U.S. patent application number 13/481460 was filed with the patent office on 2013-05-30 for currency cassette capacity monitoring and reporting.
This patent application is currently assigned to MEI, Inc.. The applicant listed for this patent is Peter Camilleri, Mark H. Greenawalt, Rick Lopez, Bob Mackenzie, Stephen Marsh, Bill Nichols, Phil Pascarella. Invention is credited to Peter Camilleri, Mark H. Greenawalt, Rick Lopez, Bob Mackenzie, Stephen Marsh, Bill Nichols, Phil Pascarella.
Application Number | 20130134011 13/481460 |
Document ID | / |
Family ID | 39028386 |
Filed Date | 2013-05-30 |
United States Patent
Application |
20130134011 |
Kind Code |
A1 |
Mackenzie; Bob ; et
al. |
May 30, 2013 |
Currency Cassette Capacity Monitoring And Reporting
Abstract
An indicator, such as an alarm or warning, is generated to
indicate that a document storage cassette attached to a document
handling device (e.g., a currency validator) has reached a
particular capacity or is approaching its full capacity.
Inventors: |
Mackenzie; Bob; (West
Chester, PA) ; Marsh; Stephen; (Parkesburg, PA)
; Greenawalt; Mark H.; (W. Berkshire, GB) ;
Nichols; Bill; (Henderson, NV) ; Pascarella;
Phil; (West Chester, PA) ; Lopez; Rick; (Reno,
NV) ; Camilleri; Peter; (West Chester, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Mackenzie; Bob
Marsh; Stephen
Greenawalt; Mark H.
Nichols; Bill
Pascarella; Phil
Lopez; Rick
Camilleri; Peter |
West Chester
Parkesburg
W. Berkshire
Henderson
West Chester
Reno
West Chester |
PA
PA
NV
PA
NV
PA |
US
US
GB
US
US
US
US |
|
|
Assignee: |
MEI, Inc.
West Chester
PA
|
Family ID: |
39028386 |
Appl. No.: |
13/481460 |
Filed: |
May 25, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11751444 |
May 21, 2007 |
8186672 |
|
|
13481460 |
|
|
|
|
60802375 |
May 22, 2006 |
|
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Current U.S.
Class: |
194/206 |
Current CPC
Class: |
B65H 2404/64 20130101;
B65H 43/06 20130101; G07F 9/026 20130101; B65H 2511/30 20130101;
B65H 2511/30 20130101; B65H 29/46 20130101; B65H 2701/1912
20130101; B65H 2220/01 20130101; B65H 2551/20 20130101 |
Class at
Publication: |
194/206 |
International
Class: |
G07F 9/02 20060101
G07F009/02 |
Claims
1. A method of providing an indication of the status of a document
storage cassette attached to a document acceptor that is coupled to
a host machine, the method being performed by the document acceptor
and comprising: monitoring the number of documents inserted into
the cassette; and generating an indicator in the vicinity of the
document acceptor when the capacity of the document storage
cassette reaches a specified level.
2. The method of claim 1 wherein generating an indicator includes
generating a visual indicator.
3. The method of claim 2 wherein generating an indicator comprises
causing a light source to be turned on.
4. The method of claim 3 wherein the light source is a LED.
5. The method of claim 2 wherein generating an indicator includes
causing a blinking rate of a light source to change in accordance
with the capacity of the document storage cassette.
6. The method of claim 2 wherein generating an indicator includes
causing a blinking rate of a light source to change in accordance
with a predicted amount of time until the document storage cassette
reaches full capacity.
7. The method of claim 1 wherein generating an indicator includes
generating an audible sound.
8. The method of claim 1 wherein monitoring the number of documents
in the cassette includes tracking the number of stack cycles that
occur.
9. The method of claim 1 wherein monitoring the number of documents
in the cassette includes monitoring a motor current associated with
the cassette, and using the motor current to estimate the number of
documents stored in the cassette.
10. A method of providing an indication of the status of a document
storage cassette attached to a document acceptor that is coupled to
a host machine, the method being performed by the document acceptor
and comprising: monitoring a number of documents in the cassette;
monitoring a feed-rate of documents being inserted into the
cassette; predicting when a capacity of the document storage
cassette is expected to reach a specified level based on the
feed-rate and the number of documents currently in the cassette;
and generating an indicator or causing a message to be sent when it
is determined that the capacity of the document storage cassette is
expected to reach the specified level within a specified amount of
time.
11. The method of claim 10 wherein said estimating includes
estimating when the capacity of the document storage cassette is
expected to reach its full capacity.
12. The method of claim 10 including generating an indicator in the
vicinity of the document acceptor when the capacity of the document
storage cassette reaches the specified level.
13. The method of claim 12 wherein the indicator comprises a visual
or audio indicator.
14. The method of claim 12 wherein generating an indicator includes
causing a blinking rate of a light source to change in accordance
with a predicted amount of time until the document storage cassette
reaches full capacity.
15. The method of claim 10 wherein the document acceptor is a
currency validator.
16. An apparatus comprising: a document acceptor; and a document
storage cassette attached to the document acceptor; wherein the
document acceptor is operable to: monitor the number of documents
inserted into the cassette; and generate a signal to provide an
indicator in the vicinity of the document acceptor when the
capacity of the document storage cassette reaches a specified
level.
17. The apparatus of claim 16 wherein the document acceptor is
operable to generate a signal to provide a visual indicator in the
vicinity of the document acceptor when the capacity of the document
storage cassette reaches a specified level.
18. The apparatus of claim 16 comprising a light source, wherein
the document acceptor is operable to generate a signal to cause the
light source to be turned on when the capacity of the document
storage cassette reaches a specified level.
19. The apparatus of claim 18 wherein the light source is a
LED.
20. The apparatus of claim 18 wherein the document acceptor is
operable to generate a signal to cause a blinking rate of the light
source to change in accordance with the capacity of the document
storage cassette.
21. The apparatus of claim 18 wherein the document acceptor is
operable to generate a signal to cause a blinking rate of the light
source to change in accordance with a predicted amount of time
until the document storage cassette reaches full capacity.
22. The apparatus of claim 16 wherein the document acceptor is
operable to generate a signal to provide an audible sound when the
capacity of the document storage cassette reaches a specified
level.
23. The apparatus of claim 16 wherein the document acceptor is
operable to track the number of stack cycles that occur.
24. The apparatus of claim 16 wherein the document acceptor is
operable to monitor a motor current associated with the cassette,
and to use the motor current to estimate the number of documents
stored in the cassette.
25. An apparatus comprising: a document acceptor; and a document
storage cassette attached to the document acceptor; wherein the
document acceptor is operable to: monitor a number of documents in
the cassette; monitor a feed-rate of documents being inserted into
the cassette; predict when a capacity of the document storage
cassette is expected to reach a specified level based on the
feed-rate and the number of documents currently in the cassette;
and generate a signal to provide an indicator or to cause a message
to be sent when it is determined that the capacity of the document
storage cassette is expected to reach the specified level within a
specified amount of time.
26. The apparatus of claim 25 wherein the document acceptor is
operable to estimate when the capacity of the document storage
cassette is expected to reach its full capacity.
27. The apparatus of claim 25 wherein the document acceptor is
operable to generate a signal to provide an indicator in the
vicinity of the document acceptor when the capacity of the document
storage cassette reaches the specified level.
28. The apparatus of claim 27 wherein the indicator comprises a
visual or audio indicator.
29. The apparatus of claim 27 comprising a light source, wherein
the document acceptor is operable to generate a signal to cause a
blinking rate of the light source to change in accordance with a
predicted amount of time until the document storage cassette
reaches full capacity.
30. The apparatus of claim 25 wherein the document acceptor is a
currency validator.
31. A method of providing an indication of the status of a document
storage cassette attached to a document acceptor that is coupled to
a host machine, each step in the method being performed by at least
one of the host machine or the document acceptor, the method
comprising: monitoring a number of documents in the cassette;
monitoring a feed-rate of documents being inserted into the
cassette; predicting when a capacity of the document storage
cassette is expected to reach a specified level based on the
feed-rate and the number of documents currently in the cassette;
and generating an indicator or causing a message to be sent when it
is determined that the capacity of the document storage cassette is
expected to reach the specified level within a specified amount of
time.
32. The method of claim 31 wherein said estimating includes
estimating when the capacity of the document storage cassette is
expected to reach its full capacity.
33. The method of claim 31 including generating an indicator in the
vicinity of the document acceptor when the capacity of the document
storage cassette reaches the specified level.
34. The method of claim 33 wherein the indicator comprises a visual
or audio indicator.
35. The method of claim 33 wherein generating an indicator includes
causing a blinking rate of a light source to change in accordance
with a predicted amount of time until the document storage cassette
reaches full capacity.
36. The method of claim 31 wherein the document acceptor is a
currency validator.
37. The method of claim 11 wherein the document acceptor is a
currency validator.
38. The method of claim 15 wherein the method further includes
determining a validity and denomination of currency documents
inserted into the currency validator and directing acceptable
currency documents to the cassette.
39. The apparatus of claim 26 wherein the document acceptor is a
currency validator.
40. The apparatus of claim 30 wherein the document acceptor is
further operable to determine a validity and denomination of
currency documents inserted into the currency validator and to
direct acceptable currency documents to the document storage
cassette.
41. The apparatus of claim 25 wherein the document acceptor is
operable to re-determine the feed rate on a fixed periodic
basis.
42. The apparatus of claim 25 wherein the document acceptor is
operable to monitor the feed rate of documents based on a number of
stack cycles that occurs during a specified period of time.
43. The apparatus of claim 25 wherein the document acceptor is
operable to monitor a number of documents stored in the cassette
based on values of motor current.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application is a continuation application of U.S. Ser.
No. 11/751,444 filed May 21, 2007 which claims the benefit of
priority from U.S. Provisional Patent Application No. 60/802,375,
filed on May 22, 2006.
BACKGROUND
[0002] Document acceptor assemblies, such as those used in the
vending and gaming industries, typically store accepted banknotes
or other documents in a cassette. A stacking mechanism may be
incorporated in the assembly to facilitate storage of the documents
in the cassette.
[0003] In various industries, the cassettes (sometimes referred to
as cash boxes) are removed in predefined cycles. In the gaining
industry, removal of the cassette is referred to as a "drop."
Removing the cassettes in predefined cycles can be wasteful because
many of the cassettes may not be at, or near, capacity at the time
of the drop. Another problem may arise as a result of cassettes
becoming full in advance of the drop, thus rendering the gaming
machine disabled until its scheduled drop.
SUMMARY
[0004] The disclosure relates to monitoring and reporting the
capacity of a currency cassette.
[0005] An indicator (e.g., an alarm or warning) is generated to
indicate that a currency storage cassette attached to a document
handling device (e.g., a currency validator or other currency
acceptor) has reached a particular capacity or is approaching its
full capacity.
[0006] The indicator can include, for example, a visual or audio
signal in the vicinity of the document acceptor so as to alert
service personnel that the cassette is near full-capacity or that
it is expected to reach full-capacity within the near future.
Visual or audio indicators that readily can be sensed by service
personnel can make it easier to identify when a full (or near-full)
cassette needs to be exchanged for an empty one. The indicator of
the cassette capacity can be controlled, for example, by the
document acceptor's processor instead of the host gaming or vending
machine. That can help avoid the need to make expensive changes to
software in the host machine.
[0007] In some implementations, the physical indicator is provided
when the cassette is filled to a predefined capacity (i.e., when
the cassette contains at least a specified number of documents). In
some implementations, the time at which the indicator occurs is
based on a prediction as to when the cassette is expected to become
filled to capacity. The predicted time can be based, for example,
on the feed rate of documents inserted into the cassette and the
actual number of documents stored in the cassette. Thus, in a
particular scenario, an indicator or other message is provided if
it is determined, based on the current feed rate and capacity, that
the cassette is expected to become full within the next fifteen
minutes.
[0008] Other features may be readily apparent from the following
detailed description, the accompanying drawings and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates an example of document acceptor that
incorporates a document stacker according to the invention.
[0010] FIG. 2 is an isometric partial section view of a document
stacker.
[0011] FIG. 3 is an end view of the document stacker of FIG. 2 with
a piston in the home position.
[0012] FIGS. 4-7 are end views of the document stacker of FIG. 2
illustrating various stages of the document stacking cycle.
[0013] FIG. 8 is a graph showing examples of motor current
curves.
[0014] FIG. 9 is an enlarged version of a portion of the graph of
FIG. 8.
[0015] FIG. 10 is a block diagram illustrating a controller for the
stacker.
DETAILED DESCRIPTION
[0016] FIG. 1 illustrates an example of an implementation of a
document acceptor assembly 10 that includes a document handling
device such as a banknote validator 12 (or other document acceptor)
connected to a piston-type currency stacker 14.
[0017] The acceptor 12 determines whether inserted currency or
other documents are acceptable. As used herein, the phrase
"currency documents" includes, but is not limited to, banknotes,
bills, security documents, paper currency checks, coupons, tickets
and the like that may be used as legal tender in exchange for goods
or service, and that may be inserted into a document handling
device for validation and storage in return for goods or
services.
[0018] Banknotes may be inserted one at a time into the acceptor 12
at entrance 16. From the entrance 16, the banknote 38 is
transported through the acceptor 12 to the acceptor's banknote
output by pairs of pulleys or rollers and belts that grip the side
edges of the banknote and that may be driven by a motor and drive
train according to known techniques.
[0019] As the banknote is transported through the acceptor 12, the
banknote may be tested by a group of sensors to ascertain its
validity and denomination. Output signals from the sensors may be
processed by logic circuits in the acceptor 12 to determine whether
the banknote is acceptable. Any of various known techniques using
optical, magnetic, inductive or other types of sensors may be used
to test the banknote. A banknote which is unacceptable may be
ejected back out through the entrance 16.
[0020] An acceptable banknote is transported into an
interconnection region 18 in which the acceptor 12 and stacker 14
are connected together. The interconnection region 18 establishes a
smooth uninterrupted path for a banknote to follow when leaving the
15 acceptor 12 and entering the stacker 14. The accepted banknote
is transported from the stacker's entrance into a pre-storage
channel 20. In a fashion somewhat analogous to the way that a
picture frame holds a picture, the channel 20 "frames" the banknote
at its side edges and holds it stiff prior to stacking. The
piston-type stacker 14, described in greater detail below, pushes
the accepted banknote into a cassette 22 where it is stored until
removed by service personnel. The cassette is designed to be
readily removed or opened by service personnel so that stacked
banknotes can be removed.
[0021] As shown in FIGS. 2 and 3, the stacker 14 includes two
apertures 24, 26 that permit a piston 28 to freely pass. The
aperture 24 should be sufficiently small that stacked banknotes or
other documents 30 cannot pass through the aperture without some
bending. The piston 28 may be in direct contact with a cam 32 that
is coupled to an electric motor 36 or other actuator. For example,
a permanent magnet direct current (DC) motor may be used. A conical
spring 34 provides a clamping force that ensures that the banknote
38 to be stacked does not slide across the document stack 30. The
spring 34 also keeps the documents in the stack 30 closely packed
and stable.
[0022] An optical switch 40 is provided for detecting the presence
of a flag 42 that indicates when the piston 28 is in the home
position (i.e., when the piston is not obstructing the pre-storage
document channel 20). The flag 42 may be formed, for example, as a
protrusion from the backside of the piston 28.
[0023] A sensor is provided to sense electrical signals from the
motor during a document stacking operation. In a particular
implementation, as shown in FIG. 10, a motor current sensor 200 is
coupled to the motor 36 and allows the motor current to be
measured. The sensor 200 may include, for example, a series
resistor coupled between the motor 36 and an analog-to-digital
converter (ADC) 202. Output signals from the ADC 202 are provided
to a control system 204.
[0024] The control system 204 may include a microprocessor 206 to
control when the motor 36 is turned on or off in response to
signals from the optical sensor 40 and the motor current sensor
200. As discussed below, the microprocessor 206 also can measure
the passage of time using, for example, an interrupt software
routine driven by a clock signal.
[0025] FIGS. 3 through 7 illustrate the sequence of operation for
stacking a document according to one implementation. For the
purposes of illustration, it may be assumed that the cassette 22 is
empty or nearly empty. FIG. 3 illustrates the stacker mechanism in
the home position, corresponding to FIG. 2. In that position, the
piston 28 is fully retracted, and the flag 42 blocks the optical
switch 40. A document 38 is in the pre-storage channel 20 ready to
be stacked in the cassette 22.
[0026] During the initial stage of the stacking state, power is
applied to the motor 36, and an eccentric begins to rotate, thereby
lifting the piston 28. As illustrated in FIG. 4, after a small
amount of rotation has occurred, the piston 28 is in contact with
the document 38, thereby causing the document to deform slightly.
In this state, the flag 42 has cleared the optical switch 40.
[0027] A DC motor (such as motor 36) with a substantially fixed
input voltage draws a current that is approximately proportional to
the mechanical load placed upon it. For example, during the
transition from the home position to the initial stacking stage of
FIG. 3, the piston 28 encounters little mechanical resistance. An
example of the profile of motor current is illustrated in FIGS. 8
and 9. The profile 50 indicates a brief inrush current 52 followed
by a low trough 54 that reflects the light mechanical load.
[0028] FIG. 5 illustrates the stacker 14 after the document 38 has
been stripped from the pre-storage document channel 20. During this
stage, the piston 28 encounters some resistance as a result of
sliding friction, the document's resistance to bending and an
increase in the force of the spring 34. As shown in FIGS. 8 and 9,
the motor current increases to a peak 56 and then decreases
briefly.
[0029] When the piston 28 is fully extended as shown in FIG. 6, the
spring 34 exerts its maximum force, and the motor current reaches
its maximum value as indicated by 58 in FIG. 9. The document 38 has
completely passed from the pre-storage channel 20 and is located
within the cassette 22.
[0030] Next, the piston 28 reverses direction and travels in the
opposite direction as illustrated by FIG. 7. During the return
stroke, the force of the spring 34 helps push the piston 28 back
toward its home position (FIGS. 2 and 3). Therefore, during the
return stroke, the motor current is at a relatively low value as
indicated by 60 in FIG. 9.
[0031] Under different circumstances, such as when the cassette 22
is substantially full, the expected values of motor current may
vary significantly from the values indicated by curve 50. An
example of the motor current profile when the cassette 22 is
substantially full is indicated by curve 62 (FIGS. 8 and 9). In
that case, the motor current during the home position and the
initial stacking stage, corresponding to FIGS. 3 and 4, is similar
to the motor current values of curve 50. In the subsequent stacking
stages, however, the motor current values diverge. For example, the
peak motor current value 64, which corresponds to the peak value 56
in curve 50, occurs at a higher value and at a later time.
[0032] The later timing of the peak value 64 when the cassette 2 is
full may be attributed to the fact that the stacker mechanism 14
slows down under the higher load. In the illustrated
implementation, the full extension state of the piston 28, as shown
in FIG. 6, is not attained when the cassette 22 is full (or almost
full) to capacity. Instead, the motor current rises to a value 66,
where it more or less remains for a period of time as a result of
the motor 36 stalling. After an algorithm in the host controller
204 (FIG. 10) indicates that a maximum time has elapsed, the
controller reverses the motor 36 so the stacker can return to its
home position. In the example of FIG. 8, that occurs after about
500 clock cycles, identified by the reference numeral 68. The
controller 204 then may report that the cassette is full and may
place the banknote acceptor in an "out-of-service" mode until a
replacement cassette is installed.
[0033] In some situations, the pre-storage document channel 20 may
become obstructed by an object other than a genuine, acceptable
document. Curve 70 (FIGS. 8 and 9) illustrate an example of the
motor current profile when such an abnormal event occurs.
[0034] In various implementations, one or more values indicative of
the motor's actual operation may be compared to one or more
reference values to determine whether the motor and, therefore, the
stacker, is operating properly. Reference values and expected
current profiles may be stored, for example, in memory 208
associated with the control system 204 (see FIG. 10).
[0035] To predict the time at which the cassette is expected to
reach its full capacity, the rate at which documents are being
inserted into the cassette is determined. The cassette's actual
capacity is determined as well. That information then is used to
predict an approximate time when the cassette will reach its full
capacity. If it determined that the cassette will reach its full
capacity within some predetermined amount of time, then an
indicator is provided to alert service personnel to the status of
the cassette. The currency acceptor's processor can be used to
track the status of the cassette, make any required calculations,
and generate appropriate signals to provide the indicator.
[0036] Various techniques can be used to track the number of
documents stored in the 20 cassette. For example, the processor
associated with the currency acceptor can keep track of the number
of stack cycles that occur. The completion of each cycle would
indicate that another document has been stored in the cassette. As
described above, a stack cycle begins with the piston in the "home"
position (FIG. 2). During the cycle, the stacking motor is
energized, the cams rotate, and the document is pressed into the
cassette. Eventually, the document is fully committed to the
cassette (FIG. 5). The motor continues to run until the cams rotate
360 degrees, and the piston returns to its starting "home" position
(FIG. 2) to complete the cycle.
[0037] In some implementations, the capacity of the cassette is
determined based on the motor current. As the cassette nears its
full capacity, the force required to stack a document increases and
the current in the motor increases. Thus, the increase in force can
be detected by measuring the current draw of the stacker motor. The
increase is predictable, and thresholds can be determined
dynamically or can be predefined. The thresholds indicate the
capacity status. For example, with reference to FIG. 8, curve 62
corresponds to a cassette at high capacity (i.e., at full or
near-full capacity). Once the characteristics for the particular
stacker-type are know, a liner calculation can be applied to
provide finer resolution.
[0038] According to some implementations, once the number of
documents stored in the cassette has been determined, the physical
indicator is provided if the number of documents in the cassette
has reached a pre-defined threshold.
[0039] Such techniques, however, do not account for the rate at
which the documents are being received and stacked in the cassette.
Thus, for example, if documents are being stacked at a relatively
slow rate (e.g., if customers are not using the gaming machine very
often), the cassette might not become full for a relatively long
time. On the other hand, if the current document feed-rate is
relatively high, the cassette may reach its full capacity
sooner.
[0040] To obtain a better sense of when the cassette is likely to
reach full-capacity, the rate at which the documents are being
stacked during a specified period (e.g., the previous half-hour)
can be monitored and used together with the actual number of
documents currently stored in the cassette to predict the amount of
time until the cassette will become full or substantially full.
Such an approach can provide an adjustable amount of warning time
and compensate for different play (i.e., document insertion) rates.
Thus, a currency acceptor associated with a busy gaming machine
will issue its alarm sooner than the currency acceptor associated
with a more slowly played machine. The warning can also be issued
in degrees as the cassette's maximum capacity is approached (i.e.,
10%, 20%, etc.).
[0041] A particular implementation uses the following comparison to
determine whether the cassette is at, or will be at, substantially
full capacity in the near future:
Is ((CC+(CR*WT))>MAX)?
[0042] where,
[0043] MAX=maximum capacity (i.e., number of documents) of the
cassette
[0044] CC=current document count in the cassette
[0045] CR=current document feed rate (e.g., documents per hour)
[0046] WT=warning time (in hours) 20
[0047] The value for "CR" may be recalculated on a periodic basis,
for example, every thirty minutes. The value for "WT" may be set
dynamically by the host or through a pre-configuration setting.
[0048] If the value (CC+(CR*WT)) is greater than the value MAX,
then the cassette is either already at full capacity or likely to
reach its full capacity soon, and an indicator is provided.
Preferably, the indicator is controlled directly by the currency
acceptor and can be sensed by service personnel. For example, the
indicator can be a visual warning such as a light emitting diode
(LED) or other light source, located on the top of the gaming
machine, being turned on. Such an LED or other physical indicator
can be located elsewhere such as on the bezel of the currency
acceptor. In some implementations, turning on the LED serves as the
indicator. In other implementations, the blinking rate of the LED
indicates the anticipated time until the cassette reached full
capacity. For example, in particular scenario, a faster blink rate
would indicate that the cassette is expected to become full sooner
than if the blink rate were slow. Audio warnings (e.g., a beeping
or other sound) also can be used in addition to, or instead of,
visual warnings. Alternatively, or in addition to the physical
indicator, a message may be sent to a remote location (i.e., remote
from the currency acceptor and host machine) to alert service
personnel.
[0049] The currency acceptor can be configured to clear the
indicator (e.g., turn off the LED) automatically once the cassette
is changed.
[0050] Various aspects of the system may be implemented in
hardware, software or a combination of hardware and software.
Circuitry, including dedicated or general purpose machines, such as
computer systems and processors, may be adapted to execute
machine-readable instructions to implement the techniques described
above. Computer-executable instructions for implementing the
techniques can be stored, for example, as encoded information on a
computer-readable medium such as a magnetic floppy disk, magnetic
tape, or compact disc read only memory (CD-ROM). In one particular
implementation, the computer-readable medium includes non-volatile
electronic memory such a PROM, EPROM or FLASH. Algorithms also may
be implemented, for example, through use of a programmable gate
array.
[0051] The foregoing implementations, including the motor current
profiles, are intended as examples only and are not intended to
limit the scope of the invention.
[0052] The techniques may be employed in connection with stackers
other than piston-type stackers, including, for example, stackers
in which banknotes are wrapped around a drum or in which banknotes
are rolled onto a stack. The techniques also may used with stackers
using actuators other than DC motors, including, for example,
actuators for stepper motors, AC motors and brushless motors. In
some cases, signals other than current, including, for example, the
phase lag may be used to measure the actuator load.
[0053] Other implementations are within the scope of the
claims.
* * * * *