Digital Filter Design for Classifying Coconut Ages using Blackman FIR and Elliptic IIR Filters

Tapping a coconut fruit is one of conventional ways that requires specialty in determining the ages of the fruit. The frequency of these taps can be used as a reference to determine the ages of coconut. This study aims to make an automatic device to determine coconut ages using digital filter based on the tapping frequency. The filter could screen the received signals in order to produce clear tapping sounds, or without noises. Two filter types namely Blackman Finite Impulse Response (FIR) and Elliptic Infinite Impulse Response (IIR) were used to reveal the filter's length and order. MATLAB software was used in the filter testing to compare the responses of the two filters used. Results depicted that Elliptical IIR was better that Blackman FIR, of which the Elliptical IIR produced less noises and better frequency responses.