Use of Savitzky–Golay Filter for Performances Improvement of SHM Systems Based on Neural Networks and Distributed PZT Sensors

Abstract

A considerable amount of research has focused on monitoring structural damage using Structural Health Monitoring (SHM) technologies, which has had recent advances. However, it is important to note the challenges and unresolved problems that disqualify currently developed monitoring systems. One of the frontline SHM technologies, the Electromechanical Impedance (EMI) technique, has shown its potential to overcome remaining problems and challenges. Unfortunately, the recently developed neural network algorithms have not shown significant improvements in the accuracy of rate and the required processing time. In order to fill this gap in advanced neural networks used with EMI techniques, this paper proposes an enhanced and reliable strategy for improving the structural damage detection via: (1) Savitzky–Golay (SG) filter, using both first and second derivatives; (2) Probabilistic Neural Network (PNN); and, (3) Simplified Fuzzy ARTMAP Network (SFAN). Those three methods were employed to analyze the EMI data experimentally obtained from an aluminum plate containing three attached PZT (Lead Zirconate Titanate) patches. In this present study, the damage scenarios were simulated by attaching a small metallic nut at three different positions in the aluminum plate. We found that the proposed method achieves a hit rate of more than 83%, which is significantly higher than current state-of-the-art approaches. Furthermore, this approach results in an improvement of 93% when considering the best case scenario.

Beam Damage Detection Under a Moving Load Using Random Decrement Technique and Savitzky–Golay Filter

“…Once the order of SGF is chosen, the coefficients of Equation (9) (i.e., β i ) will be numerically calculated using Equation (10). De Oliveira [28] utilized a SGF with order = 10 and span = 501 to implement their SHM system. Using the SGF in civil engineering, especially in SHM field, is a relatively new topic.…”

“…Some researchers demonstrated the experimental application of SGF on the modal curvature to detect the damage in the plate-like structure [26,27]. The application of SGF on enhancing the results of SHM using a neural network algorithm was also addressed and experimentally verified by means of an alloy plate [28].…”

On the Relevance of Preprocessing in Predictive Maintenance for Dynamic Systems

“…There are many possible filters to be applied, even designed, depending on the components of the data we need to filter out [109]. Just as an example, a famous digital filter for smoothing the data is Savitzky-Golay filter [96,81,84], which is based on a local low-order polynomial interpolation using for each point a window containing some of its neighbor points. Some filters are also suitable for incremental on-line applica-tion on a streaming context [102].…”

Direct Use of the Savitzky–Golay Filter to Develop an Output-Only Trend Line-Based Damage Detection Method

“…The SGF and its family mainly attempt to find a trend line for a signal. The application of SGF on enhancing/de-noising the results of damage detection techniques to detect the damage in the plate-like structure were experimentally illustrated as well [28][29][30].…”