U.S. patent application number 14/633429 was filed with the patent office on 2015-09-03 for three-axis ride controlled by smart-tablet app.
The applicant listed for this patent is George W. Batten, JR., M. Harris Milam, Robert L. Terry. Invention is credited to George W. Batten, JR., M. Harris Milam, Robert L. Terry.
Application Number | 20150246291 14/633429 |
Document ID | / |
Family ID | 54006297 |
Filed Date | 2015-09-03 |
United States Patent
Application |
20150246291 |
Kind Code |
A1 |
Milam; M. Harris ; et
al. |
September 3, 2015 |
Three-Axis Ride Controlled by Smart-Tablet App
Abstract
This motion simulator uses a spherical shape driven by
controlled wheels to produce any rotational motion within certain
limits. The range of pitch and roll motions can be at least -15 to
+15 degrees; yaw is unlimited. There are no moving electrical
connections such as slip rings. The physical system can be produced
inexpensively. Control and simulation display use a smart phone or
computer tablet, which, for example, could be one already owned by
a family using the simulator.
Inventors: |
Milam; M. Harris; (Houston,
TX) ; Batten, JR.; George W.; (Houston, TX) ;
Terry; Robert L.; (Houston, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Milam; M. Harris
Batten, JR.; George W.
Terry; Robert L. |
Houston
Houston
Houston |
TX
TX
TX |
US
US
US |
|
|
Family ID: |
54006297 |
Appl. No.: |
14/633429 |
Filed: |
February 27, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61946685 |
Feb 28, 2014 |
|
|
|
Current U.S.
Class: |
472/59 |
Current CPC
Class: |
A63G 31/16 20130101 |
International
Class: |
A63G 31/16 20060101
A63G031/16 |
Claims
1. A motion simulator comprising a base unit with a baseplate, two
drive-wheel assemblies rigidly mounted on the baseplate, at least
one freely rotating support ball mounted in a fixed position on the
baseplate, and an electronics module controlling the motions of the
drive-wheel assemblies; a moving platform with an exterior shell
which is shaped as part of a sphere, a seat for a human rider;
rider operated control units; an interior shell which supports said
seat and at least one human rider, a shell closure element which
connects the interior shell to the exterior shell and provides
support for the interior shell and items supported by the interior
shell, with the said exterior shell resting on the wheels of the
two drive-wheel assemblies and the freely rotating ball or balls;
with the wheels of the two drive-wheel assemblies frictionally
rotating the moving platform; with the said drive-wheel assemblies
positioned so there is a right angle between lines from the center
of the sphere of the exterior shell to the center of the contact
points of the two drive-wheel assemblies with said sphere; with a
retainer plate fitting between the exterior and interior shells of
the moving platform, which retainer plate is rigidly supported by a
mount rigidly fastened to the baseplate of the base unit, the mount
passing through a hole in the exterior shell, said hole being large
enough to allow useful pitch and roll motion of the moving
platform. with the said electronics module in the base unit
wirelessly connected to control units in the moving platform, said
wireless connection capable of transferring information in both
directions; with said control units in the moving platform
including a computer tablet or smart phone; with said electronics
module in the base unit receiving rotation descriptions from
control units in the moving platform, and using these descriptions
to control drive wheel motions to cause the moving platform to move
correspondingly.
2. A motion simulator as in claim 1 without the retainer plate.
3. A motion simulator as in claim 1 with an optical sensor for
determining a home position for aligning the system.
4. A motion simulator as in claim 1 with an magnetic sensor for
determining a home position for aligning the system.
5. A motion simulator as in claim 1 with at least one
freely-rotating ball and ball mount replaced by a drive-wheel
assembly.
6. A motion simulator as in claim 1 with the freely rotating ball
replaced with a freely rotating caster.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent claims the benefit of U.S. provisional patent
No. 61/946,685 filed on Feb. 28, 2014, which is herein incorporated
by reference.
TABLE-US-00001 U.S. PATENT DOCUMENTS 5,490,784 February 1996
Carmein Virtual reality system with enhanced sensory 434/55
apparatus 6,629,896 October 2003 Jones Nimble virtual reality
capsule using rotatable 472/60 drive assembly 8,939,455 January
2015 Terry Ride-on vehicle and game seat for infants 180/19.1 and
young children 14/096,986 December 2014 Batten Children's ride-on
vehicle with computer- tablet display and child supervision
62/117,491 February 2015 Batten Self-Pivoting Drive for
Spherical-Form Motion Simulators
OTHER PUBLICATIONS
[0002] www.sincraft.com Simcraft web page
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0003] Not applicable
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM
LISTING COMPACT DISC APPENDIX
[0004] Not applicable
BACKGROUND OF THE INVENTION
[0005] 1. Field of the Invention
[0006] The purpose of this invention is providing a low-cost motion
simulator to be used in homes and other venues. The invention can
be adapted for children or adults.
[0007] The invention has a seat which moves in response to signals
from a smart phone or smart tablet, hereinafter referred to as
"computer tablet." The nature of the motion is determined by
application-specific software (an "app") in the computer tablet.
The computer tablet's display is used to display motion-related
images. The seat can rotate about any axis. Pitch and roll are
limited, but the range of each is sufficient for many simulations.
Yaw is unlimited.
[0008] 2. The Prior Art
[0009] Many motion simulators have been developed. A well-known
early one was the Link Trainer, which had an analog control system
and a mechanical arrangement based of pneumatic devices. There are
many modern motion simulators using digital computers for control.
Some are large and very expensive, so they are used only by such
persons as professional aircraft pilots.
[0010] One marketed by Simcraft is small enough for nonprofessional
use. It has a seat mounted on gimbals, so any rotation is possible.
The control system is a conventional digital computer with
application-specific software. There seem to be no patents for this
device.
[0011] U.S. Pat. Nos. 5,490,784 and 6,629,896 describe large
simulators with spherical moving platforms, supported by drive
wheels which move the sphere by friction. These inventions are not
suitable for home use.
[0012] In contrast, the present invention is small enough to be
used in homes. Since it uses a computer tablet as the main control
device, a family can purchase a basic physical unit, then use an
already-owned computer tablet for the control. Thus the physical
units can be sold inexpensively.
BRIEF SUMMARY OF THE INVENTION
[0013] This invention relates generally to game seats with motion
simulation, and motion simulators in general. Related information
appears in the U.S. Pat. No. 8,939,455 and U.S. patent application
Ser. No. 14/096,986, which describe the mechanical, electrical,
control, and communication aspects of a base vehicle. The present
invention is as a stationary unit with a moving platform for a
human rider, but it does use some electrical, control, and
communication features that are similar to ones in those
patents.
[0014] The invention comprises a base unit and a moving platform.
See FIG. 1. The moving platform has an exterior shell which is
supported by a freely moving ball and two assemblies with drive
wheels for rotating the platform. FIG. 3 shows the baseplate with
the drive wheels and ball. The axes of the drive wheels rotate so
they can produce any rotation of the moving platform. Pitch and
roll are limited: typically, pitch and roll angles can be at least
-15 to +15 degrees, which is enough to be useful for many
simulations. Yaw rotation is unlimited.
[0015] The invention includes a fixed-position retainer plate 7
between the exterior and interior shells. See FIG. 2. That plate
prevents tipping, which might happen, for example, when a rider
climbs on board. The retainer plate can be made so that it does not
touch any part of the moving platform under normal conditions; this
avoids certain frictional losses that would otherwise occur with
any rotation.
[0016] Electrical signals from an electronics module (not shown in
the figures) mounted on the base unit power the drive wheels and
determine the direction and rotational speed of the wheels. The
electronics module carries out some basic computations for control,
but the motion plan is determined by a computer tablet in the
moving platform. The computer tablet is mounted on a bracket that
holds it in view of the human rider, so the computer tablet display
becomes part of the simulation. The bracket is moved out of the way
when a different display (e.g., a large, wall-mounted display) is
used.
[0017] Control signals, mostly descriptions of required rotations,
are sent from the computer tablet to the electronics module in the
base unit through a bidirectional wireless link. That link also
carries moving-platform position information from the electronics
module to the computer tablet. Thus, there are no wires between the
base unit and the moving platform; the invention does not need slip
rings or other moving electrical connections.
[0018] The computer tablet touch screen can be used as a control
for interactive simulations. Alternatively, other
controls--joystick, steering wheel, switches, etc.--can be used if
they are linked to the computer tablet. Wireless links are
preferred. One advantage of this arrangement is that controls can
be switched easily, so each type of simulation can have a
simulation-specific set of controls.
[0019] Under some conditions it might be useful to mount the
invention on a steerable base unit with powered wheels, and to
provide controls so the rider could drive the unit from place to
place. It that case it might be appropriate to apply the concepts
taught in U.S. Pat. No. 8,939,455 and U.S. patent application Ser.
No. 14/096,986.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0020] FIG. 1 shows a partial section of the ride as viewed from
one side.
[0021] FIG. 2 is the retainer plate 7 as viewed from the top.
[0022] FIG. 3 is the base plate 15 as viewed from the top.
[0023] FIG. 4 is a view of a drive wheel mechanism.
[0024] FIG. 5 is a diagram showing various points, lines, and
vectors, including a rotation vector R.
[0025] FIG. 6 is a block diagram showing a possible arrangement of
the control system.
[0026] The figures use the following reference identifiers: [0027]
1 Outer shell. [0028] 4 Inner shell. [0029] 7 Retainer plate.
[0030] 8 Ball supporting outer shell 1. [0031] 9 Mount for the
outer shell support ball 8. [0032] 10 Wheels driving movements of
outer shell 1. [0033] 11 Mount and drive motors for wheels 10.
[0034] 13 Mount for the retainer plate 7. [0035] 15 Base plate as
seen from above. [0036] 16 Floor surface. [0037] 17 Shroud. [0038]
18 Edge of clearance opening in outer shell 1. [0039] 21 Seat.
[0040] 22 Seat mounting bracket. [0041] 26 Joy stick (or other
control device). [0042] 27 Armrest-mounted controls. [0043] 28
Support for the mount and drive motors 11. [0044] 36 Bracket for
the computer tablet. [0045] 37 Alternate position of bracket 36.
[0046] 38 Shell closure and support for inner shell 4. [0047] 40
Great circle through the center C of the spherical surface and
wheel contact points. [0048] 41 Circle showing rotation
corresponding to the vector R. [0049] 50 Pivoting frame supporting
the drive wheels 52. [0050] 51 Fixed frame for the motors and angle
sensor. [0051] 52 Drive wheel. [0052] 72 Mounting plate. [0053] 79
Surface of the outer shell.
DETAILED DESCRIPTION OF THE INVENTION
[0054] A fundamental mechanical element of this invention is the
spherical surface of outer shell 1, the motion of which is driven
by the wheels of two assemblies. Each such assembly comprises a
single wheel, or a pair of wheels, frictionally contacting the
spherical surface; associated motors; and a mounting arrangement.
The mounting arrangement provides for the wheel axis direction to
be changed, thereby changing the direction of motion of the sphere.
Outer shell 1 supports the entire moving platform.
[0055] FIG. 1 is a partial sectional view with some parts rotated
into the plane of the view as is commonly done in good drafting
practice. It shows outer shell 1 resting on freely-rotating ball 8
in its mount 9, and one of the drive wheels 10 on its mechanism and
mount 11. FIG. 3 shows the ball and drive wheels arranged in a
triangular pattern on the base plate 15. Drive wheel 10 and its
mechanism 11 have controlled bidirectional motors and gears that
drive the rotation of each wheel about its axis, and set the
direction of the wheel axis, hence the direction of wheel action.
U.S. Pat. No. 5,490,764 shows three arrangements for mechanisms of
this type (in that patent's FIGS. 4, 5, and 6).
[0056] FIG. 4 shows another arrangement for the wheel mechanism. In
that figure, wheels 10 are mounted on freely pivoting frame 50. The
axles of the wheels have a common centerline. Motors driving the
wheels are in fixed frame 51. Mounting plate 72 supports the
mechanism. The wheels frictionally contact outer surface 79 of
outer shell 1 and drive the shell's motion. The direction of wheel
action is determined by controlled differential rotation of the two
wheels 10, which causes freely pivoting frame 50 to rotate. This
mechanism is described in more detail in U.S. patent application
Ser. No. 62/117,491.
[0057] One unique feature of this invention is retainer plate 7,
which is rigidly mounted on base plate 15 using mount 13. The
retainer plate prevents tipping of outer shell 1, hence that of the
moving platform. Mount 13 passes through a clearance opening, shown
as edge 18, in outer shell 1. While the retainer plate and its
mount limit the range of motion of the outer shell, a preferred
arrangement will allow sufficient motion for the intended
applications. For the configuration shown in FIG. 1, roll and pitch
can range at least from -15 to +15 degrees. Yaw is unlimited.
[0058] Shroud 17 encloses the movement mechanism. Base plate 15
rests on floor surface 16.
[0059] In the moving platform, inner shell 4, which separates the
rider space from retainer plate 7, is attached to outer shell 1 by
shell closure 38. FIG. 1 shows inner shell 4 as a spherical
section, but the shape is not important as long as it provides
clearance for retainer plate 7, and structural support for seat 21
and the rider. Seat 21, which is mounted on seat mounting bracket
22, has a movable bracket 36 to support the computer tablet within
view of the rider. FIG. 1 shows the alternate position 37 of
bracket 36 when it has been moved to an out-of-the-way position.
Various rider-operated controls 27, including, for example, a
joystick 26, are be mounted on the seat. The computer tablet is
bidirectionally linked, preferably by wireless connections, to
controls that are not part of the computer tablet and to an
electronics module (not shown in the figures) in the base unit.
That electronics module produces the electrical signals powering
the motors of the drive-wheel assemblies.
Mathematics of the Rotation
[0060] It is useful to have some mathematical notations for
describing control of the drive wheels. To that end, identify each
wheel assembly with a number 1 or 2, wheel assembly 1 being the
first one encountered in moving from the support ball in a
counterclockwise direction around the center of base 15 as seen
from above, and wheel assembly 2 being the other one. In the
following, k will denote either wheel number, and "sphere" will
mean the sphere of the exterior surface of outer shell 1.
[0061] Let u.sub.k be the unit vector pointing from the center C of
the sphere toward wheel assembly k. More specifically, u.sub.k
points toward a point P.sub.k defined as follows: if wheel assembly
k has a single wheel, then P.sub.k is the point at which the wheel
contacts the spherical surface; if wheel assembly k has a pair of
wheels, P.sub.k is midway between the points at which the two
wheels contact the spherical surface. See FIG. 5.
[0062] The two vectors u.sub.1 and u.sub.2 and the center C
determine a plane P. Let w denote the unit vector orthogonal to P
and pointing in the direction of motion of a right-handed screw
rotating about C from P.sub.1 to P2. In conventional vector
notation, w=(u.sub.1.times.u.sub.2)/|u.sub.1.times.u.sub.2|, where
.times. is the usual vector cross product, and the denominator is
the length of u.sub.1.times.u.sub.2. Let v.sub.k=w.times.u.sub.k.
Then u.sub.k, v.sub.k, and w are unit basis vectors for a
right-handed coordinate system.
[0063] FIG. 5 shows the plane P and the sphere's great circle 40
intersection with P. The great circle has its center at C, and it
passes through wheel points P.sub.1 and P.sub.2. The figure also
shows a rotation vector R and the circle of rotation 41 associated
with R. Coordinate vectors u.sub.1, u.sub.2, v.sub.1, v.sub.2, and
w (the latter in two places) are shown moved to the corresponding
wheel points P.sub.1 and P.sub.2.
[0064] Let R.sub.1, and R.sub.2 be the rotation vectors associated
with sphere rotation due to the drive wheels at P.sub.1, and
P.sub.2, respectively. Since each of these is orthogonal to the
corresponding u.sub.k, these can be expressed as follows:
R.sub.1=.beta..sub.1v.sub.1+.gamma..sub.1w, and
R.sub.2=.beta..sub.2v.sub.2+.gamma..sub.2w,
where .beta..sub.1, .gamma..sub.1, .beta..sub.2, and .gamma..sub.2
are numbers. The vectors .gamma..sub.1 w and .gamma..sub.2 w
represent rotations in the plane P. In order that there be no
conflict (i.e., jamming) between drive wheels at P.sub.1 and
P.sub.2, these must be equal, so
R.sub.1=.beta..sub.1v.sub.1+.gamma.w, and
R.sub.2=.beta..sub.2v.sub.2+.gamma.w, (1)
where .gamma. is the common value of .gamma..sub.1 and
.gamma..sub.2.
[0065] The vector .beta..sub.1 v.sub.1 represents a rotation
orthogonal to the plane P. That rotation must have P.sub.2 as a
fixed point because drive-wheel friction will block non-zero motion
there (unless the drive-wheel motion at that point is identical to
that caused by the rotation .beta..sub.1 v.sub.1). The only way
that this can be guaranteed is for the line through C and P.sub.2,
the axis of this rotation, to be parallel to v.sub.1. The same
argument can be applied to .beta..sub.2 v.sub.2, mutatis mutandis,
of course.
[0066] Thus, P.sub.1 and P.sub.2 must be positioned so that u.sub.1
and u.sub.2 are orthogonal. This is the same as requiring that the
lines from C to each of P.sub.1 and P.sub.2 be orthogonal, which is
assumed henceforth.
[0067] The overall rotation, represented by the vector R, is a
combination of R.sub.1 and R.sub.2. It is the sum of the orthogonal
in-plane components and the out-of-plane component:
R=.beta..sub.1v.sub.1+.beta..sub.2v.sub.2+.gamma.w. (2)
[0068] The first step in controlling sphere motion is determining
.beta..sub.1, .beta..sub.2, and .gamma. from a given R. Then those
values are used to set the direction and speed of the drive wheels.
Since v.sub.1, v.sub.2, and w are mutually orthogonal, this is just
a matter of computing vector dot products:
.beta..sub.1=v.sub.1R,
.beta..sub.2=v.sub.2R, and
.gamma.=wr. (3)
Drive wheel rotations R.sub.w1 and R.sub.w2 at P.sub.1 and R.sub.2,
respectively, are
R.sub.w1=-.rho.(.beta..sub.1v.sub.1+.gamma.w), and
R.sub.w2=-.rho.(.beta..sub.2v.sub.2+.gamma.w), (4)
where .rho. is the ratio of sphere radius to drive wheel radius,
and the minus sign arises from the fact that wheel rotation is
opposite to the corresponding sphere rotation.
Control
[0069] The timed sequence of rotations generated by the computer
tablet are sent through the wireless link to the electronics module
in the base unit. That module receives the required rotations, and
converts them to signals controlling the motors of the drive-wheel
assemblies.
[0070] The electronics module also determines the position of the
moving unit, for example using an optical or magnetic sensor and
corresponding marks on or magnets in the outer shell, and sends the
position information back to the computer tablet in the moving
unit. Methods for doing this will be apparent to persons
knowledgeable of the relevant art.
[0071] FIG. 6 shows a possible organization for control. The dashed
line separates the part in the moving platform from that in the
base unit. The part in the moving platform centers on the Computer
Tablet, which communicates with Other Controls, preferably by
wireless links. Control commands are communicated through the
Wireless Module of the Computer Tablet to the Wireless Module in
the electronics module of the base unit. The most common command is
to rotate the sphere according to rotation vector R to a particular
position, as indicated by the angle .theta.. Consecutively arriving
values of the pair <R, .theta.> are pushed into the first-in,
first-out register (FIFO). They are passed on at appropriate
times.
[0072] FIG. 6 shows one other type of command, the Align command.
The pitch and roll positions of the moving platform are estimated
using accelerometers in the Computer Tablet or Other Controls. Yaw
position is determined by integrating the rotation rate obtained
from drive wheel rotation and direction. Each of these positions is
subject to drift, integration errors, or changing of the position
of the computer tablet, so it is necessary to realign the moving
platform occasionally. The electronics module has an Alignment
Timeout unit which issues an Align command at appropriate times.
The OR element combines commands so that an Align command is issued
to the Alignment Control unit if the command is received from
either the Wireless Module or the Alignment Timeout element.
[0073] When the Alignment Control unit receives an Align command,
it issues a Reset signal to the Alignment Timeout unit, thereby
starting the time interval to the next timeout; then it begins
issuing rotation pairs <R, .theta.>. The Select by Priority
unit passes the <R, .theta.> pairs to the Compute
.beta..sub.1, .beta..sub.2, .gamma. unit, with commands from
Alignment Control having priority over those from FIFO. The values
of .beta..sub.1, .beta..sub.2, and .gamma. are passed to the Wheel
Motor Control, which generates signals to the motors of the
drive-wheel assemblies.
[0074] The electronics module has a Position Sensing unit which
supplies some information about the sphere position to the
Alignment Unit and, through the wireless connection, to the
Computer Tablet. In a preferred embodiment, the Position Sensor
uses optical or magnetic means to determine sufficient information
for homing (realigning) the moving platform. For example, an
optical means might sense only a few optically contrasting marks on
the sphere. One such mark is sufficient to establish a home
position for yaw. A single optical sensor can be used for homing as
follows: if yaw is moved to the home position first, a mark across
the yaw mark is sufficient for homing pitch; roll can then be homed
by using small movements of the sphere to test the orientation of
the yaw mark. More complex optical patterns can be used if more
complete position information is needed. The possibility of using
more marks and/or optical sensors to obtain more complete position
information will be apparent to persons familiar with the relevant
art.
[0075] The Computer Tablet generates commands for whatever motion
simulation is being done. A single installation of this invention
can be used for such activities as aircraft flight simulation, auto
driving simulation, space trip simulation, etc. Each kind of
simulation has a corresponding app. The exact nature of such apps
is not a part of this invention, but persons familiar with the
relevant art would be able to develop apps for particular
applications.
[0076] It will be apparent to persons familiar with the relevant
art that a freely rotating ball can be replaced by a caster or a
drive-wheel assembly. In the latter case, the electronics module
must coordinate rotation of all drive wheels.
* * * * *
References