System, apparatus, and method for ice detection

Abstract

A system, apparatus, and method for determining when an amount of ice formed on an evaporator or evaporator grid has reached a predetermined size are illustrated. An acoustic transmitter an acoustic transmitter positioned proximate to the evaporator channels acoustic signals emanating from the evaporator or evaporator grid to an acoustic sensor, which generates an electronic signal indicative of the acoustic signal. A receiver module coupled to the acoustic sensor is configured to receive the electronic signal and determine that ice formed on the evaporator has reached a predetermined size based on the electronic signal.

1 . A system comprising:
 an acoustic transmitter positioned proximate to an evaporator,   an acoustic sensor coupled to the acoustic transmitter, wherein the acoustic transmitter channels acoustic signals emanating from the evaporator to the acoustic sensor and the acoustic sensor generates an electronic signal indicative of the acoustic signal; and   a receiver module coupled to the acoustic sensor and configured to receive the electronic signal and determine that ice formed on the evaporator has reached a predetermined size based on the electronic signal.   
     
     
         2 . The system of  claim 1 , wherein the receiver module is further configured to transform the electronic signal to a frequency domain and sample one or more amplitudes of the transformed electronic signal at one or more predetermined frequencies. 
     
     
         3 . The system of  claim 2 , wherein the receiver module is further configured to compare each of the one or more sampled amplitudes to a corresponding predetermined amplitude threshold, wherein when at least one of the one or more sampled amplitudes exceeds its corresponding predetermined amplitude threshold, the receiver module determines that the ice has reached the predetermined size. 
     
     
         4 . The system of  claim 2 , wherein the receiver module is further configured to compare each of the one or more sampled amplitudes to a corresponding predetermined amplitude threshold and determine that the ice has reached the predetermined size when all of the one or more sampled amplitudes exceed the corresponding predetermined amplitude thresholds. 
     
     
         5 . The system of  claim 4 , wherein the receiver module is further configured to initiate one of a harvesting operation and a defrost operation when the ice has reached the predetermined size. 
     
     
         6 . The system of  claim 1 , wherein the receiver module is further configured to initiate one of a harvest operation and a defrost operation when the ice has reached the predetermined size. 
     
     
         7 . The system of  claim 1  wherein a diaphragm of the acoustic transmitter is positioned such that a focal point of the diaphragm faces the evaporator, whereby when the ice extends from the evaporator and physically connects to the diaphragm an amplitude of the acoustic signal transmitted by the acoustic transmitter increases. 
     
     
         8 . The system of  claim 7 , further comprising a flexible acoustical transmission tube interposed between the diaphragm of the acoustic transmitter and the acoustic sensor. 
     
     
         9 . The system of  claim 1 , wherein the evaporator includes an evaporator grid, such that the acoustic transmitter is positioned proximate to the evaporator grid. 
     
     
         10 . An apparatus comprising:
 an acoustic transmitter that channels acoustic signals emanating from an evaporator grid to an acoustic sensor that generates an electronic signal indicative of the acoustic signal; and   a receiver module coupled to the acoustic sensor and configured to receive the electronic signal and determine that ice formed on the evaporator grid has reached a predetermined size based on the electronic signal.   
     
     
         11 . The apparatus of  claim 10 , wherein the receiver module is further configured to transform the electronic signal to a frequency domain and sample one or more amplitudes of the transformed electronic signal at one or more predetermined frequencies. 
     
     
         12 . The apparatus of  claim 11 , wherein the receiver module is further configured to compare each of the one or more sampled amplitudes to a corresponding predetermined amplitude threshold and determines that the ice has reached the predetermined size when at least one of the one or more sampled amplitudes exceeds its corresponding predetermined amplitude threshold. 
     
     
         13 . The apparatus of  claim 11 , wherein the receiver module is further configured to compare each of the one or more sampled amplitudes to a corresponding predetermined amplitude threshold and determine that the ice has reached the predetermined size when all of the one or more sampled amplitudes exceed the corresponding predetermined amplitude thresholds. 
     
     
         14 . The apparatus of  claim 10 , wherein the receiver module is further configured to initiate a harvesting operation when the ice has reached the predetermined size. 
     
     
         15 . The apparatus of  claim 10  wherein a diaphragm of the acoustic transmitter is positioned such that a focal point of the diaphragm faces the evaporator grid, whereby when the ice extends from the evaporator grid and physically connects to the diaphragm an amplitude of the acoustic signal transmitted by the acoustic transmitter increases. 
     
     
         16 . The apparatus of  claim 15 , further comprising a flexible acoustical transmission tube interposed between the diaphragm of the acoustic transmitter and the acoustic sensor. 
     
     
         17 . A method comprising:
 receiving an electronic signal indicative of an acoustic signal;   transforming the electronic signal from a time domain to a frequency domain;   sampling one or more amplitudes of the transformed signal at one or more predetermined frequencies; and   initiating one of a harvest operation and a defrost cycle based on the one or more sampled amplitudes.   
     
     
         18 . The method of  claim 17 , further comprising:
 comparing each of the one or more sampled amplitudes to a corresponding predetermined amplitude threshold; and   initiating the one of the harvest operation and the defrost cycle when at least one of the one or more sampled amplitudes exceeds its corresponding predetermined amplitude threshold.   
     
     
         19 . The method of  claim 17 , further comprising:
 comparing each of the one or more sampled amplitudes to a corresponding predetermined amplitude threshold; and   initiating the one of the harvest operation and the defrost cycle when all of the one or more sampled amplitudes exceeds the corresponding predetermined amplitude thresholds.