Harnessing the Power of Sensors and Machine Learning to Design Smart Fence to Protect Farmlands
Table 1.List of features for accident detection.S.No
Download 2.4 Mb. View original pdf
|
sensors-18-01474
| Table 1. List of features for accident detection. S.No. Features 1 Time to raise the signal. 2 Time to drop signal. 3 Maximum signal magnitude per frame. 4 Minimum signal magnitude per frame. 5 Number of times the amplitude is set to zero Z t = 1 2 ∑ N n=1 | sign ( x [ n ]) − sign ( x [ n − 1 ])| 6 Signal strength Root-mean-square (RMS) X RMS = q 1 n ∑ n i=1 x 2 i 7 Standard deviation σ = r n 1 N ∑ N i=1 ( x i − µ ) 2 o 8 Spectral centroid : Center of gravity of the STFT scale spectrum C t = ∑ N n = 1 n·|M t [ n]| 2 ∑ N n = 1 |M t [ n]| 2 Where M t [ n ] is the magnitude of the Fourier transform at frame t and frequency n. 9 Spectral Flux: F t = ∑ n i=1 ( N t [ n ] − N t−1 [ n ]) 2 Spectral Crest Factor 11 Spectral Entropy H ( x ) = − ∑ N i=1 ( p ( x i ) log 2 p ( x i ) 12 Maximum frequency of every window. 13 Minimal frequency of every window. 14 Average cepstral coefficients at the start. 15 Standard deviation of basic frequency. Figure 6. Mel Frequency Cepstral Coefficients (MFCC) block diagram. Table 2 presents the data extracted for six animal crossing signals. The signs have been recorded in various places (such as the zoo, forests, open lands, etc.). Each signal has different characteristics that are affected by the condition of the ground, the depth of the optical fiber sensor in the ground, the gait of the animals, etc. To observe the signal model for different classes, the signals have been divided into multiple frames (window, and the frame size is calculated by dividing the whole signal. We attempted to find a model by dividing the signal time of the event by 10, 15, and 25. We split that signal by 15. After splitting the event signals into 15 images, the RMS value for each image was calculated. These RMS values were stored in the main database and used to analyze the signal template. An event signal may have two or more event signatures. Electronics 2021, 10, 3094 8 of Every signature had 15 RMS values. The RMS value for each image was saved separately for several signals. Figures 7 – 9 provide RMS values of 15 points for humans, tigers, and elephants for six different signals. The x-axis shows the number of frames and the y-axis shows the RMS value for six samples. The graph illustrates a trend that identifies different classes. Download 2.4 Mb. Share with your friends:
|