Experimental Characterization of the Dynamics of VO2-Based MEMS Mirrors

2016 ◽  
Author(s):  
David Torres ◽  
Tongyu Wang ◽  
Jun Zhang ◽  
Sarah Dooley ◽  
Xiaobo Tan ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Frequency Response ◽  
Dynamic Performance ◽  
Band Width ◽  
Experimental Characterization ◽  
Thermal Dynamics ◽  
Step Input ◽  
Sinusoidal Input

In this work, the time and frequency response of VO2-based MEMS mirrors are characterized across the transition for individual and simultaneous actuation. First, a step input train of increasing amplitude are applied to the device up to the point of transition is reached. Second, the frequency response is measured by applying a small sinusoidal input, where the displacement remained inside the hysteresis of the VO2. The frequency of the input varied from 0.1 to 2000 Hz. The thermal dynamics of the device is found to be the factor limiting the device’s band-width to less than 10 Hz. The average resonant frequency of the present VO2-based MEMS mirror was found to be 412.5 Hz for individual actuation. These results allow for the extraction of the necessary parameters to create a model that can be used to design devices with specific dynamic performance.

Controllable, High Force Amplification Using Elastic Cable Capstans

2012 ◽  
Author(s):  
Gray C. Thomas ◽  
Clayton C. Gimenez ◽  
Erica D. Chin ◽  
Andrew P. Carmedelle ◽  
Aaron M. Hoover
Keyword(s):  
Dynamic Performance ◽  
Experimental Results ◽  
Rotating Drum ◽  
Experimental Characterization ◽  
Experimental Apparatus ◽  
Linear Force ◽  
Low Torque ◽  
Robotic Applications

This paper presents the design and experimental characterization of a continuously variable linear force amplifier based on the theory of capstans. In contrast to traditional capstan amplifiers, the design presented here uses an elastic cable, enabling a control actuator to not only continuously clutch output to a rotating drum but also passively declutch by releasing tension. Our experimental results demonstrate successful declutching at all force amplification ratios up to the limit of our experimental apparatus, 21 — significantly higher than previously published values. A system of distributed capstan amplifiers driven by a central torque source with cable engagement switched by lightweight, low torque actuators has potential to reduce the mass of distal actuators and enable more dynamic performance in robotic applications.

Experimental Characterization of Wet Clutch Friction Behaviors Including Thermal Dynamics

2009 ◽  
Vol 2 (1) ◽  
pp. 1211-1220 ◽  
Author(s):  
Vladimir Ivanović ◽  
Zvonko Herold ◽  
Joško Deur ◽  
Matthew Hancock ◽  
Francis Assadian
Keyword(s):  
Experimental Characterization ◽  
Thermal Dynamics ◽  
Wet Clutch

scholarly journals Extended SINDICOMP: Characterizing MV Voltage Transformers with Sine Waves

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1715
Author(s):  
Gabriella Crotti ◽  
Giovanni D’Avanzo ◽  
Domenico Giordano ◽  
Palma Sara Letizia ◽  
Mario Luiso
Keyword(s):  
Resonance Frequency ◽  
Frequency Response ◽  
Low Voltage ◽  
Second Harmonic ◽  
Extended Version ◽  
Harmonic Frequency ◽  
Frequency Sweep ◽  
Medium Voltage ◽  
Sinusoidal Input

The paper presents a method for the frequency characterization of voltage transformers (VTs) for medium voltage (MV) grids which involves only sine waves. It is called extended SINDICOMP, since it is an extended version of the previously developed technique SINDICOMP. It requires, in the first step, an evaluation and a compensation of the non-linearity introduced by the VT when it is supplied with a 50 Hz sinusoidal input at rated value. Then, the VT is characterized with a low voltage sinusoidal frequency sweep from the second harmonic frequency up to the first resonance frequency. Some rules to build the approximated frequency response, starting from these two sets of data, are given in the paper. The proposed approach is applied to three commercial MV VTs. Significant improvement of the VT performance is obtained, compared to the use of a frequency response obtained from the low voltage characterization.

Analytical and experimental characterization of viscous fan clutch performances including thermal dynamics

2016 ◽  
Vol 231 (5) ◽  
pp. 876-891
Author(s):  
Zhihong Yin ◽  
Kegang Zhao ◽  
Wenbin Shangguan ◽  
Liming Song
Keyword(s):  
Mathematical Model ◽  
Laboratory Experiments ◽  
System Development ◽  
Experimental Setup ◽  
Experimental Characterization ◽  
Calculation Algorithm ◽  
Thermal Dynamics ◽  
Proposed Model ◽  
Viscosity Variation

This paper presents an investigation on the performance characterization of viscous fan clutch with double grooves including thermal behaviors. A detailed mathematical model of the fan clutch is established by taking into account the viscosity variation of the viscous fluid with shear radius and temperature, and an iterative algorithm is proposed to calculate the performances of the fan clutch. Laboratory experiments are then carried out on a performance measurement setup for viscous clutch, for validating the proposed mathematical model and calculation method. Based on the verified model and calculation algorithm and the experimental setup, the performances of six alternative viscous fan clutch designs are studied. The combined analytical/experimental results suggest that the clutch performances degrade with the increase of the input speed, and the proposed model and calculate method are valid and can be successfully employed to facilitate the design of new viscous fan clutches as well as control system development, for saving cost and shortening development period.

An Experimental Characterization of Cork Storage Modulus for Cork-Steel Applications in Vibration Attenuation

2010 ◽  
Vol 636-637 ◽  
pp. 1199-1205 ◽  
Author(s):  
Hugo Policarpo ◽  
M.M. Neves ◽  
A.M.R. Ribeiro
Keyword(s):  
Frequency Response ◽  
Storage Modulus ◽  
Force Transducer ◽  
Vibration Response ◽  
Experimental Setup ◽  
Experimental Characterization ◽  
Satisfactory Correlation ◽  
Dynamical Deformation ◽  
Vibration Attenuation

This study presents an experimental characterization of cork storage modulus used to model the vibration response of bars built using alternate layers of cork and steel. In the experimental setup, the specimen was suspended from a fixed support by two thin lines while a shaker was suspended from a mobile support by metallic chains. The shaker was connected to the bar specimen through a force transducer imposing a dynamical deformation that propagates through the specimen. An accelerometer in the opposite extremity of the bar measures the corresponding vibration response and the cork storage modulus is then obtained from the first peak of this frequency response. The proposed methodology successfully characterized the storage modulus of the cork material used in the multilaminated periodic bars. The results obtained illustrate a satisfactory correlation between

Experimental Characterization of the Reliability of 3-Terminal Dual-Damascene Copper Interconnect Trees

2002 ◽  
Vol 716 ◽  
Author(s):  
C. L. Gan ◽  
C. V. Thompson ◽  
K. L. Pey ◽  
W. K. Choi ◽  
F. Wei ◽  
...  
Keyword(s):  
Stress Conditions ◽  
Experimental Characterization ◽  
Contact Lines ◽  
Tree Structures ◽  
Similar Test ◽  
Dual Damascene ◽  
Copper Interconnect ◽  
Test Conditions

AbstractElectromigration experiments have been carried out on simple Cu dual-damascene interconnect tree structures consisting of straight via-to-via (or contact-to-contact) lines with an extra via in the middle of the line. As with Al-based interconnects, the reliability of a segment in this tree strongly depends on the stress conditions of the connected segment. Beyond this, there are important differences in the results obtained under similar test conditions for Al-based and Cu-based interconnect trees. These differences are thought to be associated with variations in the architectural schemes of the two metallizations. The absence of a conducting electromigrationresistant overlayer in Cu technology, and the possibility of liner rupture at stressed vias lead to significant differences in tree reliabilities in Cu compared to Al.

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