Washing machine control method

Details Washing machine control method Washing machine control method

2007-11-27

2007-11-27

Barr, Michael (Department: 1746)

Bleaching and dyeing; fluid treatment and chemical modification

Fluid treatment

Manipulation of liquid

C012S012000, C012S012000

Reexamination Certificate

active

10729986

ABSTRACT:
A washing machine control method accurately determines an amount of laundry in the washing machine, while driving a motor coupled to a drum under load, based on a computed average of pulse width modulation values at the time of stopping the drive of a motor and the motor's rotational angle as the motor freewheels to a stop, in order to conserve water and reduce the time required for performing a washing step. The method includes steps accelerating a motor to a target rotational speed, by periodically applying to the motor a pulse width modulation (PWM) signal having a predetermined duty ratio; storing in a memory a set of PWM values corresponding to the signal applied in the accelerating step, by sensing a rotational speed of the motor; outputting a PWM signal having a duty ratio of zero, after the sensed motor speed reaches the target rotational speed, to allow the motor to freewheel to a stop; computing an average of the stored PWM values; measuring a rotational angle of the motor as the motor freewheels to a stop; calculating a laundry amount estimation value based on the average of the stored PWM values and the motor's rotational angle; and determining a laundry amount by comparing the calculated laundry amount estimation value to a set of laundry amount reference values stored in a lookup table. The laundry amount estimation value equals w1PWMave+w2θmotor, where PWMaveis the computed average of the stored PWM values, θmotoris the measured rotational angle, and w1, and w2are weight constants.

REFERENCES:
patent: 4857814 (1989-08-01), Duncan
patent: 5092140 (1992-03-01), Matsuo et al.
patent: 5208931 (1993-05-01), Williams et al.
patent: 5341452 (1994-08-01), Ensor
patent: 5507054 (1996-04-01), Blauert et al.
patent: 6460381 (2002-10-01), Yoshida et al.
patent: 2002/0029428 (2002-03-01), Weinmann
patent: 0 704 568 (1996-04-01), None
patent: 1 201 811 (2002-05-01), None
patent: 2 247 250 (1992-02-01), None
patent: 2 325 245 (1998-11-01), None
patent: 05-003990 (1993-01-01), None
patent: 1999-0075775 (1999-10-01), None

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