Note: Descriptions are shown in the official language in which they were submitted.
I
TITLE OF THE INVENTION
ASSEMBLY AND METHOD FOR MEASURING FORCE FEEDBACK
FIELD OF THE INVENTION
[0001 ]The present invention relates to an assembly and method for measuring
a force feedback. In particular, the present invention relates adaptors for
connecting a force gauge to a control interface such as a yoke, stick,
sidestick,
rudder pedal or stab trim, in particular for use in a flight simulator or
aircraft, and
an apparatus and method for calibrating a simulated control interface such as
a
yoke, stick, sidestick, rudder pedal or stab trim in a flight simulator or
aircraft.
BACKGROUND TO THE INVENTION
[0002]Vehicle simulators such as those for simulating the operation of an
aircraft
have been developed to provide a realistic analogue of the vehicle being
simulated without the dangers inherent in having such a vehicle operated by a
novice or under extreme conditions. As the realism of the simulators has
improved, they have become an indispensable component in the certification of
vehicle operators such as pilots. In order to ensure that a given simulator
meets
the requisite realism such that they can be used as part of a certification
program,
the operation of various components must be measured versus a preapproved
certification standard and, as necessary, the components must be recalibrated.
In particular, systems such as sidesticks and stab trims, which provide an
instantaneous force feedback to the operator where the amount of force is an
indication of the current state of a component of the vehicle being operated
(such
as the flaps, ailerons and elevators on an aircraft) are required to provide a
simulated force feedback that reproduces the levels of force feedback as would
be experienced by the operator during actual operation.
Date Recue/Date Received 2023-05-16
2
[0003]Methods for measuring the force feedback of a sidestick and stab trim
during operation of the simulator are known in the art. One drawback of these
methods is that the measurements are not readily reproducible from time to
time
and simulator to simulator.
SUMMARY OF THE INVENTION
[0004]In order to address the above and other drawbacks, there is provided an
adaptor for positioning a force gauge relative to a control interface in a
flight
simulator or aircraft. The force gauge comprises a gauge handle and a gauge
connector, the control interface being moveable in at least one of a back-and-
forth direction and a side-to-side direction, the adaptor comprising a housing
positionable adjacent the control interface, said housing comprising a first
surface configured to snugly receive a predetermined surface of the control
interface, and a second surface comprising a first housing connector
configured
for connection to the gauge connector such that pressure is exertable on the
control interface by the force gauge in a first direction of measurement
aligned
with at least one of the back-and-forth direction and the side-to-side
direction.
[0005]There is also provided a kit for measuring a force feedback of a control
interface in a flight simulator or aircraft, the control interface moveable in
a back-
and-forth direction to change one of a pitch and a yaw of the simulator and in
a
side-to-side direction to change a roll of the simulator. The kit comprises a
force
gauge comprising a gauge handle, a gauge attachment portion and a first
direction of measurement, and a housing positionable adjacent the control
interface, the housing comprising a first inner surface configured to snugly
receive a predetermined surface of the control interface and a second surface
comprising a first point of attachment configured for attachment to the gauge
attachment portion such that the first direction of measurement is aligned
with
one of the back-and-forth direction and the side-to-side direction.
Date Recue/Date Received 2023-05-16
3
[0006]Additionally, there is provided a method for testing a force feedback of
a
control interface in a flight simulator, the control interface being moveable
in at
least one of a back-and-forth direction to change a pitch or a yaw of the
simulator
and in a side-to-side direction to change a roll of the simulator. The method
comprises placing an adaptor comprising a first point of attachment adjacent
the
control interface, connecting a force gauge to the first point of attachment
such
that a first direction of measurement of the force gauge is aligned with one
of the
back-and-forth direction and the side-to-side direction, and moving a gauge
handle portion of the force gauge in the first direction of measurement,
thereby
causing the force gauge to measure the force feedback generated by the control
interface in the first measurement direction.
[0007]Furthermore, there is provided an assembly for measuring a force
feedback of a stab trim in a flight simulator or aircraft, the stab trim
comprising a
trim wheel comprising a shaft receiving aperture arranged along an axis of the
trim wheel. The assembly comprises an elongate shaft configured for insertion
into the aperture and comprising a shaft axis, a handle arranged substantially
radially to the shaft axis, and a load cell interconnecting the shaft and the
handle
wherein the load cell is configured for measuring a torque between the handle
and the shaft.
[0008]Also, there is provided a method of testing a stab trim in a cockpit
simulator or aircraft, the stab trim comprising a trim wheel comprising a
shaft
receiving aperture arranged along an axis thereof. The method comprises
interconnecting a shaft to a handle wherein the shaft comprises a shaft axis
and
the handle is arranged substantially radially to the shaft axis, inserting the
shaft
into the aperture, operating the simulator, and measuring a torque between the
handle and the shaft.
Date Recue/Date Received 2023-05-16
4
BRIEF DESCRIPTION OF THE DRAWINGS
[0009]Figure 1A provides a rear right raised perspective view of an adaptor
bracket in accordance with a first illustrative embodiment of the present
invention;
[0010]Figure 1B provides a front plan view of an adaptor bracket in accordance
with a first illustrative embodiment of the present invention;
[0011]Figure 1C provides a rear plan view of an adaptor bracket in accordance
with a first illustrative embodiment of the present invention;
[0012]Figure 1D provides a top plan view of an adaptor bracket in accordance
with a first illustrative embodiment of the present invention;
[0013]Figure 1E provides a bottom plan view of an adaptor bracket in
accordance with a first illustrative embodiment of the present invention;
[0014]Figure 1F provides a right plan view of an adaptor bracket in accordance
with a first illustrative embodiment of the present invention;
[0015] Figure 1G provides a left plan view of an adaptor bracket in accordance
with a first illustrative embodiment of the present invention;
[0016] Figure 2 provides an exploded perspective view of an adaptor bracket
and
sidestick assembly in accordance with a first illustrative embodiment of the
present invention;
[0017]Figure 3A provides a rear right raised perspective view of an adaptor
bracket, sidestick and force gauge assembly for measuring force feedback in a
side-to-side direction in accordance with a first illustrative embodiment of
the
Date Recue/Date Received 2023-05-16
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present invention;
[0018]Figure 3B provides a rear right raised perspective view of an adaptor
bracket, sidestick and force gauge assembly for measuring force feedback in a
back to front direction in accordance with a first illustrative embodiment of
the
present invention;
[0019]Figure 4 provides a partially exploded perspective view of an adaptor
bracket and sidestick assembly in accordance with a second illustrative
embodiment of the present invention;
[0020]Figure 5 provides a graph of results of a force measurement of a control
column in accordance with an illustrative embodiment of the present invention;
[0021]Figure 6 provides a raised perspective view of an assembly for measuring
torque in a stab trim in accordance with an illustrative embodiment of the
present
invention;
[0022]Figure 7 provides a raised perspective view of a stab trim with a shaft
and
adaptor bracket installed in accordance with an illustrative embodiment of the
present invention;
[0023]Figure 8A provides a raised right front perspective view of an adaptor
bracket in accordance with an illustrative embodiment of the present
invention;
[0024]Figure 8B provides a front plan view of an adaptor bracket in accordance
with an illustrative embodiment of the present invention.
[0025]Figure 8C provides a side plan view of an adaptor bracket in accordance
with an illustrative embodiment of the present invention.
Date Recue/Date Received 2023-05-16
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[0026] Figure 8D provides a rear plan view of an adaptor bracket in accordance
with an illustrative embodiment of the present invention.
[0027]Figure 8E provides a raised left rear perspective view of an adaptor
bracket in accordance with an illustrative embodiment of the present
invention.
[0028] Figure 9A provides a raised left front perspective view of an adaptor
bracket in accordance with a third illustrative embodiment of the present
invention;
[0029]Figure 9B provides a right rear front perspective view of an adaptor
bracket in accordance with a third illustrative embodiment of the present
invention; and
[0030] Figure 10 provides a rear raised perspective view of an adaptor
bracket,
rudder pedal and force gauge assembly for measuring force feedback of a rudder
pedal in accordance with a third illustrative embodiment of the present
invention.
DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS
[0031]Referring now to Figure 1A, a first embodiment of an adaptor, generally
referred to using the reference numeral 10, will be described. The adaptor 10
comprises a housing 12 illustratively comprised of two complementary plastic
parts or halves 14, 16. The first complementary half 14 and the second
complementary half 16 may be assembled together using a plurality of fasteners
18. In a particular embodiment each of the fasteners 18 comprises a bolt 20
inserted through a respective bolt receiving bore 22 in a first of the
complementary halves 14, 16 and threaded into a respective one of a plurality
of
threaded inserts (not shown) in a second one of the two complementary halves
14, 16.
Date Recue/Date Received 2023-05-16
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[0032]Still referring to Figure 1A, the housing 12 further comprises a first
point
of attachment 24 and a second point of attachment 26. Each point of attachment
24, 26 illustratively comprises a threaded receptacle 28.
[0033]Referring now to Figure 2 in addition to Figure 1A, each of the
complementary halves 14, 16 comprises an outer shell 30 manufactured from a
rigid material such as hard plastic or the like, and a liner 32 manufactured
from
a flexible material such as a soft plastic or the like. The inner surface 34
of each
of the outer shells 30 is formed to receive the liner 32 in a snug fit and
such that
the liner 32 is held snugly against the inner surface 34. In a particular
embodiment an adhesive (not shown) may be used to secure the liner 32 to a
corresponding one of the outer shells 30 or the liner 32 and a corresponding
one
of the outer shells 30 may be manufactured together as a unitary piece.
[0034]Still referring to Figure 2 in addition to Figure 1A, the liner 32 is
formed
such that when the complementary halves 14, 16 are assembled together by
threading for each one of the fasteners 18 the bolt 20 into the bore 22 via a
washer 36 and a threaded insert 38, a sidestick, or control interface,
receiving
space 40 is defined which is shaped to snugly receive a sidestick/control
interface 42 such that the sidestick/control interface 42 is held securely
within the
sidestick receiving space 40 by the complementary halves 14, 16. In this
regard,
the liner 32 of each of the complementary halves 14, 16 includes features such
as a molded surface 46 or the like which is complementary to the shape of the
sidestick/control interface 42, and which ensures that each time the adaptor
10
is assembled about the sidestick/control interface 42, the positioning of the
adaptor 10 on the sidestick/control interface 42 is consistently the same.
Additionally, the complementary halves 14, 16 may further comprise apertures
48 or the like allowing control buttons 50 and the like on the
sidestick/control
interface 42 to be accessed.
[0035] Still referring to Figure 2, as known in the art the sidestick/control
interface
Date Recue/Date Received 2023-05-16
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42 is moveable from a central axis A in both a back-and-forth (B-B) direction
which for example controls the pitch of an aircraft (not shown) and a side-to-
side
(C-C) direction which for example controls the roll of the aircraft. The first
point
of attachment 24 and second point of attachment 26 are positioned on the outer
shell 30 of the housing 12 such that when the complementary halves 14, 16 are
assembled about the sidestick/control interface 42, the first point of
attachment
24 is aligned with the back-and-forth (B-B) direction, and the second point of
attachment 26 is aligned with the side-to-side (S-S) direction, the second
point
of attachment 26 being at right angles to the orientation of the first point
of
attachment 24. Additionally, the first point of attachment 24 and the second
point
of attachment 26 lie in the same plane, which is substantially normal to the
axis
A of the sidestick/control interface 42. In a particular embodiment, an
accelerometer (not shown) can for example be embedded in the outer shell 30
or the like. An exemplary embodiment of an accelerometer comprises a
PhidgetSpatial 3/3/3 Precision accelerometer/magnetometer/gyroscope.
[0036]Referring now to Figure 3A and Figure 3B in addition to Figure 2, as
discussed above each of the first point of attachment 24 and the second point
of
attachment 26 comprises the threaded receptacle 28 (which illustratively
comprises a threaded insert 52). In order to measure the force feedback, the
sidestick/control interface 42 in the back and forth (B-B) direction or the
side-to-
side (C-C) direction, once the bracket 10 has been assembled to the
sidestick/control interface 42, a force gauge 54 comprising a plunger 56 may
be
attached to the bracket 10 by threading a threaded end 58 of the plunger 56
into
the threaded receptacle 28 of a respective one of the first point of
attachment 24
and the second point of attachment 26. As known in the art, the plunger 56
moves
back and forth along a plunger axis. During measurement of the force feedback,
the angle of the sidestick/control interface 42 may be measured, for example
by
reading an output of an accelerometer or by reading the angle from a simulator
output.
Date Recue/Date Received 2023-05-16
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[0037]Referring still to Figure 3A, the force feedback of the
sidestick/control
interface 42 in the side to side (C-C) direction, which is aligned with the
plunger
axis, can be measured by the force gauge 54 by threading the threaded end 58
of the plunger 56 into the threaded receptacle 28 of the second point of
attachment 26 and pulling and pushing on the sidestick/control interface 42 in
a
side to side (C-C) direction using the force gauge 54 and such that pressure
is
exerted on the sidestick by movement of the force gauge 54. Movement of the
sidestick/control interface 42 in a side-to-side direction is typically
limited to a
maximum deflection of about 20 degrees in either direction.
[0038]Referring back to Figure 3B, the force feedback of the sidestick/control
interface 42 in the back and forth (B-B) direction can be measured by the
force
gauge 54 by threading the threaded end 58 of the plunger 56 into the threaded
receptacle 28 of the first point of attachment 24 and pulling and pushing on
the
sidestick/control interface 42 in a back and forth (B-B) direction using the
force
gauge 54. Movement of the sidestick/control interface 42 in a back-and-forth
direction is typically limited to a maximum deflection of about 18 degrees in
either
direction.
[0039] Referring now to Figure 4, a second embodiment of an adaptor 60 will be
described. The adaptor 60 comprises a housing 62 illustratively comprised of
two
complementary plastic parts or halves 64, 66. The first complementary half 64
and the second complementary half 66 may be assembled together using a
plurality of fasteners 68. In a particular embodiment the fasteners each
comprises a bolt 70 each of which is inserted through a respective bolt
receiving
bore 72 in a first of the complementary halves 64 and threaded into a
respective
one of a plurality of threaded inserts (not shown) in a second one of the two
complementary halves 64, 66. The two complementary halves 64, 66 are
securable about the sidestick/control interface 42, which is held snugly
therebetween for movement therewith.
Date Recue/Date Received 2023-05-16
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[0040]Still referring to Figure 4, the housing 62 further comprises a first
point of
attachment 74 illustratively comprising a threaded rod 76. A force gauge 78
comprising a gauge handle 80 may be secured to the adaptor 60 via the rod 76.
The force gauge 78 further comprises a sensor package 82 comprising one or
more sensors (not shown) such as a load cell or the like which measure forces
arising between the gauge handle 80 and the first point of attachment 74. An
exemplary embodiment of a suitable load cell is a six (6) degree of freedom
force-
torque sensor which comprises strain gauges able to measure force along 3
orthogonal axes and produced by JR3 Multi-Axis Load Cell Systems.
Illustratively, the sensor package 82 measures both axial forces and torque
forces vis-a-vis axis A 84 of the point of attachment 74. The elongate gauge
handle 80 is illustratively secured to the sensor package 82 such that the
gauge
handle axis B is at right angles to the axis A.
[0041]Still referring to Figure 4, in operation with the force gauge 78
secured to
the housing 62 via the point of attachment 74 and the threaded rod 76,
movement
by a user of the gauge handle 80 in either a back and forth or side-to-side
direction imparts measurable forces on the sidestick/control interface 42 in
respectively the back and forth or side-to-side directions. The sensor package
82 reads these imparted forces as axial 86 or torque 88 forces, which can be
collected and analysed in order to calibrate the sidestick/control interface
42.
[0042]Referring now to Figure 5 in addition to Figure 4, output data 90 of a
force
measurement versus angle from upright of a control column in a back and front
(fore and aft) movement is shown. Additionally, reference data 92 may also be
provided.
[0043]Referring now to Figure 6, an assembly 92 for measuring the feedback
force of a stab trim is disclosed. The assembly 92 comprises a load cell 94
for
measuring the torque between an elongate shaft 96 comprising a shaft axis A
and a handle 98 arranged radially to the shaft axis A. The shaft 96 is mounted
to
Date Recue/Date Received 2023-05-16
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the load cell 94 by a disk-shaped bracket 100 and a plurality of fasteners
such
as bolts 102 or the like. A conductive wire 104 can be provided to
interconnect
the electronics (not shown) of the load cell 94 with an external measuring
device
(also not shown), such as a multi-meter or the like, and via which measured
torque values can be read.
[0044] Referring now to Figure 7, the shaft 96 is interconnectable with a stab
trim
106, which comprises a stab trim aperture 108 into which the shaft 96 can be
inserted. In this regard, the aperture 108 and the shaft 96 are complementary
in
shape such that when inserted, the shaft 96 rotates with the stab trim 106.
Illustratively, the shaft 96 is manufactured from a square rod and comprises a
square cross-section.
[0045] Referring to Figures 8A through OF in addition to Figure 6, the bracket
100
is sized to accord with the load cell 94 and comprises a shaft receiving
aperture
110 for receiving the shaft 96 as well as a plurality of bores 112 via which
the
bolts 102 can be inserted. The shaft receiving aperture 110 is illustratively
sized
and shaped to accept the square shaft 96 in a friction fit and for rotation
therewith.
An embossment 114 is provided around the shaft receiving aperture 110 to
ensure that, when the assembly 92 is mounted to a stab trim 106, a minimum
spacing is maintained to ensure that the assembly 92 is only in contact with
the
stab trim via shaft 96.
[0046] With reference to Figure 8F, in a particular embodiment a designation
of
the aircraft 116 for which the stab trim adaptor bracket 98 is intended can be
provided.
[0047] Referring back to Figure 6 and Figure 7, in operation, the force
feedback
of the stab trim 106 can be measured by interconnecting the load cell 94 with
a
measuring device, inserting the shaft 96 of the assembly 92 into the stab trim
aperture 108 and moving the handle 98 while collecting readings via the
Date Recue/Date Received 2023-05-16
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measurement device.
[0048]Referring now to Figure 9A and Figure 9B, an adaptor 118 in accordance
with a third illustrative embodiment will now be described. The adaptor 118
comprises an adaptor body 120 comprising a foot pedal/control interface
receiving recess 122. A point of attachment 124 is provided for attaching the
plunger of a force gauge (both not shown). Illustratively the point of
attachment
124 comprises an inner surface (not shown) threaded to receive a threaded end
of the plunger.
[0049]Referring now to Figure 10, a force gauge 126 comprising a plunger 128
is secured to the adaptor 118 by threading the end of the plunger 128 into the
point of attachment 124. Once assembled, the foot pedal receiving recess 122
is placed over and pressed against a pedal/control interface 130 being tested
(illustratively a rudder pedal in an aircraft simulator). The measured result
is read
off the display 132 of the force gauge 126.
[0060]Although the present invention has been described hereinabove by way
of specific embodiments thereof, it can be modified, without departing from
the
spirit and nature of the subject invention as defined in the appended claims.
Date Recue/Date Received 2023-05-16
