scholarly journals Study of input space for state estimation of high-rate dynamics

2018 ◽  
Vol 25 (6) ◽  
pp. e2159 ◽  
Author(s):  
Jonathan Hong ◽  
Simon Laflamme ◽  
Jacob Dodson
Keyword(s):  
State Estimation ◽  
High Rate ◽  
Input Space

scholarly journals Variable input observer for state estimation of high-rate dynamics

2017 ◽  
Author(s):  
Jonathan Hong ◽  
Liang Cao ◽  
Simon Laflamme ◽  
Jacob Dodson
Keyword(s):  
State Estimation ◽  
High Rate

Optimization of Rapid State Estimation in Structures Subjected to High-Rate Boundary Change

2020 ◽  
Author(s):  
James Scheppegrell ◽  
Adriane G. Moura ◽  
Jacob Dodson ◽  
Austin Downey
Keyword(s):  
Frequency Response ◽  
State Estimation ◽  
Real Time ◽  
Performance Metrics ◽  
Numerical Models ◽  
Vertical Axis ◽  
High Rate ◽  
Position Measurement ◽  
Data Set ◽  
Variable Boundary

Abstract Many structures are subjected to varying forces, moving boundaries, and other dynamic conditions. Whether part of a vehicle, building, or active energy mitigation device, data on such changes can represent useful knowledge, but also presents challenges in its collection and analysis. In systems where changes occur rapidly, assessment of the system’s state within a useful time span is required to enable an appropriate response before the system’s state changes further. Rapid state estimation is especially important but poses unique difficulties. In determining the state of a structural system subjected to high-rate dynamic changes, measuring the frequency response is one method that can be used to draw inferences, provided the system is adequately understood and defined. The work presented here is the result of an investigation into methods to determine the frequency response, and thus state, of a structure subjected to high-rate boundary changes in real-time. In order to facilitate development, the Air Force Research Laboratory created the DROPBEAR, a testbed with an oscillating beam subjected to a continuously variable boundary condition. One end of the beam is held by a stationary fixed support, while a pinned support is able to move along the beam’s length. The free end of the beam structure is instrumented with acceleration, velocity, and position sensors measuring the beam’s vertical axis. Direct position measurement of the pin location is also taken to provide a reference for comparison with numerical models. This work presents a numerical investigation into methods for extracting the frequency response of a structure in real-time. An FFT based method with a rolling window is used to track the frequency of a data set generated to represent the range of the DROPBEAR, and is run with multiple window lengths. The frequency precision and latency of the FFT method is analyzed in each configuration. A specialized frequency extraction technique, Delayed Comparison Error Minimization, is implemented with parameters optimized for the frequency range of interest. The performance metrics of latency and precision are analyzed and compared to the baseline rolling FFT method results, and applicability is discussed.

Methodology for Real-time State Estimation at Unobserved Locations for Structures Experiencing High-rate Dynamics

2019 ◽  
Author(s):  
AUSTIN DOWNEY ◽  
JONATHAN HONG ◽  
BRYAN JOYCE ◽  
JACOB DODSON ◽  
CHAO HU ◽  
...  
Keyword(s):  
State Estimation ◽  
Real Time ◽  
High Rate

scholarly journals Multi-Sensor Linear State Estimation Under High Rate Quantization

2012 ◽  
Vol 45 (26) ◽  
pp. 115-120
Author(s):  
Alex S. Leong ◽  
Subhrakanti Dey ◽  
Girish N. Nair
Keyword(s):  
State Estimation ◽  
High Rate ◽  
Linear State

scholarly journals Introduction to State Estimation of High-Rate System Dynamics

Sensors ◽  
2018 ◽  
Vol 18 (2) ◽  
pp. 217 ◽  
Author(s):  
Jonathan Hong ◽  
Simon Laflamme ◽  
Jacob Dodson ◽  
Bryan Joyce
Keyword(s):  
System Dynamics ◽  
State Estimation ◽  
High Rate ◽  
Rate System

Structure of Palladium Single-Crystal Films Prepared by Flash Evaporation onto (001) NaCl Substrates

1970 ◽  
Vol 28 ◽  
pp. 456-457
Author(s):  
L. E. Murr ◽  
G. Wong
Keyword(s):  
Single Crystal ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
High Rate ◽  
Flash Evaporation ◽  
Optimum Load ◽  
Single Crystal Films ◽  
Crystal Films ◽  
A Current

Palladium single-crystal films have been prepared by Matthews in ultra-high vacuum by evaporation onto (001) NaCl substrates cleaved in-situ, and maintained at ∼ 350° C. Murr has also produced large-grained and single-crystal Pd films by high-rate evaporation onto (001) NaCl air-cleaved substrates at 350°C. In the present work, very large (∼ 3cm2), continuous single-crystal films of Pd have been prepared by flash evaporation onto air-cleaved (001) NaCl substrates at temperatures at or below 250°C. Evaporation rates estimated to be ≧ 2000 Å/sec, were obtained by effectively short-circuiting 1 mil tungsten evaporation boats in a self-regulating system which maintained an optimum load current of approximately 90 amperes; corresponding to a current density through the boat of ∼ 4 × 104 amperes/cm2.

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