Real-time vision-based modal parameters estimation at 10000 fps

2012 ◽  
Author(s):  
Hua Yang ◽  
Idaku Ishii ◽  
Takeshi Takaki
Keyword(s):  
Real Time ◽  
Parameters Estimation ◽  
Modal Parameters

scholarly journals Real Time Estimation of Modal Parameters and Their Quality Assessment

2008 ◽  
Vol 15 (3-4) ◽  
pp. 299-306 ◽  
Author(s):  
Tadeusz Uhl ◽  
Maciej Petko ◽  
Grzegorz Karpiel ◽  
Andrzej Klepka
Keyword(s):  
Laboratory Test ◽  
Quality Assessment ◽  
Real Time ◽  
Time Estimation ◽  
Parameters Estimation ◽  
Modal Parameters ◽  
Recursive Method ◽  
Test Rig ◽  
Confidence Bounds ◽  
Real Time Estimation

In this paper the recursive method for modal parameters estimation is formulated and verified. Formulated algorithms are implemented in the FPGA electronic chip. As a result, the modal parameters and confidence bounds for the modal parameters are obtained in real time. The algorithms and their implementations are tested on laboratory test rig data and applied to – flight modal analysis of an airframe structure.

Improving the accuracy of SOD for modal parameters estimation of damped systems

2014 ◽  
Vol 226 (6) ◽  
pp. 1673-1687 ◽  
Author(s):  
Mousa Rezaee ◽  
Gholamreza Fattahi Yam
Keyword(s):  
Parameters Estimation ◽  
Modal Parameters ◽  
Damped Systems

Output-Only Analysis for Modal Parameters Estimation of an Elastically Scaled Ship

2008 ◽  
Vol 52 (01) ◽  
pp. 45-56
Author(s):  
Giuliano Coppotelli ◽  
Daniele Dessi ◽  
Riccardo Mariani ◽  
Marcello Rimondi
Keyword(s):  
Life Prediction ◽  
Structural Response ◽  
Random Excitation ◽  
Parameters Estimation ◽  
Elastic Response ◽  
Modal Parameters ◽  
Practical Application ◽  
Scaled Model ◽  
Output Only ◽  
Ship Speed

The study of the ship structural response assumes an increasing importance as soon as the structures, characterized by much more lightness, are designed and built for faster vessels. This requisite implies a greater flexibility of the structures themselves, the elastic response of which has to be evaluated with accuracy in order to predict the dynamic behavior. In the present paper, a methodology for the identification of the modal parameters from the measurement of only the responses of a vibrating structure has been developed and applied to an elastically scaled model. This output-only technique is successfully applied to the segmented model of a real ship towed in the INSEAN linear basin. The broadband random excitation, provided by the loads exerted by an irregular sea pattern, induces a stochastic response of the model, which is monitored with accelerometers. The obtained results not only outline the parametric dependence of the modal properties on the ship speed, but also suggest a possible practical application of this technique for on-board structural monitoring and fatigue-life prediction.

scholarly journals Automated Harmonic Signal Removal Technique Using Stochastic Subspace-Based Image Feature Extraction

2020 ◽  
Vol 6 (3) ◽  
pp. 10
Author(s):  
Muhammad Danial Bin Abu Hasan ◽  
Zair Asrar Bin Ahmad ◽  
Mohd Salman Leong ◽  
Lim Meng Hee
Keyword(s):  
Feature Extraction ◽  
System Identification ◽  
Output Signal ◽  
Parameters Estimation ◽  
Human Interaction ◽  
Image Feature ◽  
Modal Parameters ◽  
Start Up ◽  
Stabilization Diagram ◽  
Harmonic Components

This paper presents automated harmonic removal as a desirable solution to effectively identify and discard the harmonic influence over the output signal by neglecting any user-defined parameter at start-up and automatically reconstruct back to become a useful output signal prior to system identification. Stochastic subspace-based algorithms (SSI) methods are the most practical tool due to the consistency in modal parameters estimation. However, it will be problematic when applied to structures with rotating machines and the presence of harmonic excitations. Difficulties arise when automating this procedure without any human interaction and the problem is still unresolved because stochastic subspace-based algorithms (SSI) methods still require parameters (the maximum within-cluster distance) that are compulsory to be defined at start-up for each analysis of the dataset. Thus, the use of image-based feature extraction for clustering and classification of harmonic components and structural poles directly from a stabilization diagram and for modal system identification is the focus of the present paper. As a fundamental necessary condition, the algorithm has been assessed first from computed numerical responses and then applied to the experimental dataset with the presence of harmonic excitation. Results of the proposed approach for estimating modal parameters demonstrated very high accuracy and exhibited consistent results before and after removing harmonic components from the response signal.

Simultaneous Dynamics-Based Visual Inspection Using Modal Parameter Estimation

2011 ◽  
Vol 23 (1) ◽  
pp. 180-195 ◽  
Author(s):  
Hua Yang ◽  
◽  
Takeshi Takaki ◽  
Idaku Ishii
Keyword(s):  
Parameter Estimation ◽  
Real Time ◽  
Visual Inspection ◽  
Dynamic Properties ◽  
Mode Shapes ◽  
Modal Parameters ◽  
Modal Parameter ◽  
Resonant Frequencies ◽  
Modal Parameter Estimation ◽  
Non Destructive

In this study, we introduce the concept of dynamicsbased visual inspection with High-Frame-Rate (HFR) video analysis as a novel non-destructive active sensing method for verifying dynamic properties of a vibrating object. The HFR video is used for determining the structural dynamic properties of an object, such as its resonant frequencies and mode shapes, which can be estimated as modal parameters by modal analysis only when the object is excited. By improving and implementing a fast output-only modal parameter estimation algorithm on a real-time 2000-fps vision platform, the modal parameters of an excited object are simultaneously estimated as its input-invariant dynamic properties for dynamics-based visual inspection evenwhen the objects undergo different excitation conditions. Our simultaneous 2000-fps visual inspection system can facilitate non-destructive and longterm monitoring of the structures of beam-shaped objects vibrating at dozens or hundreds of hertz, and it can detect small changes in the dynamic properties of these objects caused by internal defects such as fatigue cracks in real time, even when their static appearances are similar. To demonstrate the performance of the proposed 2000-fps simultaneous dynamics-based visual inspection approach, the resonant frequencies and mode shapes for beam-shaped cantilevers with different artificial cracks and weights, excited by human finger tapping, were estimated in real time.

A robust methodology for modal parameters estimation applied to SHM

2017 ◽  
Vol 95 ◽  
pp. 24-41 ◽  
Author(s):  
Rharã Cardoso ◽  
Alexandre Cury ◽  
Flávio Barbosa
Keyword(s):  
Parameters Estimation ◽  
Modal Parameters

scholarly journals Operational Modal Identification of Time-Varying Structures via a Vector Multistage Recursive Approach in Hybrid Time and Frequency Domain

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Si-Da Zhou ◽  
Li Liu ◽  
Wu Yang ◽  
Zhi-Sai Ma
Keyword(s):  
Parameter Estimation ◽  
Frequency Domain ◽  
Real Time ◽  
Time Estimation ◽  
Recursive Estimation ◽  
Modal Parameters ◽  
Time Varying ◽  
Modal Parameter ◽  
Structural Dynamic ◽  
Modal Parameter Estimation

Real-time estimation of modal parameters of time-varying structures can conduct an obvious contribution to some specific applications in structural dynamic area, such as health monitoring, damage detection, and vibration control; the recursive algorithm of modal parameter estimation supplies one of fundamentals for acquiring modal parameters in real-time. This paper presents a vector multistage recursive method of modal parameter estimation for time-varying structures in hybrid time and frequency domain, including stages of recursive estimation of time-dependent power spectra, frozen-time modal parameter estimation, recursive modal validation, and continuous-time estimation of modal parameters. An experimental example validates the proposed method finally.

scholarly journals An Effective Approach for Real-Time Parameters Estimation of Doubly-Fed Induction Machine Using Forgetting Factor RLS Algorithm

2020 ◽  
Vol 22 (2) ◽  
pp. 169-177 ◽  
Author(s):  
Seif-El Islam Chelli ◽  
Ahmed Nemmour ◽  
Mourad Ahmed ◽  
Abdelfettah Boussaid ◽  
Abdelmalek Khezzar
Keyword(s):  
Real Time ◽  
Induction Machine ◽  
Parameters Estimation ◽  
Forgetting Factor ◽  
Rls Algorithm ◽  
Doubly Fed Induction Machine ◽  
Time Parameters ◽  
Doubly Fed
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