Cloth bunching detection and adjustment for an automatic washer

Abstract

A method and apparatus for determining the bunching of fabric items during a wash process.

1 . A method for determining the degree of bunching of fabric articles in an automatic washer comprising a wash tub in which is disposed a wash basket defining a wash chamber configured to receive the fabric articles and an article mover located within the wash chamber and reciprocally driven by a motor between a forward stroke and backward stroke to impart mechanical energy to the fabric articles, the method comprising:
 determining a characteristic of a waveform for at least one of the motor speed and motor current for each of the forward and backward strokes; and   determining the degree of bunching by comparing the determined characteristic for each of the forward and backward strokes.   
   
   
       2 . The method according to  claim 1  wherein determining the characteristic comprises determining an amplitude of the waveform for each of the forward and backward strokes. 
   
   
       3 . The method according to  claim 2  wherein the comparing of the amplitudes comprises determining the difference between the amplitudes of the motor current waveform. 
   
   
       4 . The method according to  claim 3  wherein the difference is compared to a threshold value to determine the degree of bunching. 
   
   
       5 . The method according to  claim 3  wherein the comparing of the amplitudes comprises determining the mean square of the difference between the amplitudes. 
   
   
       6 . The method according to  claim 3  wherein the difference between the amplitudes is determined for multiple pairs of the forward and backward strokes. 
   
   
       7 . The method according to  claim 6  wherein the comparing of the amplitudes comprises determining the mean square of the differences for the multiple pairs of forward and backward strokes. 
   
   
       8 . The method according to  claim 6  wherein the multiple differences are averaged. 
   
   
       9 . The method according to  claim 8  wherein the average is compared to a threshold value to determine the degree of bunching. 
   
   
       10 . The method according to  claim 3  wherein the determining the difference of the amplitudes comprises at least one of determining a difference between a current wave form for each of the forward and backward strokes and determining a difference between a point of each of the waveforms for the forward and backward strokes. 
   
   
       11 . The method according to  claim 2  wherein the determining of the amplitudes comprises determining amplitudes at the same relative time for each of the forward and backward strokes. 
   
   
       12 . The method according to  claim 11  wherein the comparing of the amplitudes comprises determining the difference between the amplitudes. 
   
   
       13 . The method according to  claim 12  wherein the difference is compared to a threshold value to determine the degree of bunching. 
   
   
       14 . The method according to  claim 12  wherein the comparing of the amplitudes comprises determining the mean square of the difference between the amplitudes. 
   
   
       15 . The method according to  claim 12  wherein the difference between the amplitudes is determined for multiple pairs of the forward and backward strokes. 
   
   
       16 . The method according to  claim 15  wherein the comparing of the amplitudes comprises determining the mean square of the differences for the multiple pairs of forward and backward strokes. 
   
   
       17 . The method according to  claim 15  wherein the multiple differences are averaged. 
   
   
       18 . The method according to  claim 17  wherein the average is compared to a threshold value to determine the degree of bunching. 
   
   
       19 . The method according to  claim 1  wherein determining the characteristic comprises determining a frequency of the waveform for each of the forward and backward strokes. 
   
   
       20 . The method according to  claim 19  wherein the comparing of the frequencies comprises determining the difference between the frequencies. 
   
   
       21 . The method according to  claim 20  wherein the difference is compared to a pre-determined value. 
   
   
       22 . The method according to  claim 19  and further comprising repeating the determination of the frequencies for multiple forward strokes and backward strokes. 
   
   
       23 . The method according to  claim 22  and further comprising determining an average frequency for the forward strokes and an average frequency for the backward strokes. 
   
   
       24 . The method according to  claim 23  wherein the comparing the determined frequencies comprises comparing the average frequencies. 
   
   
       25 . The method according to  claim 24  wherein the comparing of the frequencies comprises determining the difference between the average frequencies. 
   
   
       26 . The method according to  claim 25  wherein the difference is compared to a pre-determined value. 
   
   
       27 . The method according to  claim 22  wherein the determining of the frequency comprises determining an average frequency for the forward strokes and an average frequency for the backward strokes. 
   
   
       28 . The method according to  claim 27  wherein the comparing the determined frequencies comprises comparing the average frequencies. 
   
   
       29 . The method according to  claim 28  wherein the comparing of the frequencies comprises determining the difference between the average frequencies. 
   
   
       30 . A method for controlling the operation of an automatic washer comprising a wash tub in which is disposed a wash basket defining a wash chamber configured to receive fabric articles and an article mover located within the wash chamber and reciprocally driven by a motor between a forward stroke and backward stroke to impart mechanical energy to the fabric articles, the method comprising:
 determining a characteristic of a waveform for at least one of the speed and current for the motor for each of the forward and backward strokes;   determining the bunching of the fabric articles from the determined characteristics; and   controlling an operating cycle of the automatic washer based on the determined characteristics.   
   
   
       31 . The method according to  claim 30  wherein the determining of the bunching comprises comparing the characteristics. 
   
   
       32 . The method according to  claim 31  wherein the determining a characteristic comprises determining an amplitude of the motor current waveform for each of the forward and backward strokes. 
   
   
       33 . The method according to  claim 32  wherein the comparing of the characteristics comprises comparing the amplitudes by determining the difference between the amplitudes. 
   
   
       34 . The method according to  claim 33  wherein the difference is compared to a threshold value to determine the degree of bunching. 
   
   
       35 . The method according to  claim 33  wherein the comparing of the amplitudes comprises determining the mean square of the difference between the amplitudes. 
   
   
       36 . The method according to  claim 33  wherein the difference between the amplitudes is determined for multiple pairs of the forward and backward strokes. 
   
   
       37 . The method according to  claim 36  wherein the comparing of the amplitudes comprises determining the mean square of the differences for the multiple pairs of forward and backward strokes. 
   
   
       38 . The method according to  claim 36  wherein the multiple differences are averaged. 
   
   
       39 . The method according to  claim 36  wherein the average is compared to a threshold value to determine the degree of bunching. 
   
   
       40 . The method according to  claim 36  wherein the determining the difference of the amplitudes comprises at least one of determining a difference between a current wave form for each of the forward and backward strokes and determining a difference between a point of each of the waveforms for the forward and backward strokes. 
   
   
       41 . The method according to  claim 32  wherein the determining of the amplitudes comprises determining an amplitude at the same relative time for each of the forward and backward strokes. 
   
   
       42 . The method according to  claim 41  wherein the comparing of the amplitudes comprises determining the difference between the amplitudes. 
   
   
       43 . The method according to  claim 42  wherein the difference is compared to a threshold value to determine the degree of bunching. 
   
   
       44 . The method according to  claim 42  wherein the comparing of the amplitudes comprises determining the mean square of the difference between the amplitudes. 
   
   
       45 . The method according to  claim 42  wherein the difference between the amplitudes is determined for multiple pairs of the forward and backward strokes. 
   
   
       46 . The method according to  claim 45  wherein the comparing of the amplitudes comprises determining the mean square of the differences for the multiple pairs of forward and backward strokes. 
   
   
       47 . The method according to  claim 45  wherein the multiple differences are averaged. 
   
   
       48 . The method according to  claim 47  wherein the average is compared to a threshold value to determine the degree of bunching. 
   
   
       49 . The method according to  claim 30  wherein the controlling of the operating cycle comprises adjusting at least one of the impeller stroke and water level in the wash chamber. 
   
   
       50 . The method according to  claim 49  and further comprises adjusting of the operating cycle after at least one pair of strokes and after many multiple pairs of strokes. 
   
   
       51 . The method according to  claim 49  and further comprises immediate adjustment of the operating cycle when the bunching is determined to be very high. 
   
   
       52 . The method according to  claim 51  wherein the adjustment of the operating cycle comprises stopping the cycle. 
   
   
       53 . The method according to  claim 49  wherein the adjusting of the impeller stroke comprises at least one of increasing the speed and shortening the length of the impeller stroke 
   
   
       54 . The method according to  claim 49  wherein the adjusting of the water level in the wash chamber comprises increasing the water level in at least one of the wash chamber and wash basket. 
   
   
       55 . The method according to  claim 31  wherein determining the characteristic comprises determining a frequency for each of the forward and backward strokes. 
   
   
       56 . The method according to  claim 55  and further comprising repeating the determination of the frequencies for multiple forward strokes and backward strokes. 
   
   
       57 . The method according to  claim 56  and further comprising determining an average frequency for the forward strokes and an average frequency for the backward strokes. 
   
   
       58 . The method according to  claim 57  wherein the comparing the determined frequencies comprises comparing the average frequencies. 
   
   
       59 . The method according to  claim 58  wherein the comparing of the frequencies comprises determining the difference between the average frequencies. 
   
   
       60 . The method according to  claim 55  wherein the determining of a frequency comprises determining an average frequency for each of the forward and backward strokes. 
   
   
       61 . The method according to  claim 60  wherein the determining of the bunching comprises comparing the determined average frequencies. 
   
   
       62 . The method according to  claim 61  wherein the comparing of the frequencies comprises determining the difference between the average frequencies. 
   
   
       63 . The method according to  claim 62  wherein the difference is compared to a pre-determined value. 
   
   
       64 . An automatic clothes washer comprising:
 a wash chamber for receiving fabric items;   a clothes mover located within the wash chamber;   a motor operably coupled to the clothes mover to move the clothes mover relative to the wash chamber; and   a sensor configured to determine the degree of bunching of the fabric items in the wash chamber.   
   
   
       65 . The automatic clothes washer according to  claim 64 , wherein the sensor is a real-time sensor. 
   
   
       66 . The automatic clothes washer according to  claim 65 , wherein the real-time sensor comprises at least one of a motor speed sensor and motor current sensor. 
   
   
       67 . The automatic clothes washer according to  claim 66 , wherein the real-time sensor further comprises a controller configured to receive an output from one of the motor speed sensor and the motor current sensor. 
   
   
       68 . The automatic clothes washer according to  claim 67 , wherein the controller is configured to determine the degree of bunching from the output. 
   
   
       69 . The automatic clothes washer according to  claim 70 , wherein the output is a determined characteristic of a waveform for at least one of the motor speed and motor current for each of the forward and backward strokes. 
   
   
       70 . The method according to  claim 69  wherein determining the characteristic comprises determining the amplitude from the motor current sensor. 
   
   
       71 . The method according to  claim 69  wherein determining the characteristic comprises determining the frequency from at least one of the motor current sensor or the motor speed sensor.