Laundry treatment machine and method of operating the same

Patent metadata

Field	Value
Publication number	US-9809923-B2
Application number	US-201314048990-A
Country	US
Kind code	B2
Filing date	Oct 8, 2013
Priority date	Oct 9, 2012
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

Disclosed are a laundry treatment machine and a method of operating the same. The method of operating the laundry treatment machine includes performing a primary sensing of an amount of laundry within the tub, supplying water to a first water level within the tub, sensing the level of water within the tub, performing a secondary sensing of the amount of laundry within the tub, and judging whether the laundry includes dry laundry or wet laundry using the primarily sensed amount of laundry, the secondarily sensed amount of laundry, and the sensed water level value. This method ensures efficient implementation of sensing of amount of laundry.

First claim

What is claimed is:

1. A method of operating a laundry treatment machine that processes laundry via rotation of a tub, the method comprising:
performing a primary sensing of an amount of laundry within the tub;
supplying water to a first water level within the tub;
sensing the level of water within the tub;
performing a secondary sensing of the amount of laundry within the tub;
judging whether the laundry includes dry laundry or wet laundry using the primarily sensed amount of laundry, the secondarily sensed amount of laundry, and the sensed water level value,
wherein each of the primary amount of laundry sensing and the secondary amount of laundry sensing includes:
accelerating a rotational velocity of the tub during an accelerated rotating section;
rotating the tub at a constant velocity during a constant velocity rotating section; and
calculating the amount of laundry in the tub based on a difference between an average current command value to rotate the motor during the accelerated rotating section and an average current command value to rotate the motor during a calculating section of the constant velocity rotating section,
wherein the constant velocity rotating section is divided into a stabilizing section to stabilize the tub and the calculating section to add up current command values for sensing of amount of laundry,
wherein a length of the stabilizing section is changed based on the average current command value during the accelerated rotating section, and
wherein the average current command value during the constant velocity rotating section is calculated based on the current command values during the calculating section.

2. The method of claim 1 , further comprising:
when the laundry is judged to include wet laundry, calculating the amount of laundry based on the primarily sensed amount of laundry, the secondarily sensed amount of laundry, and the sensed water level value; and
when the laundry is judged to include dry laundry, calculating the amount of laundry based on the primarily sensed amount of laundry.

3. The method of claim 1 , further comprising
rotating, in an alternating forward/reverse direction, a motor that is used to rotate the tub,
wherein said rotating occurs between the supply of water to the first water level and the sensing of the water level.

4. The method of claim 1 , further comprising
resupplying water to the first water level within the tub if the first water level is higher than the sensed water level,
wherein said resupplying occurs after the water level sensing step.

5. The method of claim 1 , wherein each of the primary amount of laundry sensing and the secondary amount of laundry sensing further comprises:
calculating a back electromotive force generated by the motor during the constant velocity rotating section,
wherein the step of calculating the amount of laundry is based on an output current during the accelerated rotating section, an output current during the constant velocity rotating section, and the back electromotive force during the constant velocity rotating section.

6. The method of claim 1 , wherein each of the accelerated rotating and the constant velocity rotating includes:
detecting current flowing through the motor;
calculating a velocity of a rotor of the motor based on the detected current;
generating a current command value based on the velocity of the rotor and a velocity command value;
generating a voltage command value based on the current command value and the detected current; and
outputting a motor drive signal based on the voltage command value.

7. The method of claim 1 , wherein the tub is accelerated to a first rotational velocity during the accelerated rotating section, and
wherein the tub is maintained at a second rotational velocity that is less than the first rotational velocity during the constant velocity rotating section.

8. The method of claim 1 , wherein the tub is accelerated to a second rotational velocity during the accelerated rotating section, and
wherein the tub is constantly rotated at the second rotational velocity during the constant velocity rotating section.

9. The method of claim 1 , wherein the judging whether the laundry includes dry laundry or wet laundry includes:
judging that the laundry includes dry laundry, if the primarily sensed amount of laundry is less than a reference value; and
judging that the laundry includes wet laundry based on the secondarily sensed amount of laundry and the sensed water level value, if the primarily sensed amount of laundry is equal to or greater than the reference value.

10. The method of claim 5 , further comprising:
aligning the motor,
wherein the motor alignment includes applying a first current to the motor and applying a second current to the motor,
wherein a tolerance between voltage command values is calculated based on the first current to the motor the second current during aligning the motor,
wherein back electromotive force compensation is calculated based on a tolerance between voltage command values, and
wherein the amount of laundry increases as the back electromotive force compensation increases.

11. The method of claim 1 , further comprising:
aligning the motor, wherein the motor alignment includes applying a first current to the motor and applying a second current to the motor,
wherein the amount of laundry increases as the difference between the average current command value to rotate the motor during the accelerated rotating section and the average current command value to rotate the motor during the constant velocity rotating section increases,
wherein equivalent resistance value of the motor is calculated based on the first current to the motor the second current during aligning the motor, and
wherein the amount of laundry increases as the calculated equivalent resistance value of the motor decreases.

Assignees

• Lg Electronics Inc

Inventors

• Lee Minkyeong
• Lee Hoonbong
• Song Hamin

Classifications

• D06F37/304

  Arrangements or adaptations of electric motors · CPC title

• D06F2202/085

  Textiles & Paper · mapped topic

• D06F39/087 Primary

  Water level measuring or regulating devices · CPC title

• D06F39/003

  Textiles & Paper · mapped topic

• D06F2202/10

  Textiles & Paper · mapped topic