U.S. patent application number 14/451712 was filed with the patent office on 2015-10-29 for toy vehicle with an adjustable dc-dc switch.
This patent application is currently assigned to Innovation First, Inc.. The applicant listed for this patent is Innovation First, Inc.. Invention is credited to Robert H. Mimlitch, III, David Anthony Norman, Mitch Randall.
Application Number | 20150306510 14/451712 |
Document ID | / |
Family ID | 51483310 |
Filed Date | 2015-10-29 |
United States Patent
Application |
20150306510 |
Kind Code |
A1 |
Mimlitch, III; Robert H. ;
et al. |
October 29, 2015 |
Toy Vehicle With An Adjustable DC-DC Switch
Abstract
In one embodiment there is a toy vehicle having a low inductance
motor powered by a high frequency switched voltage at a frequency
high enough to create continuous conduction. The vehicle further
includes an H-bridge circuit configured to control a direction of
the motor and an adjustable high frequency DC-DC switch configured
to convert a supply voltage to an output voltage, lower than the
supply voltage, for use by the H-bridge circuit to power the low
inductance motor in a forward or reverse direction. In addition, a
processor is included and has instructions configured to change the
output voltage from the DC-DC switch from a first voltage to a
second voltage.
Inventors: |
Mimlitch, III; Robert H.;
(Rowlett, TX) ; Norman; David Anthony;
(Greenville, TX) ; Randall; Mitch; (Boulder,
CO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Innovation First, Inc. |
Greenville |
TX |
US |
|
|
Assignee: |
Innovation First, Inc.
Greenville
TX
|
Family ID: |
51483310 |
Appl. No.: |
14/451712 |
Filed: |
August 5, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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14332599 |
Jul 16, 2014 |
|
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14451712 |
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61983189 |
Apr 23, 2014 |
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Current U.S.
Class: |
446/457 |
Current CPC
Class: |
A63H 11/00 20130101;
A63H 17/25 20130101; H02P 7/285 20130101; A63H 17/262 20130101;
A63H 30/04 20130101; A63H 17/00 20130101; A63H 33/30 20130101; A63H
29/22 20130101; A63H 33/42 20130101; A63C 17/12 20130101 |
International
Class: |
A63H 17/00 20060101
A63H017/00; A63C 17/12 20060101 A63C017/12 |
Claims
1. A toy vehicle comprising: a low inductance motor powered by a
high frequency switched voltage at a frequency high enough to
create continuous conduction; an H-bridge circuit configured to
control a direction of the motor; an adjustable high frequency
DC-DC switch configured to convert a supply voltage to an output
voltage, lower than the supply voltage, for use by the H-bridge
circuit to power the low inductance motor in a forward or reverse
direction; and a processor having instructions configured to change
the output voltage from the DC-DC switch from a first voltage to a
second voltage, wherein the output voltage from the DC-DC switch is
selected by a voltage divider with a first resistor value and a
second resistor value and wherein the second resistor value is
selected by the instructions from the process such that the output
voltage from the DC-DC switch can define a first output voltage, a
second output voltage, and a third output voltage.
2. The toy vehicle of claim 1, wherein the motor has an inductance
of approximately less than 500 uH.
3. The toy vehicle of claim 1, wherein the motor has an inductance
of about 140 uH.
4. The toy vehicle of claim 1, wherein the DC-DC switch is
operating at a frequency greater than 250 kHz.
5. The toy vehicle of claim 1, wherein the DC-DC switch is
operating at a frequency substantially about 1500 kHz.
6. The toy vehicle of claim 1, wherein the DC-DC switch is changed
digitally.
7. The toy vehicle of claim 1, wherein the output voltage from the
DC-DC switch is selected by a voltage divider with a first resistor
value and a second resistor value and wherein the second resistor
value is selected by the instructions from the processor such that
the output voltage from the DC-DC switch can define a first output
voltage and a second output voltage.
8. (canceled)
9. The toy vehicle of claim 1, wherein the second resistor value is
selected from a pair of resistors, defined separately to create the
first output voltage and the second output voltage respectively and
defined in series to create the third output voltage.
10. The toy vehicle of claim 1, wherein the processor further
includes instructions to the H-bridge circuit to only control the
direction of the motor.
11-19. (canceled)
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation of U.S.
application Ser. No. 14/332,599 filed Jul. 16, 2014, which claims
priority to U.S. Provisional Application Ser. No. 61/983,189 filed
Apr. 23, 2014; all of which are incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a toy vehicles and more
particularly to a toy vehicle with a low inductance motor powered
by a high frequency switched voltage.
BACKGROUND OF THE INVENTION
[0003] Toy vehicles have been a mainstay in kids toys for a number
of years. Toy vehicles come in different types one of which is a
toy skateboard referred to as finger boards because the user of the
toy skateboards uses two of their fingers in operating the toy. A
skilled operator of the toy skateboard is capable of replicating
skateboarding maneuvers with their hand. These skateboards are
extremely popular but have become stagnated in their ability to
reach a wider audience since their introduction in the 1990s.
[0004] As a consequence, various types of toy skateboards have been
proposed. Such skateboards range from simple wind-up toy
skateboards with mounted figurines, to more advanced
radio-controlled toy skateboards with figurines that can be
controlled in some degree to portray body movement during
skateboarding maneuvers and stunts. These motorized skateboards
typically include movable battery packs, changeable motor
positions, and interchangeable wheel weights to provide different
centers of balance for adjusting the performance of various
maneuvers. In addition, some motorized skateboards include a drive
mechanism but no steering mechanism. Thus, the skateboard is only
maneuverable through body movement of the figurine, as in an actual
skateboard, and therefore control of the skateboard may be less
than desirable, especially for those of less advanced skill levels.
With this need, a toy skateboard should be provided that offers the
enjoyment of both a motorized toy skateboard and a non-motorized
toy skateboard with an easy control system that allows for the
performance of various maneuvers without having to employ a toy
figurine.
SUMMARY OF THE INVENTION
[0005] The present invention provides for various embodiments and
combinations of aspects that will be described herein in greater
detail. In a first embodiment, there is provided a convertible toy
skateboard assembly. The skateboard assembly includes a deck, a
pair of non-motorized truck assemblies and a rear motorized truck
assembly. The toy skateboard is also convertible; as one of the
non-motorized truck assemblies may be easily swapped with a rear
motorized truck assembly. This allows for the toy skateboard to
either have a pair of non-motorized truck assemblies, which allows
the operator to use their fingers to manipulate and move the toy
skateboard; or have one non-motorized truck assembly and one
motorized truck assembly, which allows the operator to use a remote
control unit to control and move the toy skateboard.
[0006] The non-motorized truck assembly as used throughout the
various embodiments is typically secured to the lower surface of
the deck. The non-motorized truck assembly includes a pair of
freely rotatable wheels that are positioned transversely to a
longitudinal axis of the deck when attached. The motorized rear
truck assembly includes a housing, which is configured to removably
attach to the deck. This may include clips, fasteners, or other
attachment means well known in the art. The motorized truck
assembly is configured to house at least (i) a battery, (ii) a
processor, (iii) a receiver in communication with the processor,
and (iv) a pair of motors, each motor separately controlling a rear
wheel, of a pair of rear wheels, and wherein the pair of rear
wheels are positioned transversely to the longitudinal axis of the
deck and behind the pair of front wheels. The receiver is
configured to receive signals to control the movement of the pair
of rear wheels.
[0007] As mentioned, the toy skateboard would therefore include two
configurations: a first configuration is defined by having the
front non-motorized truck assembly attached to the lower surface
towards the front region of the deck and having the rear
non-motorized truck assembly removably attached to the lower
surface towards the rear region of the deck. In the first
configuration, the upper surface of the deck defines a finger
engaging region for a user's fingers to engage and move the toy
skateboard. A second configuration is defined by removing the rear
non-motorized truck assembly and attaching the motorized rear truck
assembly to the lower surface towards the rear region of the deck,
wherein the movement of the toy skateboard is controllable by the
processor in response to signals received by the receiver.
[0008] In accordance with one or more of the embodiments, the toy
skateboard may include a circuit in communication with the
processor and battery. The circuit is configured to change the
battery voltage to a fixed voltage to create a more consistent
performance from the battery--this may include lowering or boosting
the voltage. The change helps increase the enjoyment from the toy
skateboard as it no longer seems sluggish as the batteries wear
down. In addition, the remote control unit may include one or more
signals to initiate a set of pre-program instructions on the
processor to control the pair of rear wheels to perform one or more
skateboard maneuvers. These skateboard maneuvers may include, but
is not limited to, a skateboard trick, a hill climb, variable speed
control, and playback of user recorded input.
[0009] The skateboard in any one of the embodiments, may further be
defined to have a first motor (from the pair of motors) coupled to
a first rear wheel (from the pair of rear wheels) and the processor
configured to detect a back electromotive force ("EMF") voltage
generated by the rotation of the first motor caused by a manual
manipulation of the first rear wheel. The processor is further
configured to include at least a sleep state and a wake state and
is configured to transition between the sleep state and the wake
state when the detected back EMF voltage reaches a pre-determined
value. The processor may further control the pair of motors in
accordance with one or more pre-programmed motions resulting in a
tactile response when the detected back EMF voltage reaches a
pre-determined value. In addition, the processor may further be
configured to detect a second back EMF voltage generated by the
rotation of the first motor in an opposite direction due to a
manual manipulation of the first rear wheel in an opposite
direction. When either of the detectable back EMF voltages reaches
a pre-determined value, the processor is further configured to
control the first motor in accordance with one or more of the
following pre-programmed motions resulting in a tactile response:
(a) move the first rear wheel momentarily, (b) move the first rear
wheel continuously, (c) resist motion of the first rear wheel
momentarily, (d) resist motion of the first rear wheel
continuously, (e) oscillate the first rear wheel momentarily, and
(f) oscillate the first rear wheel continuously.
[0010] In one or more of the embodiments, the motorized rear truck
assembly includes a housing defined to include a top profile
substantially conforming to a portion of the lower surface of the
deck towards the rear region. In this instance, the battery,
processor, receiver, and pair of motors are completely positioned
within the housing below the top profile of the housing and thus
below the lower surface of the deck. The housing may also include a
front end and a rear end with an intermediate region there-between.
This provides space for a battery, defined two have two battery
compartments separately positioned in the front end and rear end of
the housing, and space for the pair of motors. The pair of rear
wheels are positioned between the two battery compartments. The
rear end of the housing containing one of the battery compartments
may be angled upwardly to match an angle of the rear end of the
deck such that the at least one battery contained in the battery
compartment is angled.
[0011] In one or more of the embodiments disclosed herein, the
receiver may be defined as an IR sensor for receiving signals from
the remote control unit. The IR sensor can be positioned in a
window defined in the motorized rear truck assembly towards a front
portion thereof and under the lower surface of the deck such that
the IR sensor is positioned to receive signals reflected from a
surface under the deck of the skateboard. In another aspect, the
toy skateboard may include a weight removably secured to a portion
of the deck to adjust a center of gravity and configured to adjust
a center of spin.
[0012] As defined in one or more aspects, the toy skateboard may be
poised to define a motorized toy skateboard that can be controlled
without needing an object on the upper surface of the deck. The toy
skateboard does not need a figurine, with linkages, and control
mechanics in the deck to maneuver properly. Separately, the toy
skateboard may include a truck assembly housing that encloses both
a front truck and a motorized rear truck. The truck assembly may be
removed and replaced with a pair of non-motorized truck assemblies
so the user is able to manually maneuver the skateboard.
[0013] In addition to a toy skateboard, the present invention may
provide for a toy that may include one or more elements, such as
the wheels on a skateboard, an appendage on a toy robot or figure,
or a propeller on a toy vehicle. These elements are external to the
toy and are moved/controlled separately by a motor. The processor
is configured to include at least a sleep state and a wake state
and is further configured to transition between the two states.
Another aspect of the embodiment is that the element is accessible
for manipulation by the user, operator, or human which when moved
will in turn rotate the motor. When the user manipulates the
element, rotating the motor, the rotation of the motor generates a
back electromotive force (herein after "EMF") voltage. The
processor is configured to detect the back EMF voltage and is
further configured to transition between the two states when the
detected back EMF voltage reaches a pre-determined value.
[0014] In another aspect of the embodiment, when the detected back
EMF voltage reaches the pre-determined value, the processor is
further configured to control the motor in accordance with one or
more pre-programmed motions, which when executed result in a
tactile response.
[0015] In accordance with an embodiment of the present invention
there is provided a toy vehicle having a low inductance motor
powered by a high frequency switched voltage at a frequency high
enough to create continuous conduction. The vehicle includes an
H-bridge circuit configured to control a direction of the motor and
an adjustable high frequency DC-DC switch configured to convert a
supply voltage to an output voltage, that is lower than the supply
voltage, for use by the H-bridge circuit to power the low
inductance motor in a forward or reverse direction. A processor is
provided with instructions configured to change the output voltage
from the DC-DC switch from a first voltage to a second voltage.
[0016] In different aspect of this embodiment, the motor may have
an inductance of approximately less than 500 uH and more preferably
of about 140 uH. The DC-DC switch may be operating at a frequency
greater than 250 kHz and more preferably at about 1000 kHz or
higher. In addition, the DC-DC switch may be changed digitally.
[0017] In addition, the output voltage from the DC-DC switch may be
selected by a voltage divider, having a first resistor value and a
second resistor value selected by the instructions from the
processor such that the output voltage from the DC-DC switch can
define a first output voltage and a second output voltage. In other
aspect the DC-DC switch can be further configured to define a third
output voltage. The second resistor value may be selected from a
pair of resistors, defined separately to create the first output
voltage and the second output voltage respectively and defined in
series to create the third output voltage. In addition, the
processor further includes instructions to the H-bridge circuit to
only control the direction of the motor.
[0018] Numerous other advantages and features of the invention will
become readily apparent from the following detailed description of
the invention and the embodiments thereof, from the claims, and
from the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] A fuller understanding of the foregoing may be had by
reference to the accompanying drawings, wherein:
[0020] FIG. 1 is a perspective view of a toy skateboard
illustrating a pair of front and rear trucks in accordance with one
embodiment of the present invention;
[0021] FIG. 2 is an exploded view of the toy skateboard from FIG. 1
in accordance with one embodiment of the present invention;
[0022] FIG. 3A is a partial exploded view of the toy skateboard
deck from FIG. 1 illustrating a front truck assembly and a
motorized rear truck assembly in accordance with one embodiment of
the present invention;
[0023] FIG. 3B is a lower view of the toy skateboard from FIG.
3A;
[0024] FIG. 4A is a perspective view of one of the non-motorized
truck assemblies in accordance with one embodiment of the present
invention;
[0025] FIG. 4B is an exploded view of FIG. 4A in accordance with
one embodiment of the present invention;
[0026] FIG. 4C is view from beneath the assembly of FIG. 4B in
accordance with one embodiment of the present invention;
[0027] FIG. 5A is a perspective view of a motorized toy skateboard
in accordance with one embodiment of the present invention;
[0028] FIG. 5B is a lower view of the motorized toy skateboard from
FIG. 5A in accordance with one embodiment of the present
invention;
[0029] FIG. 5C is a lower view of the motorized toy skateboard from
FIG. 5A in accordance with one embodiment of the present
invention;
[0030] FIG. 6 is a side view of the toy skateboard deck from FIG. 1
being further illustrated with non-motorized truck assemblies in
comparison to a non-motorized front truck and assembly and
motorized rear truck assembly to further illustrate the two
configurations in accordance with one embodiment of the present
invention;
[0031] FIG. 7A is a perspective view of the assembled motorized
rear truck assembly in accordance with one embodiment of the
present invention;
[0032] FIG. 7B is a lower view of the assembled motorized rear
truck assembly from FIG. 7A in accordance with one embodiment of
the present invention;
[0033] FIG. 8 is an exploded view of the motorized rear truck
assembly from FIG. 7A in accordance with one embodiment of the
present invention;
[0034] FIG. 9 is a partial exploded view of the motorized rear
truck assembly from FIG. 7A in accordance with one embodiment of
the present invention;
[0035] FIG. 10 is a perspective view of the housing from the
motorized rear truck assembly from FIG. 7A in accordance with one
embodiment of the present invention;
[0036] FIG. 11 is a partial perspective view of the gear housing
compartment from the motorized rear truck assembly from FIG. 7A in
accordance with one embodiment of the present invention;
[0037] FIG. 12 is an exploded view of the gear housing compartment
from FIG. 11 in accordance with one embodiment of the present
invention;
[0038] FIG. 13 is a side view perspective view of the assembled
motorized rear truck assembly from FIG. 7A in accordance with one
embodiment of the present invention;
[0039] FIG. 14A is an electrical schematic drawing of a motorized
toy skateboard in accordance with one embodiment of the present
invention illustrating the use of a direct wire to trigger
different functionality states in the vehicle;
[0040] FIG. 14B an electrical schematic drawing of a motorized toy
skateboard in accordance with one embodiment of the present
invention;
[0041] FIG. 15 is an electrical schematic drawing of a motorized
toy skateboard in accordance with one embodiment of the present
invention illustrating the use of a booster component to trigger
different functionality states in the vehicle;
[0042] FIG. 16 is an electrical schematic drawing of a motorized
toy skateboard in accordance with one embodiment of the present
invention illustrating the use of an FET component to trigger
different functionality states in the vehicle;
[0043] FIG. 17 is an electrical schematic drawing of a motorized
toy skateboard in accordance with one embodiment of the present
invention illustrating the use of an a pull-down resistor component
to trigger different functionality states in the vehicle;
[0044] FIG. 18 is an electrical schematic drawing of a motorized
toy skateboard in accordance with one embodiment of the present
invention illustrating the use of an a series resistor component to
trigger different functionality states in the vehicle;
[0045] FIG. 19 is a perspective view of a skateboard having clips
to secure the motorized truck assembly to the deck;
[0046] FIG. 20A is a perspective view of a skateboard having a
trick weight attached;
[0047] FIG. 20B is a perspective view of the skateboard of FIG. 20A
with the trick weight removed from the skateboard deck;
[0048] FIG. 21A is a box diagram of an embodiment of a toy showing
a processor monitoring one or more motors for a manual generated
back EMF voltage;
[0049] FIG. 21B is a box diagram of an embodiment of another toy
showing a processor monitoring one or more motors for a manual
generated back EMF voltage;
[0050] FIGS. 22A-22E illustrate various embodiments of toy
skateboards having various housing configurations for different
battery compartments;
[0051] FIG. 23 is a diagram representing a transmitter in
accordance with one embodiment of the present invention for use
with a motorized toy skateboard;
[0052] FIG. 24 is an electrical schematic drawing of a remote
control unit in accordance with one embodiment of the present
invention for use with a motorized toy skateboard;
[0053] FIG. 25 is a block diagram for a transmitter in accordance
with one embodiment of the present invention for use with a
motorized toy skateboard;
[0054] FIG. 26A is an electrical schematic drawing of a motorized
toy skateboard in accordance with one embodiment of the present
invention illustrating the use of a DC to DC switch to vary the
voltage power supplied to the motors;
[0055] FIG. 26B is an electrical schematic drawing of a motorized
toy skateboard in accordance with one embodiment of the present
invention illustrating the use of a DC to DC switch to vary the
voltage power supplied to the motors;
[0056] FIG. 27 is a flow chart diagram for a skateboard in
accordance with one embodiment of the present invention;
[0057] FIG. 28 is a flow chart diagram for a system in a skateboard
in accordance with one embodiment of the present invention to set
voltage and H-bridge circuits;
[0058] FIG. 29A-29C illustrates a current waveform in the motor at
three different PWM frequencies, 10 kHz, 100 kHz, and 1000 kHz;
[0059] FIG. 30 is an electrical schematic drawing of a simplified
H-bridge motor driver with four drive transistors and four flyback
diodes connected to a motor;
[0060] FIG. 31 is an electrical schematic drawing of a pair of
simplified H-bridge motor drivers each connected to a pair of
motors which are further resistively connected to provide additive
EMF detection as per a feature of the present invention; and
[0061] FIG. 32 is an electrical schematic drawing of the equivalent
circuit of a pair of simplified H-bridge motor drives each
connected to a pair of motors which are further resistively
connected to provide additive EMF detection as per a feature of the
present invention when none of the drive MOSFET transistors are
energized.
DETAILED DESCRIPTION OF THE DRAWINGS
[0062] While the invention is applicable to embodiments in many
different forms, there are shown in the drawings and will be
described in detail here in the various embodiments of the present
invention. It should be understood, however, that the present
disclosure is to be considered an exemplification of the principles
of the invention and is not intended to limit the spirit or scope
of the invention and/or claims of the embodiments illustrated.
[0063] Referring now to the drawings, and to FIGS. 1 through 3B in
particular, a toy skateboard in accordance to one embodiment of the
invention is illustrated and generally referenced as numeral 100.
The toy skateboard 100 includes a deck 102 with an upper surface
103 and a lower surface 104. As illustrated in FIGS. 1 and 3A, the
skateboard 100 includes a front truck assembly 110 secured towards
the front end 106 of the deck 102 and either a rear truck assembly
120 or a motorized rear truck assembly 200 secured towards the rear
end 108 of the deck 102. The trucks are secured to the deck 102
with fasteners 109 that the operator can easily remove. The front
and rear non-motorized truck assemblies 110 and 120 may be
configured the same as each other, however, the truck assemblies
orientation may be reversed.
[0064] Referring now to FIGS. 4A through 4C there is illustrated
one of the non-motorized truck assemblies (110/120) which includes
an axle housing hanger 122 with a pair of axles 124 that extends
transversely to the deck 102 and through the hanger 122. Wheels 126
are separately mounted at opposing ends of the pair of axles 124
and a secured onto the axles by a nut 128. Preferably, the wheels
126 rotate independently of each other so that the skateboard can
negotiate turns without binding. The nut 128 may be replaced with a
more general retainer that allows the user to replace or swap
wheels to customize the skateboard. The hanger 122 is attached to a
base plate 130, which is secured to the lower surface 104 of the
deck 102. The base plate 130 includes a pivot cup 132 (FIG. 4C)
which receives a pivot member 134 extending from the hanger 122. A
king pin 136 is placed in a bore 140 on the base plate and aligned
through an opening 142 in the hanger 122 with a king pin nut 138
being secured on the end; and a pair of bushings 144 are positioned
on either side of the opening 142 in the hanger 122.
[0065] An important aspect to one or more embodiments of the
present invention is that the deck 102 is relatively small in
thickness throughout the length of the board. This permits the deck
102 to be used by an operator as illustrated in FIG. 1 without a
motor assembly or controlled with a remote control unit when the
rear truck assembly 120 is removed and replaced with a motorized
rear truck assembly 200. As such, the motorized rear truck assembly
200 is completely self-contained. As found in the prior art,
motorized toy skateboards include one or more components in a large
constructed deck. These components may be batteries, circuit
boards, mechanical links, motors, and/or gears. As illustrated
herein, the motorized rear truck assembly 200 is completely
self-contained and therefore may be easily removed and exchanged
with a non-motorized rear truck assembly 120.
[0066] Referring now to FIGS. 5A through 6, the skateboard 100 is
illustrated with a front truck assembly 110 and a motorized rear
truck assembly 200 in accordance with an embodiment of the present
invention. As provided herein, the skateboard 100 when employed
with the motorized rear truck assembly 200 still rests on the
surface in a similar configuration as if the skateboard 100
included a non-motorized rear truck assembly 120 (see FIG. 6) and
does so without having to place any components into an oversized
deck assembly. However, when motorized, maneuverability of the
skateboard 100 can be controlled by an operator through a remote
control unit 300. Therefore, two complete play patterns are
developed. First, using a non-motorized truck assembly 120, the
skateboard 100 can be used as a typical fingerboard. Second, by
removing the fasteners 109, the non-motorized truck assembly 120
can be removed and replaced with the self-contained motorized truck
assembly 200, and then secured to the deck with the same fasteners
109.
[0067] Referring now to FIGS. 7A through 12, the motorized rear
truck assembly 200 includes a housing 202 that is elongated with an
upper surface 204 or upper profile 203 that substantially matches
the lower surface 104 of the deck 102 which aids in keeping all of
the components substantially below the lower surface of the deck
and allows the pair of rear wheels 206 to substantially align along
a similar plane as the front wheels 126 when the wheels are resting
on a surface. A fastening plate 210 is positioned under a portion
205 of the upper surface 204 of the housing 202. The portion 205 of
the upper surface 204 includes openings 207 that are aligned with
threaded openings 209 in the fastening plate 210 and which align
with the rearward openings through the deck 102 such that the
fasteners 109 can easily secure and release the entire housing 202
by the fastening plate 210, and thus configured to release or
secure the rear motor truck assembly 200.
[0068] The housing 202 includes a gear housing compartment 220, a
first battery compartment 222 forward of the gear housing
compartment 220, and includes a second battery compartment 224
rearward of the gear housing compartment 220. The first battery
compartment 222 accommodates a first battery 214 in front of the
gear housing compartment 220, while the second battery compartment
224 accommodates a pair of batteries 214 rearward of the gear
housing compartment 220. The first and second battery compartments
are accessible from under the housing 202 and secured with battery
doors 226. The batteries are connected to a circuit board 230
through various wires 228. To aid in securing the wires 228 in
place the second battery compartment 224 may include a battery
bracket 225 secured over the compartment 224.
[0069] The housing 202 further includes a forward window 232 for
the placement of an IR sensor 234 which is in communication with
the circuit board 230; its control may be shown and illustrated in
the electrical schematic of FIG. 14. The IR sensor 234 is
positioned to receive signals from the remote control unit 300.
From a top view, the circuit board 230 is positioned over the
forward window 232 with a PCB cover 240 secured over the circuit
board 230 and secured to a forward section of the housing 202.
Since all of the components are positioned within the housing and
below the lower surface of the deck, the IR sensor 234 is
positioned to receive signals from the remote control unit 205 that
are bounced from a surface S. In addition, the IR transmitter 305
from the remote control unit 300 is angled downwardly to help in
ensuring the signal is sent downwardly towards the surface.
[0070] The gear housing compartment 220 holds a pair of rotary
motors 240 separately driving each of the rear wheels 206. Each
motor 240 includes a drive gear 242 which is meshed to a gear
reducer 244 and which is further meshed to a wheel axle gear 246
that is capable of freely spinning on a rear axle 248. The rear
axle 248 extends through the housing 202 transversely to the deck
102. A pin 250 is employed to rotatably secure the gear reducer 244
to the gear hosing compartment 220. The wheel axle gear 246 further
includes an end key 252 with an external profile 254 that matches
an internal profile 256 positioned on a wheel hub 258. A tire 260
is positioned over the wheel hub 258 to create the rear wheel 206.
The gear housing compartment 220 includes a lower gear housing
cover 262 that secures the components in place.
[0071] Referring now to FIG. 13, as noted above, the housing 202
defined for the motorized rear truck assembly 200 includes an upper
surface profile 203 to match the lower surface 104 of the deck 102,
as such the housing includes a rearward portion of the second
battery compartment 224 that is angled from a horizontal at an
angle between 10 and 45 degrees and more particularly at about 22
degrees to match the upturn angle in the rear end 108 of the
deck.
[0072] As defined in various embodiments herein the remote
controlled battery powered skateboard is defined as a fingerboard
toy skateboard approximately 4 inches long. Completely positioned
underneath the deck lower surface are the batteries, motors, gears,
and circuit board. The motors may be small 6 mm diameter by 11 mm
long cylinder motors. Each motor independently controls one rear
wheel. A high efficiency gear reduction provides a drive speed near
1 meter per second. The circuit board receives power from the
battery, receives infrared signals from the remote control device,
and commands the motors using a processor, DC-DC switch, H-Bridges
and software.
[0073] It is desired in one or more embodiments to provide a toy
skateboard that is both fast and able to climb steep ramps. Various
play patterns and accessories in the field demand various
attributes in order for the toy motorized skateboard to operate
properly. Various maneuvering capabilities would include the
ability to drive straight forward or reverse, turn wide in any four
directions, spin left or right, and climb hills starting from a
stop position at the base of the hill and from a moving
position.
[0074] Placing all the components below the skateboard deck has two
specific advantages. First, this hides them from the user's line of
sight, making the skateboard look like a normal riderless
skateboard. Second, keeping the center of gravity as close to the
ground as possible reduces rolling forces on the skateboard when
turning. Reducing the rolling forces will help keep the skateboard
in full contact with the ground and improve maneuverability and
control.
[0075] Consistent repeatable performance will be critical to the
user. Typical battery powered products move faster when the
batteries are full and slower when the batteries are nearly
depleted. This would make practicing tricks more difficult as the
user would need to adjust their timing for the current battery
level. Additionally, some maneuvers may not be possible at lower
battery levels. To eliminate this issue, a constant voltage is
generated and supplied to the motors. This consistent voltage will
make all maneuvers and trick timing consistent from full battery to
depleted battery. Boost circuits, known to those in the arts, are
used to power logic circuits that require a narrow range of voltage
to operate. In this application where motor current is relatively
low, it is possible to use low cost boost circuits to power two
motors. Buck circuits, known to those skilled in the art, may also
be employed to provide a consistent and repeatable motor voltage.
The choice of buck versus boost circuit depends on whether the
motor supply voltage is required to be higher or lower than the
battery voltage, which depends on the specific requirements of the
embodiment. Either choice of converter type falls within the scope
and spirit of the present invention.
[0076] The remote for the toy skateboard will have the usual
forward/reverse and right/left controls. In another embodiment, the
remote employs "tank" control, with left controls to control the
left propulsion and right controls to control the right propulsion.
In an alternative embodiment, additional "Trick" buttons are added.
A Trick button sends a single trick command to the toy skateboard.
In one embodiment this trick is a simple 180 degree wide turn. In
another embodiment the trick is something more complex. Once the
trick command is received user controls are disabled. In another
embodiment, user controls are allowed to let the user perform a
half of a trick followed by their own move if their timing is good.
Embodiments disallowing trick termination may be better for younger
users. In another embodiment, holding the trick Play button causes
the trick to be repeated. In a further embodiment, the remote has a
record button. When the record feature is initiated, every button
pressed by the user is simultaneously transmitted and recorded
until the record button is pressed again. In this instance, when
the Trick button is pressed, the recorded moves are transmitted to
the toy skateboard, performing a custom user generated trick
maneuver.
[0077] Driving forward can be modified by the addition of a weight
350 at the rear tip of the toy skateboard as shown in FIG. 20B.
This weight shifts the center of gravity aft, allowing the
skateboard 100 to lift the front wheels 126 off the ground when
accelerating. Depending on the amount of weight, location of weight
350, and the toy skateboard 100 configuration, the front wheels 126
may stay off the ground as long as the skateboard 100 continues
forward.
[0078] Driving in a spin involves turning the rear wheels 206 in
opposite directions. This causes the toy skateboard to spin about a
center of spin. The center of spin is a function of the center of
the power wheels 206, the center of gravity, and the drag created
by friction and load on the wheels 206, 126. The addition of weight
350 at the rear tip of the toy skateboard modifies the spin. When
weight 350 is present, the center of gravity is moved aft and the
load is transferred off the front wheels. This causes the toy
skateboard to spin about a point very near the rear wheels 206,
significantly increasing the spin speed.
[0079] The two features of adding a rear weight can be accomplished
by the same weight 350, hereafter referred to as a trick weight
350.
[0080] In another embodiment of the present invention, the toy
skateboard 100 is not employed with an on/off switch. To turn on
toy skateboard 100, the operator can push or roll the toy
skateboard 100 forward while on a supporting surface. This "Turn
ON" feature simplifies use, feels more realistic for kids, and
reduces cost. Once ON, the toy skateboard 100 immediately performs
an easily recognizable pre-programmed movement pattern to indicate
that it is ON. In one embodiment, the pattern is to drive forward
for a predetermined amount of time. In another embodiment, the
skateboard 100 turns right, then left several times. In one
embodiment, the ON Pattern can be initiated immediately upon
detection. In another embodiment, the ON Pattern is delayed until
the user stops rolling the toy. In this embodiment, the delay
improves the recognition of a successful ON, and is more visually
appealing. In yet another embodiment, the motors can are pulsed in
a pattern to create a haptic response that the user can feel. In
one embodiment, detection of a forward roll is achieved by
connecting one of the two motor 240 leads to a processor 406 input.
When the toy skateboard 100 is rolled, the wheels turn, causing
motor 240 to generate a back EMF voltage. The back EMF voltage
generated is a function of the speed the motor 240 is turned and
the specific design of the motor 240. As an example, voltages of up
to 1.5 v are easily generated, and voltages up to 3 v are generated
with higher roll speeds. Once the detected back EMF voltage reaches
a pre-determined value, such as 0.7 v, or the threshold voltage of
an input pin of a processor 406 or transistor, or a specific
voltage read by an analog to digital input, the processor 406 is
configured to wake up from a sleep state. The skateboard circuit
must is carefully designed to minimize current draw during the
sleep state. This Turn ON method eliminates the typical ON button
or switch, reducing cost.
[0081] In another embodiment, the circuit connects both leads of
the motor 240 to two separate processor 406 input pins. In this
way, both roll forward and roll reverse are detected by the
processor 406. These roll commands are recognized in a sleep state,
and at any time. The processor 406 monitors the input pins to both
leads of the motor 240, when the motors 240 are not commanded to
move, thereby, processor 406 detects user roll commands. In an
alternative embodiment, this method is expanded to detect both
motors 240 and both motor 240 directions. In this embodiment
turning the skateboard is also be detected, and provides additional
user input to enhance skateboard control. In the embodiment, the
processor 406 detects roll forward to wake to the ON state, and
roll backwards to turn OFF into a sleep state.
[0082] In one embodiment the use of a plurality of controllers 300
to individually operate a plurality of skateboards 100 is
incorporated. This is done by the use of channel address bits in
the command signal emitted from the controller 300 and received by
the skateboard 100. In the embodiment, transmitters 300 are factory
preset with specific channel designators. The channel designators
are transmitted with each command by controllers 300 comprising the
channel address. When a skateboard 100 is turned ON, it initially
does not know which channel it is intended to respond to. However,
it sets its channel address based on the first command it receives.
In this way, a user can cause a particular skateboard 100 to
respond to a particular controller 300 by ensuring that the first
command the skateboard 100 receives after it is turned on comes
from the intended controller 300.
[0083] As it may be, in executing the above technique a skateboard
100 may inadvertently receive a first command from an undesired
controller, thereby incorrectly setting its channel address. In
this case, the user need only turn off skateboard 100, and then
turn on skateboard 100, this time ensuring that it receives its
first command from the desired controller 300. This may be repeated
as necessary until the appropriate pairing has been achieved.
[0084] The aforementioned technique requires a means of turning off
skateboard 100 on demand, and thus, the embodiment provides for a
means where the skateboard 100 goes to sleep when it is rolled
backwards by the user. Turning OFF additionally increases battery
life. Since rolling the skateboard forward is associated with ON,
it is intuitive and therefore provided that the opposite would turn
the device OFF. The turn ON feature's haptic response of the
skateboard 100 moving the desired intuitive feedback corresponding
to the act of turning OFF. A haptic response that does match the
action is for the skate board to stop, or resist, motion, and thus
is implemented in the preferred embodiment. In an embodiment, the
motors 240 are set into braking mode to accomplish this wherein the
motor 240 leads are shorted to one another. In an alternative
embodiment, as similar sensation is implemented by the application
of momentary power to the motor in the opposite direction, creating
more resistance than braking alone.
[0085] In an embodiment, additional rolling input from the user
changes the skateboards performance. In the embodiment, a roll
function of the skateboard 100 is recognized by processor 406 when
a roll-forward is detected after the skateboard is ON. This causes
the skateboard 100 to toggle between modes. In one example, the
skateboard 100 alternates between 100% maximum speed and 50%
maximum speed. A reduction in overall skateboard speed allows new
types of low speed tricks that are more difficult at higher
speeds.
[0086] In addition, there are more settings that may be employed
such as disable or enable coasting, disable or enable 50% max speed
or 100% max speed, slow turning with full forward/reverse, fast
turning and slower forward/reverse, forward & turning normal
with braking instead of reverse, and braking for ramps. These can
be controlled and set by the user either through a remote control
unit or through the manual manipulation of the toy skateboard, as
discussed herein.
[0087] Referring now to FIG. 19, there is shown a toy skateboard
100 in accordance with one or more of the present embodiments, in
which the rear truck assembly 200 includes clips 301 positioned on
the upper surface of the rear truck housing 202 and which are used
to attach to the deck 102. In this embodiment the rear truck
assembly 200 is removable and secured to the deck 102 such that the
rear truck housing 202 is below the lower surface of the deck 102.
However, in this embodiment the clips 301 allow the rear truck to
either snap or slide onto the deck 102.
[0088] Referring now to FIGS. 20A and 20B, there is shown a toy
skateboard 100 in accordance with one or more of the present
embodiments. The skateboard 100 includes a rear weight member 350
removably secured to the rear end 352 of the deck 102. The rear
weight member 350 includes a channel 354 that clips into or
frictionally engages the rear end of the deck 102. The weight
member 350 as noted above allows the user to move the center of
spin of the skateboard 100.
[0089] As provided in one or more embodiments of the present
invention, a processor 406 is used and discussed and may be
embodied in a number of different ways. For example, the processor
406 may be embodied as one or more of various processing means or
devices such as a coprocessor, a microprocessor, a controller, a
digital signal processor (DSP), a processing element with or
without an accompanying DSP, or various other processing devices
including integrated circuits such as, for example, an ASIC
(application specific integrated circuit), an FPGA (field
programmable gate array), a microcontroller unit (MCU), a hardware
accelerator, a special-purpose computer chip, or the like. In an
exemplary embodiment, the processor 406 may be configured to
execute instructions stored in a memory device or otherwise
accessible to the processor 406. The instructions may be permanent
(e.g., firmware) or modifiable (e.g., software) instructions. The
instructions can be bundled or otherwise associated with other
instructions in functional profiles, which can be saved as, e.g.,
an electronic file on one or more memory device. Alternatively or
additionally, the processor 406 may be configured to execute hard
coded functionality. As such, whether configured by hardware or
software methods, or by a combination thereof, the processor 406
may represent an entity (e.g., physically embodied in circuitry)
capable of performing operations according to embodiments of the
present invention while configured accordingly. Thus, for example,
when the processor 406 is embodied as an ASIC, FPGA or the like,
the processor 406 may be specifically configured hardware for
conducting the operations described herein. Alternatively, as
another example, when the processor 406 is embodied as an executor
of software or firmware instructions, the instructions may
specifically configure the processor 406 to perform the algorithms
and/or operations described herein when the instructions are
executed. The processor 406 may include, among other things, a
clock or any other type of timer, an arithmetic logic unit (ALU)
and logic gates configured to support operation of the processor
406.
[0090] In addition and as discussed herein, haptic technology or
haptics may be included in one or more of the discussed
embodiments. Haptics involve tactile feedback provided by a device
to a user. Low-cost haptic devices tend to provide tactile
feedback, in which forces are transmitted to a housing or portion
thereof and felt by the user, rather than kinesthetic feedback, in
which forces are output directly in the degrees of freedom of
motion of the interface device. The tactile feedback is typically
provided by applying forces, vibrations and/or motions to one or
more portions of a user interface device. Haptics are sometimes
used to enhance remote control devices associated with machines and
devices. In such systems, sensors in the slave device are sometimes
used to detect forces exerted upon such device. The information
relating to such forces is communicated to a processor, where the
information is used to generate suitable tactile feedback for a
user. The present invention does not use haptics to enhance the
touch experience or to allow the use to feel a virtual object or to
simulate reaction forces. The present invention creates tactile
responses to a user interaction with a device that the user can
easily correlate or deduce to an unseen setting or mode of the
object. Unlike pulsing a pager in different patterns to provide a
tactile response, the present invention provides tactile responses
so the user can determine which setting or mode the object is now
configured. Another important aspect of one or more embodiments, is
that the tactile responses are relayed back to the user through the
element or mechanism that the user touched to create the input in
the first place. Unlike the use of sensors or switches in the prior
art, the embodiments provided herein use elements, such as wheels
and actuated arms that are in communication with a motor. The
direct interaction by the user with these elements generates a back
electromotive force through the motor, which is monitored or
detected by the processor. The processor when triggered by the
generated back electromotive force can access and play-back a
pre-recorded motion to the element. The user still interacting with
the element feels the pre-recorded motion which causes the tactile
response. The tactile response felt by the user allows the user to
determine or deduce the object or toy's setting or mode, as further
detailed and explained herein.
[0091] As provided in one or more embodiments described herein and
as provided and illustrated in FIGS. 21A-21B, there is generally
illustrated a toy 400, that may include one or more elements 402,
such as the wheels on a skateboard, an appendage on a toy robot or
figure, or a propeller on a toy vehicle. These elements are
external to the toy 400 and are moved/controlled separately by a
motor 404, whether directly or indirectly moved or physically or
non-physically coupled is well within the scope of the various
embodiments provided for herein. The processor 406 is as described
herein, and as such further definition is not warranted. The
processor is configured to include at least a sleep state and a
wake state and is further configured to transition between the two
states 408. Another aspect of the embodiment is that the element is
accessible for manipulation by the user, operator, or human which
when moved will in turn rotate the motor. When the user manipulates
the element, rotating the motor, the rotation of the motor
generates a back electromotive force (herein after "EMF") voltage.
The processor is configured to detect the back EMF voltage 410 and
is further configured to transition between the two states when the
detected back EMF voltage reaches a pre-determined value.
[0092] In another aspect of the embodiment, when the detected back
EMF voltage reaches the pre-determined value 412, the processor is
further configured to control the motor in accordance with one or
more pre-programmed motions 414, which when executed result in a
tactile response. In addition, when the detected back EMF voltage
reaches the pre-determined value, the processor is yet further
configured to control the motor in accordance with one or more
pre-programmed motions resulting in auditory perception.
[0093] As provided in FIG. 21B the toy 400 may include a number of
elements connected separately to motors. All or some of the
illustrated elements (wheel 420, appendage(s) 422, propeller 424,
etc.) can be included.
[0094] The processor may yet be further configured to detect a
second back EMF voltage generated by the rotation of the motor in
an opposite direction due to the manipulation of the element by a
human in an opposite direction. In this instance, when either
detectable back EMF voltage reaches the pre-determined value, the
processor is configured to control the motor in accordance with one
or more of the following pre-programmed motions resulting in a
tactile response: (a) move said element momentarily, (b) move said
element continuously, (c) resist motion of said element
momentarily, (d) resist motion of said element continuously, (e)
oscillate said element momentarily, and (f) oscillate said element
continuously. In some instances the pre-programmed motions are
selected based on the rotational direction of the motor and based
on whether the processor is in the wake state or sleep state. This
allows for greater functions and motion responses.
[0095] In variations of the embodiments, when either the detectable
back EMF voltage reaches a pre-determined value, the processor may
be further configured to a delay by a pre-determined time internal
prior to the pre-programmed motions resulting in a tactile
response. In addition, the pre-programmed motions resulting in a
tactile response may be at less than 100% motor speed. In other
aspects, the pre-programmed motions result in a tactile response at
variating motor speed.
[0096] The embodiments may also include a second motor configured
to cause a motion of a second element of toy and the second element
is further accessible for manipulation by a human, which when moved
causes a rotation in the motor. The processor is further configured
to control the second motor and the pre-programmed output is
further configured to control both motors and rotate both wheels
resulting in a tactile response. If desired or needed an electrical
circuit can be included to alter the back EMF voltage prior to
detection by the processor. The electrical circuit may be a
transistor, resistor, booster, a combination thereof, or other
circuits known in the industry.
[0097] In another embodiment a toy vehicle is provided with an
element, a processor, and a motor configured to cause a motion of
the element. The motion of the element is further accessible for
manipulation by a human, which in turn is capable of rotating the
motor. The processor is configured to detect a back electromotive
force ("EMF") voltage that is generated by the rotation of the
motor when the element is manipulated by the user. The processor is
further configured to include at least two states and the processor
includes a function configured to transition between states when
the detected back EMF voltage reaches a pre-determined value. In
addition, the processor is further configured to control the motor
in accordance with one or more pre-programmed motions resulting in
a tactile response when the detected back EMF voltage reaches a
pre-determined value. In this embodiment, the pre-programmed
tactile responses may be turning the motor in a forward or reverse
direction or braking the motor.
[0098] In variations of this embodiment the toy may include a
second motor configured to cause a motion of a second element and
the motion of the second element is accessible for manipulation by
a human, which when manipulated in turn rotates the motor. The
processor is further configured to control the second motor, and
wherein the pre-programmed output is further configured to control
both motors and rotate both wheels resulting in a tactile
response.
[0099] The processor may be further configured to detect a second
back EMF voltage generated by the rotation of the motor in an
opposite direction due to the manipulation by a human in an
opposite direction. The processor is further configured to control
said motors in accordance with one or more pre-programmed motions
resulting in a tactile response, when either of the detectable back
EMF voltages reach a pre-determined value. The pre-programmed
motions resulting in a tactile response may include the following:
(a) move one or more of said elements momentarily, (b) move one or
more of said elements continuously, (c) resist motion of one or
more of said elements momentarily, (d) resist motion of one or more
of said elements continuously, (e) oscillate one or more of said
elements momentarily, and (f) oscillate one or more of said
elements continuously.
[0100] As noted above in other embodiments, the pre-programmed
motions may be selected based on the rotation direction of the
motor and based on whether the processor is in the wake state or
sleep state. In addition, when either detectable back EMF voltages
reaches a pre-determined value, the processor is further configured
to a delay by a pre-determined time internal prior to the
pre-programmed motions resulting in a tactile response.
[0101] As provided in yet another embodiment, there is provided a
toy vehicle having an element, a processor, and a motor configured
to cause a motion of the element and the motion of the element is
further accessible for manipulation by a human, which when moved
causes a rotation of the motor. The processor is configured to
detect a back electromotive force ("EMF") voltage generated by the
rotation of the motor due to the manipulation of the element by the
user. The processor is further configured to include at least two
of the following states: (a) a lower power state configured to turn
the at least one motor off and power the vehicle off; (b) a lower
power sleep state configured to turn the at least one motor off and
put the processor in a low power sleep state and halt executing
code; (c) a wake state configured to power the vehicle on; (d) a
wake state configured to bring the processor out of a low power
sleep state and begin to executing code; (e) a user controllable
drive state configured to control the at least one motor and rotate
the at least one wheel; (f) a user controllable drive state
configured to control the at least one motor and rotate the at
least one wheel at a slower than maximum speed; (g) a user
controllable drive state configured to control the at least one
motor and rotate the at least one wheel in accordance to a
pre-programmed set of instructions and user input from a remote
device to cause the vehicle to perform a maneuver; and (h) a
non-user autonomous drive state configured to control the at least
one motor and rotate the at least one wheel. The processor further
includes a function configured to transition between states when
the detected back EMF voltage reaches a pre-determined value.
Furthermore, when the detected back EMF voltage reaches a
pre-determined value, the processor is further configured to
control the motor in accordance with one or more pre-programmed
motions resulting in a tactile response.
[0102] In other aspect, the vehicle may include a second motor
configured to cause motion of a second element and the motion of
the second element is further accessible for manipulation by a
human, which in turn causes rotation of the motor. The processor is
further configured to control the second motor, and wherein the
pre-programmed output is further configured to control both motors
and rotate both wheels resulting in a tactile response. The
processor of the vehicle may be further configured to detect second
back EMF voltage generated by the rotation of the second motor due
to the manipulation by a human in an opposite direction. The
processor is further configured to transition between the states
when the detected second back EMF voltage reaches a pre-determined
value. The processor is yet further configured to control the
second motor in accordance with one or more pre-programmed motions
resulting in a tactile response when the detected second back EMF
voltage reaches a pre-determined value, which may be the same or
different value set to the first back EMF voltage.
[0103] Various combinations of aspects may be included to provide
for variations in the scope of the embodiments without detracting
from the spirit of the invention. As such when combined with a toy
skateboard, one embodiment of the invention may provide a toy
vehicle or skateboard which includes a deck, a front truck with a
pair of front wheels which can secure to the deck towards the front
portion, and a rear truck which can secure to the deck towards the
rear portion. The rear truck has first and second wheels and a
housing configured to include a battery, a processor, a receiver,
first and second motors separately in control of the first and
second wheels respectively. The first motor is configured to cause
a motion of the first wheel, and the motion of the first wheel is
also accessible for manipulation by a human, which when manipulated
rotates the first motor. Similarly, the second motor is configured
to cause a motion of the second wheel, and the motion of the second
wheel is also accessible for manipulation by a human, which when
manipulated rotates the second motor. The receiver is configured to
receive signals from a remote control unit and the processor is
configured to receive signals from the receiver to control the
first and second motors in response thereto. The processor is
further configured to detect a first back electromotive force
("EMF") voltage generated by the rotation of the first or second
motor due to the manipulation by a human of the toy against a
surface and in a first direction. The processor is further
configured to detect a second back EMF voltage generated by the
rotation of the first or second motor due to the manipulation by a
human of the toy against a surface and in a second direction
generally opposite the first direction. The processor is further
configured to include at least a sleep state and a wake state and
the processor has a function configured to transition between the
sleep state and the wake state when the detected back EMF voltage
reaches a pre-determined value.
[0104] In aspects of this embodiment, the processor is further
configured to control at least one of the motors in accordance with
one or more pre-programmed motions resulting in a tactile response,
when at least one of the detected first and second back EMF
voltages reaches a pre-determined value. The pre-programmed motions
resulting in a tactile response may include one or more of the
following: (a) rotate one or more of said first and second wheels
momentarily; (b) move one or more of said first and second wheels
continuously; (c) resist motion of one or more of said first and
second wheels momentarily; (d) resist motion of one or more of said
first and second wheels continuously; (e) oscillate one or more of
said first and second wheels momentarily; and/or (f) oscillate one
or more of said first and second wheels continuously.
[0105] In still other aspects, when either of the detectable first
or second back EMF voltage reaches a pre-determined value, the
processor is further configured to a delay by a pre-determined time
internal prior to the pre-programmed motions resulting in a tactile
response. The embodiment of the invention may include
pre-programmed motions resulting in a tactile response that are at
less than 100% motor speed or at variating motor speeds. In
addition thereto, the embodiment of the invention may include an
electrical circuit designed to alter at least one of the first and
second back EMF voltages prior to detection by the processor.
[0106] Conversion of the toy in accordance with one embodiment of
the present invention may be an important aspect. As such the rear
truck may be removed from the deck and a truck similar to the front
truck can be secured to the deck. In this instance, a surface of
the deck opposite of the lower surface can define a finger engaging
region accessible for manipulation by a human to move the toy
vehicle.
[0107] In accordance with the figures and various embodiments and
combinations of aspects provided herein, an embodiment of the
present invention may provide for a convertible toy skateboard
assembly. The skateboard assembly typically includes a deck, a pair
of non-motorized truck assemblies and a rear motorized truck
assembly. The toy skateboard is convertible as one of the
non-motorized truck assemblies may be easily swapped with the rear
motorized truck assembly. This allows for the toy skateboard to
either have a pair of non-motorized truck assemblies, which allows
the operator to use their fingers to manipulate and move the toy
skateboard; or have one non-motorized truck assembly and a
motorized truck assembly, which allows the operator to use a remote
control unit to control and move the toy skateboard.
[0108] The non-motorized truck assembly as used throughout the
various embodiments is typically secured to the lower surface of
the deck. The non-motorized truck assembly includes a pair of
freely rotatable wheels that are positioned transversely to a
longitudinal axis of the deck when attached. The motorized rear
truck assembly includes a housing is configured to removably
attachment to the deck. This may include clips, fasteners, or other
attachment means well known in the art. The motorized truck
assembly is configured to house at least (i) a battery, (ii) a
processor, (iii) a receiver in communication with the processor,
and (iv) a pair of motors, each motor separately controlling a rear
wheel, of a pair of rear wheels, and wherein the pair of rear
wheels are positioned transversely to the longitudinal axis of the
deck and behind the pair of front wheels. The receiver is
configured to receive signals to control the movement of the pair
of rear wheels.
[0109] As mentioned, the toy skateboard would therefore include two
configurations: a first configuration is defined by having the
front non-motorized truck assembly attached to the lower surface
towards the front region of the deck and having the rear
non-motorized truck assembly removably attached to the lower
surface towards the rear region of the deck. In the first
configuration, the upper surface of the deck defines a finger
engaging region for a user's fingers to engage and move the toy
skateboard. A second configuration is defined by removing the rear
non-motorized truck assembly and removably attaching the motorized
rear truck assembly to the lower surface towards the rear region of
the deck, wherein the movement of the toy skateboard is
controllable by the processor in response to signals received by
the receiver.
[0110] In accordance with one or more of the embodiments, the toy
skateboard may include a circuit in communication with the
processor and battery. The circuit configured to change the battery
voltage to a fixed voltage to define a more consistent performance
from the battery. This helps increase the enjoyment from the toy
skateboard and it no longer seems sluggish as the batteries wear
down. In addition, the remote control unit may include one or more
signals to initiate a set of pre-program instructions on the
processor to control the pair of rear wheels to perform one or more
skateboard maneuvers. These skateboard maneuvers may include, but
is not limited to, a skateboard trick, a hill climb, variable speed
control, and playback of user recorded input.
[0111] The skateboard in any one of the embodiment, may further be
defined to have a first motor (from the pair of motors) coupled to
a first rear wheel (from the pair of rear wheels) and the processor
is configured to detect a back electromotive force ("EMF") voltage
generated by the rotation of the first motor caused by a manual
manipulation of the first rear wheel. The processor is further
configured to include at least a sleep state and a wake state and
is configured to transition between the sleep state and the wake
state when the detected back EMF voltage reaches a pre-determined
value. The processor may further control the pair of motors in
accordance with one or more pre-programmed motions resulting in a
tactile response when the detected back EMF voltage reaches a
pre-determined value. In addition, the processor may further be
configured to detect a second back EMF voltage generated by the
rotation of the first motor in an opposite direction due to a
manual manipulation of the first rear wheel in an opposite
direction. When either of the detectable back EMF voltages reaches
a pre-determined value, the processor is further configured to
control the first motor in accordance with one or more of the
following pre-programmed motions resulting in a tactile response:
(a) move the first rear wheel momentarily, (b) move the first rear
wheel continuously, (c) resist motion of the first rear wheel
momentarily, (d) resist motion of the first rear wheel
continuously, (e) oscillate the first rear wheel momentarily, and
(f) oscillate the first rear wheel continuously.
[0112] In one or more of the embodiments, the motorized rear truck
assembly includes a housing defined to include a top profile
substantially conforming to a portion of the lower surface of the
deck towards the rear region. In this instance, the battery,
processor, receiver, and pair of motors are completely positioned
within the housing below the top profile of the housing and thus
below the lower surface of the deck. The housing may also include a
front end and a rear end with an intermediate region there-between.
This provides space for a power source, such as batteries, defined
by two battery compartments separately positioned in the front end
and rear end of the housing and the pair of motors and the pair of
rear wheels being positioned between the two battery compartments.
The rear end of the housing containing one of the battery
compartments may be angled upwardly to match an angle of the rear
end of the deck such that the at least one battery contained in the
battery compartment is angled. In various embodiments, the
placement and number of battery compartments may change, as
illustrated in FIGS. 22A-22E.
[0113] In one or more of the embodiments disclosed herein, the
receiver may be defined as an IR sensor for receiving signals from
the remote control unit. The IR sensor can be positioned in a
window defined in the motorized rear truck assembly towards a front
portion thereof and under the lower surface of the deck such that
the IR sensor is positioned to receive signals reflected from a
surface under the deck of the skateboard. In other aspect, the toy
skateboard may include a weight removably secured to a portion of
the deck to adjust a center of gravity and configured to adjust a
center of spin.
[0114] As defined in one ore move aspects, the toy skateboard is
poised to define a motorized toy skateboard that can be controlled
without needing an object on the upper surface of the deck. The toy
skateboard does not need a figurine, with linkages, and control
mechanics in the deck to maneuver properly. Separately, the toy
skateboard may include a truck assembly housing that encloses both
a front truck and a motorized rear truck. The truck assembly may be
removed and replaced with a pair of non-motorized truck assemblies
so the user is able to manually maneuver.
[0115] In another embodiment and building on the ability to have a
toy vehicle, whether it be a skateboard, car, motorcycle or any
other wheeled motorized vehicle there is a continued need to
provide meaningful physical user input combined with an
understandable wheel driven haptic feedback. This type of
user-machine interface that involves physical input, machine
interpretation and adaptions thereto can be combined with a tactile
wheel based feedback. For a user's point of view, Young users
typically do not read users manuals. Additionally small products
require very small users manuals with very small print, increasing
the likelihood that the user will not read the manual. Conversely
there is a distinct need for manufacturers to increase the number
of features contained within a toy, either to differentiate the
toy, or to allow more flexible usage patterns. The third driving
factor of manufacturers is cost reduction, which makes it desirable
to eliminate or reduce buttons, switches, and LEDs. It is therefore
desirable to make a product that is easy to use, feature rich, and
low cost. A method of physically manipulating a toy and having the
toy provide physical and meaningful feedback can eliminate the need
for reading users manuals to understand what the different buttons,
switches, and LED blink patterns mean.
[0116] Pushing and/or rolling a toy on the floor or tabletop is a
natural play pattern for children. Therefore incorporating rolling
can be natural to children. However just the action of rolling a
toy is not enough for the child to infer what they just instructed
the toy to do. Using the wheels to provide a specialized form of
haptic feedback can present the child with a physical
acknowledgement to their action, as well as relay the meaning of
the action.
[0117] In addition, auditory tactile response may be included. For
example, spinning a motor creates sound, and the frequency can be
changed with the speed such that slow speeds create lower
frequencies of sound which can the interpreted as slow, while high
speeds create high frequencies of sound which can the interpreted
as fast. In addition, pulsing a motor on and off at a low frequency
creates lower frequencies of sound which can the interpreted as
slow speeds. Pulsing a motor on and off at a high frequency creates
higher frequencies of sound which can the interpreted as fast
speed.
[0118] The following are examples of meaningful physical user input
combined with understandable wheel driven haptic feedback, visual
feedback, and audible feedback. Multiple toy responses are
proposed. Turn the toy ON: The child picks up a toy that is OFF and
wishes to turn it ON. One possible input action is that the child
rolls the toy forward across the floor. The toy could include
multiple responses, such as: Toy response A: While the child is
rolling the toy along a surface, the toy wakes from sleep mode and
applies power to the wheels in the same direction it was just
rolled, while the toy is still in contact with the child's hand and
while the toy is still in contact with the surface, resulting in a
tactile response of the toy no longer requiring energy to roll but
now pulling the child's hand forward; alternately the child may
have released the toy after it wakes from sleep but before or
during the time power is applied to the wheels, providing a
combination of tactile response until the toy is released and an
additional visual response as the toy continues to move ahead under
its own power. Alternately the child may lift the toy off the
surface after it wakes from sleep but before or during the time
power is applied to the wheels, providing a combination of tactile
response until the toy is lifted from the surface and an additional
audible response as the toy continues to apply power to the motor
creating sound from a combination of the spinning motor, gears,
axles, and/or wheels.
[0119] Toy response B: Before the child finishes rolling the toy,
the toy wakes from sleep mode and pulses power to the wheels in the
same direction it was just rolled and in a fashion that resembles a
car's engine being revved; or Toy response C: Before the child
finishes rolling the toy, the toy wakes from sleep mode and applies
a percentage of full power to the wheels in the same direction it
was just rolled and in a fashion that resembles a car's engine
being revved. From the user's perception, the user feels that the
toy is no longer just rolling forward but is now trying to
accelerate forward with his hand, relaying to the child that the
toy is ON and ready to go. The result of the actions and functions
of the vehicle is that the toy is now in normal drive mode.
[0120] Turn the toy OFF, the child picks up a toy that is ON and
wants to turn it OFF. One action is that the child pulls the toy
backward across the floor. The toy could include multiple
responses, such as: Toy response A: Before the child finishes
pulling, the toy applies power to the wheels in the opposite
direction it was just pulled; Toy response B: Before the child
finishes pulling, the toy pulses power to the wheels in a opposite
direction it was just pulled; or Toy response C: Before the child
finishes pulling, the toy applies brakes to the wheels. From the
user's perception, the user feels that the toy is no longer just
rolling backward but is now trying to stop his hand, relaying to
the child that the toy is trying to stop and turn OFF. The result
of the actions and functions of the vehicle is that the toy goes
into a low power sleep mode.
[0121] To Select the Next Mode, the child is playing with a toy
that is ON and wishes to alter the way it behaves and/or change an
action state of the toy. The child as an example, rolls the toy
forward across the floor. The toy could include multiple responses,
such as: Toy response: After the child finishes rolling the toy,
the toy briefly applies low speed power to the wheels in the same
direction it was just rolled. From the user's perception, the user
feels that the toy is spinning its wheels slowly, relaying to the
child that the toy is now in a low speed drive mode. The result of
the actions and functions of the vehicle is that the toy is now set
to low speed mode.
[0122] In another section of the Next Mode--Now in High Speed, the
child is playing with a toy that is ON and wishes to alter the way
it behaves and/or change an action state of the toy. The child
rolls the toy forward across the floor. The toy could include
multiple responses, such as: Toy response: After the child finishes
rolling the toy, the toy briefly applies high speed power to the
wheels in the same direction it was just rolled. From the user's
perception, the user feels that the toy is spinning its wheels
quickly, relaying to the child that the toy is now in a high speed
drive mode. The result of the actions and functions of the vehicle
is that the toy is now set to high speed mode.
[0123] In another aspect, the vehicle may be able to Directly Set a
Mode from the user's interface with the vehicle. The child is
playing with a toy that is ON and wishes to alter the way it
behaves/or change an action state of the toy. The child rolls the
toy forward across the floor at a slow or fast speed. After the
child finishes rolling the toy, the toy briefly applies power to
the wheels in the same direction it was just rolled and at a speed
similar to the speed the child rolled the toy. The child feels that
the toy is spinning its wheels at a specific speed, relaying to the
child that the toy is now in a customized speed mode. The toy is
now set to high speed, slow speed, or specific measured speed mode
respectively.
[0124] Other Embodiments that could benefit from back EMF wake,
processor changes, haptic response could include vehicles, robots,
and cars.
[0125] Referring now to FIGS. 23 through 25 there are illustrated
electrical schematic and flow chart diagrams to illustrate
embodiment of the present invention. In FIGS. 23 and 24 a remote
control unit 500 is shown having various functional buttons 502 and
slide switches 504. The remote control unit 500 may be fixed to a
channel selection or may have a further slide switch to allow the
user to switch channels. The remote control unit 300 includes a
transmitter 506 to send signals or packets of information to the
skateboard 100. In FIG. 25, the remote control unit executes WAKE
UP (box 510) when any button is pressed. The remote control unit
may first DETERMINE THE CHANNEL (box 512) and then completes a POLL
of the buttons and switches (box 514). A 1.sup.st Packet of Date is
transmitted (box 516) to the receiver and then the remote control
unit sets the Time and Sleep functions to Zero (box 518). The unit
will then WAIT for 25 mSec (box 520), sets TIME to TIME+1 (box 522)
and then POLLS the buttons and Switches (box 524). The remote
control unit will then determine IF the buttons or switch have
changed (box 526), if no, the remote control unit then determines
IF the time internal is equal to 4 (or about 100 mSec) (box 528).
If not the remote control unit returns to box 520 to WAIT. If the
buttons or Switch have changed (from box 526) or if TIME is equal
to 4 (from box 528), then the remote control unit transmits a
Packet of data to the receiver (box 530). After transmission, the
remote control unit checks IF All buttons Off then the remote
control unit will set Sleep to Sleep+1, otherwise Sleep is set to
Zero (box 532). If Sleep is greater than 10 (about 1 second) (box
534), then the remote control unit will SLEEP (box 436); otherwise
the remote control unit returns to box 520 and WAITS.
[0126] It is well known that the speed of a DC motor can be
controlled by changing the voltage. Chopping the DC current into
"on" and "off" cycles which have an effective lower voltage is one
manner in reducing or controlling the speed. This method is also
called pulse-width modulation (PWN) and is often controlled by a
processor. Since the skateboard in accordance with the present
invention incorporates an extremely small DC motor (in the range of
4 mm to 8 mm diameter DC motor), the motor has a low inductance of
approximately 140 uH.
[0127] FIGS. 29A thru 29C show the current waveform in the motor at
three different PWM frequencies, 10 kHz, 100 kHz, and 1000 kHz. It
can be seen that a 10 kHz PWM frequency has not achieved continuous
current conduction, which results in current surges that will
adversely affect battery run time. It can be see that 100 kHz
results in an improvement, but 1000 kHz is approximately required
in order to approach acceptable continuous current conduction.
Common low cost processers, which are found in low cost toys and
vehicles, cannot create the desired 1000 kHz PWM frequency.
[0128] In reference to FIGS. 26A-28, in one embodiment of the
present invention there is employed a novel and unique method of
controlling and changing the voltage to extremely small DC motors.
DC-DC switches, often called buck converters, can be used to
achieve PWM frequencies in excess of 1000 kHz. The embodiment
employs a variable output DC-DC switch 600 with the voltage set by
a voltage divider. The output voltage is typically fixed to one
value as defined by the circuits' needs. The voltage divider can be
changed by the use of processor IO pins and multiple resistors R8
and R9, resulting in three output speeds by connecting R8, R9, or
R8+R9 to the voltage divider (as illustrated in FIG. 26A). The
resulting voltage supplied to the H-bridge circuits (referred to
herein as DRVs) 610, which are in communication with the motors and
controlled to direct the direction of the motors at a high
frequency. The result is continuous current conduction to the
motor. A second benefit of this design is the processor is not
required to generate a PWM frequency, simplifying software and
allowing the use of a less expensive processor. In FIG. 26B the
three output speeds are represented by connecting different
resistor values to the R31 resistor value.
[0129] In accordance with an embodiment of the present invention
there is provided a toy vehicle having a low inductance motor
powered by a high frequency switched voltage at a frequency high
enough to create continuous conduction. The vehicle includes an
H-bridge circuit configured to control a direction of the motor and
an adjustable high frequency DC-DC switch configured to convert a
supply voltage to an output voltage, that is lower than the supply
voltage, for use by the H-bridge circuit to power the low
inductance motor in a forward or reverse direction. A processor is
provided with instructions configured to change the output voltage
from the DC-DC switch from a first voltage to a second voltage.
[0130] In different aspect of this embodiment, the motor may have
an inductance of approximately less than 500 uH and more preferably
of about 140 uH. The DC-DC switch may be operating at a frequency
greater than 250 kHz and more preferably at about 1000 kHz or
higher. In addition, the DC-DC switch may be changed digitally.
[0131] In addition, the output voltage from the DC-DC switch may be
selected by a voltage divider, having a first resistor value and a
second resistor value selected by the instructions from the
processor such that the output voltage from the DC-DC switch can
define a first output voltage and a second output voltage. In other
aspect the DC-DC switch can be further configured to define a third
output voltage. The second resistor value may be selected from a
pair of resistors, defined separately to create the first output
voltage and the second output voltage respectively and defined in
series to create the third output voltage. In addition, the
processor further includes instructions to the H-bridge circuit to
only control the direction of the motor.
[0132] As shown in reference to FIG. 27, the processor WAKEs on a
roll in either direction (box 620), the processor SETs OLD PACKET
to 0,0,0,0 (box 622) and then SETs Sleep=0 and NoPacketTime=0 (box
624). The processor then checks to see if the IR Data has Started
(box 626). If no IR Data is received, the processor sets
Sleep=Sleep+1 (box 628), sets NoPacketTime=NoPacketTime+1 (box
630), and If NoPacketTime>200 mSec then the processor Disables
the DC-DC switch and Disables the DRVs (box 632). The processor
then determines if Sleep is greater than 2 minutes (box 634). If
Yes then the processor with Go To Sleep (box 636), if No then the
process returns to box 626 to determine if IR Data is received.
When IR Data is started, the processor Receives the IR Packet (box
638) and Checks to determine IF the Packet is Good (box 640). If
not, the processor returns to box 626. If Yes, the process will set
the Channel to Match if the Packet is the 1.sup.st Packet (box
642). If the Packet is not the 1.sup.st Packet the processor Checks
to ensure the Packet is from the Correct Channel (box 644). If it
is not the correct Channel, the processor determines If
NoPacketTime>200 mSec then the processor Disables the DC-DC
switch and Disables the DRVs (box 646) and then returns to box 626.
If the Channel is correct, the processor Sets Sleep=0 (box 648),
the processor Moves to FIG. 28 (box 650) and then when the
processor returns from FIG. 28, the processor save last Packet
information (box 652) and moves to box 626 to continue.
[0133] In Reference also to FIG. 28, from box 650, the processor
check to see if the Buttons from the Remote Control are Off (box
660), if All the Buttons are Off, the processor Disables the DC-DC
switch and Disables the DRVs (box 662) and then returns to Box 652
(see FIG. 27). If All the Buttons are not Off, then the processor
Enables the DC-DC switch and Enables the DRVs (box 664). The
processor then checks to determine if Any Button moved from 0 to 1
(box 668). If no, the processor sets the Ramp Time=Ramp Time+1 (box
670). The processor then Check to determine if Ramp Time is equal
to 2 (box 672). In this aspect Ramp Time may be equated to the user
holding a button down or holding a slider in a specific position
for a predetermined time. If the Ramp Time is 2 then the processor
Sets the DC-DC switch to change the voltage to either Normal Speed
or Turbo (high) Speed based on the Slider button input on the
remote control (box 674). If the Ramp Time is not 2 (from box 672);
or after the DC-DC switch is set (from box 674) the processor will
Set the DRV directions based on input from the remote control such
that the skateboard is moving Forward, Coasting, Reverse or Turning
(box 680). Going back to box 668, if any Buttons did move from 0 to
1, the processor will Set the DC-DC switch speed to 1 (box 676),
and set the Ramp Time=0 (Box 678). The processor will then Set the
DRV directions based on input from the remote control such that the
skateboard is moving Forward, Coasting, Reverse or Turning (box
680). From box 680 the processor returns to box 652 (FIG. 27).
[0134] In this aspect the DC-DC switch is able to change the speed
of the motor(s) by adjusted voltages by resistor changes to 3
separate speeds, a Start Up Speed, a Normal Speed, and a High
Speed; which as noted herein was extremely difficult to obtain
using convention chop cycles.
[0135] In one embodiment, motors 240 are connected by resistor
means to provide increased back EMF detection by processor 406. A
simplified schematic drawing of an H-bridge 700 is shown in FIG. 30
to illustrate the protective flyback diodes D1, D2, D3, D4 integral
to such an H-bridge 700. In some integrated circuit H-bridge 700
devices commercially available, diodes D1, D2, D3, D4 are present
as the parasitic diode intrinsic to the MOSFET Q1, Q2, Q3, Q4
drivers. In other integrated circuit H-bridge devices, diodes D1,
D2, D3, D4 are explicitly built into the IC to provide faster
reverse recovery performance. Regardless of the specific
implementation of H-bridge 700, the present feature of the
invention requires diodes D1, D2, D3, D4 to be electrically
present.
[0136] During operation, MOSFET Q1, Q2, Q3, Q4 are energized in
various combinations to provide drive to motor 240. During the
period when processor 406 is attempting to detect a back EMF signal
from motor 240, MOSFET Q1, Q2, Q3, Q4 of the simplified schematic
of FIG. 30 are not energized, and so appear as open circuits. In
the non-energized state H-bridge 700, only diodes D1, D2, D3, D4
may conduct electrical current so as to present motor 240 back EMF
across its terminals 702, 704 to generate voltages V1, V2.
[0137] FIG. 31 illustrates the resistive interconnection means of a
feature of the present invention. Resistor R1 is connected between
motor lead 702a of motor 240a and the voltage sense terminal at the
node denoted by voltage V1. Resistor R2 is connected between motor
lead 704a of motor 240a and a lead of resistor R2 at the node
denoted by voltage V2. The remaining lead of resistor R2 at the
node denoted by voltage V3 is connected to motor lead 702b of motor
240b. Motor lead 704b is connected to resistor R3. The remaining
lead of resistor R3 connects to the voltage sense terminal at the
node denoted by voltage V4. Voltage sense terminal V1 and voltage
sense terminal V4 constitute the forward and reverse EMF sense
signals that drive inputs of processor 406 in order to sense and
back EMF voltage from motors 240a, 240b.
[0138] When motors 240a, 240b are being driven by MOSFET Q1, Q2,
Q3, Q4, Q5, Q6, Q7, Q8, in various combinations, resistors R1, R3
prevent damage to processor 406 inputs, while resistor R2 prevents
excessive current from flowing between the nodes labeled voltage V2
and voltage V3. During EMF measurement state periods when processor
406 configures itself to measure sense voltages V1, V4, MOSFET Q1,
Q2, Q3, Q4, Q5, Q6, Q7, Q8 are all off. In this state, the
equivalent circuit is as shown in FIG. 32. It is also assumed, but
not shown in any figure, that the back EMF sense inputs of
processor 406 provide a pull-down resistance that offers a
high-impedance (but finite) current path from the inputs to ground.
Thus, nominally when the motors are not turning, and the processor
is in the EMF measurement state, the voltages V1, V2, V3, V4 are
all near zero volts.
[0139] The feature of the present invention in which the
sensitivity of back EMF detection is enhanced is now described
referring to the simplified equivalent circuit of FIG. 32. In the
case of a toy skateboard embodiment of the present invention where
the player moves the skateboard, motors 240a, 240b are caused to
rotate, thereby generating back EMF signals Vemf. In this case, the
current through resistors R1, R2, R3 would quickly settle to
substantially zero. Thus voltage V2 would be approximately equal to
voltage V3. The back EMF, defined as V1-V2 for motor 240a and V3-V4
for motor 240b, would be substantially equal at a value of
Vemf.
[0140] In the case of the skateboard rolling forward, Vemf is
positive. Thus D7 conducts to hold voltage V4 to a diode drop below
ground (approximately -0.65V). In this case voltages V2, V3 are
approximately Vemf-0.65V. By the means of this invention, the back
EMF of motor 240a adds to voltage V2 to produce a voltage V1 equal
to 2.times.Vemf-0.65V. This enhanced voltage exceeds the input
logic high threshold of processor 406 with approximately half the
rolling velocity required without this feature.
[0141] Similarly, in the case of the skate board rolling backward,
Vemf is negative. Thus D1 conducts to hold voltage V1 to a diode
drop below ground (approximately -0.65V). In this case voltages V2,
V3 are approximately -Vemf-0.65V. By the means of this invention,
the back EMF of motor 240b adds to voltage V3 to produce a voltage
V4 equal to -2.times.Vemf-0.65V. This enhanced voltage exceeds the
input logic high threshold of processor 406 with approximately half
the rolling velocity required without this feature.
[0142] In some embodiments, supply voltage Vm may be produced by an
adjustable regulator that is disabled when processor 406 is in a
sleep state. In this case, the sense voltage that appears on the
nodes demarked by V1 and V4 may be high enough to cause conduction
in diodes D2 and D8 respectively. This conduction, in turn, charges
the capacitance on the supply voltage Vm signal through resistor
R2. Provided the time constant defined by the capacitance of the
power supply and the resistor R2 is sufficiently small, the
embodiment of this feature of the invention continues to provide
enhanced back EMF sensitivity.
[0143] The sensitivity enhancement feature of the present invention
may be extended to electromechanical devices employing three or
more electric motors. This is implemented by cascading additional
H-bridges 700 for each additional electric motor. For example, if a
third electric motor were used, the method of this feature of the
present invention would call for a third motor 240 and H-bridge 700
as shown in FIG. 30 added to the right-hand side of the schematic
of FIG. 31. The node demarked by voltage V4 is connected to the
node demarked V1 in FIG. 30. An additional resistor R4 connects to
the node demarked V2 of FIG. 30 to the input of processor 406. In
this way, the back EMF of three motors would add to create the back
EMF sense signal.
[0144] From the foregoing and as mentioned above, it is observed
that numerous variations and modifications may be effected without
departing from the spirit and scope of the novel concept of the
invention. It is to be understood that no limitation with respect
to the embodiments illustrated herein is intended or should be
inferred. For example, the defined orientation placed at either a
front end or rear end can be easily reversed without deviating from
the scope of the invention. As such, orientation terms such as
front and rear can be used interchangeable to place the wheels and
truck assemblies. It is therefore intended to cover by the appended
claims all such modifications within the scope of the appended
claims.
* * * * *