Detecting satellization of a laundry load

• US 8,689,641 B2
• Filed: 07/17/2012
• Issued: 04/08/2014
• Est. Priority Date: 07/17/2012
• Status: Active Grant

• Current Assignee: Whirlpool Corporation
• Original Assignee: Whirlpool Corporation
• Inventors: Janke, Brian P., Richmond, Peter J., Keres, Stephen L.
• Primary Examiner(s): Caputo, Lisa
• Assistant Examiner(s): WILLIAMS, JAMEL E
• Application Number:
  US13/550,989
• Publication Number:
  US 20140020482A1
• Time in Patent Office: 630 Days
• Field of Search: 738/621.91, 738/621.92, 738/621.93
• US Class Current: 73/862.192
• CPC Class Codes: D06F 33/48 Preventing or reducing imbalance or noise
• CPC Class Codes: D06F 37/203 Arrangements for detecting or measuring unbalance; Preventing vibrations by regulating the speed of rotation of the drum sensing vibrations to control introduction of counterbalancing liquid D06F37/225, D06F37/245

Abstract

A method of determining satellization of a laundry load in a washing machine by filtering a drum motor torque signal to block drum frequencies and pass high frequencies to enable further conditioning of the high frequencies and facilitate efficient and accurate determination of satellization.

Claims

1. A method of determining when a laundry load has satellized within a rotating drum of a laundry treating appliance having a motor for rotating the drum and a controller for controlling the rotation of the drum, the method comprising:

accelerating the rotational speed of the drum from a non-satellizing speed to a satellizing speed by supplying a control signal from the controller to the motor;

monitoring a high frequency component of a torque signal of the motor by applying, during the accelerating, one of a high pass filter, a band pass filter, and a band stop filter to the torque signal, to permit the passing of frequencies greater than the drum frequency to generate a filtered torque signal, with the high frequency component having a frequency greater than a rotational frequency of the drum;

determining that the load is satellized when the amplitude of the high frequency component lies below a predetermined threshold relative to zero.

2. The method of claim 1, wherein the supplying a control signal comprises supplying a constant acceleration control signal.

3. The method of claim 1 wherein the high pass filter permits the passing of frequencies greater than 1.2 times the drum frequency.

4. The method of claim 1 wherein the applying a high pass filter to the torque signal comprises applying an array of high pass filters having sequentially increasing cutoff frequencies.

5. The method of claim 4 wherein each of the high pass filters comprises a stop band and a pass band, with the stop bands selected such that adjacent high pass filters have, lines, overlapping portions of the stop bands, and a transition from one of the high pass filters to the next high pass filter occurs when the drum frequency lies within the overlapping portions.

6. The method of claim 5 wherein each pass band has a frequency greater than the drum frequency.

7. The method of claim 6 wherein frequencies that are greater than or equal to 1.2 times the drum frequency are contained within the pass band of the high pass filter.

8. The method of claim 5 wherein the determining the load is satellized comprises determining when the filtered torque signal lies within a predetermined threshold relative to zero.

9. The method of claim 8 wherein the filtered torque signal is squared to generate a power signal and the determining the load is satellized comprises determining when the power signal lies within a predetermined threshold relative to zero.

10. The method of claim 9 wherein the power signal is averaged over a time window to form a windowed averaged power value and the determining the load is satellized comprises determining when the windowed averaged power value lies within a predetermined threshold relative to zero.

11. The method of claim 1 wherein the determining the load is satellized comprises determining when a filtered torque signal lies within a predetermined threshold relative to zero.

12. The method of claim 11 wherein the filtered torque signal is squared to generate a power signal and the determining the load is satellized comprises determining when the power signal lies within a predetermined threshold relative to zero.

13. The method of claim 12 wherein the power signal is averaged over a time window to form a windowed averaged power value and the determining the load is satellized comprises determining when the windowed averaged power value lies within a predetermined threshold relative to zero.