(s):  
Simulation Software ◽  
Dynamics Simulation ◽  
Multibody Simulation ◽  
Experimental Platform ◽  
Speed Controller ◽  
Potential Applications ◽  
Dimensional Parameters ◽  
3D Printed ◽  
Planet Exploration ◽  
Multi Mode

Abstract This paper introduces a minimalistic design of a monopedal robot (monobot) with C-shaped legs which can achieve multiple locomotion modes (multi-mode) such as walking, leaping, as well as backward and forward flipping. The monobot contains an actuator, speed controller, 3D-printed base frame and legs, and battery set. The weight of the whole robot is less than 80 g. Dimensional parameters are optimized to simplify the design process and to identify effective factors for locomotion. Potential locomotion modes of the robot are analyzed by dynamics simulation. A simplified virtual prototype is tested within the multibody simulation software. An experimental platform of the monobot is also developed. The speed of the platform is adjusted to verify the correspondence between the actuator speed and locomotion mode as obtained by simulation. Potential applications of the multi-mode monobot include disaster rescue, planet exploration, and reconnaissance.

Integrated Methodology for Investigation of Wagon Bogie Concepts by Simulation

2014 ◽  
Author(s):  
S. S. N. Ahmad ◽  
C. Cole ◽  
M. Spiryagin ◽  
Y. Q. Sun
Keyword(s):  
Dynamic Behaviour ◽  
Simulation Software ◽  
Dynamics Simulation ◽  
Concept Design ◽  
Multibody Simulation ◽  
Worst Case ◽  
Multibody Model ◽  
Second Stage ◽  
Force Components ◽  
Train Simulation

Implementation of a new bogie concept is an integrated part of the vehicle design which must follow a rigorous testing and validation procedure. Use of multibody simulation helps to reduce the amount of time and effort required in selecting a new concept design by analysing results of simulated dynamic behaviour of the proposed design. However, the multibody simulation software mainly looks at the dynamics of a single vehicle; hence, forces from the train configuration operational dynamics are often absent in such simulations. Effects of longitudinal-lateral and longitudinal-vertical interactions between rail vehicles have been found to affect the stability of long trains [1,2]. The effect of wedge design on the vertical dynamics of a bogie has also been discussed in [3,4]. It is important to apply the lateral and vertical forces from a train simulation into a single multibody model of a wagon to check its behaviour when operating in train configuration. In this paper, a novel methodology for the investigation of new bogie designs has been proposed based on integrating dynamic train simulation and the multibody vehicle modelling concept that will help to efficiently achieve the most suitable design of the bogie. The proposed methodology suggests that simulation of any configuration of bogie needs to be carried out in three stages. As the first stage, the bogie designs along with the wagon configurations need to be presented as a multibody model in multibody simulation software to test the suitability of the concept. The model checking needs to be carried out in accordance with the wagon model acceptance procedure established in [5]. As the second stage, the wagon designs need to be tested in train configurations using a longitudinal train dynamics simulation software such as ‘CRE-LTS’ [2], where a train set consisting of the locomotives and wagons will be simulated to give operational wagon parameters such as lateral and vertical coupler force components. As the third stage, the detailed dynamic analysis of bogies and wagons needs to be performed with a multibody software such as ‘Gensys’ where lateral and vertical coupler force components from the train simulation (second stage) will be applied on the multibody model to replicate the worst case scenario. The proposed methodology enhances the selection procedure of any alternate bogie concept by the application of simulated train and vehicle dynamics. The simulated case studies show that simulation of wagon dynamic behaviour in multibody software combined with data obtained from longitudinal train simulation is not only possible, but it can identify issues with a bogie design that can otherwise be overlooked.

scholarly journals Design and characterization of 3D printed, neomycin-eluting poly-L-lactide mats for wound-healing applications

2021 ◽  
Vol 32 (4) ◽  
Author(s):  
Mahima Singh ◽  
Sriramakamal Jonnalagadda
Keyword(s):  
Release Kinetics ◽  
Biological Properties ◽  
In Vitro Dissolution ◽  
3D Printer ◽  
Topical Antibiotic ◽  
Young’S Moduli ◽  
Base Polymer ◽  
Potential Applications ◽  
3D Printed

AbstractThis study evaluates the suitability of 3D printed biodegradable mats to load and deliver the topical antibiotic, neomycin, for up to 3 weeks in vitro. A 3D printer equipped with a hot melt extruder was used to print bandage-like wound coverings with porous sizes appropriate for cellular attachment and viability. The semicrystalline polyester, poly-l-lactic acid (PLLA) was used as the base polymer, coated (post-printing) with polyethylene glycols (PEGs) of MWs 400 Da, 6 kDa, or 20 kDa to enable manipulation of physicochemical and biological properties to suit intended applications. The mats were further loaded with a topical antibiotic (neomycin sulfate), and cumulative drug-release monitored for 3 weeks in vitro. Microscopic imaging as well as Scanning Electron Microscopy (SEM) studies showed pore dimensions of 100 × 400 µm. These pore dimensions were achieved without compromising mechanical strength; because of the “tough” individual fibers constituting the mat (Young’s Moduli of 50 ± 20 MPa and Elastic Elongation of 10 ± 5%). The in vitro dissolution study showed first-order release kinetics for neomycin during the first 20 h, followed by diffusion-controlled (Fickian) release for the remaining duration of the study. The release of neomycin suggested that the ability to load neomycin on to PLLA mats increases threefold, as the MW of the applied PEG coating is lowered from 20 kDa to 400 Da. Overall, this study demonstrates a successful approach to using a 3D printer to prepare porous degradable mats for antibiotic delivery with potential applications to dermal regeneration and tissue engineering.

Case Study on Modeling Fire Action Complexity in Fire Safety Engineering of Structures

2017 ◽  
Vol 21 ◽  
pp. 102-107
Author(s):  
Constantin Sorin Scutarasu ◽  
Dan Diaconu-Şotropa ◽  
Marinela Barbuta
Keyword(s):  
Numerical Simulation ◽  
Fire Safety ◽  
Simulation Software ◽  
Dynamics Simulation ◽  
Structural Safety ◽  
Modular Organization ◽  
Field Of Study ◽  
Safety Design ◽  
Fire Safety Design ◽  
Technical Regulations

Important goals in the fire safety design, such as preventing loss of life and goods damage, are achieved by maintaining the stability of structures exposed to fire for a period of time established by norms and standards. Real fire scenarios confirm that the specific technical regulations which actually have a prescriptive character (both national and international) do not deal with sufficient possibilities regarding the assessment of structural fire safety. The new approach on structural safety, based on engineering notions, gives us additional prospects on it and it is included in the issues of the fire safety design of structures. A relatively new field of study, known by a few professionals focused on fire safety (but well acknowledged in the research area), fire safety design met with lots of changes and restructuring of the governing concepts and procedures and of the information with which they operate, due to the fast accumulation of experience in this area of engineering activity. Consequently, after countries such as Australia, Canada, New Zeeland or USA provided towards professionals specific technical regulations for fire safety design, groups of experts in these aforementioned countries have joined their forces to try to diminish the differences that exists between those regulations and to give a unitary character to them, a better conceptualized engineering approach of the fire safety design. The result: occurrence of the publication International Fire Engineering Guidelines (last edition from 2005). The systematic approach of fire safety design in constructions pointed, once again, the possibility of modular organization of this field of study, the relations between modules being established according to the objective or objectives in the fire safety design for a specified building. This article aims to put forward, from this modularized perspective, the study of the fire safety design of a building exposed to fire; hence, the practical part of the article exhibits the numerical simulation of initialization and development of the fire process for a large scale religious building. The main features of the building represent the amount of space that facilitates the spreading of smoke and warm gases and which increases the risk of damaging the structural reinforced concrete elements. Application calls to specific numerical simulation with a higher degree of credibility, such as those realized by the FDS (Fire Dynamics Simulation) software.

The Application of Second-Developed ADAMS on Simulation of Individual Soldier Automatic Weapon

2012 ◽  
Vol 182-183 ◽  
pp. 1056-1059
Author(s):  
Yan Jun Zhao ◽  
Wen Qing Ge ◽  
Cheng Xu
Keyword(s):  
Simulation Software ◽  
Dynamics Simulation ◽  
Design Efficiency ◽  
Parameter Modification

Based on ADAMS, The dynamics simulation software of individual soldier automatic weapon was developed. Parameter modification, remodeling, dynamics simulation, simulation replay, obtain and save of results of Individual Soldier Automatic weapon model by finely Chinese interface were completed. The software brings convenient for user,and improves design efficiency. The results show that the software is reliable.

scholarly journals Hybrid Spine Simulator Prototype for X-ray Free Pedicle Screws Fixation Training

2021 ◽  
Vol 11 (3) ◽  
pp. 1038
Author(s):  
Sara Condino ◽  
Giuseppe Turini ◽  
Virginia Mamone ◽  
Paolo Domenico Parchi ◽  
Vincenzo Ferrari
Keyword(s):  
Augmented Reality ◽  
Low Cost ◽  
Lumbar Vertebrae ◽  
Pedicle Screws ◽  
Simulation Software ◽  
Patient Specific ◽  
Innovative Strategy ◽  
X Ray ◽  
3D Printed ◽  
Harmful Radiation

Simulation for surgical training is increasingly being considered a valuable addition to traditional teaching methods. 3D-printed physical simulators can be used for preoperative planning and rehearsal in spine surgery to improve surgical workflows and postoperative patient outcomes. This paper proposes an innovative strategy to build a hybrid simulation platform for training of pedicle screws fixation: the proposed method combines 3D-printed patient-specific spine models with augmented reality functionalities and virtual X-ray visualization, thus avoiding any exposure to harmful radiation during the simulation. Software functionalities are implemented by using a low-cost tracking strategy based on fiducial marker detection. Quantitative tests demonstrate the accuracy of the method to track the vertebral model and surgical tools, and to coherently visualize them in either the augmented reality or virtual fluoroscopic modalities. The obtained results encourage further research and clinical validation towards the use of the simulator as an effective tool for training in pedicle screws insertion in lumbar vertebrae.

A Novel Method for Constructing Multi-Mode Deployable Polyhedron Mechanisms Using Symmetric Spatial RRR Compositional Units

2018 ◽  
Author(s):  
Jieyu Wang ◽  
Xianwen Kong
Keyword(s):  
Kinematic Chain ◽  
Degree Of Freedom ◽  
Single Loop ◽  
Kinematic Chains ◽  
The Third ◽  
Motion Modes ◽  
3D Printed ◽  
Novel Method ◽  
Multi Mode ◽  
Motion Mode

A novel construction method is proposed to construct multimode deployable polyhedron mechanisms (DPMs) using symmetric spatial RRR compositional units, a serial kinematic chain in which the axes of the first and the third revolute (R) joints are perpendicular to the axis of the second R joint. Single-loop deployable linkages are first constructed using RRR units and are further assembled into polyhedron mechanisms by connecting single-loop kinematic chains using RRR units. The proposed mechanisms are over-constrained and can be deployed through two approaches. The prism mechanism constructed using two Bricard linkages and six RRR limbs has one degree-of-freedom (DOF). When removing three of the RRR limbs, the mechanism obtains one additional 1-DOF motion mode. The DPMs based on 8R and 10R linkages also have multiple modes, and several mechanisms are variable-DOF mechanisms. The DPMs can switch among different motion modes through transition positions. Prototypes are 3D-printed to verify the feasibility of the mechanisms.

scholarly journals Study on Interface Structure of Cu/Al Clad Plates by Roll Casting

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 770 ◽  
Author(s):  
Qinghua Chang ◽  
Jingpei Xie ◽  
Aixia Mao ◽  
Wenyan Wang
Keyword(s):  
Molecular Dynamics ◽  
Electron Microscope ◽  
Molecular Dynamics Simulation ◽  
Large Scale ◽  
Aluminum Atom ◽  
Simulation Software ◽  
Dynamics Simulation ◽  
Aluminum Composite ◽  
Atom Diffusion ◽  
Heating And Cooling

Large scale Atomic/Molecular dynamic Parallel Simulator (LAMMPS) molecular dynamics simulation software was used to simulate the copper and aluminum atom diffusion and changes of interface during heating and cooling process of copper and aluminum composite panels. The structures of the interface were characterized through scanning electron microscope (SEM), X-ray diffraction (XRD), and transmission electron microscope (TEM), and the mechanical properties were also tested. The simulation results show that the diffusion rate of copper atom is higher than that of aluminum atom, and that the CuAl2 radial distribution function of the interface at 300 K is consistent with that of pure CuAl2 at room temperature. At 930 K, t = 50 ps Cu atoms spread at a distance of approximately four Al lattice constants around the Al layer, and Al atoms spread to about half a lattice constant distance to the Cu layer. The experimental results show that the thickness of the interface in copper–aluminum composite plate is about 1 μm, and only one kind of CuAl2 with tetragonal phase structure is generated in the interface, which corresponds with the result of molecular dynamics simulation.

scholarly journals Effect of Input Amplitude to Power Amplification in Various Orientation of Ring Resonator

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Haryana Mohd Hairi
Keyword(s):  
Ring Resonator ◽  
Simulation Software ◽  
Ring Resonators ◽  
Input Amplitude ◽  
Power Amplification ◽  
Optical Circuit ◽  
Potential Applications ◽  
Wavelength Filter ◽  
Waveguide Resonators ◽  
Wavelength Filtering

<p>Photonic ring waveguide resonators have great potential applications in wavelength filtering, switching, modulation and multiplexing.  The response of coupled ring resonators can be designed by using various coupling configurations. Particularly, ring resonators can be used as wavelength filter when the wavelength fits a whole multiple times in the circumference of the ring.  In this paper, we investigate the effect of input amplitude to power amplification in four ring resonator configurations and vary the input amplitude on five different wavelengths.  With OptiFDTD Photonics Simulation Software V8.0, the results show the intensity phenomenon of filtering in optical circuit.</p><p> </p>

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