Method and apparatus for controlling motor, washing machine, and method of controlling the washing machine

Abstract

A method and apparatus for controlling a motor, a washing machine, and a method of controlling the washing machine that efficiently calculate an amount of laundry within a drum are provided. The method of controlling a washing machine that calculates an amount of laundry housed within a drum rotating by a motor, the method includes: accelerating the drum from a first rotation speed to a second rotation speed by enabling the motor to apply torque to the drum in a predetermined direction and decelerating the drum from the second rotation speed to the first rotation speed by enabling the motor to apply torque to the drum in an opposite direction; and calculating the laundry amount from the sum of currents applied to the motor at the accelerating of the drum.

1 . A method of controlling a washing machine that calculates an amount of laundry housed within a drum rotated by a motor, the method comprising:
 accelerating the drum from a first rotation speed to a second rotation speed by enabling the motor to apply torque to the drum in a predetermined direction and decelerating the drum from the second rotation speed to the first rotation speed by enabling the motor to apply torque to the drum in an opposite direction; and   calculating the amount of laundry from a sum of currents applied to the motor at the accelerating of the drum.   
     
     
         2 . The method of  claim 1 , wherein the first rotation speed and the second rotation speed are speeds at which laundry sticks to the drum and rotates. 
     
     
         3 . The method of  claim 2 , wherein the first rotation speed is 70 rpm, and the second rotation speed is 120 rpm. 
     
     
         4 . The method of  claim 1 , wherein accelerating the drum comprises repeatedly accelerating the drum, and thereafter the calculating the amount of laundry. 
     
     
         5 . The method of  claim 1 , wherein partial acceleration that accelerates the drum from the first rotation speed to the second rotation speed and partial deceleration that decelerates the drum from the second rotation speed to the first rotation speed have the same magnitude. 
     
     
         6 . The method of  claim 5 , wherein a magnitude of the partial acceleration is 20 rpm/s. 
     
     
         7 . The method of  claim 1 , wherein calculating the amount of laundry comprises calculating the sum of currents applied to the motor and the amount of laundry from a position of the motor. 
     
     
         8 . The method of  claim 1 , wherein accelerating the drum comprises accelerating the drum to the second rotation speed, maintaining the drum at the second rotation speed, and decelerating the drum to the first rotation speed. 
     
     
         9 . A washing machine comprising:
 a rotatable drum that receives laundry;   a motor that rotates the drum;   a motor driver that controls the motor by applying a current to the motor to accelerate the drum from a first rotation speed to a second rotation speed by enabling the motor to apply torque to the drum in a predetermined direction and to decelerate the drum from the second rotation speed to the first rotation speed by enabling the motor to apply torque to the drum in an opposite direction; and   a laundry amount calculation unit that calculates an amount of laundry housed to the drum from the sum of currents which the motor driver applies to the motor.   
     
     
         10 . The washing machine of  claim 9 , wherein the first rotation speed and the second rotation speed are speeds at which laundry sticks to the drum and rotates. 
     
     
         11 . The washing machine of  claim 10 , wherein the first rotation speed is 70 rpm, and the second rotation speed is 120 rpm. 
     
     
         12 . The washing machine of  claim 9 , wherein the motor driver controls the motor to repeatedly accelerate and decelerate the drum. 
     
     
         13 . The washing machine of  claim 9 , wherein partial acceleration in which the motor accelerates the drum from the first rotation speed to the second rotation speed and partial deceleration in which the motor decelerates the drum from the second rotation speed to the first rotation speed have the same magnitude. 
     
     
         14 . The washing machine of  claim 13 , wherein a magnitude of the partial acceleration is 20 rpm/s. 
     
     
         15 . The washing machine of  claim 9 , wherein the laundry amount calculating unit stores the sum of currents corresponding to various laundry amounts as a profile and calculates the laundry amount using the profile. 
     
     
         16 . The washing machine of  claim 9 , wherein the motor driver accelerates the drum to the second rotation speed, maintains the drum at the second rotation speed, and decelerates the drum to the first rotation speed.