Experimental Kinematics of a Special Shape Actuator

2014 ◽  
Author(s):  
Alberto Borboni ◽  
Stefano Pandini ◽  
Danilo Cambiaghi ◽  
Matteo Lancini ◽  
Riccardo Adamini ◽  
...  
Keyword(s):  
Melting Temperature ◽  
Ad Hoc ◽  
Biomedical Application ◽  
Experimental Tests ◽  
Recovery Process ◽  
Cylindrical Shape ◽  
Cylindrical Annulus ◽  
Human Body Temperature ◽  
Temporal Function ◽  
Circular Function

This paper investigates the kinematical behavior of a polymer based star-shaped actuator, able to produce mechanical work through the shape memory effect, that allows a significant shape variations on the application of an external stimulus. The adopted material is a semicrystalline network based on poly(ε-caprolactone) crosslinked by thermal curing; the material was adopted due to its fast recovery process when heated close to the melting temperature and the high recovery degree, and, due to its good biocompatibility, it may suitable for biomedical application. The original, or “permanent”, material shape is that of a cylindrical annulus, which is set in a “temporary” configuration as a six spikes star. The temporary shape is fixed through a thermo-mechanical program, involving deformation above melting temperature and cooling under fixed strain and carried out by means of an ad-hoc designed fixture. By heating the deformed specimen above the melting temperature, the system is able to recover the original cylindrical shape realizing a motion and a mechanical power. This peculiar response, consisting in a progressive radial expansion activated by temperature, may be considered for application as self-expanding stenting device triggered by the human body temperature. The shape of the system, that changes during the transformation, can be described as a two dimensional temporal function that represents the mean line of the section of the cylindrical annulus (perpendicular to the height of the annulus). This temporal function is a combination of a circular function and of a modified rhodoneal function and, after a proper calibration through experimental tests, is used to evaluate the kinematics of the system. The function is able to describe adequately the shape evolution experimentally displayed by the samples, with a very good agreement at the starting and final instants of the transformation, while the accuracy during the transformation is acceptable for the proposed application.

scholarly journals ByeLab: An Agricultural Mobile Robot Prototype for Proximal Sensing and Precision Farming

2017 ◽  
Author(s):  
Renato Vidoni ◽  
Raimondo Gallo ◽  
Gianluca Ristorto ◽  
Giovanni Carabin ◽  
Fabrizio Mazzetto ◽  
...  
Keyword(s):  
Health Status ◽  
Mobile Robot ◽  
Ad Hoc ◽  
Experimental Tests ◽  
Precision Farming ◽  
Controlled Environment ◽  
Mechatronic Systems ◽  
Proximal Sensing ◽  
Bionic Eye ◽  
Outdoor Environments

At today, available mechatronics technology allows exploiting smart and precise sensors as well as embedded and effective mechatronic systems for developing (semi-)autonomous robotic platforms able to both navigate in different outdoor environments and implementing Precision Farming techniques. In this work, the experimental outdoor assessment of the performance of a mobile robotic lab, the ByeLab — Bionic eYe Laboratory — is presented and discussed. The ByeLab, developed at the Faculty of Science and Technology of the Free University of Bolzano (I), has been conceived with the aim of creating a (semi-)autonomous robotic system able to sense and monitor the health status of orchards and vineyards. For assessing and measuring the shape and the volume of the canopy, LIDAR technology coupled with ad-hoc developed algorithms have been exploited. To validate the ByeLab different experimental tests have been carried out. In addition to the in-lab and structured environments experimental tests that allowed to tune the algorithms, in this work the assessment of its capabilities — in particular the sensoric system — has been made outdoor controlled environment tests.

scholarly journals PMU’s Behavior with Flicker-Generating Voltage Fluctuations: An Experimental Analysis

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3355 ◽  
Author(s):  
Paolo Castello ◽  
Carlo Muscas ◽  
Paolo Pegoraro ◽  
Sara Sulis
Keyword(s):  
Distribution Systems ◽  
Ad Hoc ◽  
Current Trend ◽  
Experimental Tests ◽  
Distribution Networks ◽  
Distribution Grid ◽  
Voltage Fluctuations ◽  
Wide Area Monitoring ◽  
Accuracy Measurement ◽  
New Generation

Phasor measurement units (PMUs), which are the key components of a synchrophasor-based wide area monitoring system (WAMS), were historically conceived for transmission networks. The current trend to extend the benefits of the synchrophasor technology to distribution networks requires the PMU to also provide trustworthy information in the presence of signals that can occur in a typical distribution grid, including the presence of severe power quality (PQ) issues. In this framework, this paper experimentally investigates the performance of PMUs in the presence of one of the most important PQ phenomena, namely the presence of voltage fluctuations that generate the disturbance commonly known as flicker. The experimental tests are based on an ad-hoc high-accuracy measurement setup, where the devices under test are considered as “black boxes” to be characterized in the presence of the relevant signals. Two simple indices are introduced for the comparison among the different tested PMUs. The results of the investigation highlight possible critical situations in the interpretation of the measured values and provide a support for both the design of a new generation of PMUs and the possible development of an updated synchrophasor standard targeted to distribution systems.

Experimental Chatter Modeling of Milling Operations

2007 ◽  
Author(s):  
Giuseppe Catania ◽  
Nicolo` Mancinelli
Keyword(s):  
Ad Hoc ◽  
Dynamical Behavior ◽  
Measurement Data ◽  
Period Doubling ◽  
Experimental Tests ◽  
Cutting Parameters ◽  
Operating Conditions ◽  
Depth Of Cut ◽  
Wide Range ◽  
Excited Vibration

This study refers to the investigation on the critical operating condition occurring on high productivity milling machines, known as chatter. This phenomenon is generated by a self-excited vibration, associated with a loss of stability of the system, causing reduced productivity, poor surface finish and noise. This study consists of the theoretical and experimental modeling of machining chatter conditions, in order to develop a real-time monitoring system able to diagnose the occurrence of chatter in advance and to dynamically modify the cutting parameters for process optimization. A prototype NC 3-axis milling machine was ad hoc realized to accomplish this task. The machine was instrumented by a dynamometer table, and a series of accelerometer sensors were mounted in the proximity of the tool spindle and the workpiece. An analytical model was developed, taking into account the periodic cutting force arising during interrupted cutting operation in milling. The system dynamical behavior was described by means of a set of delay differential equations with periodic coefficients. The stability of this system was analyzed by the semi discretization approach based on the Floquet theory. Lobe stability charts were evaluated and associated with frequency diagrams. Two chatter types were analytically and experimentally detected: period-doubling bifurcations and secondary Hopf bifurcations. Measurement data were acquired and analyzed in the time and frequency domain. Several tests were conducted in a wide range of operating conditions, such as radial immersion, depth of cut and spindle speeds and using different tools. Results are reported showing agreement between the numerical analysis and the related experimental tests.

scholarly journals On-Body Characterization of Planar Differential Antennas for Multiple, Wide, and Narrow Bands

2016 ◽  
Vol 2016 ◽  
pp. 1-9
Author(s):  
Luigi Vallozzi ◽  
Domenico Pepe ◽  
Thijs Castel ◽  
Hendrik Rogier ◽  
Domenico Zito
Keyword(s):  
Human Body ◽  
Ad Hoc ◽  
Low Cost ◽  
Experimental Tests ◽  
Body Measurements ◽  
Antenna Performance ◽  
Sensing Applications ◽  
The Impact ◽  
Narrow Bands

This paper reports the results of the on-body experimental tests of a set of four planar differential antennas, originated by design variations of radiating elements with the same shape and characterized by the potential for covering wide and narrow bands. All the antenna designs have been implemented on low-cost FR4 substrate and characterized experimentally through on-body measurements. The results show the impact of the proximity to the human body on antenna performance and the opportunities in terms of potential coverage of wide and narrow bands for future ad hoc designs and implementations through wearable substrates targeting on-body and off-body communication and sensing applications.

Experimental Validation and Updating of the Flexible Multibody Model of a Commercial 3R Planar Manipulator

2011 ◽  
Author(s):  
Stefano Fiorati ◽  
Emiliano Mucchi ◽  
Raffaele Di Gregorio ◽  
Giorgio Dalpiaz
Keyword(s):  
Ad Hoc ◽  
Low Frequency ◽  
Experimental Tests ◽  
Low Speed ◽  
Operational Conditions ◽  
Multibody Model ◽  
Planar Manipulators ◽  
Flexible Multibody ◽  
Modes Of Vibration ◽  
Synthesis Methodology

Serial planar manipulators are diffusely used either as stand-alone machines or as part of more complex cells, and many commercial planar manipulators are available on the market. These commercial machines are mainly destined to accomplish low-speed tasks, and they are designed by taking into account their flexibility at most in the joints. Unfortunately, there are particular installation conditions in which even low-speed tasks can generate low-frequency vibrations that highly interfere with the task. This aspect is highlighted here with reference to a commercial 3R planar manipulator, and how to manage this problem is explained. In this sight, a flexible multibody model is developed where the flexibility of the frame, the manipulator is fixed to, is modeled over the flexibility of the joints, that is introduced as lumped stiffness. In particular, the flexible frame is included in the model by using a Component Mode Synthesis methodology, in which only the natural modes of vibration and the static constrain modes are accounted. The model is validated through an experimental campaign. The experimental tests consist of several modal analyses, together with acceleration and laser Doppler measurements in operational conditions. This methodology allows to provide a model which takes into account the installation conditions, and gives a tool for studying ad-hoc solutions which prevent the occurrence of low-frequency vibrations.

scholarly journals A Sterescopic System to Measure Water Waves in Laboratories

2020 ◽  
Vol 12 (14) ◽  
pp. 2288
Author(s):  
Matteo Gianluca Molfetta ◽  
Maria Francesca Bruno ◽  
Luigi Pratola ◽  
Antonio Rinaldi ◽  
Alberto Morea ◽  
...  
Keyword(s):  
Optical Sensors ◽  
Water Waves ◽  
Water Surface ◽  
Ad Hoc ◽  
Experimental Tests ◽  
Automatic Recognition ◽  
Large Wave ◽  
Significant Wave ◽  
New System ◽  
Over Time

A new system for estimating the synthetic parameters of sea states during physical investigations has been implemented. The technique proposed herein is based on stereographic analysis of digital images acquired with optical sensors. A series of ad hoc floating markers has been made and properly moored to the bottom of a large wave tank to estimate the synthetic parameters of generated waves. The implemented acquisition system and the proposed algorithm provide automatic recognition of all markers by a pair of optical sensors that synchronously captures their instantaneous location and tracks their movements over time. After transformation from the image to the real-world coordinates, water surface elevation time series have been obtained. Several experimental tests have been carried out to assess the feasibility and reliability of the proposed approach. The estimated wave synthetic parameters have been then compared with those obtained by employing standard resistive probes. The deviation were found to be equal to ~6% for the significant wave height and 1% for peak, mean, and significant wave periods.

Deeper Insight into the Protease-Mediated Formation of Pyronin Dyes and Possible Implications in the Design of Fluorogenic Probes for Bioimaging and Theranostic Prodrugs

2019 ◽  
Author(s):  
Kévin RENAULT ◽  
Sylvain DEBIEU ◽  
Jean-Alexandre RICHARD ◽  
Anthony ROMIEU
Keyword(s):  
Ad Hoc ◽  
Biomedical Application ◽  
Disease Diagnosis ◽  
Structural Features ◽  
Fluorescent Reporter ◽  
Enzymatic Assays ◽  
Fluorogenic Probes ◽  
Image Guided Drug Delivery

We report a rational and systematic study devoted to structural optimisation of a novel class of protease-sensitive fluorescent probes recently reported by us (<i>Org. Biomol. Chem.</i>, 2017, <b>15</b>, 2575-2584), based on the "covalent-assembly" strategy and using the targeted enzyme (penicilin G acylase as model protease) to build a fluorescent pyronin dye by triggering a biocompatible domino cyclisation-aromatisation reaction. The aim is to identify <i>ad hoc</i> probe candidate(s) that might combine fast/reliable fluorogenic "turn-on" response, full stability in complex biological media and ability to release a second molecule of interest (drug or second fluorescent reporter), for applications in disease diagnosis and therapy. We base our strategy on screening a set of active methylene compounds (C-nucleophiles) to convert the parent probe to various pyronin caged precursors bearing Michael acceptor moieties of differing reactivity. <i>In vitro</i> stability and fluorescent enzymatic assays combined to HPLC-fluorescence analyses provide data useful to define the most appropriate structural features for these fluorogenic scaffolds depending on the specifications required by the biomedical application (<i>e.g.</i>, <i>in vivo</i> molecular imaging, image-guided drug delivery and theranostics) for which they will be used.

Residual Vibration Reduction With Commanded Motion Optimization

2014 ◽  
Author(s):  
Alberto Borboni ◽  
Matteo Lancini ◽  
Rodolfo Faglia
Keyword(s):  
Natural Frequencies ◽  
Experimental Tests ◽  
Mechanical Power ◽  
Optimization Approach ◽  
Cyclic Movements ◽  
Work Cycle ◽  
Temporal Function ◽  
Physical Elements ◽  
Definition Of ◽  
Motion Profile

Residual vibrations affect machines at the end of commanded motion and represent an amplification factor for the work cycle. Furthermore, in repetitive cyclic movements, residual vibrations can lead to an important degeneration of the executed motion, due to a summation effect of undesired dynamic phenomena. For these reasons, the problem of residual vibrations is widely studied in literature and it is faced with different techniques. A first type of approach consists in the production of a structural device realized with proper mechanical solutions devoted to avoid the sources of vibrations. The second approach consists in introducing passive/active physical elements able to attenuate vibrations, by passively consuming their mechanical power or by actively counteracting them with external mechanical power. A third approach is the smart definition of the motion profile of each machine movable part to minimize the vibrational effects. The proposed work is addressed in this direction, with an optimization approach based on the Fourier transformation of the motion profile. More precisely, the natural frequencies of the system are evaluated through experimental tests, the designed motion profile is transformed with a Fourier analysis, a band around the natural frequencies of the system is suppressed from the motion profile spectrum, an antitransformation is implemented to obtain a temporal function, and, finally, a proper optimization is implemented to respect desired kinematical constraints. Experimental results confirmed a significant improvement, in terms of residual vibrations, with respect to the state of the art of motion profiles specifically designed for residual vibrations reduction.

Fusing Multiple Inexpensive GPS Heading Data via Fuzzified Ad-Hoc Weighing

2015 ◽  
Vol 776 ◽  
pp. 425-430
Author(s):  
Felipe P. Vista IV ◽  
Deok Jin Lee ◽  
Kil To Chong
Keyword(s):  
Fuzzy Logic ◽  
Ad Hoc ◽  
Experimental Tests ◽  
Gps Data ◽  
Dilution Of Precision ◽  
Gps Devices ◽  
The Individual ◽  
Electronic Compass

Applying the same principle behind the Ad-hoc weighing used in fusing data from two inexpensive GPS and an electronic compass (EC) brought up the problem of numerous conditions when trying to fuse data from three GPS devices. Fusing data from two GPS and one EC required at least thirty-two (32) conditions while using three GPS would require 182 conditions that would have entailed a complex set of programming codes. Fuzzy logic was explored as a possible candidate to replace the hard-coding of if-then-statements but still perform the ad-hoc algorithm as desired. The GPS Fix and HDOP (horizontal dilution of precision) values are utilized to derive the corresponding weight to be assigned to the individual GPS as well as the overall fused GPS data. Experimental tests using actual GPS data showed the effectivity of the proposed method.

scholarly journals Synthesis of Low Melting Temperature Aliphatic-Aromatic Copolyamides Derived from Novel Bio-Based Semi Aromatic Monomer

Polymers ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 793 ◽  
Author(s):  
Syang-Peng Rwei ◽  
Palraj Ranganathan ◽  
Whe-Yi Chiang ◽  
Yi-Huan Lee
Keyword(s):  
Melting Temperature ◽  
Average Molecular Weight ◽  
Weight Ratio ◽  
Sebacic Acid ◽  
Aromatic Polyamide ◽  
Polyamide 6 ◽  
Condensation Process ◽  
Weight Content ◽  
Human Body Temperature ◽  
Aromatic Monomer

This work investigated the synthesis of a novel low melting temperature polyamide 6 (PA6) copolyamide (PA6-BABT/SA) with different aliphatic/aromatic units weight content using a melt poly-condensation process. The bio-based aromatic N1,N4-bis(4-aminobutyl) terephthalamide diamine (BABT) and long-chain aromatic polyamide salt (BABT/SA, salt of BABT, and sebacic acid), components used for the synthesis of copolyamides, were obtained from bio-based monomers. For the first time, the pertinent BABT/SA aromatic polyamide salt was isolated as a white solid and completely characterized. By varying the weight ratio of BABT/SA salt, a series of copolyamides with different molecular weights and physical properties were prepared. The aromatic BABT/SA salt disrupted crystallization of the final copolyamides and lowered the onset of melting. The Fourier transform infrared spectroscopy and X-ray diffraction results indicated a steady decrease in the degrees of crystallinity with increasing BABT/SA salt segment ratio. Furthermore, compared to neat PA6, the obtained PA6-BABT/SA copolymers possessed a similar thermal stability and high transparency, but lower glass transition temperature around human body temperature. The PA6-BABT/SA copolymers with number-average molecular weight ≥30,000 Da presented good mechanical properties, specifically showing excellent tensile strength and elongation at break up to 105.2 MPa and 218.3%, respectively.

Sign in / Sign up

Export Citation Format

Share Document