Power spectrum blind sampling using minimum mean square error and weighted least squares

Structural Health Monitoring

2017

This article assesses numerically the potential of two different spectral estimation approaches supporting non-uniformin-time data sampling at sub-Nyquist average rates (i.e. below the Nyquist frequency) to reduce data transmission payloads in wireless sensor networks for operational modal analysis of civil engineering structures. This consideration relaxes transmission bandwidth constraints in wireless sensor networks and prolongs sensor battery life since wireless transmission is the most energy-hungry on-sensor operation. Both the approaches assume acquisition of sub-Nyquist structural response acceleration measurements and transmission to a base station without on-sensor processing. The response acceleration power spectral density matrix is estimated directly from the sub-Nyquist measurements, and structural mode shapes are extracted using the frequency-domain decomposition algorithm. The first approach relies on the compressive sensing theory to treat sub-Nyquist randomly sampled data assuming that the acceleration signals are sparse/compressible in the frequency domain (i.e. have a small number of Fourier coefficients with significant magnitude). The second approach is based on a power spectrum blind sampling technique considering periodic deterministic sub-Nyquist ''multi-coset'' sampling and treating the acceleration signals as wide-sense stationary stochastic processes without posing any sparsity conditions. The modal assurance criterion is adopted to quantify the quality of mode shapes derived by the two approaches at different sub-Nyquist compression rates using computer-generated signals of different sparsity and field-recorded stationary data pertaining to an overpass in Zurich, Switzerland. It is shown that for a given compression rate, the performance of the compressive sensing-based approach is detrimentally affected by signal sparsity, while the power spectrum blind sampling-based approach achieves modal assurance criterion .0.96 independently of signal sparsity for compression ratios as low as 22% the Nyquist rate. It is concluded that the power spectrum blind sampling-based approach reduces effectively data transmission requirements in wireless sensor networks for operational modal analysis, without being limited by signal sparsity and without requiring a priori assumptions or knowledge of signal sparsity.

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Section: Mode Shapes Estimation Of the Bärenbohlstrasse Bridgementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Assessment of sub-Nyquist deterministic and random data sampling techniques for operational modal analysis

Structural Health Monitoring

2017

show abstract

“…The cross-spectrum matrix in (6) is efficiently computed directly from the cross-correlation estimator of the compressed acceleration measurements from the array of D AIC devices. This is achieved by exploiting the sparse structure of the c R matrix as detailed in [12].…”

Section: A Multicoset Sampling Strategy and Devicementioning

confidence: 99%

“…The proposed approach builds on recent work by the authors on power spectrum blind sampling (PSBS) for system identification of white-noise excited structural systems [9], [10], and extends the works in [11], [12], to achieve cross-spectral estimation from simultaneous multiple sensing channels. Specifically, the multi-coset sampling device in [11] is adopted yielding deterministic, non-uniform, periodic samples taken at a sub-Nyquist rate [13].…”

Section: Introductionmentioning

confidence: 99%

“…Specifically, the multi-coset sampling device in [11] is adopted yielding deterministic, non-uniform, periodic samples taken at a sub-Nyquist rate [13]. The PSBS technique in [12] is extended to estimate the cross-spectral matrix from subNyquist measurements from an array of such devices. The standard frequency domain decomposition algorithm [14] is finally employed to retrieve structural modal properties.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Multi-channel sub-Nyquist cross-spectral estimation for modal analysis of vibrating structures

Tausiesakul

2015 International Conference on Systems, Signals and Image Processing (IWSSIP)

2015

Self Cite

A multi-sensor sub-Nyquist power spectrum blind sampling approach for low-power wireless sensors in operational modal analysis applications

Mechanical Systems and Signal Processing

2019