Laundry treating appliance and methods of operation

Patent metadata

Field	Value
Publication number	US-9988753-B2
Application number	US-201514945903-A
Country	US
Kind code	B2
Filing date	Nov 19, 2015
Priority date	Nov 19, 2015
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

Abstract

A method of operating a laundry treating appliance includes controlling rotation of a drum during a cycle of operation by a controller communicably coupled to a motor, sending an excitation signal to a controller that randomly fluctuates an acceleration command to affect acceleration of the motor, determining, by the controller during excitation, one or more inputs sensed from the motor, and estimating with a parameter estimator parameter values of a laundry load in the drum based on the inputs. The cycle of operation can then be adjusted based on the estimated parameter values of the laundry load.

First claim

What is claimed is:

1. A method of operating a laundry treating appliance having a drum at least partially defining a treating chamber for receiving a laundry load for treatment according to a cycle of operation, and a motor operably coupled with the drum to rotate the drum, the method comprising:
controlling rotation of the drum during the cycle of operation by a controller communicably coupled to the motor;
sending an excitation signal to the controller wherein the excitation signal randomly fluctuates an acceleration command to effect acceleration of the motor;
determining, by the controller during excitation, at least one input sensed from the motor;
estimating with a parameter estimator parameter values of the laundry load in the drum based on the at least one input; and
adjusting the cycle of operation based on the estimated parameter values of the laundry load.

2. The method of claim 1 wherein the excitation signal is derived from a uniform white noise sequence.

3. The method of claim 2 wherein the uniform white noise sequence is generated by a logic for a fundamental period comprising:
{dot over (ω)}* Exc ←A WN *U[− 1,1]

where A WN is an amplitude, {acute over (ω)}* Exc is the excitation signal, and U[a,b] denotes a uniform random number in an interval [a,b].

4. The method of claim 2 wherein the excitation signal is tunable in amplitude or duration.

5. The method of claim 1 wherein the excitation signal is derived from a pseudo-random binary sequence.

6. The method of claim 5 wherein the pseudo-random binary sequence is generated by a logic comprising:
Initialize {acute over (ω)}* Exc =A PRBS ,T Exc =U[T min ,T PRBS ];

Repeat:
Wait T Exc , Wait until hold time has expired;
{acute over (ω)}* Exc ←−{acute over (ω)}* Exc , Switch to the other acceleration level;
T Exc ←U[T min , T PRBS ], Draw a new random time;
where {acute over (ω)}* Exc is the excitation signal, T Exc is an excitation time, U is a uniform random number, T PRBS is a maximum hold time, and A PRBS is an amplitude of the sequence, T min is a fixed parameter representing a minimum hold time of the sequence.

7. The method of claim 5 wherein the excitation signal is tunable in duration and the sequence alternates between two fixed acceleration levels.

8. The method of claim 1 wherein estimating the parameter values utilizes a model comprising:
T=J{dot over (ω)}+bω+c+A sin(α+β)

wherein T=torque, J=inertia, {dot over (ω)}=acceleration of the drum, ω=rotational speed of the drum, b=viscous friction, c=coulomb friction, A=amplitude of a basket speed first harmonic torque disturbance, which may be a function of an unbalance mass, surface tilt angle, gravitational acceleration, unbalance mass position, and basket speed, α=rotational position of the drum, and β=rotational position of an imbalance of the laundry load relative to the rotational position of the drum.

9. The method of claim 1 wherein the at least one input is one of a torque of the motor, an acceleration of the drum, a rotational speed of the drum, or an angular position of the drum.

Assignees

• Whirlpool Co

Inventors

• Janke Brian P
• Keres Stephen L

Classifications

• D06F37/04

  adapted for rotation or oscillation about a horizontal or inclined axis · CPC title

• D06F37/12

  adapted for rotation or oscillation about a vertical axis · CPC title

• D06F2204/065

  Textiles & Paper · mapped topic

• D06F35/005

  Methods for washing, rinsing or spin-drying · CPC title

• D06F37/304 Primary

  Arrangements or adaptations of electric motors · CPC title