U.S. patent application number 11/235990 was filed with the patent office on 2007-06-21 for computerized method and system for fitting a bicycle to a cyclist.
This patent application is currently assigned to Crucial Innovation, Inc.. Invention is credited to Douglas Ogden, Clifford Simms.
Application Number | 20070142177 11/235990 |
Document ID | / |
Family ID | 38174385 |
Filed Date | 2007-06-21 |
United States Patent
Application |
20070142177 |
Kind Code |
A1 |
Simms; Clifford ; et
al. |
June 21, 2007 |
Computerized method and system for fitting a bicycle to a
cyclist
Abstract
This invention is an apparatus for quantitatively measuring the
fit of an individual to one or more bicycles or other such
human-powered conveyances. The apparatus comprises at least a
three-dimensional marker tracking system, a software-based data
analysis and presentation computer system, and (if necessary) a
means of supporting a bicycle in a stationary location such that
the individual being fit can pedal their bicycle in a normal yet
stationary manner. In advanced embodiments, the system includes a
means of simulating a bicycle, and perhaps even a means of altering
the position of the bicycle components to perform a bicycle fit in
a fully automated way.
Inventors: |
Simms; Clifford; (Boulder,
CO) ; Ogden; Douglas; (Lyons, CO) |
Correspondence
Address: |
WALDEAN A. SCHULZ
1919 FOURTEENTH STREET
SUITE 500
BOULDER
CO
80302
US
|
Assignee: |
Crucial Innovation, Inc.
Boulder
CO
|
Family ID: |
38174385 |
Appl. No.: |
11/235990 |
Filed: |
September 26, 2005 |
Current U.S.
Class: |
482/8 |
Current CPC
Class: |
A61B 5/0816 20130101;
A63B 69/16 20130101; A61B 5/145 20130101; A61B 5/1127 20130101;
A63B 2069/164 20130101; A61B 5/1114 20130101; A61B 5/024
20130101 |
Class at
Publication: |
482/008 |
International
Class: |
A63B 71/00 20060101
A63B071/00 |
Claims
1. A system for quantitatively evaluating the ergonomic fit between
a person and a person-propelled conveyance comprising a coordinate
system; a plurality of detectible markers affixed to the person; a
marker tracking subsystem which is situated so to detect each
marker at least 50% of the time, which measures the locations of
the markers relative to the coordinate system, and which can
measure the locations for at least one complete cycle of the motion
that propels the conveyance; a digital computer and software;
wherein the software is adapted to configure and control operation
of the tracking subsystem; the software is adapted to acquire,
measure, and record the locations of the markers automatically; the
software is adapted to determine statistics about the locations of
the markers, the distances between specified pairs of markers, and
the angular relationships among specified trios of markers; the
software is adapted to recommend a specific alteration to the
conveyance to optimize a physiological goal of the person based on
the acquired statistics; and the software is adapted to generate a
report of such recorded measurements and recommendations.
2. The system of claim 1, wherein the conveyance is a bicycle.
3. The system of claim 1, wherein the conveyance is a bicycle
simulator.
4. The system of claim 1, wherein the markers are actively
illuminated light emitting diodes (LEDs).
5. The system of claim 1, wherein the markers are powered and
flashed through a wiring harness attached to the person.
6. The system of claim 5, wherein the harness is attached to the
person using quickly attached fasteners.
7. The system of claim 1, wherein the markers are battery powered
and are activated wirelessly.
8. The system of claim 1, wherein the markers are passive
retro-reflectors illuminated by at least one light source directed
at the markers.
9. The system of claim 1, wherein the markers have a known,
optically distinguishable pattern and color.
10. The system of claim 1, wherein at least one marker is also
affixed to the conveyance.
11. The system of claim 1, wherein the markers are placed at
several specific, well-defined anatomical locations on at least one
side of the person's body.
12. The system of claim 11, wherein at least one such marker
location is on the spine.
13. The system of claim 1, wherein the tracking subsystem is an
optical tracking system.
14. The system of claim 1, wherein the physiological goal to be
optimized is the comfort of the person.
15. The system of claim 1, wherein the physiological goal to be
optimized is the long-term endurance of the person.
16. The system of claim 1, wherein the physiological goal to be
optimized is the power output efficiency of the person.
17. The system of claim 1, wherein the alteration includes
replacement of the current conveyance with a specific
recommendation chosen from a database of models, styles and sizes
of commercially available conveyances.
18. The system of claim 1, wherein the alteration is a recommended
geometry for a custom design for a conveyance tailored for the
person.
19. The system of claim 1, wherein the alteration suggests optimal
sizes and positions for changeable components which includes as
least handlebars, handlebar stems, seats, crank arms, shoe wedges,
and spacers.
20. The system of claim 1, wherein the recommended alterations are
based on an historical database of successful fitting sessions.
21. The system of claim 1, wherein the recommended alterations are
based on the experience of experts.
22. The system of claim 1, wherein the software is further adapted
to display the locations of the markers on the monitor screen of
the computer in substantially real time.
23. The system of claim 1, wherein the software is further adapted
to display cumulative paths of the markers on the monitor screen of
the computer for at least one cycle of motion.
24. The system of claim 1, wherein the measurements include at
least some non-empty subset of the following measurements: the mean
and extreme vertical, lateral, and forward location coordinates of
specific markers; the mean motion range of specific markers;
centroid of each marker's motion; the maximum, minimum, and mean
angles formed among specific markers; and the minimum, maximum, and
mean distances between specific pairs of markers.
25. The system of claim 1, wherein the original data and analysis
can be stored and later retrieved for the person.
26. The system of claim 1, wherein the computer system measures
velocities and accelerations of motion.
27. The system of claim 1, wherein the computer controls the
resistance of the conveyance to the motion of the person.
28. The system of claim 1, wherein the computer measures and
records power output from the person through the conveyance.
29. The system of claim 1, wherein the system senses at least one
physiological measurement of the person to estimate user effort and
uses the estimate to rate the benefit of the current configuration
of the conveyance.
30. The system of claim 29, wherein the physiological measurement
of the person is heart rate.
31. The system of claim 29, wherein the physiological measurement
of the person is respiration rate.
32. The system of claim 29, wherein the physiological measurement
of the person is blood oxygen level.
33. The system of claim 1, wherein the computer can measure the
posture of the person conveyance to determine an optimal posture
for riding the conveyance based on the person's desired riding
style and goals.
34. The system of claim 1, wherein the system additionally
comprises a real-time video camera to record the measurement
session.
35. The system of claim 1, wherein the analysis for a given person
can be used to compare the quality of fit between a person and each
of at least two different instances of a conveyance.
36. The system of claim 1, which additionally comprises at least
one mechanical actuator to automatically perform a recommended
alteration under control of the computer hardware and software.
37. A system for quantitatively evaluating the ergonomic fit
between a person and a bicycle, wherein the system comprises a
coordinate system a purality of detectible markers affixed to the
person a marker tracking subsystem which is situated so to detect
each marker at least 50% of the time, which measures the locations
of the markers relative to the coordinate system, and which can do
so at least for one complete cycle of the pedals; and a digital
computer system and software; wherein the system is adapted to
configure and control operation of the tracking subsystem; to
acquire and record the locations of the markers automatically; to
determine statistics about the locations of the markers over time;
to compute the distances between specified pairs of markers at
specified times; to compute the angular relationships among
specified trios of markers at specified times; to recommend a
specific alteration to the bicycle configuration to optimize a
specified physiological goal of the person; to generate a report of
the recorded locations and computed values; and to recommend an
alteration to the bicycle configuration.
38. The system of claim 37, wherein the bicycle is a bicycle
simulator with an adjustable frame.
39. The system of claim 38, wherein the adjustable frame can be
adjusted automatically by the computer software in accordance with
the recommended alteration.
40. The system of claim 39, which additionally comprises at least
one mechanical actuator to automate a recommended alteration under
control of the computer hardware and software.
41. The system of claim 37, wherein the markers are actively
illuminated light emitting diodes (LEDs).
42. The system of claim 37, wherein the markers are powered and
flashed through a wiring harness attached to the person.
43. The system of claim 42, wherein the harness is attached to the
person using quickly attached fasteners.
44. The system of claim 37, wherein the markers are battery powered
and are activated wirelessly.
45. The system of claim 37, wherein the markers are passive
reflectors illuminated by at least one light source directed at the
markers.
46. The system of claim 37, wherein the markers have a known,
optically distinguishable pattern and color.
47. The system of claim 37, wherein at least one marker is also
affixed to the bicycle.
48. The system of claim 37, wherein the markers are placed at
several specific, well-defined anatomical locations on at least one
side of the person's body.
49. The system of claim 48, wherein one such location is on the
foot and closest to the axis of a pedal.
50. The system of claim 48, wherein one such location is the lower
lateral prominence of the fibula bone (the ankle).
51. The system of claim 48, wherein one such location is the upper
lateral prominence of the fibula bone.
52. The system of claim 48, wherein one such location is the
lateral prominence on the hip (crest of the ilium).
53. The system of claim 48, wherein one such location is on one arm
at the upper lateral prominence of the humorous bone.
54. The system of claim 48, wherein one such location is one wrist
at the prominence of the radius bone.
55. The system of claim 37, wherein the tracking subsystem is an
optical tracking system.
56. The system of claim 37, wherein the physiological goal to be
optimized is the comfort of the person.
57. The system of claim 37, wherein the physiological goal to be
optimized is the long-term endurance of the person.
58. The system of claim 37, wherein the physiological goal to be
optimized is the power output efficiency of the person.
59. The system of claim 37, wherein the alteration includes
replacement of the whole bicycle with a different bicycle chosen
from a database of models.
60. The system of claim 37, wherein the alteration is an improved
custom design geometry for the bicycle.
61. The system of claim 37, wherein the alteration suggests an
optimal size for at least one changeable component.
62. The system of claim 61, wherein the changeable components
include handlebars, handlebar stems, seats, crank arms, and
spacers.
63. The system of claim 37, wherein the recommended alterations are
based on an historical database of successful fits.
64. The system of claim 37, wherein the recommended alterations are
based on the advice and experience of experts.
65. The system of claim 37, wherein the software is further adapted
to display the locations of the markers on the monitor screen of
the computer in substantially real time.
66. The system of claim 37, wherein the software is further adapted
to display cumulative paths of the markers on the monitor screen of
the computer for at least one cycle of motion.
67. The system of claim 37, wherein the measurements include some
subset of the following measurements: extrema of vertical, lateral,
and forward locations for specific markers; mean motion range of
specific markers; centroid of each marker's motion; maximum,
minimum, and mean angles formed among specific markers; and
minimum, maximum, and mean distances between specific pairs of
marker.
68. The system of claim 37, wherein the original data can be stored
and later retrieved for the person.
69. The system of claim 37, wherein the computer system measures
velocities and accelerations of motion.
70. The system of claim 37, wherein the computer controls
resistance of the bicycle to the motion of the person.
71. The system of claim 37, wherein the computer measures and
records power output from the person through the bicycle.
72. The system of claim 37, wherein the computer measures a
physiological characteristic of the person as an estimate of effort
and uses the estimate to rate the quality of the current
configuration of the conveyance with respect to the goal of the
person.
73. The system of claim 72, wherein the physiological
characteristic of the person is heart rate.
74. The system of claim 72, wherein the physiological
characteristic of the person is respiration rate.
75. The system of claim 72, wherein the physiological
characteristic of the person is blood oxygen level.
76. The system of claim 37, wherein the system additionally
comprises a real-time video camera to record the measurement
session.
77. The system of claim 37, wherein the reported measurements can
be used to recommend the proper bicycle size and accessory sizes
for the person.
78. The system of claim 37, wherein the reported measurements can
be used to design and dimension a customized bicycle.
79. The system of claim 37, wherein the system can be used for
constructing a customized version of the bicycle.
80. The system of claim 37, wherein the system can be used to
compare the quality of fit between a person and each of two or more
bicycles.
81. The system of claim 37, wherein the system can be used to
adjust one bicycle so that the fit between the person and the
bicycle duplicates the fit between the person and another
bicycle.
82. A method of quantitatively evaluating the ergonomic fit between
a person and human-powered vehicle comprising steps of attaching
detectable markers to the person; establishing a coordinate space
to which the marker locations are relative; acquiring details and
characteristics about the person and the vehicle; directing the
person to begin powering the vehicle; acquiring discrete times and
locations of the markers for a period of time to acquire at least
one cycle of the person's motion in powering the vehicle; fitting
continuous trajectories to the set of discrete locations for at
least one marker; computing statistical information about each
marker's acquired locations; computing the distance between at
least one specified pair of marker locations; computing at least
one angle formed by a specified trio of marker locations;
displaying at least some of the above acquired and computed data on
a computer screen; recording at least some of the above acquired
and computed data for later use; determining whether the computed
data is satisfactory according to the desired goals of the person;
if the last data is satisfactory, saving the acquired data and
vehicle configuration; if the last data is unsatisfactory,
recommending at least one vehicle-specific adaptation; if there is
at least one unimplemented recommended adaptation, adjusting the
vehicle configuration according to the adaptation; and then
repeating at least some of the above steps with the adaptation
applied to configuration.
83. The system of claim 82, wherein the markers are attached to one
side of the person.
84. The system of claim 82, wherein the markers are attached to two
sides of the person.
85. The system of claim 82, wherein the some markers are also
attached to the vehicle.
86. The system of claim 82, wherein the markers attached to the
vehicle define a vehicle-relative coordinate system.
87. The system of claim 82, wherein the vehicle is held stationary
but otherwise simulates normal operation.
88. The system of claim 82, further comprising the step of
transforming the time and spatial coordinates to a more convenient
coordinate system.
89. The system of claim 82, further comprising the step of
overlaying at least some of the above data onto a stylized
graphical depiction of the person and vehicle.
90. The system of claim 82, further comprising the step of matching
and comparing the trajectory of at least one marker to the
best-fitting trajectory of a set of ideal, standardized
trajectories.
91. The system of claim 82, further comprising the step of printing
at least some of the above acquired and computed data for a
permanent record.
92. The system of claim 82, further comprising the step of
computing the cadence of the human's motions relative to time.
93. The system of claim 82, further comprising the step of
repeating the above for the other side of the person as
necessary;
94. The system of claim 82, further comprising the step of
comparing the corresponding acquired data from both sides of the
person, if available.
95. The system of claim 82, further comprising the step of
recommending adaptations to optimize the comfort of the person.
96. The system of claim 82, further comprising the step of
recommending adaptations to optimize the endurance of the
person.
97. The system of claim 82, further comprising the step of
recommending adaptations to optimize the power output performance
of the person.
98. The system of claim 82, further comprising the step of
measuring a physiological characteristic of the person to estimate
the effort expended by the person in powering the vehicle.
Description
FIELD OF INVENTION
[0001] This invention relates to an automated way of customizing
and optimizing the fit of a bicycle (or other human powered
conveyance) to a particular person.
BACKGROUND
[0002] Historically, most individuals who purchase a bicycle were
steered toward a bicycle frame that appeared to be a good fit for
their height and stature. Over time, many bicycle shop employees
have become experienced at approximating what frame size will be a
reasonable match. A bicycle can be chosen from off-the-shelf sizes
that range from 13-26 inches. This is a measurement of the distance
from the center of the pedal crank bearing (bottom bracket) at the
bottom of the bicycle to top of the top tube that connects the
saddle to the handlebars. Once a bicycle was chosen, the only
refinements to the selected bike were typically limited to minor
adjustments made to the height of the saddle.
[0003] More recently, two options for bicycle fitting have become
available. The first of these is a fully manual technique, which
measures basic body dimensions, including inseam and arm length.
These dimensions are usually taken using a tape measure, and then
these dimensions, along with subjective knowledge of the art of
bicycle fitting, translate into either a selected frame size,
adjustments to the components on the frame, or both. This approach
is a static fit, and yields an approximate adaptation of the body
size to the bicycle. What follows typically is a brief test ride by
the buyer, who very subjectively evaluates the quality of the fit
(generally without any knowledge of what constitutes a good
fit).
[0004] The second, more recent, option involves performing a
dynamic bicycle fit and uses an optical tracking system and a
computer. This analysis utilizes either a bicycle that the cyclist
already owns, one that the cyclist may purchase if the fit is
successful, or a "bicycle simulator" with an adjustable frame. In
the case of a traditional bicycle, the rear wheel is held off the
ground with a mechanical stand that permits pedaling of the bicycle
at a stationary location. (The stand may also include a separate
power output sensor and indicator.) This test is dynamic, with the
cyclist pedaling the bicycle while the cyclist is videotaped from
various angles. The computer may convert the optical information
into a stick figure. The information in such graphical pictures is
analyzed by the system operator for the quality of the fit to the
individual or for adjustments to components on the bicycle or the
cyclist. Automated analysis by the computer may include certain
generic, automated distance and angle measurements. Such a system
is described in Andy Pruitt's Medical Guide for Cyclists (available
on the Internet as an e-book from www.roadbikerider.com). It
employs a Motus marker tracking system (www.peakperform.com, Vicor
Peak, Colorado Springs, Colo.), which is a generic motion tracking
system, not specifically designed for bicycle fitting.
[0005] Andy Pruitt, a leading expert in the field, explains in his
aforementioned book why dynamic fitting is preferable. However, his
methods and his system require experiential intuition and are at
best only partly quantitative and automated. The optical tracking
system is generic and not specific to bicycle fitting. What is
lacking is a system (a) which is more quantitative and automated,
(b) which is specific to bicycle fitting, (c) which leverages a
computerized quantitative database of experience, and (d) which is
easy for a less qualified bicycle shop employee or racing team
mechanic to use.
BRIEF SUMMARY OF THE INVENTION
[0006] The purpose of the present invention is to perform a
semi-automated, low cost, high accuracy bicycle fit for an
individual. One objective of the invention is to determine the
proper bicycle frame size and geometry for the individual who is
purchasing a new bicycle, possibly from a database of geometries of
available models. A second objective of the invention is to
determine how to adjust a bicycle so that the bicycle-to-cyclist
interface is optimized. A third objective of the system is to
determine which components on a bicycle could be changed so that
the bicycle-to-cyclist interface is optimized. A fourth objective
of the system is to determine which components should be added to
the bicycle or the cyclist, or deleted from the bicycle or the
cyclist, so that the bicycle-to-cyclist interface is optimized.
This optimization can be directed at riding comfort, riding
endurance, riding performance, or some other target criterion.
[0007] The invention is a system that performs precision
measurements of body motions while a rider (cyclist) pedals a
bicycle, potentially with realistic resistance, which itself might
be used to quantify power output. The invention tracks the
repetitive motions of pedaling a bicycle, and provides both visual
outputs and quantitative measurements of the repetitive motions,
which are then analyzed for correctable variations or anomalies in
the movements. The analysis is dynamic, integrated, and
synchronized.
[0008] In use, the invention is operated by "harnessing" the
individual to be fitted. This process consists of attaching
sensible markers--such as light emitting diodes (LED's)--to the
individual's foot, ankle, knee, hip, shoulder, and wrist or other
such locations. These markers are attached by means of a double
sided adhesive pad, Velcro.RTM. straps, elastic straps, or similar
fasteners. The markers are attached such that they can be viewed
from the left or right side of the individual or both. A marker
location tracking system (optical tracker) capable of detecting the
moment-by-moment 3-dimensional locations of the markers (as well as
the times of their acquisition) is positioned in proximity to the
stationary bicycle, such as to one side. The individual is then
asked to pedal the stationary bicycle while the tracker captures
data. The test is then repeated on the other side of the
individual's body. Alternatively, if the system employs a more
sophisticated tracker (or multiple trackers), the data from more
than one viewpoint (sides or front) could be acquired
simultaneously.
[0009] A preferred method of use of the present invention gathers
dynamic data to determine the optimum size of an "in-stock" bicycle
for an individual purchasing a new bicycle. For this use of the
invention, manual adjustments could be made to a commercially
available bicycle between repeated sessions using the present
invention. For example, the height, angle, and setback (fore-aft)
position of the saddle are typical adjustments. Similarly, the
height and angle of the handlebar may be adjustable. In addition,
after-market components could be evaluated based on their proper
fit to the cyclist being fitted. Such components include, but are
not limited to, handlebar, saddle, pedals, and shoes. For example,
the handlebar can be positioned forward or upward by replacing the
handlebar stem with a longer one. Additionally, the angle of the
handlebar within the stem can be adjusted. Similarly, the crank
arms of the pedals may be replaced to change their length as
necessary, or spacers or wedges may be added to the pedals or
shoes.
[0010] In another preferred method of use of the invention, the
data gathered by the system is used to determine the dimensions for
a custom frame to be manufactured to fit the particular cyclist
being fitted. The dimensions obtained from measuring the individual
are used in a manual or automatic manner to manufacture the frame
built to that cyclist's specifications. As with other methods of
use, after-market or custom components could be evaluated for
attachment to the custom bicycle frame. An advanced form of the
invention could even suggest components from a database of
component options of known dimensions and geometry.
[0011] In an additional method of use of the invention, the data
gathered by the system is used to perform manual adjustments or
changes to a bicycle that a cyclist already owns. In this
embodiment, the data obtained from the invention is used to analyze
opportunities to adjust the bicycle or the riding position
favorably to a more comfortable or more efficient riding position.
The data can also be used to determine opportunities to employ
substitute bicycle components to provide a more comfortable or more
efficient riding position. Upon completion of adjustments or
component substitutions, the test is repeated. An updated set of
data is gathered, and compared to the previous results for changes.
This process applies to all adjustable or alterable dimensions of
the bicycle and cyclist riding position. The process may be
repeated as many times as is necessary or desirable to optimize all
of the adjustable geometries available to the cyclist.
[0012] In an advanced embodiment of the apparatus of the invention,
the data gathered by the system is used to dynamically and
automatically adjust a bicycle simulator to the optimum riding
position for the cyclist. In this embodiment, information from the
system is fed back on a real-time basis to adjust various
individual bicycle fit parameters sequentially and dynamically in a
way that optimally modifies all dimensions that are critical to a
proper fit. These changes are made on a real-time, automated basis
while the cyclist is riding a bicycle fitting apparatus
(simulator). This advanced embodiment of the present invention
could employ computer-controlled motors, pneumatics, or hydraulics
to modify the simulator's geometry automatically and dynamically to
fit the cyclist. The output of the session would be the set of
dimensions to which to adjust an existing or new bicycle in order
to achieve the same "fit" on that bicycle as was obtained on the
bicycle simulator. Alternatively, the dimensions would serve as
specifications for a custom built bicycle.
[0013] In another embodiment of the invention, a database is
maintained in which are collected the bicycle fit measurements of
many successful fittings, which have been performed previously.
This data is used to aid in future products and services as may be
developed. This data may also be reused when a previously fitted
individual purchases a new bicycle or wishes to have the fit
optimized to a different choice of comfort, endurance, or
performance.
DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings, which are incorporated herein and
form a part of the specification, illustrate a preferred embodiment
of the present invention and, together with the description, serve
to explain the principle of the invention.
[0015] FIG. 1 is a simplified perspective view of the major
components of this invention as an apparatus.
[0016] FIG. 2 is a flow chart summarizing the method of performing
a bicycle fit using the invention.
[0017] FIG. 3 is a flow chart summarizing the automated portion of
the method of performing a bicycle fit using the invention.
[0018] FIG. 4 depicts an example of what might appear on the screen
of the computer operating the present invention.
[0019] The figures contain the following numerically identified
elements: [0020] 1 a cyclist for whom a bicycle fitting session is
being performed [0021] 10 a bicycle, training bike, bicycle fit
simulator, exercise bike, or the like [0022] 11 a bicycle support
stand, trainer base, or similar support [0023] 12 a bicycle frame
(optionally supplied by the cyclist) [0024] 13 a bicycle handlebar
(optionally supplied by the cyclist) [0025] 14 a bicycle saddle
(optionally supplied by the cyclist) [0026] 15 each of two pedals
(optionally supplied by the cyclist) [0027] 16 each of two wheels
(optionally supplied by the cyclist) [0028] 20 an implicit
3-dimensional coordinate system [0029] 22 a wiring harness for
powering and controlling markers 24 [0030] 24 each of a plurality
of trackable markers (such as light emitting diodes) [0031] 28 at
least one marker tracker able to locate each marker in 3-dimensions
[0032] 30 a computer system (such as a laptop) and operating system
[0033] 32 a data path between each tracker and the computer system
[0034] 34 application software (instructions and data) running on
computer system 30 [0035] 40 optional power output sensor
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0036] A preferred embodiment of this invention, as an apparatus,
is shown in FIG. 1. FIG. 1 includes a cyclist 1, which of course is
not part of the invention apparatus proper, and it shows a
conventional bicycle 10. The bicycle comprises a frame 12,
handlebar 13, saddle 14, each of two pedals 15, and (generally)
each of two wheels 16. Because the bicycle must be pedaled in a
stationary location, a support stand 11 is normally required. The
support stand 11 should allow the rear wheel to rotate but hold the
bicycle in a stationary and level position. The bicycle may be one
owned and supplied by the cyclist, may be a potential purchase by
the cyclist, may be an exercise bike, or may be an adjustable
trainer or simulator (such as one designed specifically for fitting
purposes). In the latter two cases, there may be less than two
wheels 16 and the support 11 may be built in, but there will be
some sort of frame 12, handlebar 13, saddle 14, and two pedals 15
which presumably are offset from and rotate around a rotational
axis in the usual way.
[0037] For simplicity of explanation but without limiting the
generality of the invention, we will assume a cyclist and a
conventional bicycle hereafter unless otherwise noted.
Nevertheless, the frame 12, handlebar 13, saddle 14, and pedals 15
could instead be those of a tricycle (with three wheels 16), a
recumbent bicycle (with a chair-like seat instead of a conventional
saddle 14), a unicycle, a motorbike (with pedals 15), a rickshaw,
an exercise machine, a rowing bike, a human-powered water vessel,
or other human-powered device, for example. However, because of
sheer numbers, the most important application of the invention is
to conventional bicycles. Nevertheless, in spite of the
bicycle-oriented description of a preferred embodiment, the claims
below will use more general terms.
[0038] FIG. 1 also shows wired LEDs used as trackable markers 24
affixed to appropriate locations on the body of the cyclist 1.
(Desirable locations for the markers will be suggested later.)
Because the markers 24 are actively illuminated in this preferred
embodiment, they are powered and actuated electrically through a
wiring harness 24. An alternative implementation might use optical
fibers instead of electrical wires. Furthermore, the harness 24
might include batteries and a radio or infrared receiver so that
there is no electrical cable between such a harness 24 and the
computer 30 which otherwise powers and controls the LED
activation.
[0039] The markers 24 are attached to the cyclist 1 or the
cyclist's clothing so as to minimize movement with respect to the
body part of the cyclist to which it is attached. The attachment
means could be double-sided adhesive tape or foam, Velcro.RTM.
patches or strips, elastic bands, or the like. The major
requirements are that each marker 24 remain essentially immobile
with respect to the closest bone or joint of the body and maximize
visibility of the markers 24 by the marker tracker 28.
[0040] Preferred locations for the markers 24 are the following
(and these particular locations will be assumed subsequently in the
description). Each is associated with their brief descriptive
nickname: The "foot" marker is affixed on the side of the cycling
shoe vertically above the pedal axis and farthest from the frame.
The "ankle" marker is affixed to the outside (farthest from the
frame) of the ankle directly on the most prominent boney protrusion
at the bottom of the fibula. The "knee" marker is affixed directly
on the lateral protrusion of the upper fibula, and preferably not
on the patella (knee cap). The "hip" marker is affixed on the boney
prominence of the crest of the ilium (pelvis). The "shoulder"
marker is affixed where the upper end of the humorous (arm) bone
extends most outwardly when the arm hangs down. (This is the least
obvious landmark location) The "wrist" marker is affixed on the
lateral boney prominence of the wrist (the distal prominence of the
radius arm bone). These landmark locations are preferred, because
they (a) are most rigidly related to the skeleton of the cyclist,
(b) should be rather unambiguous to find on most cyclists 1, and
(c) are favorable for nearly exact repeatable placement at some
future time. Clearly, additional or alternative locations (such as
the elbow) could be used.
[0041] The moment-by-moment three-dimensional (3-d) location of
each individual marker 24 is determined in real time by tracker 28
multiple times per second. An example of such a tracker 28 is the
FlashPoint 5500 system manufactured by Boulder Innovation Group
(www.boulderinnovators.com, Boulder, Colo.). It flashes each LED
marker sequentially for a few milliseconds and uses multiple
charge-coupled devices (CCDs) in the tracker 28 to determine the
3-d location of each LED and computes its coordinates in
millimeters with respect to a 3-d coordinate system 20. These
coordinates along with a millisecond-accuracy time stamp and a
status code in a digital format are provided through a serial data
cable 32 to application software running on computer system 30. The
status code, for example, would indicate whether the LED was
visible at the time of attempted acquisition.
[0042] The markers 24 and marker tracker 28 are herein assumed to
be part of an actively pulsed optical tracking system. Alternative
marker tracking systems could be used instead, such as those which
use conventional video cameras and passive markers (typically
retro-reflective spheres 1 centimeter or more in diameter). An
example is the Motus system from Vicon Peak (www.peakperform.com,
Colorado Springs, Colo.). However, passive systems operate less
reliably for several reasons: (a) reflective markers which are
smudged or partially eclipsed yield inaccurate location centroids;
(b) the markers cannot be unambiguously identified especially when
the trajectories of two cross; and (c) specular reflections off
shiny surfaces in the field of view cause anomalous, extraneous
marker detections. Generally such anomalies require manual,
interactive post-processing. Therefore, a tracker 28 which tracks
active sequentially illuminated markers 24 is described as part of
the preferred embodiment of the present invention.
[0043] Magnetic-based or sonic-based tracking systems have further
disadvantages (such as distortion around metallic, conductive
objects or limited acquisition speed respectively) and are even
less practical for the present bicycle fitting invention, but
presumably could be used instead of an optical system.
[0044] Computer system 30 preferably is a contemporary desktop or
laptop personal computer running a conventional operating system
such as Windows XP (Microsoft Corp.), MAC OS X (Apple Computer), or
Linux. Alternatively, system 30 could be a custom, proprietary
combination of computing hardware, a liquid-crystal display (LCD)
screen, and software. Computer 30 is programmed with application
software 34, which directs operation of the markers 22 and
tracker(s) 28 and acquires marker location data therefrom. Details
of the procedural steps of that software are given in the flowchart
of FIG. 3. An example of the graphical output of the software is
shown in FIG. 4.
[0045] During operation of the invention, the locations of the
markers 24 on the cyclist's body 1 are tracked by the system in
real time and saved as XYZ coordinates with respect to a three- or
four-dimensional coordinate system (three spatial dimensions,
possibly including time too). If additional markers 24 are also
attached to the bicycle 10, these would be tracked as well to
monitor lateral sway of the bicycle 10 and to relate the cyclist's
movements relative to the instantaneous position of the frame 11.
Such additional markers could be used to define an XYZ coordinate
system which is relative to the bicycle rather than to the tracker
itself. Each marker 24 is tracked for its location every few
milliseconds. Optionally, but preferably, the location coordinates
are augmented with time coordinates (timestamps) indicating when
each marker location was sensed (for example, in milliseconds since
the beginning of the current system session). This allows
computation of pedaling speed and better correlation between marker
locations at the same moment in time. At least one data file is
created for the sequence of coordinates of the markers' spatial
locations and corresponding timestamps, and each marker's spatial
and time coordinate datum is associated with the marker to which it
corresponds. The data is preferably preserved for future reference.
This same raw coordinate data is imported into programmed computer
software 34 for analysis--either immediately or later or both. The
software 34 may be a programmed spreadsheet (preferably with
graphical plots as well as numeric computations) or may be custom
software written in a programming language such as C++, for
example.
[0046] Data can be acquired for a duration of just a few seconds or
over a period of several minutes. Taking data over a period of
several minutes affords the ability to look for trends, changes as
the cyclist warms up, or unexpected shifts in body position on the
bicycle. Furthermore, if the subject's output power is periodically
measured by optional power output sensor 40 and the measurements
correlated to the location and time data, further analysis can also
quantify how cyclist position and bicycle configuration relates to
performance or efficiency.
[0047] An advanced embodiment would further measure the cyclist's
effort by monitoring one or more of the following physiological
functions: heart rate, respiration rate, and blood oxygen level.
For example, the moment-by-moment data from a commercial pulse
oximeter could also be supplied electronically to the computer
software 34 for correlation with the power output to calculate the
cyclist's efficiency. Then the computer software 34 would use that
to rate the bicycle configuration or cyclist's posture.
[0048] Once imported into the analysis software 34, the
trajectories of each of the tracked markers are analyzed for
anomalies, statistical characteristics (such as means and extrema),
and transitions outside of expected limits. Suspect data might be
discarded, such as those with anomalous, sudden changes in speed,
for example. The limits are obtained from a database, which is
representative of many individuals' data sets, which are considered
to represent a good fit for the target criterion. Furthermore, the
center and radius of the ellipse which most closely fits the
trajectory of the "foot" marker might be computed, as well as
statistics of the deviation of that trajectory from the ellipse. In
addition, the cyclical motions of other markers 24 might be
"summarized" by matching their trajectories to expected or ideal
motions such as line segments, ellipses, "figure 8s", or other
planar cyclic curves--all of which experience shows generally
appear in data sets from successful fitting sessions.
[0049] When relating the locations of markers 24 to each other
(such as computing the distance between two distinct markers) at a
given time, the time difference must be taken into
account--especially for a marker tracker 28 which senses the
location of only one marker at a time--even if the timestamps for
the marker locations are only a few milliseconds apart. For
instance, we might estimate the locations of two markers at exactly
the time (which might be the average of the time stamps for those
two locations, say). Such an estimate of the location of any marker
at any given instant in time T must use non-linear interpolation,
because linear interpolation for the cyclical movements would not
yield the most accurate estimate. One well-known non-linear
interpolation method is cubic interpolation. For it, take the
marker's four coordinates with timestamps closest to T; compute the
coordinates of the formulas for the 3-d cubic polynomial curve
(parameterized by T), which passes through the four points; and
then determine the point on that curve which corresponds to time T.
This is a well-known technique in such disciplines as computer
graphics.
[0050] Data analysis may include but is not limited to the
following statistics: [0051] vertical hip motion range: The marker
mounted to the hip is tracked for up and down range of motion,
where ranges which are too small or too large suggest that the
saddle height is not properly adjusted. It can also indicate that a
different saddle altogether is appropriate. [0052] wrist motion
range: The marker mounted to the wrist is tracked for any motions
that stray significantly from a single point. If the wrist is
moving during cycling, it indicates that the arms of the cyclist
are over-extended or under-extended. Either of these conditions
suggests that the handlebars are not in an optimum position for the
cyclist, and should be adjusted or replaced. [0053] lateral knee
motion range: The marker on the knee should describe a repetitive
nearly planar pattern. Deviations from a plane indicate that the
knee is swinging outward or inward from a "same-plane" position and
that adjustment is needed (such as wedges between the shoe and the
pedal). [0054] ankle motion range: Similarly, unexpected inward or
outward movement (toward or away from the frame) with respect to
the foot indicates that wedges or spacers are advisable. [0055]
foot motion range: The foot marker should describe a nearly perfect
circle; the foot should be pedaling pedals that themselves are
traveling in a circular motion. Any deviation from nearly a planar
circle suggests that foot wedges or other adjustments are needed.
[0056] ankle-knee-hip angle range: Mean and extrema values for the
knee angle range which are too large indicate that the saddle is
too high; values which are too small indicate that the saddle is
too low. [0057] mean knee-hip-shoulder angle: The mean value of
this angle relates to the goal of the cyclist: small angle for
speed, large for comfort; the invention might suggest certain
angular ranges corresponding to various goals based on historically
accumulated data. [0058] relative forward-aft location of knee and
pedal: Non-zero forward-aft horizontal displacement of the knee
marker with respect to the foot marker indicates that the saddle is
too far forward or rearward.
[0059] Recommended ranges for the above should not be applied to an
unconventional bicycle, such as a recumbent bike, of course. A
separate set of optimal geometry statistics and recommended ranges
must be kept for this and for other classes of unconventional
bicycles. Even for conventional bicycles, separate optimal geometry
statistics should be kept for different classes (goals) of cyclist:
competitive road racers, competitive mountain racers, "serious"
road or mountain bike enthusiasts, recreational cyclists,
commuters, subclasses of these, and so forth.
[0060] Once a bicycle fitting session has been completed, and all
variations in motion of the cyclist on the bicycle are found to be
within the proper limits, the data from that session is added to a
master database of successful fit sessions. For privacy reasons,
the names (addresses, phone numbers, . . . ) of the cyclists would
not be recorded therein. Hence, the more fitting sessions that are
performed, the more honed the recommendation process becomes. That
is, rather than using fixed, predetermined rules for making
recommendations, the system can "learn" as it is updated with
additions and modifications to the master database. Data from
multiple systems can be pooled, analyzed, and shared to more
quickly build quantitative ranges describing good versus bad fits
for individuals of various body geometries. Session data from
recognized expert fitters might be weighted more heavily.
[0061] Because cyclists differ substantially in size, some
thresholds, limits, and recommendations should be scaled relative
to distances between markers, which will presumably be proportional
to the size of (the relevant body parts of) the subject cyclist.
For example, the upper limit for inward-outward motion of the knee
should be proportional to the leg size, which will roughly be
proportional to the ankle-to-knee distance plus ankle-to-hip
distance.
[0062] Once all data is gathered, it is analyzed for potential
adjustments to bicycle components, substitution of different
bicycle components, or even substitution of a different bicycle or
bicycle frame. Without re-harnessing the cyclist, one or more
acquisition sessions are repeated after the adjustments until the
desired quality fit is achieved. Each of the measured statistical
values can be re-measured and evaluated individually to optimize
each aspect of the bicycle fit.
[0063] The detailed procedural steps for the preferred embodiment
of the present invention are listed in FIGS. 2 and 3. FIG. 2 lists
the steps that the operator of the system generally would perform
manually (although the software 34 might at least prompt the
operator for each step to perform and prompt the operator to input
session and cyclist parameters). FIG. 3 lists the automated steps
that would normally be implemented in or controlled by the bicycle
fitting application software 34 running on computer 30. The
division of tasks between the operator (FIG. 2) and the invention
hardware and software (FIG. 3) is not absolute; an advanced system
might do more steps automatically.
[0064] In FIG. 2, the method begins with step 101, which attaches
detectable markers to at least one side of the cyclist (rider,
person) and optionally to the bicycle (or other vehicle or
conveyance being powered by the person). If additional markers are
also attached to the bicycle, those markers can serve to define a
coordinate system relative to the bicycle rather than relative to
the tracker which detects and measures the locations of the
markers. In either case, step 102 defines the axes of a
three-dimensional coordinate system.
[0065] Step 103, which checks the orientation of the saddle or seat
may be either manual step or may use a probe tracked by the
tracking system to automate partially the check. This might also
involve noting the style and width of the saddle. This check would
be ignored or would use a very different criterion for a recumbent
bicycle.
[0066] Step 104 acquires details and characteristics about the
rider (cyclist) and the bicycle (or other conveyance). This would
presumably include at least the name of the rider so that saved
information can later be retrieved by name. Other pertinent
information might include the cyclist's gender, age, experience
(from beginner to racer) and goal (comfort, endurance, or
performance efficiency). Other relevant information would
characterize the bicycle. Because a 3-dimensional tracking system
can also track markers on a probe, it is possible to arrange for
such a probe to measure certain landmark locations on the bicycle
such as the axis of the pedals, the top of the seat, wheel centers,
points along the top tube or handlebars, and the like. More
preferably the computer system would have a database of bicycle
models and their geometry, so that once the bicycle model is
identified, all its geometry would be available.
[0067] After directing the cyclist to begin powering the bicycle
(step 105), which would normally be well supported in a stationary
but otherwise normal mode of operation, step 106 would invoke the
computer system to begin executing steps 201 through 208 in FIG. 3.
(Note that the computer system may already be prompting the
system's human operator to perform the manual steps of the method:
namely, those listed in FIG. 2.) Step 201 sets up a marker tracking
system to acquire a sequence of discrete locations at discrete
times for each marker for a period of time. Step 202 then actually
acquires and saves the sequence of locations for each marker. Along
with the spatial coordinates are saved the time of acquisition, the
success or failure of acquisition, and some association between
markers and their corresponding temporal-spatial coordinates, such
as an index number or mnemonic identifier. The acquisition time
might be as short as a few seconds to as long as many minutes, but
should include at least a number of sample locations over at least
one cycle of the motion which powers the bicycle or other vehicle
(such as at least one revolution of pedals or the complete cycle of
a rowing stroke).
[0068] Optional step 203 transforms the coordinates to a more
computationally convenient or standard coordinate space, such as a
coordinate system with the origin at the center of the circle
approximately traced by the foot marker and one with, for example,
the +Z coordinate axis pointing up and the +X axis pointing
forward. Similarly, the time coordinates may be adjusted to be
relative to the beginning of the sequence of time coordinates.
[0069] In order to summarize the location information about each
marker, step 204 computes statistics about each marker. This likely
would include at least its mean XYZ location (centroid) and range
of motion along each of the X, Y, and Z axes (corresponding perhaps
to forward-aft motion, lateral motion, and vertical motion).
[0070] In a similar vein, step 205 would compute statistics about
the distances between certain specified pairs of marker locations
(each at the same instant in time). For example, one typically
significant statistic would be the mean distance between the hip
marker and the wrist marker. The most straightforward way to
compute that would simply be the distance between the hip mean
location and the wrist mean location. Another significant statistic
would be the horizontal forward-aft displacement of the knee marker
relative to the foot marker (such as the difference between their X
coordinates). Changes in the pedaling cadence would also indirectly
indicate the relative comfort and effort.
[0071] Still in the same vein, step 205 would compute at least one
angle formed by a specified trio of markers. One obvious example is
the angle of the bent leg at the knee and how it relates to proper
saddle height. If the maximum angle is too near 180 degrees the
seat is too high; if it is too small, the seat is too low. The leg
angle is approximated by the angle formed by the ankle-knee-hip
trio of markers at some moment. The mean value of this angle is
probably not as interesting as the maximum angle.
[0072] Once sufficient discrete locations are acquired for each
marker, each marker's sequence of locations may be fit to a
continuous trajectory which approximates the actual path of the
marker. This may be as simple as a sequence of connected straight
line segments or may be represented by smooth curves such as
cubic-polynomial splines. Although not absolutely necessary, there
are two reasons for fitting the discrete locations to a continuous
trajectory: (a) for a displaying visually pleasing graphical
presentation of the marker paths to the system operator and (b) to
provide the capability to interpolate locations of a marker at
times between the times of two or more known, nearby acquired
locations. The latter is particularly important if the location of
only one marker is determined at a time. Interpolation allows the
system to estimate the position of some or all of the markers at
the same instant in time even though the locations of the markers
were acquired at slightly different times.
[0073] Furthermore, the actual trajectory might be matched with or
compared to an ideal or standardized trajectory or to all
historically recorded marker trajectories of the same cyclist.
[0074] Step 206 of FIG. 3 allows for the optional visual depiction
at least some of the acquired and computed data overlaid onto a
stylized graphical representation of the person (cyclist) and
vehicle (bicycle). Alternatively, as shown in FIG. 4, the data may
be in a tabular form with reference identifiers associating each
datum with the distance or angle identified on the graphical
representation of the cyclist. Step 207 further provides for a
permanent printed or electronic report that the can be kept for
future reference or given to the person. This may include the
original acquired coordinates or simply the computed results and
recommend changes or both. Similarly, the computed results (angles,
distances, their ratios, and like statistical results) can be
compared with norms or with results from previous sessions (step
208).
[0075] The computer software would compare the results of the
current session with a database of norms, measurement ranges, and
other criteria, where the database is built from experts' advice
and from collected results of successful fittings. The software
would match the present session results with entries in the
database. Associated with entries in the database would be
recommended alterations to the bicycle (or other vehicle) or its
components. Alternatively, for somebody desiring to purchase a
bicycle, the database would list possible models, frame sizes, and
changeable components which best match the present results. This
could be implemented using common database software. Obtaining the
data content for the database is the bigger practical
challenge.
[0076] Because all fitting data is available on the computer
system, over time it is available for compiling into statistical
norms which would form a growing and improving content for the
database. Data from many installations of the invention would be
centrally compiled and shared. It would be important to attach to
each cyclist's data file a rating indicating how satisfactory the
cyclist found the fit to be. Ideally this assessment would be made
after a period of real-world experience riding the bicycle.
[0077] Once the computer system has acquired motion data, processed
it into meaningful summary statistics, and supplied
database-oriented recommendations, the level of satisfaction is
determined in step 109 of FIG. 2. If the statistics are within
norms that match the cyclist's goals (comfort, endurance,
efficiency or the like) and if the cyclist is satisfied with the
quality of fit with the bicycle the session may be completed simply
by saving acquired data and/or computed results in a form for
possible future reference. The results would then be used to design
a custom bike, finalize purchase of the bike used, finalize
purchase of the new components used, or aid in some other decision
for which the invention was used to quantify the quality of
fit.
[0078] If data was acquired from only one side of the cyclist, it
might be desirable to acquire data from the other side and compare
the results for equality or symmetry, for example. This could be
done whether or not the results suggested that the
cyclist-to-bicycle interface (fit) was satisfactory. The latter
suggests that the computer software be capable of overlaying the
results for both sides for visual comparison--this in addition to
the obvious item-for-item comparison of the numeric results. See
step 108 of FIG. 2.
[0079] However, if the last report of results was unsatisfactory or
the computer software recommended a substitution or a
bicycle-specific alteration to the configuration, the cyclist or
operator can choose whether to comply. See step 107 of FIG. 2.
After making the change, the whole method would be
reapplied--presumably returning to step 105 (if not an earlier
step). The alteration would be tailored to the cyclist's goal
(comfort, endurance, maximal power output, or so on) and skill
level (beginner to professional). Potential alterations (besides
substitution of a wholly different frame or bicycle) could include
any of the following: longer or shorter pedal crank arms, pedal
spacers or wedges, seat width, seat height, seat angle, seat
fore/aft position, handlebar height, handlebar stem length,
handlebar style, and handlebar angle. If the cyclist is riding a
bicycle simulator instead of a normal bicycle, frame geometry and
dimensions can also be adjusted (manually or perhaps even
automatically under computer control)--as if a new bicycle was
being substituted.
* * * * *
References