Dehydration control apparatus and method for washing machine

Abstract

The present invention discloses a dehydration control apparatus and method for a washing machine. The dehydration control apparatus for the washing machine includes: a storing unit for storing reference unbalance quantities according to each load quantity; and a control unit for detecting a load quantity and an unbalance quantity by accelerating or decelerating a motor of the washing machine, comparing a reference unbalance quantity from the stored reference unbalance quantities that correspond to the detected load quantity with the detected unbalance quantity, and determining dehydration completion according to the comparison result.

1 . A dehydration control apparatus for a washing machine, comprising: 
 a storing unit for storing reference unbalance quantities according to each load quantity; and    a control unit for detecting a load quantity and an unbalance quantity by accelerating or decelerating a motor of the washing machine, comparing a reference unbalance quantity from the stored reference unbalance quantities that corresponds to the detected load quantity with the detected unbalance quantity, and determining dehydration completion based upon the comparison.    
   
   
       2 . The dehydration control apparatus as claimed in  claim 1 , wherein the control unit detects first, second and third load quantities and first, second and third unbalance quantities at first, second and third target speeds, selects first, second and third reference unbalance quantities corresponding to the detected first, second and third load quantities, compares the selected first, second and third reference unbalance quantities with the first, second and third unbalance quantities, respectively, and determines final dehydration based upon the comparison.  
   
   
       3 . The dehydration control apparatus as claimed in  claim 2 , wherein the first target speed, the second target speed and the third target speed satisfy ‘the first target speed<the second target speed<the third target speed’.  
   
   
       4 . The dehydration control apparatus as claimed in  claim 2 , wherein, when the first unbalance quantity detected at the first target speed is smaller than the first reference unbalance quantity corresponding to the first load quantity, the control unit increases the dehydration speed to the second target speed, constantly maintains the second target speed, and performs the dehydration operation.  
   
   
       5 . The dehydration control apparatus as claimed in  claim 2 , wherein, after performing the dehydration operation at the second target speed for a predetermined time, the control unit decreases the second target speed to the first target speed by dynamic braking, and detects the second load quantity and the second unbalance quantity.  
   
   
       6 . The dehydration control apparatus as claimed in  claim 2 , wherein, when the first unbalance quantity is larger than the first reference unbalance quantity corresponding to the first load quantity, the control unit repeatedly performs the dehydration operation by applying the first unbalance quantity, and determines final dehydration.  
   
   
       7 . The dehydration control apparatus as claimed in  claim 2 , wherein, when the second unbalance quantity detected at the second target speed is smaller than the second reference unbalance quantity corresponding to the second load quantity, the control unit increases the dehydration speed to the third target speed, constantly maintains the third target speed, and performs the dehydration operation.  
   
   
       8 . The dehydration control apparatus as claimed in  claim 2 , wherein, after performing the dehydration operation at the third target speed for a predetermined time, the control unit decreases the third target speed to the first target speed by dynamic braking, and detects the third load quantity and the third unbalance quantity.  
   
   
       9 . The dehydration control apparatus as claimed in  claim 2 , wherein, when the second unbalance quantity is larger than the second reference unbalance quantity corresponding to the second load quantity, the control unit repeatedly performs the dehydration operation by applying the second unbalance quantity, and determines final dehydration.  
   
   
       10 . The dehydration control apparatus as claimed in  claim 2 , wherein, when the third unbalance quantity is larger than the third reference unbalance quantity corresponding to the third load quantity, the control unit repeatedly performs the dehydration operation by applying the third unbalance quantity, and determines final dehydration.  
   
   
       11 . The dehydration control apparatus as claimed in  claim 2 , wherein, when the third unbalance quantity is smaller than the third reference unbalance quantity corresponding to the third load quantity, the control unit increases the dehydration speed to the third target speed, decreases the third target speed to the first target speed, and repeatedly updates the third load quantity and the third unbalance quantity until the third unbalance quantity is larger than the third reference unbalance quantity corresponding to the third load quantity.  
   
   
       12 . A dehydration control method for a washing machine which spin-dries the laundry in an optimum state, the method comprising: 
 detecting a load quantity and an unbalance quantity of the laundry by increasing or decreasing a dehydration speed; and    comparing a reference unbalance quantity corresponding to the detected load quantity with the detected unbalance quantity, and determining dehydration completion according to the comparison.    
   
   
       13 . The dehydration control method as claimed in  claim 12 , further comprising storing optimum reference unbalance quantities corresponding to each load quantity.  
   
   
       14 . A dehydration control method for a washing machine which spin-dries the laundry in an optimum state, the method comprising: 
 detecting a first load quantity and a first unbalance quantity at a first target speed in a dehydration mode;    comparing the first unbalance quantity with a first reference unbalance quantity corresponding to the first load quantity, one of accelerating a wash tub to a second target speed according to the comparison result and decelerating the wash tub to the first target speed, and detecting a second load quantity and a second unbalance quantity;    comparing the second unbalance quantity with a second reference unbalance quantity corresponding to the second load quantity, one of accelerating the wash tub to a third target speed according to the comparison result and decelerating the wash tub to the first target speed, and detecting a third load quantity and a third unbalance quantity; and    comparing the third unbalance quantity with a third reference unbalance quantity corresponding to the third load quantity, and confirming final dehydration according to the comparison result.    
   
   
       15 . The dehydration control method as claimed in  claim 14 , wherein the first target speed, the second target speed and the third target speed satisfy ‘the first target speed<the second target speed<the third target speed’.  
   
   
       16 . The dehydration control method as claimed in  claim 14 , further comprising storing optimum reference unbalance quantities corresponding to each load quantity.  
   
   
       17 . The dehydration control method as claimed in  claim 14 , wherein detecting the second load quantity and the second unbalance quantity comprises: 
 when the first unbalance quantity is smaller than the first reference unbalance quantity corresponding to the first load quantity, increasing a dehydration speed to the second target speed;    when the dehydration speed reaches the second target speed, constantly maintaining the second target speed and performing the dehydration operation; and    after a predetermined time, decreasing the second target speed to the first target speed by dynamic braking, and calculating the second load quantity and the second unbalance quantity.    
   
   
       18 . The dehydration control method as claimed in  claim 17 , wherein, in the dynamic braking, a positive terminal, a negative terminal and a ground terminal of the motor are shorted by a switch for driving the motor, and a braking torque generated by the short is applied to the motor.  
   
   
       19 . The dehydration control method as claimed in  claim 14 , further comprising repeatedly performing the dehydration operation by applying the first unbalance quantity, and determining final dehydration, when the first unbalance quantity is larger than the first reference unbalance quantity corresponding to the first load quantity.  
   
   
       20 . The dehydration control method as claimed in  claim 14 , wherein detecting the third load quantity and the third unbalance quantity comprises: 
 when the second unbalance quantity is smaller than the second reference unbalance quantity corresponding to the second load quantity, increasing the dehydration speed to the third target speed;    when the dehydration speed reaches the third target speed, constantly maintaining the third target speed and performing the dehydration operation; and    after a predetermined time elapses, decreasing the third target speed to the first target speed by dynamic braking, and calculating the third load quantity and the third unbalance quantity.    
   
   
       21 . The dehydration control method as claimed in  claim 19 , further comprising repeatedly performing the dehydration operation by applying the second unbalance quantity, and determining final dehydration, when the second unbalance quantity is larger than the second reference unbalance quantity corresponding to the second load quantity.  
   
   
       22 . The dehydration control method as claimed in  claim 14 , wherein confirming final dehydration comprises: 
 when the third unbalance quantity is larger than the third reference unbalance quantity corresponding to the third load quantity, repeatedly performing the dehydration operation by applying the third unbalance quantity, and determining final dehydration; and    when the third unbalance quantity is smaller than the third reference unbalance quantity corresponding to the third load quantity, increasing the dehydration speed to the third target speed, decreasing the third target speed to the first target speed, and repeatedly updating the third load quantity and the third unbalance quantity until the third unbalance quantity is larger than the third reference unbalance quantity corresponding to the third load quantity.