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Description  |
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BACKGROUND OF THE INVENTION
This invention relates generally to physical training aids, and more
particularly to an electronic physical trainer system which produces
periodic tone signals at an adjustable rate to establish an exercise
rhythm and which senses the calisthenic activity of a performer in
response to these signals to evaluate and improve his performance.
The distinction between exercise and physical education or training is that
exercise acts to enhance muscle tone and to cause the blood to circulate
more efficiently so that waste matter from the tissues can be eliminated
more effectively and the tissues can better repair themselves, whereas
physical training involves some form of calisthenic activity carried out
in a rhythmic pattern so that the beneficial effects of muscular exertion
are accompanied by improved body coordination and physical grace.
Lack of exercise leads to flabbisness and even maldevelopment of muscle and
bone. In the United States, the opportunity to exercise the muscles in
day-to-day living has become so limited among large sections of the
population that there is a growing concern with the problem of obesity and
ailments resulting from overweight.
One popular exercise in physical training is jumping jacks, a conditioning
exercise performed from a standing position by jumping to a position with
legs spread apart and hands touching overhead, and then back to the
original position. In a gymnasium, a physical training instructor usually
calls out the rhythm for this exercise. At the outset, the instructor's
rhythm is slow and as the exercise progresses, the beat is gradually
increased. The performer is evaluated by his ability to keep up with the
changing rhythm.
Skip rope exercise is also beneficial but in this instance the performer
sets his own rhythm. In skip rope, the performer holds the ends of a rope
in his hands and creates a hoop by centrifical force which he rotates in a
circular orbit about his body. To avoid intercepting the rotating hoop,
the performer must leap upwardly just before the hoop reaches his feet and
he must coordinate the rate of hoop rotation with his jumps. Once this
coordination is lost, the hoop strikes the feet and collapses.
In other forms of conditioning exercise such as push-ups, it is not the
feet which are periodically raised about the ground, but the torso or some
other part of the body. Thus most physical training exercises involve the
raising of a body part above the ground at a rhythmic rate controlled by
an instructor or by the performer himself.
When a performer wishes to exercise by himself at home, he is often faced
with a practical situation which militates against effective conditioning.
Thus in the case of skip rope exercises, the home environment may be such
that there is insufficient room for a rotating rope hoop. Moreover, the
rope constitutes a hazard in that it may intercept and damage fragile
articles.
But even in the case of exercises that require no rope or other equipment,
in the absence of a trainer or instructor the exerciser must set up the
rhythm and also make his own evaluation. This does not lead to
satisfactory results, for a self-regulating performer lacks the necessary
objectivity for effective conditioning. It is only by independent
evaluation that a performer can be motivated to improve his performance.
SUMMARY OF INVENTION
In view of the foregoing it is the main object of this invention to provide
an electronic physical trainer (EPT) system that produces periodic tone
signals to establish an exercise rhythm and which senses the calisthenic
activity of a performer in response to the signals to evaluate and improve
his performance.
More particularly, it is an object of this invention to provide an EPT
system which generates exercise pulses to produce periodic tone signals
and which detects the position of the performer's feet or other moving
body member within a restricted exercise area to develop action pulses as
the member goes from one position to another, the exercise pulses and the
action pulses being compared to evaluate the performer's ability to remain
in step with the tone signals.
Yet another object of this invention is to provide an EPT system which not
only counts the number of times the performer is in step with the sound
signals but also the number of times he is out of step and which
separately displays these counts to afford a reading from which the
performance may be scored.
One problem with conventional physical training exercises is that of
boredom, for if the exercise is unvaried, the performer loses interest in
continuing to repeat the same calisthenic sequence. Such boredom, is
normally avoided by a physical training instructor who in the course of a
given regimen will increase the rhythm rate and thereby introduce a
challenge which maintains the performer's interest. A significant feature
of the present invention is that the repetition rate of the periodic tone
signals may be varied in the course of an exercise regimen or from one
exercise cycle to the next.
Another advantageous aspect of an EPT system in accordance with the
invention is that it not only determines whether the action pulses
produced by the performer are in step with the exercise pulses but also
the phase relationship or degree of overlap therebetween, so that if the
phase displacement is such that the action pulses are almost but not quite
out of step, they may then be scored as misses, not as hits. The degree of
phase displacement which constitutes a miss can be varied and hence
represents a "difficulty" adjustment. Thus the set poingt of the EPT
system may be set so that unless an action pulse is closely in step with
an exercise pulse, it is treated as a miss -- or the system may be more
liberally adjusted so that as long as there is even a small overlap
between an action and an exercise pulse it is treated as a hit.
Briefly stated these objects are attained in an EPT system including a
position sensor constituted by a light source that directs a beam in a
path traversing a restricted exercise area toward a photodetector whereby
as a performer in this area repeatedly raises both his feet or some body
member above ground to an extent clearing the beam and he then returns his
feet to ground to block the beam, the detector output takes the form of
action pulses which reflect this repetitive activity.
The sensor is not limited to exercises such as skip rope in which both feet
must be simultaneously above ground. Thus in the case of a jogging
exercise in which the feet of the performer are alternately raised above
ground, the beam may be directed toward one of the two feet so that as
this foot pumps up and down, action pulses are produced.
Also included in the system is a pulse generator whose frequency is
adjustable to produce exercise or pacing pulses at a desired rate which
may be varied in the course of an exercise regimen. The exercise pulses
activate a tone generator whose output is amplified and reproduced to
produce tone signals establishing an exercise rhythm. The calisthenic
activity of the performer in response to the exercise pulses is reflected
by the action pulses and these pulses are compared in a coincidence
network with the exercise pulses.
The coincidence network yields a hit pulse each time the overlap between an
action pulse and an exercise pulse exceeds a predetermined phase
displacement or set point and a miss pulse for all other displacements.
If, for example, the feet of the performer is raised to unblock the beam
at a point in time subsequent to the trailing edge of the exercise pulse,
this being indicative of the fact that the performer is altogether out of
step, then a "miss" pulse will be registered. But if this point in time
which represents the leading edge of the action pulse coincides with any
point within the exercise pulse, then a "hit" pulse will be registered. On
the other hand, one can adjust the coincidence network so that unless the
point in time of the action pulse at least coincides with the midway or
some other set point in the exercise pulse, a miss pulse will be
registered.
The hit and miss pulses are separately counted and these counts are
displayed to provide a reading of the performance. Preferably a single
digital display device serves selectively to afford a reading of hits and
misses.
OUTLINE OF DRAWING
For a better understanding of the invention as well as other objects and
further features thereof, reference is made to the following detailed
description to be read in conjunction with the accompanying drawings,
wherein:
FIG. 1 schematically illustrates an EPT system in accordance with the
invention;
FIG. 2 is a block diagram of the circuit arrangement of the system; and
FIG. 3 illustrates pulse waves produced at various points in the circuit.
DESCRIPTION OF THE INVENTION
The System:
Referring now to FIG. 1, there is shown an EPT system in accordance with
the invention adapted to generate periodic tone siganals that are
reproduced by a loud speaker 10 to establish an exercise or pacing rhythm
for a performer 11.
By way of example, we shall assume that the system is to function as a skip
rope simulator whereby performer 11 proceeds to jump up and down within a
restricted area 12, just as if he were to do so to escape a hoop rotating
about his body. In this instance, the periodic tone signals from speaker
10 represents those points in time when the imaginary hoop is about to
strike the feet of the performer. The performer must therefore, in
synchronism with the tone signals, jump upwardly to avoid being struck by
the hoop. Should the performer succeed in jumping in synchronism with the
tone signals, then he effectively is skipping rope.
To further aid in simulating a skip rope exercise, a pair of handles 12 and
13 may be pivotally mounted on standards at an appropriate level above
ground which may be adjustable. These handles are grasped by the performer
as if he were holding onto the ends of a rope. Positioned on one side of
exercise area 12 is a light projector 14 adapted to direct a beam 15
across this area toward a photodetector 16. When the performer's feet are
on the ground they intercept the beam and block the flow of light to
detector 16. When the performer leaps upwardly the feet clear the beam and
the detector in response to the light impinging thereon produces an output
voltage.
Thus as the performer jumps up and down more or less in synchronism with
the periodic tone signals, detector 16 yields periodic action pulses which
reflect this calisthenic activity. The tone signals emitted by loud
speaker 10 are derived from a tone generator which is activated by
exercise pulses produced by a pulse generator. The frequency of the pulse
generator is adjustable so that the rhythm can be made slow or fast, as
desired, or as will be explained later, the repetition rate of the
exercise pulses may be advanced in the course of an exercise regimen to
make the exercise progressively more difficult and challenging.
The action pulses derived from photodetector 10 are compared with the
exercise pulses from the pulse generator in a coincidence network, to be
later described, to determine their degree of coincidence. In its simplest
embodiment, the EPT system may be operated so that as long as a particular
action pulse overlaps to any extent a corresponding exercise pulse, this
condition is treated as a "hit," whereas when an action pulse is out of
phase with an exercise pulse it is treated as a "miss."
The hits and misses are represented by pulses yielded by the coincidence
circuit and these are applied to separate pulse counters. After the
performer has completed his exercise regimen which may last say 10
minutes, the respective counts registered in the counters are presented on
a digital display device 17 which in practice may be an LED display.
While it is possible to provide separate LED display stations for hits and
misses, it is less expensive to use a single display, and for this purpose
a manually operated gate is provided to selectively feed the counts from
the miss and hit counters to the display device.
Such scoring makes it possible for the performer to evaluate and improve
his performance. Thus assuming that an exercise regimen lasts 10 minutes
during which 400 exercise pulses are generated, and the display indicates
342 hits and 58 misses, this performance deserves a "good" grade, but if
the display indicates a score of 396 hits and 4 misses, then the performer
is entitled to an "excellent" rating. This grading serves to inspire the
performer toward greater effort in attaining a higher grade. It may also
be used for competition between two or more performers.
The system is arranged to announce misses through the same speaker which
emits the exercise tone signals, a miss being represented by a buzzer-like
sound or other penetrating tone which is readily distinguishable for a
pacing tone. In this way the performer is immediately made aware that he
has fallen out of step and he can then take corrective measures.
It will be appreciated that visible rather than tone signals may be used to
establish the rhythm, or one may employ a combination of light and sound
for this purpose. In practice the system may be arranged to delay counting
after a reset to zero until after say the fifth tone signal to that the
performer is given a brief warm-up period in which to fall into step with
the pacing tones.
The Circuit:
Referring now to FIG. 2, the circuit arrangement of the EPT system is
shown. It will be seen that the output of detector 16 which picks up light
beam 15 from projector 14 is applied to an amplifier 18 whose action pulse
output is applied to one input of a coincidence network 19. In practice,
detector 10 may be a photodiode and the light projector 14 a strobe light
source.
Applied to the other input of coincidence network 19 is the exercise pulse
output of a pulse generator 20 which, in practice, may be a Schmidt
trigger. Pulse generator 20 is activated by a voltage-controlled
oscillator 21 (VCO) whose operating frequency is adjusted by a
potentiometer 22 coupled to a D-C voltage source 23, the greater the
voltage applied to the VCO, the higher its operating frequency.
Thus, if the oscillator frequency is 3 Hz, the exercise pulse from
generator 20 is then 3 pulses per second. Potentiometer 22 which varies
the exercise pulse frequency may be manually adjusted, or it may be
operated by a clock motor 24 such that during an exercise regimen lasting
say 10 minutes, the motor slowly rotates the potentiometer to gradually
increase the exercise pulse rate. In this way, the pacing may be slow at
the outset of the exercise and progressively sped up. Or the speed-up may
be effected in discrete steps, by a step motor rather than continuously.
The output of pulse generator 20 is also applied to a normally quiescent
tone generator 25 whose output is applied through an amplifier 26 to
speaker 10. Tone generators produce a distinctive and pleasing tone, say,
a 1200 Hz tone or beep each time it is activated by an exercise pulse from
generator 20. These tones are reproduced by speaker 10.
In practice, rather than maintaining an unchanged tonal pitch, the pitch
may be raised as the exercise rhythm becomes faster so as to make the
performer aware that the rhythm is speeding up. This can be done by
integrating the pulses from the pulse generator 20 to produce an analog
voltage whose magnitude depends on the pulse rate and applying this analog
voltage to a voltage-controlled oscillator functioning as tone generator
20. In this way, the pulse generator not only activates the tone generator
but it also determines by the rate of activation the tone produced.
Thus for an exercise rhythm of one per second, the tone frequency can then
be 1000 Hz, for a rhythm of two per second; the tone frequency can be 1500
Hz, for three per second, 2000 Hz and so on. Psychologically, one relates
pitch to the intensity of a given activity and a higher pitch accompanying
a higher exercise rate tends to incite the performer to heightened effort.
Thus applied to coincidence network 20 are rectangular exercise pulses from
pulse generator 20, as indicated on line A of FIG. 3 as well as action
pulses derived from the position sensor, as shown on line B in FIG. 3. The
phase relationship between action pulses B and exercise pulses A depends
on the extent to which the performer is in step with the rhythm. If the
performer's feet are always on the ground each time he hears a tone
signal, then he will be altogether out of step. The action pulses will
then be out of phase with the exercise pulses and there will be no overlap
at all in time between these pulses.
FIG. 3B shows action pulses B which have some degree of overlap with
exercise pulses A, two conditions I and II being represented on line B.
Condition I indicates a high degree of overlap, for here the leading edge
of the action pulses is about at the midpoint of the exercise pulses,
whereas Condition II indicates a lesser degree of overlap.
The coincidence pulses produced in coincidence network 19, as indicated in
line C of FIG. 3, have a duration that corresponds to the extent of
overlap between the action and exercise pulses. Hence, coincidence pulses
I derived from action pulses I are broader than coincidence pulses II
derived from action pulses II. Coincidence network 19 includes a
coincidence gate to which the action and exercise pulses are applied, the
gate yielding the coincidence pulses (shown in line 3C.
These coincidence pulses are applied to an integrator to produce integrated
coincidence pulses. For the broader coincidence pulses I, the resultant
integrated coincidence pulses, as shown in FIG. 3D, exceed a predetermined
set point represented by dashed line SP in a level detector which yields
hit pulses, as shown in line E. But for the shorter coincidence pulses II,
the resultant integrated coincidence pulses, as shown in line F, fall
below set point level SP, and the level detector then yields in a separate
output the miss pulses shown in line G.
Thus coincidence network 19, which includes the integrator and the level
detector, yields at output H "Hit" pulses when the degree of overlap
between the action and exercise pulses is sufficiently high to exceed a
predetermined set point, and it yields at output M "Miss" pulses when
there is no overlap or the degree of overlap falls below the set point.
The set point is adjustable, and the knob for this purpose constitutes a
"Difficulty" adjustment; for the higher the set point, the more difficult
it is to score a hit.
The Miss pulses from output M are applied to a digital counter 27 and also
to a buzzer tone generator 28. Generator 28 is activated by each Miss
pulse to produce a distinctive rasping tone that is applied to amplifier
26 and reproduced by speaker 10 so that the performer is immediately made
aware of his misstep.
The Hit pulses from output H are applied to a digital counter 29. Both
counters 27 and 29 may be simultaneously reset to zero by a manual reset
button 30. Upon the completion of an exercise regimen, the counts held in
counters 27 and 29 are applied through a gate 31 to a 3 digit display
device 32 which is so arranged that when a button is depressed and the
read-out shifts from the Hit counter to the Miss counter. In this way, the
performer, upon the completion of an exercise regimen, obtains a score of
his performance. In lieu of electronic counters operating in conjunction
with an electronic display, electromechanical register may be used to
count and display the hits and misses.
While there has been shown and described a preferred embodiment of an
electronic physical trainer system in accordance with the invention, it
will be appreciated that many changes and modifications may be made
therein without, however, departing from the essential spirit thereof. For
example, one may provide a predetermined delay between the tone signal and
the exercise pulse such that the performer is signalled to jump at the
instant he hears the tone, rather than in anticipation of the tone. In
other words, the tone signal represents, in the case of a skip rope
simulator, a given position of the rope hoop relative to ground, and this
position in space can be adjusted by a variable delay.
Also, instead of a position sensor in which a light projector is used which
is separate from the photodetector, one may use a light projector in the
same housing as the detector, the beam from the projector being picked up
by a separate reflector on the other side of the exercise area and
redirected toward the detector.
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