title: An intelligent procedure for watermelon ripeness detection based on vibration signals.
abstract: In this paper, an efficient procedure for ripeness detection of watermelon was presented. A nondestructive method was used based on vibration response to determine the internal quality of watermelon. The responses of samples to vibration excitation were optically recorded by a Laser Doppler (LD) vibrometer. Vibration data was collected from watermelons of two qualities, namely, ripe and unripe. Vibration signals were transformed from time-domain to frequency-domain by fast Fourier transform (FFT). Twenty nine features were extracted from the FFT amplitude and phase angle of the vibration signals. K-nearest neighbor (KNN) analysis was applied as a classifier in decision-making stage. The experimental results showed that the usage of the FFT amplitude of the vibration signals gave the maximum classification accuracy. This method allowed identification at a 95.0 % level of efficiency. Hence, the proposed method can reliably detect watermelon ripeness.
authors.affiliation: Agricultural Research Institute, Iranian Research Organization for Science and Technology (IROST), Tehran, Iran.
authors.forename: Rouzbeh
authors.initials: R
authors.lastname: Abbaszadeh
authors.affiliation: Department of Mechanical Engineering of Agriculture Machinery, Tarbiat Modares University, P.O. Box: 14115-111, Tehran, Iran.
authors.forename: Ashkan
authors.initials: A
authors.lastname: Moosavian
authors.affiliation: Department of Agricultural Machinery, Faculty of Agricultural Engineering & Technology, College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Rajabipour
authors.affiliation: Department of Mechanical Engineering of Agriculture Machinery, Tarbiat Modares University, P.O. Box: 14115-111, Tehran, Iran.
authors.forename: Gholamhassan
authors.initials: G
authors.lastname: Najafi
keywords: Fast Fourier transform; Feature extraction; K-nearest neighbor; Laser Doppler vibrometry; Ripeness detection; Watermelon