| United States Patent Application |
20190202506
|
| Kind Code
|
A1
|
|
Kamen; Dean
;   et al.
|
July 4, 2019
|
CONTROL OF A TRANSPORTER BASED ON ATTITUDE
Abstract
A transporter for transporting a load over a surface. The transporter
includes a support platform for supporting the load. The support platform
is characterized by a fore-aft axis, a lateral axis, and an orientation
with respect to the surface, the orientation referred to as an attitude.
At least one ground-contacting element is flexibly coupled to the support
platform in such a manner that the attitude of the support platform is
capable of variation. One or more ground-contacting elements are driven
by a motorized drive arrangement. A sensor module generates a signal
characterizing the attitude of the support platform. Based on the
attitude, a controller commands the motorized drive arrangement.
| Inventors: |
Kamen; Dean; (Bedford, NH)
; Heinzmann; Richard Kurt; (Francestown, NH)
; Ambrogi; Robert R.; (Manchester, NH)
|
| Applicant: | | Name | City | State | Country | Type | DEKA Products Limited Partnership | Manchester | NH | US | | |
| Family ID:
|
30115896
|
| Appl. No.:
|
16/296488
|
| Filed:
|
March 8, 2019 |
Related U.S. Patent Documents
| | | | |
|
| Application Number | Filing Date | Patent Number | |
|---|
| | 15150723 | May 10, 2016 | 10227098 | |
| | 16296488 | | | |
| | 14589116 | Jan 5, 2015 | 9545963 | |
| | 15150723 | | | |
| | 13908587 | Jun 3, 2013 | 8925657 | |
| | 14589116 | | | |
| | 11691903 | Mar 27, 2007 | 8453768 | |
| | 13908587 | | | |
| | 10617598 | Jul 11, 2003 | 7210544 | |
| | 11691903 | | | |
| | 60395589 | Jul 12, 2002 | | |
|
|
| Current U.S. Class: |
1/1 |
| Current CPC Class: |
B62K 11/00 20130101; B60G 2400/82 20130101; B60G 11/14 20130101; B60L 15/20 20130101; B60K 26/02 20130101; Y02T 10/7258 20130101; B60G 2400/05 20130101; B62D 51/001 20130101; B62D 51/002 20130101; B62K 11/007 20161101; Y02T 10/72 20130101; B60G 17/019 20130101; B62D 51/02 20130101 |
| International Class: |
B62D 51/00 20060101 B62D051/00; B60K 26/02 20060101 B60K026/02; B62K 11/00 20060101 B62K011/00; B60G 17/019 20060101 B60G017/019; B60G 11/14 20060101 B60G011/14; B60L 15/20 20060101 B60L015/20; B62D 51/02 20060101 B62D051/02 |
Claims
1. A transporter for transporting a load comprising: a plurality of
support platforms; at least one ground contacting element coupled to the
transporter; a motorized drive arrangement driving the at least one
ground contacting element; and a controller commanding the motorized
drive arrangement to apply a torque to the at least one ground contacting
element based at least on a control algorithm, the control algorithm
responding to least one sensor signal indicative of an attitude of one of
the plurality of support platforms, the control algorithm being
configured in real time.
2. The transporter of claim 1, wherein the control algorithm comprises
being configured based at least on an operating mode, at least one user
preference, and operating conditions.
3. The transporter of claim 1, wherein at least one point on one of the
plurality of support platforms comprises a displaceable point with
respect to a frame used to support the at least one ground contacting
element.
4. The transporter of claim 1, wherein at least one the plurality of
support platforms being tiltable based on a position of a center of mass
of the load relative to the at least one ground contacting element.
5. The transporter of claim 1, wherein the controller further comprises
determining an inclination in the fore-aft plane of one of the plurality
of support platforms.
6. The transporter of claim 1 further comprising: an axle associated with
the at least one ground contacting element, the axle including a parallel
orientation to a lateral axis of the transporter, the at least one of the
plurality of support platforms being tiltable, in a fore-aft plane of the
transporter, with respect to the axle.
7. The transporter of claim 1, wherein the torque comprises positive and
negative values based on changes detected by the at least one sensor
signal.
8. A transporter comprising; a plurality of support platforms; at least
one ground contacting element coupled to the plurality of support
platforms; a motorized drive arrangement for driving the at least one
ground contacting element; at least one sensor generating at least one
sensor signal indicative of an attitude of one of the plurality of
support platforms; and a controller commanding the motorized drive
arrangement to apply a torque to one or more of the at least one ground
contacting elements, the torque being based at least on a control
algorithm, the control algorithm including the at least one sensor
signal, the control algorithm being configured based at least on
preferences of the user.
9. The transporter of claim 8, wherein the at least one ground contacting
element comprises a first ground contacting element and a second ground
contacting element.
10. The transporter of claim 8, further comprising a pivot mechanism
tiltably attaching one of the plurality of support platforms to another
of the plurality of support platforms.
11. The transporter of claim 8, wherein at least one of the plurality of
support platforms tilting in a fore-aft plane relative to at least a
portion of the transporter.
12. The transporter of claim 11, wherein the fore-aft plane comprises an
orientation perpendicular to an axis of the at least one ground
contacting element.
13. The transporter of claim 8, wherein one of the plurality of support
platforms tilting relative to another of the plurality of support
platforms.
14. The transporter of claim 8, wherein the at least one sensor signal
sensing a tilt difference between one of the plurality of support
platforms and another of the plurality of support platforms.
15. The transporter of claim 8, wherein the at least one ground
contacting element comprises a first ground contacting element and a
second ground contacting element, the first ground contacting element and
second ground contacting element being laterally disposed.
16. The transporter of claim 15, wherein the motorized drive arrangement
comprises a first motor driving the first ground contacting element and a
second motor driving the second ground contacting element.
17. The transporter of claim 16, wherein the controller including
determining, based at least in part on the at least one sensor signal, a
desired first torque for the first motor separately from a desired second
torque for the second motor.
18. The transporter of claim 17, wherein the desired first torque and the
desired second torque comprise positive and negative values based on
changes detected by the at least one sensor signal.
19. The transporter of claim 8, wherein the first ground contacting
element and the second ground contacting element comprise wheels, the
wheels rotating about a first wheel axle and a second wheel axle, at
least one of the at least one sensor signals indicating a location of a
fiducial point on the transporter, the fiducial point being in relation
to at least one of the first wheel axle and the second wheel axle.
20. The transporter of claim 8, wherein the control algorithm including
being configured based at least on current operating mode and operation
conditions.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No.
15/150,723 filed May 10, 2016, which is a divisional of U.S. application
Ser. No. 14/589,116 filed Jan. 5, 2015, now U.S. Pat. No. 9,545,963,
which is a continuation of U.S. application Ser. No. 13/908,587 filed
Jun. 3, 2013, now U.S. Pat. No. 8,925,657, which is a continuation of
U.S. application Ser. No. 11/691,903 filed Mar. 27, 2007, now U.S. Pat.
No. 8,453,768, which is a continuation of U.S. application Ser. No.
10/617,598, filed Jul. 11, 2003, now U.S. Pat. No. 7,210,544, which
claims priority from U.S. provisional patent application Ser. No.
60/395,589, filed Jul. 12, 2002, each of which is hereby incorporated by
reference herein in its entirety.
TECHNICAL FIELD
[0002] The present invention pertains to transporters and methods for
transporting a load, which may be a living subject, and more particularly
to controlling motion of a transporter.
BACKGROUND ART
[0003] A wide range of vehicles having a motorized drive arrangement are
known for conveying various subjects, either for purposive locomotion or
for recreational purposes.
[0004] The means used to command the motorized drive arrangement of these
vehicles varies greatly. For example, an operator may manipulate an
accelerator pedal to control forward motion of an automobile, while
steering is typically performed using a steering wheel. Or the motion of
a sporting vehicle may be controlled by rocking a foot board upon which a
user is balanced towards the front or rear to mechanically move a
throttle cable, as described in U.S. Pat. No. 4,790,548 (Francken). Based
on the operator's physical attributes for example, or the transporter's
intended functionality, alternative methods for controlling motion of a
transporter may be desirable.
SUMMARY OF THE INVENTION
[0005] In a first embodiment of the invention there is provided a
transporter for transporting a load over a surface. The transporter
includes a support platform for supporting the load. The support platform
is characterized by a fore-aft axis, a lateral axis, and an orientation
with respect to the surface, the orientation referred to as an attitude.
At least one ground-contacting element, which is driven by a motorized
drive arrangement, is coupled to the support platform in such a manner
that the attitude of the support platform is capable of variation. A
sensor module generates a signal characterizing the attitude of the
support platform. Based on the attitude, a controller commands the
motorized drive arrangement.
[0006] In accordance with related embodiments of the invention, one or
more ground-contacting elements may be flexibly coupled to the support
platform in such a manner that the attitude of the support platform is
capable of variation based on a position of a center of mass of the load
relative to the at least one ground-contacting element. The sensor module
may include at least one distance sensor for measuring a distance
characteristic of the attitude of the platform. The distance sensor may
be selected from the group of distance sensors consisting of an
ultrasonic distance sensor, an acoustic distance sensor, a radar distance
sensor, optical distance sensor, and a contact sensor, such as a
whisker(s). The at least one distance sensor may sense the distance
between a fiducial point on the platform and a position on the surface
disposed at a specified angle with respect to the support platform. In
other embodiments, the transporter may include a first component that
remains in a substantially fixed vertical position relative to the
surface, wherein the at least one distance sensor senses the distance
between a fiducial point on the platform and the first component. One or
more ground contacting elements may include a wheel having an axle, and
the first component is fixed relative to the axle. Alternatively, and not
meant to be limiting, one or more ground contacting elements may include
a wheel supported by a frame, and the first component is fixed relative
to the frame.
[0007] In accordance with other related embodiments of the invention, the
attitude of the support platform is capable of variation based at least
on a signal generated by a remote control device. The transporter may
include a powered strut coupled to the platform, the powered strut
capable of varying the attitude of the support platform based at least on
the signal generated by the remote control device. The transporter may
further include a user interface, wherein the attitude of the support
platform is capable of variation based on a signal generated by the user
interface. The controller may command motion of the transporter in the
fore-aft plane and/or the lateral plane.
[0008] In accordance with another embodiment of the invention, a method
for controlling a transporter having a support platform for supporting a
load is presented. The support platform is characterized by an attitude
with respect to the surface. The transporter includes at least one ground
contacting elements flexibly coupled to the support platform in such a
manner that the attitude of the platform is capable of variation. The
transporter also includes a motorized drive arrangement for driving the
at least one ground contacting elements. The method includes generating a
signal characterizing an attitude of the support platform. The motorized
drive arrangement is commanded based at least on the attitude.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The foregoing features of the invention will be more readily
understood by reference to the following detailed description, taken with
reference to the accompanying drawings, in which:
[0010] FIG. 1 depicts one embodiment of a human transporter, lacking a
distinct user input device, to which the present invention may
advantageously be applied;
[0011] FIG. 2 is a side view of a transporter, in accordance with one
embodiment of the invention;
[0012] FIG. 3 is an expanded side view of a transporter, in accordance
with one embodiment of the invention;
[0013] FIG. 4 is a side view of a transporter, in accordance with one
embodiment of the invention; and
[0014] FIG. 5 is a block diagram of a controller of a transporter, in
accordance with one embodiment of the invention.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
[0015] In accordance with one embodiment of the invention, FIG. 1 shows a
transporter, 1 lacking a distinct input device, to which the present
invention may advantageously be applied. Transporter 1 is described in
detail in U.S. Pat. No. 6,302,230, which is incorporated herein by
reference in its entirety. Transporter 1 includes a support platform 11
for supporting a load, which may be a living subject 9, over the ground
or other surface, such as a floor, which may be referred to herein
generally as "ground". A subject, for example, may stand or sit on
support platform 11. Attached to support platform 11 may be a handlebar
12 that can be gripped when riding transporter 1.
[0016] One or more ground-contacting elements 2, 7 provide contact between
support platform 11 and the ground. Ground-contacting elements 2, 7 may
include, but are not limited to, arcuate members, tracks, treads, and
wheels (hereinafter the term "wheel" will be used in the specification to
refer to any such ground-contacting element without limitation). While
the transporter 1 depicted in FIG. 1 lacks stability in its operating
position unless subject to controlled balancing, the application of the
present invention is specifically not limited to transporters of that
sort and embodiments of the present invention may advantageously be
applied to statically stable transporters as well.
[0017] Support platform 11 may be flexibly coupled to the wheels 2, 7 by
various means known in the art, for example, a pivot mechanism, springs,
or pneumatic pistons. In other embodiments, the wheels 2, 7 may have some
compliance and serve the function of a spring. For purposes of the
present description, platform 11 may be characterized by a fore-aft axis,
a lateral axis, and an orientation with respect to the surface, which is
referred to herein as an attitude. The fore-aft axis, X-X, is
perpendicular to the wheel axis, while the lateral axis, Y-Y, is parallel
to the axis of the wheels. Directions parallel to the axes X-X and Y-Y
are called the fore-aft and lateral directions respectively.
[0018] Referring now to FIG. 2, which shows a transporter 10 in accordance
with one embodiment of the invention, the attitude of support platform 11
may, for example, be capable of variation based on a position of a center
of mass of the load relative to one or more wheels 13, 14. Alternatively,
transporter 10 may include a power strut or other mechanism capable of
altering the attitude of the support platform 11. The power strut may be
controlled by a user interface located on transporter 10, such as a
joystick or a rotatable potentiometer located on handlebar 12. In other
embodiments, the power strut may also be controlled by a remote control
device, such as, but not limited to, an infrared or radio controlled
remote control device.
[0019] The motion of transporter 10 is based, at least in part, on the
attitude of the support platform 11. To determine the attitude of the
support platform 11, transporter 10 includes a sensor module. Sensor
module may include at least one distance sensor 17, 18 for measuring a
distance characteristic of the attitude of the support platform 11. The
distance measured may be, for example, the distance between a fiducial
point on the support platform 11 and a surface 19, or alternatively,
another component on transporter 10. A plurality of distances measured by
the sensor module may be combined to generate at least one signal
characteristic of the platform attitude.
[0020] Attitude/distance sensor may be one of many sensor types, such as,
for example, an ultrasonic, optical, acoustic or radar sensor wherein a
signal generated by a source is reflected back by a surface to a sensor
receiver. The distance from the sensor to the surface can then be
calculated based on the time (or phase) difference between when the
signal was generated and when the reflected signal was received.
Triangulation may be performed. In other embodiments, distance sensor can
be a contact sensor(s) such as, without limitation, a whisker(s). For
example, a plurality of whiskers, each having a predetermined length may
be utilized, with distance determined based on which whisker bends or is
otherwise activated when making contact with the surface. A single
whisker may be utilized with distance determined based, at least on part,
on the bending angle of the whisker.
[0021] Referring to FIG. 2, distance sensors 17, 18 sense the distance
between a fiducial point on the platform and a position on the surface
that is disposed at a specified angle 3, 4, with respect to the support
platform. First distance sensor 17 is located at the front (fore) of
platform 11 and senses a first distance 5 between platform 11 and surface
19.
[0022] Second distance sensor 17 is located at the back (aft) of platform
11 and senses a second distance 6 between platform 11 and surface 19. By
comparing distances 5 and 6, a signal indicative of an attitude of the
platform 11, and more specifically, the inclination of the platform 11 in
the fore-aft plane with respect to the surface 19, can be determined.
[0023] In another embodiment, at least one distance sensor 22 may sense
the distance between a fiducial point on the transporter platform 11 and
a first component 23 that remains in a substantially fixed vertical
position relative to the surface 19, as shown in the expanded view of a
transporter in FIG. 3. First component 23 may be, for example, a wheel
axle 23 or a frame used to support the at least one wheel 14. In various
embodiments, first component 23 may include a reflector for reflecting
the signal generated by distance sensor 22.
[0024] FIG. 4 shows a transporter 60 that includes a first support
platform 69 and a second support platform 61, in accordance with one
embodiment of the invention. At least one wheel 63 and 64 provides
contact between the first support platform 69 and the ground. Second
support platform 61 is coupled to the first support platform 69 such that
the second support platform 61 can tilt in the fore-aft plane based, for
example, on a position of a center of mass of the loaded second support
platform 61. Second support platform 61 may be tiltably attached to the
first support platform 69 using, without limitation, springs 65 and 66
and/or a pivot mechanism 68. Similar to above-described embodiments,
based on the tilting of the second support platform 61, at least one
sensor 67 and 70 generates a signal indicative of the attitude of the
second support platform 61. Attached to the first support platform 69 or
second support platform 61 may be a handlebar 62 that can be gripped
while operating the transporter 60.
[0025] A controller receives the signal characteristic of the attitude
from the sensor module. Based at least on this signal, the controller
implements a control algorithm to command a motorized drive arrangement
so as to drive the at least one wheel. The controller may also respond to
commands from other operator interfaces, such as a joystick or dial
attached, for example, to handlebar.
[0026] FIG. 5 shows a controller 30 for controlling the motorized drive of
the transporter, in accordance with one embodiment of the invention.
Controller 30 receives an input characteristic of platform attitude from
sensor module 34. Based at least on the input from the sensor module,
controller 30 commands at least one motorized drive 35, 36. Controller 30
also interfaces with a user interface 31 and a wheel rotation sensor 33.
[0027] User interface 31 may include, among other things, controls for
turning the controller 30 on or off. When the controller 30 is turned
off, the at least one wheel of the transporter may be free to move, such
that the transporter acts as a typical push scooter. User interface 31
may also control a locking mechanism 32 for locking the at least one
wheel.
[0028] The controller 30 includes a control algorithm to determine the
amount of torque to be applied to the at least one wheel based on the
sensed attitude of the support platform. The control algorithm may be
configured either in design of the system or in real time, on the basis
of current operating mode and operating conditions as well as preferences
of the user. Controller may implement the control algorithm by using a
control loop. The operation of control loops is well known in the art of
electromechanical engineering and is outlined, for example, in Fraser &
Milne, Electro-Mechanical Engineering, IEEE Press (1994), particularly in
Chapter 11, "Principles of Continuous Control" which is incorporated
herein by reference.
[0029] As an example, and not meant to be limiting, the control algorithm
may take the form:
Torque Command to Wheel=K[.theta.+.largecircle.] [0030] where K=gain
[0031] .theta.=support platform attitude, and [0032]
.largecircle.=offset.
[0033] The support platform attitude, .theta., may be in the form of an
error term defined as the desired support platform attitude minus the
measured support platform attitude. The gain, K, may be a predetermined
constant, or may be entered/adjusted by the operator through user
interface 31. Responsiveness of the transporter to attitude changes can
be governed by K. For example, if K is increased, a rider will perceive a
stiffer response in that a small change in platform attitude will result
in a large torque command. Offset, .largecircle., may be incorporated
into the control algorithm to govern the torque applied to the motorized
drive, either in addition to, or separate from, the direct effect of
.theta.. Thus, for example, the user may provide an input by means of a
user interface of any sort, the input being treated by the control system
equivalently to a change, for example, in platform attitude.
[0034] Thus, referring back to FIG. 2, motion of the transporter 10 may be
controlled by a subject changing the attitude of the platform 11. This
change in attitude is reflected by distances 5, 6 sensed by the sensor
module. Depending on the control algorithm, an initial change in
attitude, such that first distance 5 is less than second distance 6, may
result in positive torque being applied to one or more wheels 23, 24,
causing the wheels 23, 24 to move forward. Likewise, an initial change in
the attitude, such that first distance 5 is greater than second distance
6 may result in a negative torque applied to one or more wheels 23, 24,
causing the wheels 23, 24 to move in the aft direction. If the subject
then remains in his changed position on the platform such that the
platform attitude remains the same, the motor will continue to torque at
approximately the same rate.
[0035] In various embodiments of the invention, the sensor module may
sense changes in platform attitude in addition to, or instead of
inclination of support platform in the fore-aft plane. For example,
sensor module may provide an attitude signal indicative of inclination of
the support platform in the lateral plane relative to the surface. This
may be accomplished by the use of two laterally disposed distance
sensors. Changes in the angle of inclination of the support platform in
the lateral plane can then be used either separately or in combination
with other attitude changes to control motion of the transporter. For
example, changes in the angle of inclination in the fore-aft plane can be
used to control fore-aft motion, while changes in the angle of
inclination in the lateral plane can be used to control steering of the
transporter.
[0036] Steering may be accomplished in an embodiment having at least two
laterally disposed wheels (i.e., a left and right wheel), by providing
separate motors for left and right wheels. Torque desired for the left
motor and the torque desired for the right motor can be calculated
separately. Additionally, tracking both the left wheel motion and the
right wheel motion permits adjustments to be made, as known to persons of
ordinary skill in the control arts, to prevent unwanted turning of the
vehicle and to account for performance variations between the two motors.
[0037] The described embodiments of the invention are intended to be
merely exemplary and numerous variations and modifications will be
apparent to those skilled in the art. All such variations and
modifications are intended to be within the scope of the present
invention as defined in the appended claims.
* * * * *