Note: Descriptions are shown in the official language in which they were submitted.
TITLE: STEERING WHEEL CONTROLLER
FIELD
[0001] This disclosure relates to the field of steering wheel
controllers and methods
of electronically controlling the steering wheel of a vehicle.
INTRODUCTION
[0002] Self-driving vehicles may use a series of actuation systems
to control a
vehicle's maneuvers, based on data gathered from environmental sensors. Such
systems
typically require control over the vehicle's brakes, accelerator, and steering
wheel. In some
vehicles, "drive by wire" technology has been designed into the vehicle from
the onset
which allows for both human and machine control of the steering system. These
systems
typically use an integrated electric/hydraulic actuator for the steering
column and steering
rack.
SUMMARY
[0003] In one aspect, a steering wheel controller is provided. The
steering wheel
controller comprises a steering wheel mount, a wheel ring, and a ring driver.
The wheel
ring is connected to the steering wheel and defines an axis of rotation. The
ring driver is
drivingly coupled to the wheel ring and controllable, to selectively torque
the wheel ring, to
rotate with the steering wheel mount about the axis of rotation.
[0004] In another aspect, a method of electronically controlling the
steering wheel of
a vehicle is provided. This method comprises of a ring driver, applying torque
to a wheel
ring, connected to the steering wheel, thereby rotating the steering wheel
about the axis of
a steering column connected to the steering wheel.
DRAWINGS
[0005] FIG. 1 is a perspective view of a steering wheel controller
mounted to a
vehicle, in accordance with an embodiment;
[0006] FIG. 2 is a cross-sectional view taken along line 2-2 in FIG.
3;
[0007] FIG. 3 is a front elevation view of the steering wheel
controller of FIG. 1 with a
protective cover;
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=
=
[0008] FIG. 4 is a perspective view of an exploded steering wheel
mount, wheel ring,
steering wheel and dashboard;
[0009] FIG. 5 is a partial front elevation view of the steering
wheel controller of FIG.
1;
[0010] FIG. 6 is a front elevation view of a steering wheel controller
mounted to a
vehicle in accordance with another embodiment;
[0011] FIG. 7 is a cross-sectional view taken along line 7-7 in FIG.
6;
[0012] FIG. 8 is a front elevation view of the steering wheel
controller of FIG. 1 with a
drive gear;
[0013] FIG. 9 is a side elevation view of the steering wheel controller of
FIG. 1;
[0014] FIG. 10 is a front elevation view of a steering wheel
controller mounted to a
vehicle in accordance with another embodiment;
[0015] FIG. 11 is a cross-sectional view taken along line 11-11 in
FIG. 10;
[0016] FIG. 12 is a front elevation view of a steering wheel
controller mounted to a
vehicle in accordance with another embodiment;
[0017] FIG. 13 is a cross-sectional view taken along line 13-13 in
FIG. 12;
[0018] FIG. 14 is a side elevation view of the steering wheel
controller of FIG. 5;
[0019] FIG. 15 is a schematic of the steering wheel controller of
FIG. 1;
[0020] FIG. 16 is a front elevation view of a steering wheel
controller mounted to a
vehicle in accordance with another embodiment;
[0021] FIG. 17 is a perspective view of the steering wheel
controller of FIG. 16;
[0022] FIG. 18 is a perspective view of a steering wheel controller
mounted to a
vehicle in accordance with another embodiment;
[0023] FIG. 19 is a cross-sectional view taken along line 19-19 in
FIG. 18;
[0024] FIG. 20 is a front elevation view of the steering wheel controller
of FIG. 18;
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=.
[0025] FIG. 21 is a perspective view of a steering wheel controller
in accordance with
another embodiment;
[0026] FIG. 22A is a front elevation view of the steering wheel
controller of FIG. 21,
in a disengaged position;
[0027] FIG. 22B is a front elevation view of the steering wheel
controller of FIG. 21,
in an engaged position;
[0028] FIG. 23A is a cross-sectional view taken along line 23A-23A
in FIG. 22A;
[0029] FIG. 23B is a cross-sectional view taken along line 23B-23B
in FIG. 22B;
[0030] FIG. 24A is a front elevation view of the steering wheel
controller of FIG. 21,
in a disengaged position and shifted radially outwardly;
[0031] FIG. 24B is a front elevation view of the steering wheel
controller of FIG. 21 in
a disengaged position and shifted radially inwardly;
[0032] FIG. 25A is a cross-sectional view taken along line 25A-25A
in FIG. 24A; and
[0033] FIG. 25B is a cross-sectional view taken along line 25B-25B
in FIG. 24B.
DESCRIPTION OF VARIOUS EMBODIMENTS
[0034] Numerous embodiments are described in this application, and
are presented
for illustrative purposes only. The described embodiments are not intended to
be limiting in
any sense. The invention is widely applicable to numerous embodiments, as is
readily
apparent from the disclosure herein. Those skilled in the art, will recognize
that the present
invention, may be practiced with modification and alteration, without
departing from the
teachings disclosed herein. Although particular features of the present
invention may be
described with reference to one or more particular embodiments or figures, it
should be
understood that such features are not limited to usage in the one or more
particular
embodiments or figures with reference to which they are described.
[0035] The terms "an embodiment," "embodiment," "embodiments," "the
embodiment," "the embodiments," "one or more embodiments," "some embodiments,"
and
"one embodiment" mean "one or more (but not all) embodiments of the present
invention(s)," unless expressly specified otherwise.
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[0036] The terms "including," "comprising" and variations thereof
mean "including but
not limited to," unless expressly specified otherwise. A listing of items does
not imply that
any or all of the items are mutually exclusive, unless expressly specified
otherwise. The
terms "a," "an" and "the" mean "one or more," unless expressly specified
otherwise.
[0037] As used herein and in the claims, two or more parts are said to be
"coupled",
"connected", "attached", or "fastened" where the parts are joined or operate
together either
directly or indirectly (i.e., through one or more intermediate parts), so long
as a link occurs
(e.g. mechanical, electronical or magnetic link). As used herein and in the
claims, two or
more parts are said to be "directly coupled", "directly connected", "directly
attached", or
"directly fastened" where the parts are connected in physical contact with
each other. As
used herein, two or more parts are said to be "rigidly coupled", "rigidly
connected", "rigidly
attached", or "rigidly fastened" where the parts are coupled so as to move as
one while
maintaining a constant location and orientation relative to each other. None
of the terms
"coupled", "connected", "attached", and "fastened" distinguish the manner in
which two or
more parts are joined together.
[0038] Further, although method steps may be described (in the
disclosure and / or
in the claims) in a sequential order, such methods may be configured to work
in alternate
orders. In other words, any sequence or order of steps that may be described
does not
necessarily indicate a requirement that the steps be performed in that order.
The steps of
methods described herein may be performed in any order that is practical for
the particular
design and embodiment of the invention. Further, some steps may be performed
simultaneously, and some steps may be omitted.
[0039] The present application is directed to a steering wheel
controller, which can
be installed on vehicles that are not equipped with "drive by wire"
technology. The steering
wheel controller can form part of a 'self-driving add-on kit' or be used to
provide an
alternative control methods, such as joystick or buttons, for persons with
disabilities. The
wheel controller is intended to be a retrofit to a manually steered vehicle to
enable electric
actuation of the steering wheel. The steering wheel controller, provides
electric actuation of
the steering wheel for accurate control of the vehicle's heading. In one
aspect, the steering
wheel controller may provide a method by which a steering system can be
retrofitted with
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'drive-by-wire' capability. As disclosed below, the steering wheel controller
provides
external control of the steering wheel while retaining the ability for the
human driver to
quickly regain control of the vehicle using its originally intended manual
steering method at
any time.
[0040] Reference is made to FIG. 1, which shows a steering wheel controller
100
retrofitted onto the steering wheel 104 of a vehicle. The vehicle can be any
vehicle having
a steering wheel 104, such as an automobile (e.g. car, sports utility vehicle,
or truck), boat,
or airplane. As shown, the steering wheel 104 includes a rim 108 rigidly
connected to a
hub 112. The steering wheel rim 108 at least partially surrounds the steering
wheel hub
112 to provide a handgrip for a user to grasp with the user's hands. The
steering wheel rim
108 can have any shape known in the art, such as the substantially circular
shape shown.
[0041] Referring to FIGS 1-2, the steering wheel hub 112 includes a
rear portion 116
that connects (e.g. rigidly connects) to a steering column 120. In some cases,
the steering
wheel hub 112 also includes a horn button, an air bag assembly, and user
controls (e.g.
multimedia controls).
[0042] The steering wheel 104 has an axis of rotation 124 that is
typically collinear
with the axis of rotation 128 of steering column 120. In use, a user can grip
the steering
wheel 104 by the steering wheel rim 108 and apply torque to rotate steering
wheel 104
about the rotation axis 124, to steer the vehicle (e.g. to turn left or
right).
[0043] The steering wheel controller 100 provides electronic control over
the steering
wheel 104 by acting upon the steering wheel 104 instead of acting upon
internal
components of the steering assembly such as the steering column 120. This
allows the
steering wheel controller 100 to be easily retrofitted to a wide variety of
vehicles, including
vehicles without drive-by-wire capability. As shown, the steering wheel
controller 100
includes a wheel ring 132 mounted to the steering wheel 104, and a ring driver
136
drivingly coupled to the wheel ring 132. In use, the ring driver 136 torques
the wheel ring
132 to rotate the wheel ring 132 and the steering wheel 104 together about the
steering
wheel rotation axis 124.
[0044] The wheel ring 132 can be connected to the steering wheel 104
in any
manner that allows the steering wheel 104 to be rotated about the steering
wheel rotation
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axis 124 by applying torque to the wheel ring 132. For example, the wheel ring
132 may be
rigidly connected to the steering wheel 104 so that the wheel ring 132 and
steering wheel
104 rotate as one.
[0045] The wheel ring 132 may be connected to the steering wheel 104
in a manner
that does not obstruct or interfere with a user's grip on the steering wheel
rim 108. This
helps to reduce the impact of the steering wheel controller 100 on a user's
control over the
steering wheel 104. For example, the steering wheel rim 108 may include hand
gripping
surfaces 140 that face away (e.g. radially outwardly) from the steering wheel
rotation axis
124, and the wheel ring 132 may be connected to the steering wheel 104 by a
steering
wheel mount 144 that overlies no portion of the hand gripping surfaces 140 and
that holds
the wheel ring 132 behind the steering wheel rim 108.
[0046] Referring to FIGS. 1 and 3, steering wheel rim 108 includes
inner surfaces
148 that face towards the steering wheel rotation axis 124 (e.g. radially
inwardly). For
example, inner surfaces 148 may border portions of the steering wheel rim 108
that are
spaced apart from the steering wheel hub 112 by an air gap 152. The steering
wheel
mount 144 may bear against inner surfaces 148 of the steering wheel rim 108 to
secure the
wheel ring 132 to the steering wheel 104. For example, the steering wheel
mount 144 may
include one or more steering wheel rim couplers 156. Each steering wheel rim
coupler 156
may include an engagement surface 160 that faces away from the steering wheel
rotation
axis 128 and that engages a steering wheel rim inner surface 148. As shown,
steering
wheel rim couplers 156 may extend into air gaps (e.g. apertures or open
areas), 152 to
engage steering wheel rim inner surfaces 148.
[0047] The steering wheel mount 144 can include any number of
steering wheel rim
couplers 156, which can have any configuration suitable for collectively
securing wheel ring
132 to the steering wheel 104. In the illustrated example, the steering wheel
mount 144 is
shown including three steering wheel rim couplers 156, which are spaced apart
and
distributed around the steering wheel rotation axis 124. In other embodiments,
the steering
wheel mount 144 may include just one steering wheel rim coupler 156, or a
plurality of
steering wheel rim couplers 156.
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[0048] In some embodiments, steering wheel rim coupler(s) 156 may
rigidly secure
wheel ring 132 to steering wheel 104 in a manner that is removable and non-
destructive
(e.g. does not make any physical modification to the steering wheel 104). For
example,
steering wheel rim couplers 156 may be configured to apply a coupling force in
an outward
direction (i.e. away from steering wheel rotation axis 124) against the
steering wheel 104.
In some embodiments, steering wheel rim coupler(s) 156 may be connected to the
steering
wheel 104 by other methods, such as by adhesive, magnets, or clamps for
example.
Alternatively, or in addition, steering wheel rim coupler(s) 156 may be
secured to the
steering wheel 104 by penetrative fasteners (e.g. screws, or bolts), or welds
for example.
[0049] Reference is now made to FIG. 4. In some embodiments, the steering
wheel
mount 144 rigidly secures the wheel ring 132 to the steering wheel hub 112,
instead of or in
addition to securing the wheel ring 132 to steering wheel rim 108. Steering
wheel mount
144 may bear against an outer surface 164 of the steering wheel hub 112 to
secure the
wheel ring 132 to the steering wheel 104. For example, the steering wheel
mount 144 may
include one or more steering wheel hub couplers 168. Each steering wheel hub
coupler
168 may include an engagement surface 172 that engages steering wheel hub
outer
surface 164.
[0050] In some embodiments, steering wheel hub coupler(s) 168 may
rigidly secure
wheel ring 132 to steering wheel 104 in a manner that is removable and non-
destructive
(e.g. does not make any physical modification to the steering wheel 104). In
the illustrated
example, the steering wheel mount 144 includes two steering wheel hub couplers
168 that
fasten to each other and together surround the steering wheel hub rear portion
116. As
shown, the steering wheel hub couplers 168 may be connected by one or more
fasteners
176 that can be tightened to clamp the steering wheel mount 144 onto the
steering wheel
hub 112. In some embodiments, steering wheel hub couplers 168 may be connected
to the
steering wheel 104 by other methods, such as by adhesive, magnets, or clamps
for
example. Alternatively, or in addition, steering wheel hub couplers 168 may be
secured to
steering wheel 104 by penetrative fasteners (e.g. screws, or bolts), or welds
for example.
[0051] Referring to FIG. 1, in some embodiments, the steering wheel
mount 144 is
adjustable to accommodate differently sized and shaped steering wheels. For
example,
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the steering wheel mount 144 may include steering wheel couplers 156 and/or
168 (FIG. 4)
that are selectively movable inwardly and outwardly (e.g. movable radially) to
make bear
against the steering wheel surfaces 148 and/or 164. In the illustrated
example, steering
wheel rim couplers 156 are selectively radially movable to enhance the force
of the steering
wheel rim couplers 156 against the steering wheel rim 108. For example,
steering wheel
mount 144 may include adjustment screws 180 as shown, which can be manually
turned to
move the steering wheel rim couplers 156 radially into engagement with the
steering wheel
surfaces 148, ensuring a concentric arrangement between the axis of rotation
of the
steering wheel 124 and the wheel ring 132.
[0052] Referring to FIG. 5, the wheel ring 132 forms a closed loop around
the
steering wheel rotation axis 124.the ring driver 136 operates to apply a
physical or
magnetic force onto the wheel ring 132 to rotate it and the steering wheel 104
around the
steering wheel rotation axis 124. The ring driver 136 may be stationary
relative to the
wheel ring 132. Preferably, the wheel ring 132 forms a circular loop centered
on the
steering wheel rotation axis 124 so as to simplify the coupling between the
ring driver 136
and the wheel ring 132.
[0053] Referring to FIG. 1, the wheel ring 132 can be connected to
the steering
wheel mount 144 in any way that allows the wheel ring 132 to transmit torque
to the
steering wheel 104 by way of the steering wheel mount 144. Preferably, the
wheel ring 132
is rigidly connected to the steering wheel mount 144 so that the two rotate as
one. For
example, the wheel ring 132 and the steering wheel mount 144 may be integrally
formed,
as seen in FIG. 4, or discretely formed and subsequently attached as seen in
FIGS. 6-7.
[0054] Referring to FIG. 5, the ring driver 136 can be drivingly
coupled to the wheel
ring 132 in any manner that allows the ring driver 136 to impart a torque upon
wheel ring
132 to rotate it and the steering wheel 104 together about the steering wheel
rotation axis
124. For example, ring driver 136 may be configured to transmit torque to the
wheel ring
132 physically (e.g. by physical contact, such as friction) or magnetically
(e.g. by magnetic
fields).
[0055] In the illustrated example, the wheel ring 132 includes an
engagement
surface 184, and the ring driver 136 includes a rotor that engages the wheel
ring
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engagement surface 184, so the rotor 188 torques the engagement surface 184
when
rotated, and thereby rotates the wheel ring 132. As shown, the engagement
surface 184
forms a closed loop around the steering wheel rotation axis 124. Preferably,
the
engagement surface 184 is circularly shaped and centered on the steering wheel
rotation
axis 124.
[0056] In some embodiments, the rotor 188 frictionally engages the
ring engagement
surface 184. For example, the rotor 188 may include a wheel 192 that makes
frictional
rolling engagement with the engagement surface 184. This can allow the wheel
192 to slip
in a high torque event, which can signal a user's intent to override the
steering wheel
controller 100 and can avoid damaging the ring driver motor. It will be
appreciated that the
wheel 192 may make direct physical contact with the engagement surface 184 as
shown,
or may make indirect frictional rolling engagement by way of an intermediate
member, such
as a belt or another wheel. Using an intermediary member can provide more
flexibility in
the mounting of the ring driver 136 inside the vehicle. The wheel 192 and
engagement
surface 184 may be made of any materials that providing sufficient friction to
rotate the
steering wheel 104, such as a low stiffness rubber for example.
[0057] FIG. 8 shows an example in which rotor 188 includes a drive
gear 196 that is
meshed with a toothed engagement surface 184. Effectively, toothed engagement
surface
184 forms a large gear. The drive gear 196 may be directly meshed with the
toothed
engagement surface 184 as shown, or indirectly by way of a chain, timing belt
or another
gear for example.
[0058] Engagement surface 184 may face in any direction that can
allow for driving
engagement with the rotor 188. In the illustrated example, the surface 184
faces outwardly
away from the steering wheel rotation axis 124 (e.g. radially outwardly).
In this
configuration, the ring driver rotor 188 may be positioned outwardly (e.g.
radially outwardly)
of engagement surface 184 (and the wheel ring 132 as a whole). As a result,
the wheel
ring 132 may have a compact form that does not need to accommodate the ring
driver rotor
188 inwardly of engagement surface 184.
[0059] FIGS. 6-7 show another example in which the surface 184 faces
inwardly
towards the steering wheel rotation axis 124 (e.g. radially inwardly). In this
configuration,
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the ring driver rotor 188 may be positioned inwardly (e.g. radially inwardly)
of engagement
surface 184 (and wheel ring 132 as whole). As a result, the ring driver rotor
188 may be at
least partially concealed and protected within the wheel ring 132. This can
help reduce
instances of user-contact with the rotor 188 that can lead to injury, and
reduce the visual
distraction of the rotor 188.
[0060] In some embodiments, the engagement surface 184 may face
axially (e.g.
forwardly or rearwardly, such as in parallel with the steering wheel rotation
axis 124). In
some embodiments, the wheel ring 132 may include a plurality of engagement
surfaces
184 that face in different directions (e.g. radially inwardly and outwardly),
and ring driver
136 may include a plurality of ring driver rotors 188 that collectively engage
with the
plurality of engagement surfaces 184.
[0061] Reference is now made to FIGS. 2-3. In some embodiments, the
steering
wheel controller 100 includes a protective cover 204 that overlies at least a
front portion of
the ring driver 136 where the ring driver 136 is drivingly coupled to the
wheel ring 132. For
example, the protective cover 204 may overlie at least the ring driver rotor
188. This can
help prevent user-contact with the rotor 188 that can lead to injury, help
block dirt and
debris from accumulating on the ring driver 136, and block visibility of the
rotor 188 which
can be a distraction to the driver. As shown, the protective cover 204 may be
connected to
the wheel ring 132. For example, the protective cover 204 may be integrally
formed with
the wheel ring 132 as shown, or discretely formed and joined to the wheel ring
132 (e.g. by
fasteners, adhesives, magnets, welds, rivets, or another means). The
protective cover 204
may extend along any portion of the wheel ring 132. In the illustrated
example, the
protective cover 204 extends the full length of the wheel ring 132 (e.g.
forming a closed
loop). In alternative embodiment, the protective cover 204 may extend only
along a portion
the wheel ring 132, such as where the rotor 188 is positioned.
[0062] Reference is now made to FIG. 9. The ring driver rotor 188
can be driven in
any manner that can provide sufficient torque and speed to rotate the steering
wheel 104 to
steer the vehicle in expected driving conditions (e.g. on roads and in
traffic). For example,
the ring driver rotor 188 may include a motor 208 which drives the rotation of
the rotor 188,
as shown. The ring driver motor 208 may be drivingly connected to the rotor
188 in any
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way, such as a direct drive configuration, or an indirect drive by way of one
or more
intermediaries (e.g. gears 212, chains, belts, or wheels). In one aspect, an
indirect drive
connection may provide greater flexibility in positioning the motor 208 to
accommodate the
vehicle being retrofitted with the steering wheel controller 100.
[0063] In some embodiments, the ring driver motor 208 is connected to the
rotor 188
by way of transmission. The transmission may be a reducing transmission, such
as
reducing gearbox 216. This can allow a relatively high-speed motor 208 (which
are widely
available, and relatively inexpensive) to be employed, whereby the reducing
gearbox 216
slows the output speed and increases the torque output to the rotor 188.
Alternatively, a
ring driver motor 208 that natively outputs the desired speed and torque may
be used,
which can avoid the use of a reducing transmission and thereby provide a more
compact
configuration.
[0064] The ring driver 136 can be secured in position in any manner
suitable to allow
the wheel ring 132 to be driven to move relative to the ring driver 136. Also,
the ring driver
136 can be mounted at any location relative to the wheel ring 132. FIGS. 1-3
show an
example of the ring driver 136 mounted above the wheel ring 132 and to the
left of center.
As shown, the steering wheel controller 100 may include a dashboard mount 228
that
secures the ring driver 136 to the dashboard 220 (e.g. to dashboard upper
surface 224).
This may provide a convenient mounting location as the dashboard upper surface
224 may
provide a relatively smooth open area for mounting the ring driver 136.
However,
depending on the configuration of the vehicle, this mounting configuration may
partially
obstruct the user's view of the instrument panel and/or view through the
windshield. In
other embodiments, steering wheel controller 100 may include a steering column
mount
that secures the ring driver 136 to the steering column 120 (FIG. 1), or
another mount that
secures the ring driver to another fixed surface of the vehicle.
[0065] FIGS. 6-7 show an example of the ring driver 136 mounted
below the wheel
ring 132 and right of center. As shown, ring driver 136 may be mounted below
the
dashboard 220. This mounting configuration can avoid interfering with the
user's visibility.
However, depending on the vehicle configuration, it may interfere with the
user's leg room
or may not provide ideal surfaces for securely mounting the ring driver 136.
FIGS. 10-11
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show an example of the ring driver 136 mounted below the wheel ring 132 and to
the left of
center. FIGS. 12-13 show an example of the ring driver 136 mounted within
(e.g. radially
inwardly of) the wheel ring 132 by dashboard mount 228 to an inward facing
surface 232 of
the dashboard 220. This mounting configuration may reduce or eliminate any
obstruction
of the user's view of the instrument panel and through the windshield by the
ring driver 136.
In other embodiments, the ring driver 136 may be mounted to the left or right
of the ring
driver 136 for example.
[0066] Reference is now made to FIG. 14. In some embodiments, the
ring driver
136 (or a component thereof, such as ring driver rotor 188) is resiliently
biased into physical
engagement with the wheel ring 132 (e.g. into engagement with engagement
surface 184).
This increases the normal force applied to the ring driver rotor 188 to the
engagement
surface 184. Where the ring driver rotor 188 includes a wheel 192 (FIG. 5) in
frictional
rolling engagement with the engagement surface 184, a greater normal force can
increase
this friction and thereby reduce instances of slippage. Where the ring driver
rotor 188
includes a drive gear 196 (FIG. 8), a greater normal force can help maintain
engagement
between the drive gear 196 and the toothed engagement surface 184. The biased
engagement can also help to accommodate for any shape irregularities, which
may
develop from wear in the ring driver rotor 188 and the engagement surface 184,
for
example.
[0067] The ring driver 136 may be resiliently biased into physical
engagement with
the wheel ring 132 in any manner. In the illustrated example, the ring driver
136 is pivotally
connected to the dashboard mount 228 about a pivot axis 236 (FIG. 1), and
includes a bias
240 (e.g. a spring) that pivots the ring driver rotor 188 about pivot axis 236
(FIG. 1) towards
the engagement surface 184. As shown, the pivot axis 236 may be perpendicular
to and
offset from the steering wheel rotation axis 124. Alternatively, or in
addition, the ring driver
136 (or a component thereof, such as the ring driver rotor 188) may be
linearly movable
relative to wheel ring 132 and biased linearly towards the wheel ring 132.
Further, as
shown, bias 240 may include a passive device such as a spring. Alternatively
or in
addition, bias 240 may be an active device, such as a servo or solenoid 242
that can be
selectively activated or deactivated.
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[0068] Referring to FIG. 9, in some embodiments, the steering wheel
controller 100
includes a clutch assembly 244. The clutch assembly 244 can be any device that
can be
selectively activated to stop the transmission of torque from the ring driver
136 to the wheel
ring 132. For example, the clutch assembly 244 may be operable to mechanically
disconnect a connection between the ring driver motor 208 and the ring driver
rotor 188
(e.g. to separate mating gears in the transmission 216) whereby the ring
driver rotor 188 is
allowed to rotate independently from the wheel ring 132 and hence the steering
wheel 104.
Alternatively, or in addition, the clutch assembly 244 may be operable to
disengage ring
driver rotor 188 from engagement surface 184. For example, the clutch assembly
244 may
include a selectively operable clutch actuator 242 (e.g. solenoid, or another
electrical,
pneumatic, or hydraulic device) to pivot ring driver 136 about the pivot axis
236 to move the
ring driver rotor 188 away from the engagement surface 184, discontinuing the
transmission of torque from the ring driver to the steering wheel.
[0069] Thus, the clutch assembly 244 can be activated to cease
control of steering
wheel controller 100 over the steering wheel 104, whereby the user may be
allowed to
retake control. The clutch assembly 244 may be automatically activated (e.g.
by electronic
control) in response to predetermined conditions. For example, clutch assembly
244 may
be activated to stop torque transmission in response to sensing user-applied
torque on the
steering wheel 104.
[0070] Preferably, clutch assembly 244 is activated to stop torque
transmission
automatically in response to system power loss. This assures that the user can
retake
control over the vehicle in the event that the steering wheel controller 100
loses power. In
the illustrated example, the transmission gear 248 is meshed with the
transmission gear
252. A spring bias 256 biases the transmission gear 248 against a cam block
264. A ram
260 acts on cam block 264 and is horizontally movable to move the cam block
264
between a first position (shown) in which the transmission gear 248 is meshed
with the
transmission gear 252, and a second position in which the transmission gear
248 is
decoupled from transmission gear 252. As shown, a ram 260 is connected to a
ram
actuator 268 (e.g. a solenoid, hydraulic actuator, or pneumatic actuator) that
is selectively
activated to move the ram 260 horizontally. Preferably, in the event of a
power loss, the
ram actuator 268 is deactivated, whereby the spring bias 256 is able to move
transmission
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gear 248, cam block 264, and ram 260 from the first position to the second
position in
which transmission gear 248 is decoupled from transmission gear 252.
[0071] The steering wheel controller 100 may include one or more
sensor 276. The
sensors 276 can be any type of sensor known in the art that can sense the
movement
and/or position of the ring driver rotor 188 and the wheel ring 132. For
example, sensors
276 may be optical encoders, haul effect sensors, or combinations thereof. In
the illustrated
embodiment, the steering wheel controller 100 includes a wheel ring sensor
276a that
senses the movement and/or position (e.g. rotational movement/position around
steering
wheel rotation axis 124) of the wheel ring 132, and a ring driver sensor 276b
that senses
the movement and/or position of the ring driver rotor 188.
[0072] As shown in FIG. 15, the steering wheel controller 100 may
include a
computing device 280 (e.g. having a processor 284 and memory 288) that is
communicatively coupled (e.g. by wire or wirelessly) to sensors 276 and the
ring driver 136
that together, provide a feedback loop. For example, computing device 280 may
direct
(e.g. send control signals to) the ring driver 136 to torque the wheel ring
132, receive
sensor information from sensors 276 on the position and/or movement of the
wheel ring
132 and the ring driver rotor 188, and then based on the sensor information
issue further
directions to the ring driver 136.
[0073] In some embodiments, the computing device 280 may determine
whether
there are any inconsistencies between the sensed movement/position of the
wheel ring
132, and the movement/position of the ring driver rotor 188. For example, each
rotation of
ring the driver rotor 188 may correspond to a specific angular rotation of the
wheel ring 132,
and slippage between the ring driver rotor 188 can be inferred where that
relationship is not
reflected in the sensor readings. The nature of the slippage may indicate that
the user is
attempting to retake control over the steering wheel 104. In this case, the
computing
device 280 may direct (e.g. send control signals to) clutch assembly 244 to
stop torque
transmission and allow the user to have control over the steering wheel 104.
Alternatively,
the nature of the slippage may indicate unintentional slippage, free of any
user intervention
to retake control over the steering wheel 104. In this case, computing device
280 may
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CA 2986672 2017-11-24
compensate for the slippage by sending additional directions to the ring
driver 136 (e.g. by
applying additional torque).
[0074] Reference is now made to FIG. 16, which shows a steering
wheel controller
100 in accordance with another embodiment in which the ring driver 136
magnetically
transmits torque to the wheel ring 132. The ring driver 136 can magnetically
transmit
torque to the wheel ring 132 in any manner. In the illustrated embodiment, the
wheel ring
132 includes an array of rotor magnets 292 distributed along the wheel ring
132 around the
steering wheel rotation axis 124, and the ring driver 136 has at least two
stator magnets
296. As shown, the rotor magnets 292 may be permanent magnets, and the stator
magnets 296 may be electromagnets selectively able to be energized in order to
magnetically torque wheel ring 132 to rotate.
[0075] Turning to FIG. 17, the rotor magnets 292 may be identical
and evenly
distributed in a closed loop around the wheel ring 132 according to a rotor
magnet pitch
304 (center-to-center distance between adjacent rotor magnets 292). Together,
rotor and
stator magnets 292 and 296 may form a stepper motor, where the rotor magnet
pitch 304
defines the step size, which affect positioning tolerance of the wheel ring
132. A smaller
rotor magnet pitch 304 (or greater number of rotor magnets 292) may allow for
greater
positional accuracy as the ring driver 136 magnetically torques the wheel ring
132 to rotate.
In some embodiments, the wheel ring 132 includes at least 180 rotor magnets
292 to
provide a positional accuracy of 2 degrees or better (i.e. 2 degrees or less).
[0076] It will be appreciated that a ring driver 136, which
transmits torque
magnetically, may not include a clutch assembly, which moves components to
mechanically disconnect the transfer of torque from the ring driver 136 to the
wheel ring
132. Instead, the torque transmission can be stopped by cutting power to the
ring driver
136, which deactivates stator electromagnets 296 and thereby ceases the
magnetic field
that was acting on the rotor magnets 292, freeing the wheel ring and hence the
steering
wheel to rotate freely by the operator's hands.
[0077] Still referring to FIG. 17, stator magnets 296 can have any
configuration
suitable for generating a magnetic field that can drive rotor magnets 292 to
rotate with the
wheel ring 132 about steering wheel rotation axis 124. In the illustrated
embodiment, stator
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magnets 296 are substantially C-shaped, each having a central portion 308
wound with
wire 312 and two opposed end portions 316 which define the north and south
poles. As
shown, stator magnets 296 are positioned and oriented with the opposed end
portions 316
flanking the opposed north and south poles of the rotor magnets 292. The
stator electro-
magnet coil 312 is wound with a center axis aligned with the rotor magnet
poles in the end
portion 316.
[0078]
In the illustrated example, the rotor and stator magnets 292 and 296
are
oriented with their poles aligned axially (e.g. in parallel with the steering
wheel rotation axis
124). In this configuration, the axial forces are substantially cancelled by
the flanking
configuration of the stator magnets 296. The air gap 320 between the stator
magnet end
portions 316 and the rotor magnets 292 is preferably small, such as less than
5mm.
[0079]
FIG. 18 shows another embodiment in which the rotor and stator magnets
292 and 296 are oriented with their poles aligned radially (e.g. perpendicular
to steering
wheel rotation axis 124). This orientation can allow up to twice as much
torque to be
developed, all else being equal. However, the radial orientation may also
lead to
misbalanced loads towards/away from the steering wheel rotation axis 124.
Referring to
FIG. 19, this misbalance in radial force may be reduced by providing a
radially outer air gap
320a that is lesser than the radially inner air gap 320b.
[0080]
Turning to FIG. 20, the ring driver 136 can include two or more stator
magnets 296. In the illustrated embodiment, the ring driver 136 includes two
stator
magnets 296. Alternatively, the ring driver 136 may include three, four, or
more stator
magnets 296. As shown, stator magnets 296 are spaced apart according to a
stator
magnet pitch 324 (center-to-center spacing). Stator magnets 296 should be
positioned out
of phase with rotor magnets 292. In other words, the stator magnet pitch 324
should not be
a whole number multiple of the rotor magnet pitch 304. This can allow stator
magnets 296
to be activated in alternating fashion to generate magnetic fields that propel
the wheel ring
132 to rotate. Reversing the polarity of current through stator magnet
windings 312 (FIG.
17) reverses the direction of rotation. In the illustrated embodiment, the
stator magnets 296
are out of phase with the rotor magnets 292 by one half the rotor magnet pitch
304, such
that when one stator magnet 296a has poles aligned exactly with the poles of
the rotor
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CA 2986672 2017-11-24
magnets 292, the other stator magnet 296b has poles aligned exactly half way
between the
poles of the rotor magnets 292.
[0081]
Reference is now made to FIG. 21, which illustrates a steering wheel
controller 100 in accordance with another embodiment. As shown, steering wheel
controller 100 may include one or a plurality of ring drivers 136, and one or
a plurality of
ring idlers 328. Collectively, the ring driver(s) 136 and ring idler(s) 328
may be movable
between a disengaged position (FIG. 22A) in which at least ring driver(s) 136
is disengaged
from wheel ring 132, and an engaged position (FIG. 22B) in which driver(s) 136
and ring
idler(s) 328 clamp onto wheel ring 132. In the engaged position (FIG. 22B),
ring driver(s)
136 is urged into firm contact with wheel ring 132 to mitigate slippage as
ring driver(s) 136
is energized to apply torque to drive wheel ring 132. In the disengaged
position (FIG. 22A),
ring driver(s) 136 is disengaged (e.g. spaced apart) from wheel ring 132 to
permit manual
user operation of the steering wheel attached to wheel ring 132.
[0082]
Still referring to FIG. 21, the illustrated example shows a steering
wheel
controller 100 including two circumferentially spaced apart ring drivers 136,
and two
circumferentially spaced apart ring idlers 328. The use of a plurality of ring
drivers 136 as
shown may permit better detection of slippage and provide greater torque as
compared
with a single ring driver 136, all else being equal.
[0083]
Referring to FIG. 22B, in the engaged position, the ring drivers 136
and ring
idlers 328 may contact opposite sides of wheel ring 132. This allows ring
drivers 136 and
ring idlers 328 to apply compressive clamping forces onto wheel ring 132 when
in the
engaged position, which may mitigate slippage. The illustrated example shows
an
engaged position in which ring drivers 136 engage an inner surface 1841 of
wheel ring 132
and ring idlers 328 engage an outer surface 1842 of wheel ring 132. As shown,
inner
surface 1841 may face radially inwardly of wheel ring 132, and outer surface
1842 may face
radially outwardly of wheel ring 132. In alternative embodiments, ring drivers
136 may
engage outer surface 1842, and ring idlers 328 may engage inner surface 1841.
[0084]
Returning to FIG. 21, each ring driver 136 includes a ring driver rotor
188 that
engages wheel ring 132. Ring driver rotor 188 can take any form suitable for
applying
torque to wheel ring 132 for rotating the steering wheel attached to wheel
ring 132. For
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example, ring driver rotor 188 may include a wheel 192 as shown, or a drive
gear.
Similarly, each ring idler 328 includes an idler rotor 332 that engages wheel
ring 132. Idler
rotors 332 can take any form suitable for applying and maintaining an opposing
clamping
force upon wheel ring 132 when in the engaged position, as ring driver 136
torques wheel
ring 132 to rotate the connected steering wheel. For example, idler rotor 332
may include a
wheel 336 as shown, or a drive gear.
[0085] Referring to FIGS. 22A-22B, ring driver rotors 188 are shown
positioned
radially inwardly of inner surface 1841 and idler rotors 332 are shown
positioned radially
outwardly of outer surface 1842. In use, ring driver rotors 188 are movable
radially relative
to idler rotors 332 to transition between the disengaged position (FIG. 22A)
and the
engaged position (FIG. 22B). In the example shown, ring driver rotors 188 are
movable
radially outwardly relative to idler rotors 332, towards inner surface 1841,
from the
disengaged position (FIG. 22A) to the engaged position (FIG. 22B), and vice
versa. This
allows ring driver rotors 188 and idler rotors 332 to collectively clamp onto
wheel ring 132 in
the engaged position, and unclamp from wheel ring 132 in the disengaged
position.
[0086] Ring driver rotors 188 and idler rotors 332 may have any
alignment in the
engaged position that allows for the rotors 188 and 332 to clamp onto wheel
ring 132
securely. In some embodiments, each corresponding pair of rotors 188 and 332
(e.g. first
rotor pair 1881 and 3321, and second rotor pair 1882 and 3322) may be
substantially radially
aligned. For example, the two radial lines connecting a center of wheel ring
132 to the rotor
centers of a pair of rotors 188 and 332 may form an angle of less than 5
degrees. This
may reduce the bending moment developed by the combination of normal forces
applied by
the rotors 188 and 332 within each pair.
[0087] Referring to FIG. 21, each ring driver 136 may include a
motor 208 which
drives the rotation of the ring driver rotor 188. This may provide greater
total torque across
ring drivers 136, all else being equal. In alternative embodiments, the
plurality of ring
drivers 136 may be driven by a common motor 208. This may reduce the size and
cost of
steering wheel controller 100, all else being equal.
[0088] Steering wheel controller 100 may include any type(s) of
rotary or position
sensors suitable to determine the rotational position of wheel ring 132. For
example, one
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CA 2986672 2017-11-24
or more (or all) of ring drivers 136 and ring idlers 328 may be equipped with
a sensor (e.g.
rotary encoder) that can sense angular rotation of the respective rotor(s) 188
and 332. The
rotary sensors are communicatively coupled (e.g. by wire or wirelessly) to
computing
device 280 (FIG. 15), and send signals indicative of the sensed angular
rotation to
computing device 280 (FIG. 15). Computing device 280 (FIG. 15) interprets the
signals
received to determine the rotational position of wheel ring 132 and/or the
connected
steering wheel.
[0089] In the illustrated example, all of ring drivers 136 are
equipped with a sensor
276, and sensors 276 are communicatively coupled to computing device 280 (FIG.
15). By
having a plurality of ring drivers 136, each including its own motor 208 and
sensor 276,
computing device 280 (FIG. 15) may be better able to detect slippage (i.e.
rotation of a ring
driver rotor 188 that does not perfectly correspond to movement of wheel ring
132). For
example, computing device 280 (FIG. 15) may compare angular rotation indicated
by
sensor signals from sensor 2761 (obscured from view) to angular rotation
indicated by
sensor signals from sensor 2762, and determine there is slippage if the
angular rotations (or
the corresponding wheel ring rotation, e.g. in the case of differently sized
wheels 192) do
not match.
[0090] Still referring to FIG. 21, one or more (or all) of ring
idlers 328 may be
equipped with a sensor 276 that is communicatively coupled to computing device
280 (FIG.
15). Further, idler rotors 332 may retain rolling engagement with wheel ring
132 when
steering wheel controller 100 is in the disengaged position (FIG. 22A). This
may permit the
sensor 276, which is positioned to sense the rotation of idler rotors 332, to
continue to
transmit sensor signals to computing device 280 (HG. 15) when steering wheel
controller
100 is in the disengaged position (FIG. 22A; e.g. when the user is manually
controlling the
steering wheel). As a result, computing device 280 (FIG. 15) may have accurate
information about the position of wheel ring 132 and the connected steering
wheel when
steering wheel controller 100 is moved to the engaged position (FIG. 22B).
[0091] Ring driver rotors 188 and idler rotors 332 may be mounted in
any manner
that allows ring driver rotors 188 to move radially relative to idler rotors
332 between the
disengaged position (FIG. 22A) and the engaged position (FIG. 22B). Turning to
FIGS. 21
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CA 2986672 2017-11-24
and 22A, rotors 188 and 332 are movably connected to one another by a rotary
cross-
mount 340. Rotary cross-mount 340 includes a first arm 344 that joins
diagonally opposed
rotors 1881 and 3322, and a second arm 348 that joins diagonally opposed
rotors 1882 and
3321. Each of first and second arms 344 and 348 may be rotatable about a
common axis
352. As shown, rotation axis 352 may extend parallel to the rotation axes of
rotors 188 and
332. In the example shown, rotation axis 352 is located between rotors 188 and
332. As
exemplified, rotation axis 352 may intersect wheel ring 132.
[0092] In use, rotary cross-mount 340 may articulate in a scissor-
like fashion. First
arm 344, carrying rotors 1881 and 3322, may rotate in a first direction about
axis 352 (e.g.
clockwise or counterclockwise), and second arm 348, carrying rotors 1882 and
3321, may
rotate in the opposite direction about axis 352 (e.g. counterclockwise or
clockwise), to
move rotors 188 and 332 between the engaged and disengaged positions. For
example,
FIGS. 22A-22B show an example in which first arm 344 rotates clockwise and
second arm
348 rotates counterclockwise to transition from the disengaged position to the
engaged
position. This causes rotors 1881 and 3321 to move toward each other and clamp
(i.e.
sandwich) onto wheel ring 132, and rotors 1882 and 3322 to move toward each
other and
clamp onto wheel ring 132, as shown. In the illustrated example, ring drivers
136 (including
ring driver rotor 188 and motor 208) and ring idlers 328 (including idler
rotor 332) are
mounted to mounting arms 344 and 348, and move with rotors 188 and 332.
[0093] Turning to FIGS. 22A-22B and 23A-23B, steering wheel controller 100
may
include an engagement actuator 356 that is operable to move steering wheel
controller 100
between the engaged position (FIG. 22A) and the disengaged position (FIG.
22B).
Actuator 356 may be any device suitable to move steering wheel controller 100
between
the engaged and disengaged position. In the illustrated embodiment, actuator
356 includes
a linkage 360 driven by a powered mover 364 (e.g. motor as shown, or
solenoid). As
shown, linkage 360 may be connected to first and second arms 344 and 348 of
rotary
cross-mount 340, and synchronize the movement of arms 344 and 348 between the
disengaged position (FIGS. 22A and 23A) and engaged position (FIGS. 22B and
23B).
[0094] In some embodiments, linkage 360 may provide mechanical
advantage
between motor 364 and rotary cross-mount 340, at least when moving toward the
engaged
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CA 2986672 2017-11-24
position to provide a greater clamping force. Linkage 360 can be any
mechanical linkage
suitable to provide such mechanical advantage. In the illustrated embodiment,
linkage 360
is a toggle linkage. As shown, linkage 360 includes first and second arms 368
and 372.
Each arm 368 and 372 has a first end 376 pivotally connected to a different
one of cross-
mount arms 344 and 348, and a second end 380 pivotally connected to a common
drive pin
384. As shown, the first and second ends 376 and 380 may be pivotally
connected to
rotate about respective axes 388 and 392 substantially parallel to rotary
cross-mount axis
352.
[0095] In use, motor 364 may be activated, such as by control
signals from
computing device 280 (FIG. 15), to drive linkage drive pin 384 to move
radially relative to
rotary cross-mount 340 (e.g. rise or fall). For example, motor 364 may drive
linkage drive
pin 384 to move in a radial direction aligned with rotary cross-mount axis
352. This may
cause first and second linkage arms 368 and 372 to rotate about their
respective first ends
376, whereby the second ends 380 of linkage arms 368 and 372 may move apart or
toward
each other. As the second ends 380 of linkage arms 368 and 372 move apart or
toward
each other, the connected rotary cross-mount arms 344 and 348 rotate about
cross-mount
axis 352 between the disengaged position (FIG. 22A and 23A) and engaged
position (FIG.
22B and 23B).
[0096] FIGS. 22A-22B show an example where moving linkage drive pin
384 radially
outwardly rotates first and second linkage arms 368 and 372 outwardly about
axis 392 (e.g.
towards a tangential orientation) whereby linkage arm second ends 380 move
apart and
the connected rotary cross-mount arms 344 and 348 rotate about rotary cross-
mount axis
352 from the disengaged position (FIG. 22A) to the engaged position (FIG.
22B).
[0097] Each of linkage arm 368 and 372 has a respective longitudinal
axis 396
extending from the respective first end axis 388 to the second end axis 392.
As shown,
longitudinal axes 3961 and 3962 of first and second arms 368 and 372 may form
an inside
angle 404 that increases as the linkage 360 moves from the disengaged position
(FIG.
22A) to the engaged position (FIG. 22B). When actuating linkage 360, the
movement
speed of first and second linkage arms 368 and 372 decreases and the
mechanical
advantage increases towards infinity, as inside angle 404 approaches 180
degrees. This
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CA 2986672 2017-11-24
may permit linkage 360 to provide tremendous mechanical advantage in the
engaged
position (FIG. 22B) for robust clamping performance. In the other direction,
the movement
speed of first and second linkage arms 368 and 372 increases and the
mechanical
advantage decreases as inside angle 404 decreases. This may permit linkage 360
to
provide rapid disengagement of ring drivers 136 from wheel ring 132, such as
to allow the
human operator to quickly take over manual control of the steering wheel.
[0098]
Referring to FIGS. 23A-23B, motor 364 may have any connection to linkage
360 that is suitable to permit motor 364 to drive linkage 360 between the
disengaged
position (FIG. 23A) and the engaged position (FIG. 23B). In the illustrated
example, motor
364 is connected to linkage 360 by a transmission 408. Transmission 408 may be
a rotary-
to-linear movement converter, which converts the rotary output of motor 364
into a linear
movement of linkage drive pin 384. As shown, transmission 408 may include a
threaded
shaft 412 that is threadably engaged with a nut 416. Nut 416 is connected to
linkage drive
pin 384. In use, motor 364 rotates threaded shaft 412 whereby nut 416 and the
linkage
drive pin 384 connected thereto are driven to translate along threaded shaft
412. As
shown, threaded shaft 412 may be radially aligned for moving drive pin 384 in
a radial
direction.
[0099]
Motor 364 may be positioned to drive threaded shaft 412 directly or
indirectly
(e.g. by way of one or more belts or gears). In the illustrated example, motor
364 drives
threaded shaft 412 indirectly by way of bevel gears 420. This allows motor 364
to be
oriented perpendicular to threaded shaft 412. As show motor 364 may be
positioned
parallel with (e.g. collinear to) rotary cross-mount axis 352. This may
provide a compact
configuration, which may make steering wheel controller 100 more compatible
with the
space available in existing automobile models.
[00100] Reference is now made to FIGS. 24A-24B and 25A-25B.
In some
embodiments, steering wheel controller 100 may include a stationary portion
424 and a
mobile portion 428. Stationary portion 424 may include a dashboard mount 228,
and
mobile portion 428 may include the ring driver(s) 136, ring idler(s) 328 and
associated
mount(s) 340 and actuator(s) 356. Mobile portion 428 may also be referred to
as the 'drive
assembly' 428. Mounting assembly 424 may also be referred to as the 'mounting
- 22 -
CA 2986672 2017-11-24
assembly' 424. Drive assembly 428 may be movably connected to mounting
assembly
424. For example, drive assembly 428 may be rotatably connected to mounting
assembly
424 (i.e. connected to mounting assembly 424 in a manner that permits drive
assembly 428
to rotate relative to mounting assembly 424) or translationally connected to
mounting
assembly 424 (i.e. connected to mounting assembly 424 in a manner that permits
drive
assembly 428 to translate in a straight or curved path relative to mounting
assembly 424).
In one aspect, this may permit drive assembly 428 to move to accommodate
radial runout
of wheel ring 132 (e.g. imperfections in the circularity of wheel ring 132),
and some
misalignment between drive assembly 428 and wheel ring 132.
[00101] In the illustrated example, drive assembly 428 is radially movable
relative to
mounting assembly 424. FIGS. 24A and 25A show drive assembly 428 in a first
radial
position, and FIGS. 24B and 25B show drive assembly 428 moved radially
inwardly to a
second radial position. Drive assembly 428 may be connected to mounting
assembly 424
in any manner suitable to allow drive assembly 428 to translate or rotate
relative to
mounting assembly 424 radially towards and away from wheel ring 132. In the
illustrated
example, drive assembly 428 is translationally connected to mounting assembly
424 by a
sliding bearing assembly 432. Sliding bearing assembly 432 may include a
linear bearing
slideably mounted to a rail. One of mounting assembly 424 and drive assembly
428 may
include the linear bearing, and the other of mounting assembly 424 and drive
assembly 428
may include the rail. In the illustrated example, drive assembly 428 includes
the linear
bearing 436, and mounting assembly 424 includes the rail 440. However, this
arrangement
may be reversed.
[00102] Referring to FIG. 25B, drive assembly 428 may be biased
relative to mounting
assembly 424 to urge ring idlers 328 into contact with wheel ring 132. For
example, drive
assembly 428 may be pivotably or translationally biased relative to mounting
assembly 424
(according to whether the connection between assemblies 424 and 428 is
rotational or
translational) whereby ring idlers 328 are urged radially inwardly towards
wheel ring 132.
This may provide constant contact between ring idlers 328 and wheel ring 132,
so that
sensors 276 of the ring idlers 328 can provide position and/or movement
information
related to wheel ring 132 whether steering wheel controller 100 is in the
engaged position,
the disengaged position, or transition ing between positions.
- 23 -
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[00103] In the illustrated example, drive assembly 428 is
translationally biased radially
inwardly relative to mounting assembly 424. Drive assembly 428 may be biased
in any
manner suitable to promote engagement between idler rotors 332 and wheel ring
132. In
the example shown, sliding bearing assembly 432 includes a bias 442 (e.g. a
spring) that
connects linear bearing 436 to rail 440 and urges linear bearing 436 to slide
radially
inwardly along rail 440.
[00104] Reference is now made to FIGS. 21 and 23A. In some
embodiments,
steering wheel controller 100 may include a homing sensor 444. Homing sensor
444 may
be configured to detect an absolute reference feature 448 provided on wheel
ring 132.
Homing sensor 444 may be communicatively coupled to computing device 280 (FIG.
15,
e.g. by wire or wirelessly). In use, homing sensor 444 may transmit a sensor
signal to
computing device 280 (FIG. 15) in response to detecting the absolute reference
feature
448. In response to receiving the sensor signal from homing sensor 444,
computing device
280 (FIG. 15) may reset the determined position of wheel ring 132 to a
predetermined
absolute reference position associated with absolute reference feature 448.
This may
permit computing device 280 (FIG. 15) to correct accumulating position error
which may
result from micro-slippage, wear (e.g. of wheel ring 132 and/or rotor 188
and/or rotors 332),
or foreign objects on the wheel ring surfaces 184.
[00105] Homing sensor 444 may be a sensor of any kind suitable to
detect an
absolute reference feature 448 provided on wheel ring 132. For example, homing
sensor
444 may be a magnetic sensor, an optical sensor, or a beam sensor. The
absolute
reference feature 448 may be any senseable feature having a fixed position on
wheel ring
132. For example, absolute reference feature 448 may be a visibly distinct
marking (e.g.
bright white line), a magnet or magnetic member, or an aperture. In the
illustrated
embodiment, absolute reference feature 448 is an aperture and homing sensor
444 is a
beam sensor. As shown, aperture 448 is formed as a slit which pierces wheel
ring 132
radially from inner surface 1841 to outer surface 1842. Beam sensor 444 is
shown including
a beam emitter 452 (e.g. infrared light source), and a beam receptor 456,
which are radially
aligned so that aperture 448 is aligned between beam emitter 452 and beam
receptor 456
when wheel ring 132 is in an absolute reference position known to computing
device 280
(FIG. 15). In use, when wheel ring 132 is in the absolute reference position,
beam receptor
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CA 2986672 2017-11-24
456 shines a light beam through aperture 448 which is detected by beam
receptor 456, and
homing sensor 444 reports this to computing device 280. In every other
position of wheel
ring 132, light from beam receptor 456 is occluded by wheel ring 132 and not
detected by
beam receptor 456. It will be appreciated that the signal from homing sensor
444 indicative
of alignment with aperture 448 may be a positive signal reporting this
alignment, or a signal
discontinuity (e.g. where sensor 444 sends a positive signal at all other
times). In some
embodiments, absolute reference feature 448 may be positioned in association
with a
neutral position of the connected steering wheel (e.g. when the vehicle is
driving exactly
straight forward). This may permit the absolute reference feature 448 to be
frequently
detected, and accumulating errors to be frequently mitigated.
[00106] While the above description provides examples of the
embodiments, it will be
appreciated that some features and/or functions of the described embodiments
are
susceptible to modification without departing from the spirit and principles
of operation of
the described embodiments. Accordingly, what has been described above has been
intended to be illustrative of the invention and non-limiting and it will be
understood by
persons skilled in the art that other variants and modifications may be made
without
departing from the scope of the invention as defined in the claims appended
hereto. The
scope of the claims should not be limited by the preferred embodiments and
examples, but
should be given the broadest interpretation consistent with the description as
a whole.
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CA 2986672 2017-11-24
