U.S. patent application number 12/108564 was filed with the patent office on 2009-10-29 for adaptive drain algorithm for clothes washers.
This patent application is currently assigned to General Electric Company. Invention is credited to Stephen Edward Hettinger, James Quentin Pollett.
Application Number | 20090265863 12/108564 |
Document ID | / |
Family ID | 41212296 |
Filed Date | 2009-10-29 |
United States Patent
Application |
20090265863 |
Kind Code |
A1 |
Hettinger; Stephen Edward ;
et al. |
October 29, 2009 |
ADAPTIVE DRAIN ALGORITHM FOR CLOTHES WASHERS
Abstract
This disclosure is related to a system and method which
minimizes the period of time in which a drain pump is running in a
washing machine unit. The method includes determining the amount of
washer fluid used to fill a washing machine tub when the washing
machine has entered the draining portion of the cycle, measuring
the time it takes in order to trip a water level sensor. The method
generally continues with calculating a predicted time to drain and
operating a drain pump according to the predicted time to drain.
Use of this method minimizes the opportunities for machine
malfunctions while further minimizing the opportunity for the pump
to run dry, creating noise and increasing the length of the entire
washing cycle.
Inventors: |
Hettinger; Stephen Edward;
(Louisville, KY) ; Pollett; James Quentin;
(Louisville, KY) |
Correspondence
Address: |
Fay Sharpe LLP
1228 Euclid Avenue, 5th Floor, The Halle Building
Cleveland
OH
44115
US
|
Assignee: |
General Electric Company
|
Family ID: |
41212296 |
Appl. No.: |
12/108564 |
Filed: |
April 24, 2008 |
Current U.S.
Class: |
8/158 ;
68/12.05 |
Current CPC
Class: |
D06F 2202/085 20130101;
D06F 2204/084 20130101; D06F 33/00 20130101; D06F 2220/00 20130101;
D06F 39/085 20130101 |
Class at
Publication: |
8/158 ;
68/12.05 |
International
Class: |
D06F 33/02 20060101
D06F033/02; D06F 39/08 20060101 D06F039/08 |
Claims
1. A method for minimizing the period of time in which a drain pump
is running in a vertical load washing machine comprising:
determining an amount of fluid to fill a washing machine tub;
measuring a time between a first level and a second level in said
washing machine tub during draining; calculating a predicted time
to drain based at least in part on said time and said amount to
fill; and operating a drain pump for a period of time related to
said predicted time to drain.
2. The method according to claim 1, further comprising: deriving a
minimum drain time; and operating said drain pump for at least said
minimum drain time.
3. The method according to claim 1, further comprising: setting
minimal threshold for said predicted time to drain; and if
predicted time to drain does not meet said threshold, operating
said drain pump for said predicted time to drain and operating said
drain pipe a second time for at least a portion of time until said
threshold is meet.
4. The method according to claim 1, wherein at said first level
there is a first pressure switch and at said second level there is
a second pressure switch.
5. The method according to claim 4, further comprising checking for
defects in said first and second pressure switches.
6. The method according to claim 4, wherein said first pressure
switch is configured to act as a safety switch in order to prevent
flooding.
7. The method according to claim 1, wherein determining said amount
of fluid to fill said washing machine tub includes using a constant
flow rate valve.
8. The method according to claim 1, wherein the determining said
amount of fluid to fill said washing machine tub included using a
flow meter.
9. The method according to claim 1, further comprising proceeding
to the next cycle after said period of time has passed.
10. The method according to claim 1, wherein calculating said
predicted time is according to the formula A+B(TTT)-C(GTF) where A,
B and C are constants and TTT is the time to trip and GTF is said
measure of fluid.
11. A method of operating a drain pump in order to minimize the
length of time a drain pump is running to drain a washer tub
comprising: determining a measure of fluid to fill said washer tub;
initiating a timer; initiating a drain pump; recording a time to
trip where said time to trip is the time it takes from the start of
said drain pump to when a lower switch trips; and calculating a
predicted time to drain based at least in part on said time to trip
and said measure of fluid to fill said washer tub.
12. The method according to claim 11, further comprising: turning
off the drain pump if an upper level switch does not trip and said
lower level switch does trip; and registering a fault of the upper
level switch.
13. The method according to claim 11, further comprising if said
lower level switch has not tripped when said timer reaches a
predetermined amount of time turning off said drain pump; and
registering a lower switch fault.
14. A system for an adaptive drain that calculates a predicted time
for a washing machine to drain out fluid comprising: a washer tub
having an upper level switch and a lower level switch; a drain pump
configured to pump an amount of fluid out of said washer tub; and a
controller adapted to regulate said drain pump to drain said washer
tub for a period of time calculated to reflect a relationship
between the time between the initiation of said drain pump, the
time for said upper level switch to trip, and the time for said
lower level switch to trip and the amount of fluid that said tub is
holding.
15. The system according to claim 14 wherein said upper level
switch is a control switch that signals when said washer tub is in
danger of overflowing.
16. The system according to claim 14 wherein said upper level
switch and lower level switch are pressure switches.
17. The system according to claim 14 wherein said upper level
switch and said lower level switch include fault detection.
18. The system according to claim 17 wherein said upper level
switch and said lower level switch reset after a fault is
cleared.
19. The system according to claim 14 wherein said controller is
further configured to calculate said period of time to drain based
on a predicted to drain according to the formula A+B(TTT)-C(GTF)
where A, B and C are constants and TTT is the time to trip and GTF
is said measure of fluid.
20. The system according to claim 14 further comprising a constant
flow rate value adapted to measure the amount of fluid used to fill
said washer tub.
Description
BACKGROUND
[0001] This disclosure relates to a method and apparatus for an
adaptive drain. More particularly, this disclosure is directed
towards a method and apparatus for minimizing the period of time in
which a drain pump is running in a washing machine by use of an
adaptive drain that can establish a predicted time to drain so that
a washing machine cavity or tub may be drained during a portion of
time within the washing cycle. However, this application should not
be limited to that particular application and may find application
benefit in related environments and uses. For example, this
disclosure may have application in regulating the time it takes to
drain other appliances.
[0002] A need exists for a product that provides a means to predict
the time in which a washer tub will become empty during the
draining portion of the washing cycle. Currently in the art, washer
machines generally have a default time in which a drain pump
operates. Historically, this default time would be a time between
when a drain pump is initiated and the unit proceeds to the next
cycle. While this works in many cases, it has the disadvantage of a
pump running for that full time period when it is not necessary.
This situation unnecessarily generates noise, especially when the
washer tub has already emptied and can lead to customer
dissatisfaction. In other situations, the tub may not have fully
emptied within the set period of time. This may be the result of
restrictive drain situations (e.g. elevated drainage systems) or
when there are large loads put into the washer and may create
machine malfunctions upon progressing to the next washer cycle, for
example, the spin cycle.
[0003] Some newer washers have electronic controls which monitor
the pump current draw. When the wash tub empties and the pump runs
dry, the pump current draw correspondingly decreases. The control
senses this decrease in current draw and can hence take appropriate
action, such as shut off the drain pump. While this system works
well, it adds a significant cost to the washing machine through
adding current sensing hardware to the electronic control.
[0004] Therefore, there is a need in the industry to provide a
method and system for predicting when a tub will empty given
different variable factors. These factors may include load size and
drain system restrictions. Furthermore, there exists a need in the
industry for this system not to add significant cost to the washer
machine. This disclosure solves the aforementioned problems and
others.
SUMMARY OF THE DISCLOSURE
[0005] A method for minimizing the period of time in which a drain
pump is running in a vertical load washing machine is
disclosed.
[0006] An exemplary method includes determining an amount of fluid
to fill a washer machine tub; measuring a time to reach a first
level and a second level in the washing machine tub during
draining; calculating a predicted time to drain the wash tub based,
at least in part, on the time to reach a predetermined level in the
wash tub during drain and the initial amount of fill, and operating
a drain pump for a period of time related to the predicted time to
drain.
[0007] An exemplary method may also include that the first and
second levels are pressure switches that may contain fault
detection mechanisms.
[0008] An exemplary embodiment of a method of operating an adaptive
drain includes determining a measure of fluid in a washer tub;
initiating a timer; initiating a drain pump; recording a time to
reach a predetermined level in the wash tub, and calculating a
predicted time to drain based at least in part on the time to reach
a predetermined level in the wash tub and the measure of fill in
the washer tub.
[0009] An exemplary embodiment may also include a system for an
adaptive drain that calculates a predicted time for a washing
machine to drain out fluid comprising a washer tub having an upper
level switch and a lower level switch; a drain pump configured to
pump an amount of fluid out of the washer tub, and a controller
adapted to regulate the drain pump in order to drain the washer tub
for a period of time that is calculated to reflect a relationship
between the time between initiation of the drain pump and the time
to reach a predetermined lower level and the amount of fluid in the
tub.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 shows the environment in which the adaptive drain
system is configured to operate including a washer tub and a drain
pump;
[0011] FIG. 2 shows the washer tub of FIG. 1 with fluid filled to a
first level or amount;
[0012] FIG. 3 shows the washer tub of FIG. 1 and FIG. 2 with fluid
filled to a second level;
[0013] FIG. 4 shows a flow diagram outlining the method according
to one embodiment of the disclosure;
[0014] FIG. 5a shows a flow diagram outlining a method according to
another embodiment of the disclosure.
[0015] FIG. 5b shows the continuation of FIG. 5a.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0016] This disclosure relates to software program that provides a
means to predict the time when a washer tub will become empty
during the draining portion of a cycle without adding product cost.
In one embodiment of this disclosure, the washing machine includes
of a tub for holding wash water and at least one water level
detection sensor which is used to detect the water level. Upon the
washing machine filling with water, a controller records the amount
of water being dispensed into the tub. After the unit fills, the
agitation portion of the cycle is completed. The unit then proceeds
to the draining portion of the cycle. A timer is initiated when the
drain pump begins draining the water from the tub. The level
detection sensor monitors the time at which the water reaches a
predetermined level. This information is recorded and a controller
tabulates the empirical data and performs a calculation in order to
predict a time period upon which the tub will be emptied. The pump
then proceeds to pump that duration of calculated time.
[0017] Shown in FIG. 1 is a representation of some of the relevant
elements of a washing machine. As shown, FIG. 1 includes a washer
tub 102 including an upper level sensor 104 and a lower level
sensor 106. Inside of the washer tub 102 is an agitation device 108
which may be an agitator, a pulsator, an impeller, a wash plate, or
any other comparable device used to impart mechanical action to the
wash load. Adjacent to the washer tub is a fill pipe 112 and a
drain pump 114. This is but one embodiment of the system into which
the claimed disclosure may be implemented. A variety of other
systems exists and will still fit within the scope and spirit of
the present disclosure.
[0018] The washer tub 102 may be filled by the fluid passing (or
flowing) through the fill pipe 112. The fill pipe 112 is configured
to dispense washer fluid, e.g., water into the washer tub 102, in
order to wash clothes. The amount of fluid introduced into the tub
can be determined by a flow rate valve 116. The flow rate valve 116
is adjacent to the fill pipe 112 and is generally adapted to
measure the amount of fluid that passes through the fill pipe 112
and into the washer tub 102. A controller 118 records the amount of
water dispensed into the tub 102. This may be accomplished through
multiple means, although one common implementation includes using a
timed fill with the regulated flow rate.
[0019] After the unit fills with wash water, the washer proceeds to
the washing portion of the cycle. This portion is well known in the
art and may include an agitation cycle where the agitation device
108, moves the clothes that need to be washed.
[0020] Once the washing portion of the cycle is complete the unit
proceeds to the draining portion of the cycle. At this portion, the
drain pump 114 is actuated and the fluid begins to be removed from
the washer tub 102. The controller 118, through a process described
in further detail below, dictates how long the drain pump 114
operates. This time period is preferably the minimal amount of time
required for the fluid to be removed from the tub 102. This
calculation takes into account the amount to fill the tub 102 which
was previously recorded and the time for the water level to reach
at least the lower level sensor 106.
[0021] FIG. 2 shows the system of FIG. 1 with water 120 filled up
to the upper level sensor 104. One level of water while the washing
machine unit is engaged in the washing portion of the cycle is
illustrated. It should, however, be noted that this is but one
embodiment of the disclosure. The washing machine tub is filled
with water up to or above the upper level sensor. In another
embodiment, the water does not fill to an upper level sensor. In
yet another embodiment, there is no upper level sensor in which to
measure the level of water. It should also be noted that these
levels and proportions illustrated in the figures are not
necessarily shown to scale and the sensors may be spaced in
different positions relative to the washer tub 102.
[0022] FIG. 3 shows the water level 122 after the tub has been
drained to the height of the lower level sensor 106. At this point
a time to trip (TTT) may be measured by calculating the time from
the initiation of the drain pump 114 until the water level has
reached the lower level sensor 106 as shown as the difference in
water height level when comparing FIG. 2 to FIG. 3. A first level
could be used while not including an upper level sensor 104. For
example, in this embodiment the time to trip may equal the time
between when the drain pump 114 was initiated until the time the
water level 122 reached the lower level sensor 106. In any event,
the controller 118 may use the time to trip value and amount to
fill value in order to calculate a predicted time to drain (PTTD)
value. In this manner the controller 118 regulates the amount of
time in which the drain pump 114 will operate in relation to the
predicted time to drain. This value is useful in calculating a
minimum time that the drain pump should run that will still ensure
that all of the fluid will be drained from the washer tub 102.
[0023] Now referring to FIG. 4, a flow chart showing some of the
steps for one embodiment of the disclosure is shown. The method
begins with determining the fill amount (at step 402). In one
embodiment, the fill amount through the fill pipe 112 is calculated
by measuring the consistent flow rate as regulated by the flow
valve 116 as multiplied by the time the valve is open. This step
may be recorded by a controller 118 as the washing fluid fills the
tub 102.
[0024] The method continues with actuating or operating the drain
pump (at step 404). This step allows the washing fluid to be
drained from the tub 102. As the pump 114 drains the tub 102, the
fluid will generally pass through at least two significant points.
The first point relates to a first pressure switch 104 (or, in the
alternative, at the level of water fluid at the initiation of the
drain pump 114 operation) and the second point relates to the level
of the lower level switch 106.
[0025] The method continues (at step 406) with recording the time
to trip. The time to trip is generally calculated by measuring the
time between two significant points of the previous step. This time
may vary depending on the implementation of the method. For
example, the time may be very short if the two points in which this
calculation is measured are very close together. This time may also
depend on the amount and absorbency of the items which are
currently in the washer tub 102.
[0026] The method continues with calculating a predicted time to
drain (at step 408). The predicted time to drain may be calculated
using the fill amount and the time to trip number. The formula in
which the predicted time to drain is calculated may vary depending
on the washer unit. However, this predicted time to drain should be
a relatively accurate time measurement determining when the drain
pump 114 has removed a sufficient amount of water out of the tub
102.
[0027] The method continues (at step 410) with operating the drain
pump according to the calculated predicted time to drain. Once the
predicted time to drain is known, the controller 118 uses this
information to operate the pump for the minimum amount of time
required in order to drain a sufficient amount of fluid out of the
tub 102. This may be useful in both ensuring that the tub 102 is
fully drained and preventing the pump from running dry. When the
pump runs dry, generally it creates noise and lengthens the time
for the washer cycle. Furthermore, it creates situations where
customers may call a service technician in order to repair the
washing machine unit, even though pump operability is not an
issue.
[0028] Now referring to FIG. 5a and FIG. 5b, a more detailed
embodiment of the method disclosed in FIG. 4 is shown. The method
begins (at step 502) with initiating the fill. This step may be
implemented through actuating the fill valve in order to fill the
washing machine tub 102 through the fill pipe 112. Generally (at
step 504), the number of Gallons To Fill (GTF) may be determined.
This may be done through a flow regulated valve 116 which can
regulate the flow to a rate which may easily be calculated.
[0029] The method continues (at step 506) with completing the fill
and beginning agitation. The method continues on (at step 508) with
agitation. In these two steps, the agitation device 108 is used in
order to wash the clothes. The method continues until (step 510)
when agitation is completed.
[0030] The method continues (at step 512) with setting the timer to
zero and then starting the timer. The timer is useful in
calculating the time to trip. Therefore, it is initiated right
before step 514 of turning on or operating the drain pump. Once the
drain pump operation is initiated, the fluid will begin to drain
from the tub 102 and this time is useful in calculating how long it
takes the water level to reach the lower level switch 106. The time
is measured, as shown in this preferred embodiment, from the time
that the drain pump is initiated, or alternatively the time may be
measured at some other point, such as when the upper level switch
114 is open. In any event, a time to trip is calculated based at
least in part on the timer.
[0031] The method continues with determining if the upper level
switch is open (at step 516). In this embodiment, the switch is
open when water has cleared from the switch. Stated another way,
the switch will be open when there is no water at the level of the
switch 104. If the switch is not open, the next step in the process
(at step 518) is determining if the lower level switch is open. If
neither switch is open, the cycle is repeated until one of the
switches opens. If the lower level switch is open, the upper level
switch should also be open. Otherwise, the method continues on (at
step 520).
[0032] The method continues (at step 520) with turning off the
drain pump. The drain pump will need to be turned off in this case
because there is a hardware error. Therefore, when the situation
occurs when the lower switch opens before the upper switch, a
switch fault is registered. When the lower level switch opens while
the upper level switch is not open, a signal is provided to the
controller 118 that there is fluid e.g. water at the upper level
switch 104 while there is no fluid at the lower level switch 106.
Since this situation is seemingly not possible under intended
operation, a presumption is then made that there is a mechanical
issue with the upper level switch 104.
[0033] If at step 516 it is determined that the upper level switch
is open, at step 524, then represents the process of determining if
the lower level switch is open. In this embodiment, if the lower
level switch is not open, continued verifications are undertaken
checking and running the timer for 6 minutes (360 seconds). Of
course it will be understood by one skilled in the art that "6
minutes" is merely representative of a time period and that other
time periods may be used without departing from the features of the
present disclosure. At step 526, there is a determination as to
whether the time has exceeded the additional time period, i.e., the
6 minute threshold.
[0034] If the 6 minute threshold has not been exceeded, the method
continues with testing of the lower level switch to determine
whether it has been open continuously or the 6 minute threshold has
passed. If the 6 minute threshold has been exceeded, next step in
the process continues (at step 528) by turning off the drain pump.
Once the timer has surpassed the lower level switch time threshold,
if the switch has not opened, the drain pump is shut off. This
action is taken because after the threshold has been exceeded,
either the fluid has drained out of the wash tub 102 and the lower
level switch 106 has errored (exhibits a fault), or the pump 114 is
not draining fluid out of the washer tub 102. In either condition,
the method continues on (to step 530). At step 530, the control
registers a lower switch fault and the method comes to an end.
[0035] If the upper level switch 104 is open and the lower level
switch 106 is also opened, then the process is continued (at step
532) with recording the time. This recorded time value becomes the
time to trip (TTT) and is used (at step 534) in order to determine
the predicted time to drain.
[0036] The predicted time to drain (PTTD) may be calculated through
a variety of methods. In a preferred embodiment, the calculation
includes 59.4+20+1.64 TTD-3.62 GTF. However, this is but one
embodiment and the predicted time to drain may be calculated
through a variety of means. However, generally the predicted time
to drain will take into account the time to trip and the amount of
fluid required to fill the washer tub 102 for this wash. The
constants of the equation may be unique for each washer
configuration.
[0037] The method continues (at step 536) with determining if the
predicted time to drain is greater than a minimum drain time. In
this embodiment, the minimum drain time is equal to 165 seconds.
However, the minimum drain time may vary and still fall within the
scope of the disclosure.
[0038] If the predicted time to drain is greater than the minimum
drain time, e.g., 165 seconds, then the method continues at step
538 by adding 15 more seconds to the predicted time to drain and
allowing the pump to drain fluid (at step 540) out of the tub 102
until the new PTTD is surpassed. Once the new PTTD has been
surpassed, the pump is turned off (at step 552).
[0039] At step 542, when the predicted time to drain is not greater
than the minimum threshold, the method continues by letting the
pump drain until it reaches the predicted time to drain. Once the
time has reached the predicted time to drain, step 544 indicates
that the drain pump is turned off until it reaches the minimum
drain time (at step 546). The method continues by re-operating the
drain pump (at step 548) for an additional time period (in this
embodiment, 15 more seconds at step 550) and then turning off the
drain pump (at step 552).
[0040] Turning the pump off and then turning it on again before a
final shut off are generally used steps to prevent the pump from
running dry. Typically, 180 seconds is a minimum threshold in order
to drain the water. Therefore, when the predicted time to drain has
not reached the threshold of 180 seconds, the drain is turned off
and then turned back on in order to drain any water that is drained
from the load of items that may have dripped down into the washer
tub 102 while the pump is turned off. In this manner, the time that
the pump is on and running without water passing through it will be
minimized. However, typically the minimum drain time is used in
order to allow for sufficient time for water to drip off of the
load being washed.
[0041] The method continues with proceeding to the next washer
cycle (at step 554). Generally this cycle may be the spin cycle,
however, this cycle may vary depending on the design and
functionality of the washer machine unit.
[0042] The above description merely provides a disclosure of the
some of the embodiments which may be implemented throughout the
system. The above-provided description is not intended for purposes
of limiting the claims. As such, this description is not limited
only to the above described embodiments. Rather, one skilled in the
art may conceive alternative embodiments which fall within the
scope of the claims.
* * * * *