Note: Descriptions are shown in the official language in which they were submitted.
CA 02332486 2001-O1-26
ELECTRONIC CONTROL IGNITION BOX AND
FAULT MONITORING SYSTEM FOR A TRENCH ROLLER
BACKGROiTI~TD OF THE TNVENTION
E,; P1 r3 of the Invention
The present invention is related to the field of
construction equipment and, more particularly, to an electronic
control system for manual as well as remote control of construction
equipment such as a trench roller, the electronic control system
including an integrated display and acting as a fault monitoring
system for providing information pertaining to equipment operation
to an operator.
nod ript;gin of the Related Art
Trench rollers are used to compact soil during a wide
range of construction projects, including soil compaction of
roadside trenches in the construction of roads and highways. The
environmental conditions for a typical construction project are
harsh, with the trench rollers often operating in trenches having
a depth in excess of ten feet in which the banks are vulnerable to
caving in and showering or burying the equipment with dirt and mud.
In addition to exposure to unstable surrounding materials during
operation, the trench roller is thereafter cleaned with a high-
pressure washer, subjecting the mechanical parts thereof to further
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CA 02332486 2001-O1-26 '
r
environmental stress.
Traditionally, control components are housed in a metal
box containing terminal strips into which discrete relays are
plugged. Most, if not all, of the wiring is susceptible to damage
due to exposure to the aforementioned environmental factors
including dust and moisture inherent to trench roller operation and
maintenance. As a result, trench roller performance and
reliability have been significantly degraded.
In addition to the stress of operational surroundings,
the trench roller is inherently prone to break down due to the
nature of its own operation. Compacting soil with forces of 13,000
pounds or more, with or without additional vibration, trench
rollers may experience a range of operating malfunctions that
result in engine shut-down of the machine. In the existing trench
rollers, there is no way of knowing which of a range of possible
problems was responsible for an engine shut-down. Resulting
machine down-time as an operator or mechanic attempted to
troubleshoot the problem by navigating the morass of often
contaminated wiring represented considerable lost production time
and wasted man-hours.
Accordingly, there is a need for a system that is both
impervious to environmental factors and which allows for rapid
diagnosis of engine faults in order to minimize machine down-time
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and optimize equipment operability.
~TTMMARY OF THE INVENTION
In order to overcome the problems encountered in the
prior art, the present invention is directed to an electronic
control ignition (ECI) box for use with a trench roller or other
construction-type equipment. Using circuit board construction and
a microprocessor programmed with software to interpret feedback
devices and react accordingly, the ECI box controls engine
operation and the distribution of electrical power to various
components. The ECI box also monitors engine failure faults and
operating parameters, and archives hours of use. Faults, operating
parameters and hours are displayed on an associated LED display.
The entire ECI is then encapsulated in a suitable plastic material
to form a unitary component that is both vibration-resistant and
weatherproof. The ECI box may be manually or remotely controlled.
In view of the foregoing, one object of the present
invention is an electronic control ignition (ECI) box that provides
the operator with electronic readouts of engine operating
parameters, machine failure faults and hours of machine use using
an embedded LED display.
Another object of the present invention is a
microprocessor driven solid-state circuit board design for an ECI
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box that is resistant to vibration and the environment, being
encapsulated in a polymeric material to form a weatherproof control
"brick" .
A further object of the present invention is an ECI box
for construction-type equipment that controls and routes power to
and from devices on the machine being controlled.
A still further object of the present invention is an ECI
box that enables a trench roller to be operated both manually and
by radio frequency remote control, with simple transition from one
operational mode to the other.
Another object of the present invention is a trench
roller with improved component reliability due to environmental
shielding, and reduced down-time through the ready availability of
system feedback information.
These together with other objects and advantages which
will become subsequently apparent reside in the details of
construction and operation as more fully hereinafter described and
claimed, reference being had to the accompanying drawings forming
a part hereof, wherein like numerals refer to like parts
throughout.
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Figure 1 is a perspective view of a trench roller with
control panel and LED display in accordance with the present
invention;
Figure 2 is a front view of the control panel and LED
display on the trench roller of Figure 1;
Figure 3 is an exploded view of the hood assembly
incorporating the control panel and LED display of Figure 2;
Figure 4 is a perspective view of the ECI box mounted
under the hood of the trench roller of Figure 1;
Figure 5 is a top view of a remote operator control
transmitter handset for use with the trench roller of Figure l;
Figure 6 is an exploded view of the remote assembly for
operation of the trench roller using the remote operator control
transmitter handset of Figure 5;
Figure 7A is a schematic drawing depicting the ECI box
system interface, in accordance with the present invention;
Figure 7B is a schematic drawing illustrating the
electrical circuitry of the ECI box, in accordance with the present
invention;
Figure 8 is a schematic drawing of the controller circuit
of Figure 7B;
Figure 9 is a schematic drawing of the display circuit of
CA 02332486 2001-O1-26~
Figure 7B;
Figure 10 is a schematic drawing of the input signal
conditioning circuits of Figure 7B;
Figure 11 is a schematic drawing of the power supply
circuit of Figure 7B;
Figure 12 is a schematic drawing of the first solenoid
driver circuit of Figure 7B;
Figure 13 is a schematic drawing of the second solenoid
driver circuit of Figure 7B;
Figure 14 is a schematic drawing of the third solenoid
driver circuit of Figure 7B;
Figure 15 is a flowchart of the initialization routine
for the ECI box, in accordance with the present invention;
Figures 16A-16K are a flowchart of the INT routine for
the ECI box, in accordance with the present invention;
Figure 17A is a flowchart of the save-fault data routine
for the ECI box, in accordance with the present invention;
Figure 17B is a flowchart of the restore-fault data
routine for the ECI box, in accordance with the present invention;
Figure 18 is a flowchart of the restore-fault byte
routine for the ECI box, in accordance with the present invention;
Figure 19 is a flowchart of the save-fault byte routine
for the ECI box, in accordance with the present invention;
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Figure 20 is a flowchart of the display warning message
routine for the ECI box, in accordance with the present invention;
Figure 21 is a flowchart of t:he get battery voltage
routine for the ECI box, in accordance with the present invention;
Figure 22 is a flowchart of the save-settings routine for
the ECI box, in accordance with the present invention;
Figure 23 is a flowchart of the restore-settings routine
for the ECI box, in accordance with the present invention;
Figure 24 is a flowchart of the display voltage routine
for the ECI box, in accordance with the present invention;
Figure 25 is a flowchart of the display-run time hours
routine for the ECI box, in accordance with the present invention;
Figure 26 is a flowchart of the display RPM number
routine for the ECI box, in accordance with the present invention;
Figure 27 is a flowchart of the display message routine
for the ECI box, in accordance with the present invention; and
Figures 28A-28L are a flowchart of the main program for
the ECI box, in accordance with the present invention.
Although only one preferred embodiment of the invention
is explained in detail, it is to be understood that the embodiment
is given by way of illustration only. It is not intended that the
CA 02332486 2001-O1-26
invention be limited in its scope to the details of construction
and arrangement of components set forth in the following
description or illustrated in the drawings.
In describing a preferred embodiment of the invention
illustrated in the drawings, specific terminology will be resorted
to for the sake of clarity. However, the invention is not intended
to be limited to the specific terms so selected, and it is to be
understood that each specific term includes all technical
equivalents which operate in a similar manner to accomplish a
similar purpose.
Figure 1 is a perspective view of a trench roller
equipped with an ECI box in accordance with the present invention.
The trench roller, generally designated by the reference numeral
10, includes conventional components, except for the ECI box and
LED display, and can be of standard known construction. As
disclosed, the trench roller 10 has left drums 12, right drums 14,
a hood 16, and a control panel, generally designated by the
reference numeral 22, with an LED display 24.
The control panel 22 with LED display 24 is shown in
greater detail in Figure 2, and in an exploded view in Figure 3.
More specifically, the control panel 22 includes a keyswitch 26
having an OFF position 26a, a RUN position 26b, an engine START
position 26c, and an accessory position 26d, described later in
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detail. The control panel 22 further includes an emergency stop
(E-Stop) button 28, a vibration direction switch 30, a vibration
on/speed switch 32, an engine throttle switch 34, a left side
forward/reverse control lever 36, and a right side forward/reverse
control lever 38. The vibration direction switch 30, vibration
on/speed switch 32, and the engine throttle switch 34 may be
embodied as rocker switches.
As shown in Figure 3, the LED display 24 is covered by a
clear window 25 secured to the front of the control panel 22 in any
suitable manner such as a gasket 23. The ECI box 50 is rigidly
mounted under the hood 16 and positioned so that the LED display 24
is viewable through the window 25 in the control panel 22. Figure
4 is a perspective view of the ECI box 50 mounted rigidly beneath
the hood 16, with the hood 16 shown in the open position. The ECI
box 50 is rigidly mounted in position underneath the hood 16 by any
suitable attaching mechanism.
During manual operation of the trench roller, the
operator controls drum operation on the left and right sides of the
trench roller with left and right side forward/reverse control
levers 36, 38, respectively. If vibration is desired, the
vibration shaft direction is selectable using the vibration
direction switch 30, and vibration is turned on and the speed
adjusted using the vibration on/speed switch 32. The engine
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CA 02332486 2001-O1-26
throttle switch 34 is adjustable between idle speed and run speed.
As described above, the LED display 24 is located on the
control panel 22. This LED display is preferably embedded into the
ECI box 50 and is controlled through the' microprocessor. The
display's main function is to provide specific machine-operating
information to the operator or to a mechanic who is accessing
information about operation of the trench roller. By providing a
read-out of the particular problem encountered, the display in
conjunction with the ECI box represents a valuable improvement over
the prior art. Rather than having to begin a troubleshooting
sequence with no idea as to the basis of the problem, while
associated work crews stand idle, the ECI box and display of the
present invention greatly reduces engine down-time with the
assistance of machine self-diagnosis through on-board sensors and
related circuitry.
The LED display 24 preferably has the capability to
display five categories of messages and information. These
categories are presented through various displays including those
presented while the engine is running, which can include the normal
display as well as warnings; the display during engine start-up;
and display values when the engine is not running. The display of
values when the engine is not running includes a display of the
hour meter and fault messages.
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During engine start-up, while the keyswitch 26 is in the
START position 26c, the battery voltage level is shown on the
display 24. Once the engine has started and the keyswitch 26 has
been rotated to the RUN position 26b, engine RPM is shown on the
display 24. Engine RPM constitutes the normal display while the
engine is running, and represents a valuable output for performance
evaluation. More particularly, RPM may be used to evaluate the
performance and efficacy of other machine systems, such as impact
force, which are dependent on the maintenance of an appropriate RPM
for their optimal effectiveness.
When the engine is running, with the keyswitch 26 in the
RUN position 26b, the LED display 24 may display warning messages
regarding engine or battery trouble during machine operation.
Warnings are defined as messages that indicate the electrical
system is not charging properly and are flashed on the display
intermittently with RPM when the machine is running in the manual
mode. Warning messages may include, among others, a voltage
regulator low message (V Reg L) when the system is not charging
properly; and a battery low message (Bat Low) when the voltage
level of the battery is low. In a preferred embodiment, the Bat
Low message is displayed at 10 volts.
When the engine is not running, the keyswitch may be
moved to the accessory position 26d. In the accessory position
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26d, the LED display 24 will show three different pieces of
information, namely the hour meter, a fault message and the
software revision level. The hour meter monitors machine run time
and reflects the number of hours of operat:ion. The fault message
shows the last fault that occurred, and the software revision level
indicates the revision level of the software that is controlling
the microprocessor. This information is stored in non-volatile
memory such that, in the event electrical power is lost, this
information will remain intact and will again be available for
display when electrical power has been reestablished.
A fault is defined as a situation that causes the
machine/engine to shut down or to not start:. Such engine shut-down
may be initiated by engine protect circuits or machine protect
devices. The fault messages are associated with particular faults
and are shown on the display to indicate what is happening within
the machine. As such, fault messages are very helpful during
troubleshooting or when performing preventive maintenance.
Fault messages may include communications indicating one
or more of the following, among others:
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low oil or no oil proper oil pressure cannot be
achieved and maintained
cylinder temperature motor cylinder heads exceed
safe operating temperature
tilt machine tip angle has been
exceeded
emergency stop emergency stop button has been
(E-stop) depressed and has not been
reset
RPM low engine speed has dropped
below a minimum speed
Various sensors may be used to monitor the fault conditions. In a
preferred embodiment oil pressure is monitored by an oil pressure
switch, motor cylinder temperature is monitored by a head
temperature switch, trench roller tilt is monitored by a tip
switch, emergency stop is monitored by the emergency stop button,
and low RPM is monitored by the machine alternator output.
In the event of a fault, the engine will either refuse to
start or will cease running. To view the fault message or
messages, the keyswitch is turned to the accessory position 26d.
There is always a fault message in the display when the keyswitch
26 is turned to the accessory position 26d. Therefore, the last
fault message will be displayed even after the fault has been
corrected. The fault messages are also stored in non-volatile
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E'
memory.
The trench roller 10 may be manually controlled through
the control panel 22 or may be remotely controlled using a remote
operator control transmitter handset, generally designated by the
reference numeral 40, and shown in Figure 5. The remote operator
control transmitter handset 40 preferably includes the following:
a power-on indicator 114, indicating when the transmitter handset
is on; an ON/start button 116 for starting the engine in the
remotely-located machine; a stop button 118 for stopping the engine
of the remotely-located machine; a left side forward/reverse button
126, for controlling operation of the left drums 12; a right side
forward/reverse button 128, for controlling operation of the right
drums 14; a vibration ON/direction button 122, for turning
vibration on and for controlling the direction of vibration; and a
high/low speed button 124 for controlling engine speed and for
shutting off vibration. In a preferred embodiment, switching
engine speed to low also shuts off vibration.
When operating in the remote mode, machine functions are
manipulated through radio frequency (RF) control of a remote
assembly. Figure 6 shows an exploded view of the remote assembly
for the trench roller 10. The remote assembly includes the
transmitter handset 40, a receiver 44, and an antenna 46.
In Figure 6, the transmitter handset 40 is shown as
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fitting into a transmitter box 42 for convenient storage. During
remotely-controlled operation, however, the transmitter handset 40
would, of course, be located remotely from the transmitter box 42.
Information is transmitted from the transmitter handset 40 to the
receiver antenna 46. The antenna 46 directs the transmission to
the receiver 44, conveniently mounted on the roller 10 such as
under the hood 16 (see Figure 4, where it is decoded and used to
manipulate relays and switches which control engine and machine
functions.
Signal transmission may be checked at the transmitter and
at the receiver independently. At the transmitter, the power-on
indicator 114 is preferably an LED window on the face of the
transmitter handset 40. When the window is lit, glowing red in
color and pulsing slowly, this indicates that the transmitter is on
and functioning properly. When control buttons are depressed, the
pulse rate in the window quickens. If the window color is amber,
this indicates that the battery power of the transmitter is low and
the batteries should be replaced. If the window fails to light,
this indicates that the batteries are depleted and should be
replaced.
The receiver 44 includes circuit boards having a series
of LED lamps. These lamps light up when the receiver receives a
signal from the transmitter to perform a function. Failure of the
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lamps to light indicates that the remote assembly is not
functioning properly.
In a preferred embodiment, both the transmitter handset
40 and the receiver 44 are battery-powered. The transmitter
preferably requires two AA 1.5 volt alkaline batteries, and the
receiver is powered by a 12-volt machine battery 48. The receiver
44 is initialized through the accessory position 26d of the
keyswitch 26.
Figure 7A depicts the system concept for the ECI box and
fault monitoring system in accordance with the present invention.
As shown, the ECI box 50 receives inputs from and directs outputs
to a plurality of sensors and other devices. The ECI box includes
the necessary interfaces to control both manual and remote
operation of the trench roller.
Figure 7B is a schematic drawing illustrating the
electrical circuitry of the ECI box 50. As shown, the ECI box 50
includes a controller circuit 130 shown in more detail in Figure 8,
a display circuit 140 shown in more detail in Figure 9, input
signal conditioning circuitry 150 shown in more detail in Figure
10, a power supply circuit 160 shown in more detail in Figure 11,
and first, second and third solenoid driver circuits 170, 180, 190
shown in more detail in Figures 12, 13 and 14, respectively. In
the preferred embodiment, the box housing the entire assembly is
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encapsulated in a polymeric material to protect the assembly from
vibration and the environment. While a range of polymeric
encapsulant materials may be employed, including acrylics,
plastics, epoxies, and the like, the encapsulating material chosen
should preferably be thermally conductive in order to dissipate
heat generated by the internal components. The encapsulant should
preferably also have a low coefficient of thermal expansion in
order to reduce stress on the embedded components and be
sufficiently hard to adequately protect such components. If an
epoxy is used, the catalyst should also demonstrate thermal shock
and impact resistance. While commercially available, thermally-
conductive epoxy encapsulants with suitable catalysts have been
found to provide preferred performance characteristics, other
materials which provide the necessary sealing and protection of the
internal circuitry against environmental factors may also be used.
The input signal conditioning circuitry includes a
plurality of equipment sensors for monitoring operation of the
construction equipment or vehicle being controlled by the ECI box
50. These sensors include fault indicating sensors and warning
indicating sensors as have already been described. The display
circuit presents pertinent engine operating parameters to an
operator in response to direction received from the controller
circuit. The operation of the ECI box is functionally set forth in
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the flowcharts of Figures 15-28.
In response to the application of power to the ECI box,
an initialization routine is executed as depicted in Figure 15.
This routine, which is executed whenever battery power is applied
to the ECI box, initializes the microcontrollers input/output pins,
variables, and interrupts; resets the battery; and puts the remote
to sleep.
Figures 16A-16K summarize the INT routine of the ECI box,
in accordance with the present invention. The INT routine is
executed every 0.25 seconds and performs a number of functions
including sensing motor speed and shutting the engine down if the
revolutions per minute (RPM'S) are below a predetermined threshold,
engaging the starter motor for 0.75 seconds upon initial start-up,
sensing manual throttle switch input and de-energizing the
solenoids, energizing remote power based on ignition switch and
system on/off time, displaying message timing, resetting solenoid
timers and updating the hour meter. In a preferred embodiment, the
first timer (Timer 1) is the RPM counter, and the second timer
(Timer 2) is a 0.25 second timer, as set in the initialization
routine.
As depicted in Figure 16A, when starting, the starter
motor needs to be engaged for approximately 0.75 seconds in order
for the RPM to be stable. Thereafter, when in the manual mode, the
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throttle switch must be turned on in order for the throttle
solenoids to be energized. In the remote mode, the throttle
solenoid is engaged automatically after the starter motor solenoid
is disabled.
Updating of the hour meter, generally summarized in
Figure 16B, allows the use of engine on-time to be tracked. This
can be particularly useful in machine rental situations. The
battery timer also keeps track of system on-time and, as shown in
the Figure, increases the time the remote solenoid is on as the
system on-time increases.
Figure 16C presents the steps undertaken for the display
of battery charging and voltage status. If the generator is not
charging the battery properly, the LCD display 24 will flash a
warning message. Similarly, if the battery voltage is low, the LCD
display will flash a "bat low" warning message.
Figure 16D summarizes an optional fuel fault warning
routine, and updating and clearing of the display. If no warnings
exist, then engine RPM is displayed (see Figure 16E). With regard
to the tilt switch operation, in a preferred embodiment the tilt
switch is a normally open-contacts tip switch. During normal
operation of the trench roller, the leads associated with the
switch are not connected but, should the switch be tilted past a
threshold, the leads are connected to complete the switch and
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trigger engine shut-down. Such switches are known to persons of
skill in the art.
Due to the inherent vibration of the trench roller during
normal operation, rolling of the internal switch material often
results in brief connections of the leads in the tilt switch for
which engine shut-down would be inappropriate. Accordingly, as
shown in Figure 16E, when activation of the tilt switch is sensed,
a trip will only occur if the switch is on for a duty cycle greater
than approximately 62%. Other durations of switch closure
prerequisite for engine shut-down may, of course, be implemented.
Fault detection steps for oil pressure detection and
timing are set forth in Figures 16F and 16G. In a preferred
embodiment, Timer 0 is set to count oil pressure switch closures.
If Timer 0 counts more than ten oil pressure closures or pulses in
a 20 second period, the ECI box 50 will automatically shut down the
trench roller engine. As also shown in Figure 16G, the tilt,
cylinder temperature and oil pressure switches are preferably
sensed after 15 seconds although other intervals may also be
established.
Figures 16H-16K summarize the updating of various timers
in accordance with the present invention. When the ignition switch
is set to the accessory position, the hour meter, fault and
software revision code are displayed for a specified time and then
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the display shuts down to save power. As shown, the remote
solenoid off-time is increased the longer the system is off.
As set forth in Figures 17A and 17B, respectively, the
save fault data routine saves the current fault to EEPROM, and the
restore fault data restores the last fault from EEPROM and saves it
to a fault message array. The restore_fault byte routine of Figure
18 restores fault byte from EEPROM, and the save-fault byte routine
of Figure 19 saves fault byte to EEPROM.
As shown in Figure 20, the display warning message
routine displays multi-word warning and fault messages. The
get battery voltage routine of Figure 21 retrieves battery voltage,
with a .062mV resolution and 16.065V full scale in a preferred
embodiment. The save_settings routine of Figure 22 saves the hour
timer to EEPROM, and the restore settings routine of Figure 23
restores the hour timer from EEPROM.
Routines for the display of voltage, hours of engine
operation, RPM, and warning and fault messages are summarized in
Figures 24-27, respectively. As has already been discussed, the
number of engine hours is displayed when the ignition key is in the
accessory position 26d, and RPM is displayed when the engine is
running normally.
In a preferred embodiment, each warning and fault message
has an assigned message number. A "get message" routine uses a
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f
lookup table to find the appropriate message to be displayed based
on the fault/warning message number. The use and accessing of
look-up tables is well known in the art.
The main program is summarized in the flowchart of
Figures 28A through 28L. There are three primary loops within the
main program, namely remote, accessory switch, and manual mode.
The main program continually checks each mode in an endless loop.
If conditions for a particular mode are true, the program will
execute that mode.
While the encapsulated ECI box 50 with display, and
related circuit boards, wiring and microprocessor of the present
invention are preferably for a trench roller, the present invention
may be used on any type of motorized equipment, including earth
moving equipment, backhoes, bull dozers, front loaders, excavators,
etc. While many of these devices would not be remotely controlled,
all would benefit from the solid-state microprocessor driven
circuit board construction which render the ECI box rugged and
vibration resistant, enabling reliable display of engine functions
and fault indications.
The foregoing descriptions and drawings should be
considered as illustrative only of the principles of the invention.
The invention may be configured in a variety of shapes and sizes
and is not limited by the dimensions of the preferred embodiment.
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Numerous applications of the present invention will readily occur
to those skilled in the art. Therefore, it is not desired to limit
the invention to the specific examples disclosed or the exact
construction and operation shown and described. Rather, all
suitable modifications and equivalents may be resorted to, falling
within the scope of the invention.
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