U.S. patent application number 13/254810 was filed with the patent office on 2012-03-08 for automated weightlifting spotting machine.
This patent application is currently assigned to AUTOMORPHE LIMITED. Invention is credited to Mark Elsom-Cook, Michael Escott, Steve Morris.
Application Number | 20120058859 13/254810 |
Document ID | / |
Family ID | 40566043 |
Filed Date | 2012-03-08 |
United States Patent
Application |
20120058859 |
Kind Code |
A1 |
Elsom-Cook; Mark ; et
al. |
March 8, 2012 |
AUTOMATED WEIGHTLIFTING SPOTTING MACHINE
Abstract
A weight training assistance apparatus which requires a user to
overcome the force exerted by one or more weights comprising: one
or more sensors for monitoring a user's activity by monitoring the
position of an item indicative of the position of the weights
during a weight training exercise; a processor in communication
with said sensors; the processor enabled to dynamically compare the
user's activity of the item during the exercise with a
predetermined activity profile to determine a dynamic level of
fatigue for the user; the processor further enabled to determine a
response at a given moment based on the exercise undertaken, the
current user activity and the determined dynamic level of fatigue;
a load bearing device that is controllable by the processor, the
load bearing device enabled to dynamically vary the magnitude of
the net force exerted by the weight as determined by the response,
the processor further enabled to maintain the magnitude of the
force when the user's activity is within a predetermined limit of
the predetermined activity profile.
Inventors: |
Elsom-Cook; Mark; (Coventry
West Midlands, GB) ; Escott; Michael; (Coventry West
Midlands, GB) ; Morris; Steve; (Coventry West
Midlands, GB) |
Assignee: |
AUTOMORPHE LIMITED
Stratford Upon Avon
GB
|
Family ID: |
40566043 |
Appl. No.: |
13/254810 |
Filed: |
March 3, 2010 |
PCT Filed: |
March 3, 2010 |
PCT NO: |
PCT/GB2010/050374 |
371 Date: |
November 14, 2011 |
Current U.S.
Class: |
482/4 |
Current CPC
Class: |
A63B 2071/0072 20130101;
A63B 21/00181 20130101; A63B 2220/805 20130101; A63B 2220/10
20130101; A63B 2220/833 20130101; A63B 21/078 20130101; A63B
2220/802 20130101; A63B 21/0783 20151001; A63B 2220/20 20130101;
A63B 21/153 20130101 |
Class at
Publication: |
482/4 |
International
Class: |
A63B 24/00 20060101
A63B024/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 3, 2009 |
GB |
0903601.3 |
Claims
1-40. (canceled)
41. A weight training assistance apparatus which requires a user to
overcome the force exerted by one or more weights comprising: one
or more sensors for monitoring a user's activity by monitoring the
position of an item indicative of the position of the weights
during a weight training exercise; a processor in communication
with said sensors; the processor enabled to dynamically compare the
user's activity of the item during the exercise with a
predetermined activity profile to determine a dynamic level of
fatigue for the user; the processor further enabled to determine a
response at a given moment based on the exercise undertaken, the
current user activity and the determined dynamic level of fatigue;
a load bearing device that is controllable by the processor, the
load bearing device enabled to dynamically vary the magnitude of
the net force exerted by the weight as determined by the response,
the processor further enabled to maintain the magnitude of the
force when the user's activity is within a predetermined limit of
the predetermined activity profile.
42. The apparatus of claim 41, wherein the item indicative of the
position of the weights are the weights used during the
exercise.
43. The apparatus of claim 41, wherein the dynamic comparison to
determine user activity is a comparison of the position of the
item.
44. The apparatus of claim 41, wherein the processor is further
enabled to determine a level of muscle fatigue based on the dynamic
comparison of user activity and the predetermined profile and
determines the response based on user activity, fatigue and
failure.
45. The apparatus of claim 41, wherein the predetermined activity
profile is a user specific profile for the weight training activity
undertaken by the user.
46. The apparatus of claim 41, wherein the comparison is
substantially a real-time comparison, and the determination of the
response is in substantially real-time.
47. The apparatus of claim 41, wherein the response to fatigue is
one or more of the following: the load bearing device varying the
magnitude of the net force exerted by the weight to zero; the load
bearing device varying the magnitude of the net force exerted by
the weight wherein the net force exerted by the weight is reduced
by an amount proportional to the level of fatigue detected.
48. The apparatus of claim 41, wherein where the load-bearing
device is a motor, and where the apparatus further comprises a
braking mechanism coupled to the cable and wherein the processor is
enabled to control one or more of the speed, torque and braking of
the motor.
49. The apparatus of claim 41, wherein the processor is further
enabled to compare of the user activity against one or more
profiles, which form a pattern profile library to determine if the
user activity is indicative of a particular pattern profile wherein
the pattern profile library contains known incorrect lifting
profiles thereby allowing the identification of incorrectly
performed lifts.
50. The apparatus of claim 41, wherein the one or more sensors are
contactless sensors selected form the group of: infra-red,
ultrasonic or laser based sensors.
51. The apparatus of claim 41, wherein the level of assistance
provided by said load bearing device varies according to a measure
of the divergence between the predetermined activity profile and
the actual user activity.
52. The apparatus of claim 41, where the decision to engage the
load bearing device is based on a comparison of the relative
position, velocity or acceleration of the weight compared to an
expected position based on a pre-determined model.
53. The apparatus of claim 41, further comprising a form of
writeable memory and where data regarding previous exercises
performed on the apparatus is stored on the writeable memory and
wherein the model is based on historic data of previous instances
of the same or similar exercise, preferably by the same user.
54. The apparatus of claim 41, wherein the processor is enabled to
compare one of more of the following of a user's activity against
the predetermined activity profile: full extension of the user
during the exercise; time between repetitions; velocity of the
weights.
55. The apparatus of claim 41, wherein the processor is enabled to
determine if the user has reached failure, where the comparison of
the user's activity and predetermined profile is beyond a
predetermined limit and further comprising a safety mechanism to
bear the entire load wherein the safety mechanism is enabled by the
processor in response to high level of fatigue or failure as
determined by the processor.
56. The apparatus of claim 41, wherein the apparatus further
comprises one or more additional motors, said motors selectively
engaged to provide different levels of lift to reduce the net force
exerted.
57. A method of self-spotting weightlifting the method which
requires to overcome the force exerted by one or more weights
comprising; attaching a load bearing means to one or more weights;
exercising with the weights attached to the load bearing means;
monitoring the position of an item indicative of the position of
the weights through one or more sensors; determining if a user
requires help by comparing the position of the item to a
pre-determined model; selectively engaging the load bearing means
to dynamically vary the magnitude of the force exerted by the
weights in response to the determining step until such time that
the user is determined to no longer require assistance; and
maintaining the magnitude of the net force exerted once the user is
determined not to require further assistance.
58. The method of claim 57, further comprising the step of:
determining a parameter associated with the item; determining if
the parameter was within a predetermined limit of the predetermined
model, and in the event that the parameter is outside of the
selectively engaging the load bearing means.
59. The method of claim 58, wherein the parameter associated with
the item is one of: position, velocity, acceleration.
60. The method of claim 57, wherein the method further comprises
storing information regarding completed exercises to a form of
writeable memory.
Description
TECHNICAL FIELD
[0001] The invention relates to an automated spotting machine for
weightlifting that applies to both free-weights and stacked weight
machines. The device is enabled to provide assistance to a
weightlifter when required and to bear the load of weight such as a
barbell if a user has reached muscle failure or the exercise has
potentially become dangerous.
BACKGROUND TO THE INVENTION
[0002] In weight training it is known for the weightlifter to ask
for a spotter to monitor the exercise and to provide assistance to
the weightlifter when required. The assistance provided may involve
taking the whole weight to avert a dangerous situation when using
free weights or to assist with a lift using free weights or stacked
weight machines, allowing the weightlifter to continue with an
exercise so that they may complete more repetitions than they would
normally do without assistance (forced repetitions). The assistance
of a spotter also allows the weightlifter to perform negative
repetitions where the spotter lifts the weight to the starting
position and the weightlifter then slowly lowers it whilst being
monitored. A spotter may also help the weightlifter perform `drop
sets` where once failure has been reached at a given weight,
weights are removed to allow the exercise to continue.
[0003] In order to achieve the most effective method for building
muscle mass, the lifter should be at the limit of their lifting
ability for a period of time during an exercise session. This limit
will vary during the session since the lifter will progressively
fatigue muscle, becoming weaker and more tired as the session
progresses.
[0004] Without a spotter, the lifter will reach the `failure`
point, at which they cannot complete a lift, but a spotter can take
part of the weight to extend this point so that the lifter can
complete more repetitions (reps). It is also known for a lifter who
has reached fail to normally complete additional assisted reps,
example forced or negative reps.
[0005] A disadvantage of free weight training is that a spotter is
not always available and subsequently the user may not partake in
free weights or does so without a spotter, which is potentially
dangerous. Self spotting devices are known in the art but these
rely on the weightlifters input to provide assistance. For example
U.S. Pat. No. 5,823,921 requires the user to engage a foot pedal to
initiate the spotter and is subsequently complex to use.
[0006] Another disadvantage of many of the self spotting
weightlifting machines is that they only act as a safety device,
and are unable to provide assistance to the weightlifter to help
them complete a repetition as is required for human spotters.
SUMMARY OF THE INVENTION
[0007] The invention seeks to avoid or at least mitigate these and
other problems in the prior art, the present invention provides an
apparatus for a weight lifting machine, which is able to provide
assistance to a user as well as acting as a safety mechanism.
[0008] The spotting device is an electro-mechanical system, which
can replicate the role of a human `spotter` in a free weights
environment. This entails being able to take the full weight of the
bar if the lifter is unable to hold it (hence acting as a safety
feature) and slightly easing the weight when the lifter is on the
limit of their strength.
[0009] In an embodiment of the invention, the main focus is on the
latter part of the task. In the present invention, a key aspect is
detecting the level of fatigue and providing the right amount of
support to keep the lifter making maximum use of the muscles.
Without a spotter, the lifter will reach the `failure` point, at
which they cannot complete a lift, but a spotter can take part of
the weight to extend this point so that the lifter can complete
more repetitions (reps).
[0010] The spotter will use the first rep as a calibration rep, or
offer the user the option of performing a calibration rep. The
lifter engages the spotter with a predetermined activity profile,
by entering their personal profile and/or enters initial
calibration data. Once the apparatus has been calibrated, the
lifter performs their exercise, which is monitored by one or more
sensors. A processor is enabled to determine the lifter's need for
assistance and actively support some or all of the weight if
required.
[0011] In one aspect of the invention there is provided a weight
training assistance apparatus comprising a sensor for monitoring a
user's activity during weight training exercise, a processor in
communication with the sensor adapted to compare the user's
activity during the exercise with a predetermined activity profile
and to determine the user's need for assistance, the processor
being further adapted to control a load bearing device thereby to
assist the user during weight training.
[0012] According to another aspect of the invention there is
provided a weight training assistance apparatus which requires a
user to overcome the force exerted by one or more weights
comprising: one or more sensors for monitoring a user's activity by
monitoring the position of an item indicative of the position of
the weights during a weight training exercise; a processor in
communication with said sensors; the processor enabled to
dynamically compare the user's activity of the item during the
exercise with a predetermined activity profile to determine a
dynamic level of fatigue for the user; the processor further
enabled to determine a response at a given moment based on the
exercise undertaken, the current user activity and the determined
dynamic level of fatigue; a load bearing device that is
controllable by the processor, the load bearing device enabled to
dynamically vary the magnitude of the net force exerted by the
weight as determined by the response, the processor further enabled
to maintain the magnitude of the force when the user's activity is
within a predetermined limit of the predetermined activity
profile.
[0013] Further aspects, features and advantages of the present
invention will be apparent from the following description and
appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] An embodiment of the invention will now be described by way
of example only, with reference to the following drawings, in
which:
[0015] FIG. 1 is a schematic perspective view of an apparatus in an
embodiment of the invention;
[0016] FIG. 2 is a schematic side elevation of the apparatus shown
in FIG. 1;
[0017] FIG. 3 is a schematic of the spotting mechanism;
[0018] FIG. 4 is an example of a distance versus time graph of a
single rep;
[0019] FIG. 5 is an example of a velocity versus time for a single
rep;
[0020] FIG. 6 is an example of a acceleration versus time graph for
a single rep;
[0021] FIG. 7 is a flow chart of the process of the spotting
mechanism in use;
[0022] FIG. 8 is a schematic perspective view of an apparatus
according to a further embodiment of the invention; and
[0023] FIG. 9 is a schematic end elevation of an apparatus
according to yet another embodiment of the invention.
DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION
[0024] FIG. 1 shows an embodiment of the invention, in which there
is shown apparatus 10, bench 12, rack 14, barbell 16, vertical
support 18, pulleys 20, and 24, horizontal support 22, groove 23,
motor 42, brake 26, motor 25, control panel 28, cable 30, barbell
attachment means 32, sensor 34, reflective strips 36, sensor 40,
sensor 44 and processor 38 (located inside control panel 28).
[0025] The apparatus 10 shown in FIG. 1 is a variation of bench
press apparatus. The bench 12, rack 14 and barbell 16 are all
standard pieces of equipment. The invention comprises the addition
of the vertical support 18 and horizontal support 22 which define a
structure, which preferably extends over the bench 12. Pulleys 20
and 24 are attached to the horizontal support 22 and pulley 24 is
preferably moveable along the grove 23 powered by motor 25. A motor
26 is attached to vertical support 18 and the cable 30 runs from
the motor 26, through brake 42, along the vertical support 18, over
the pulley 20 along the grove 23 and pulley 24 and is attached to
the barbell 16 via the barbell attachment means 32. The barbell 16
further comprises reflective strips 36 which allow sensors 40, to
sense the barbells vertical position. The sensor 34 moves along the
groove 23 to enable calculation of the horizontal position of the
barbell 16 and allows the pulley 24 to maintain position above the
barbell 16. Sensor 40 enables calculation of the position of the
barbell 16. The sensor 34 and sensor 40 are linked to a processor
38, which is preferably integrated into the control panel 28,
attached to the vertical support 18. A control panel 28, which is
enabled to display information and allow a user to input
information is also integrated into the vertical support 18. Pulley
24 and sensor 34 move along the groove 23 by means of a motor 25.
The term user and lifter are used interchangeably during the course
of the specification, and they represent the same person.
[0026] The cable 30 is attached to the barbell 16 at barbell
attachment means 32. The barbell attachment means 32 are preferably
releasable allowing the barbell 16 to be detached from the
apparatus and another form of bar to be attached. The cable 30 runs
from the barbell 16 to pulley 24, along the horizontal support 22
through pulley 20, down the vertical support 18 and through the
brake 42 to the motor 26. The motor 26 houses the excess cable 30
and in the preferred embodiment the motor 26 provides some
resistive force to the cable 30 thereby keeping the cable 30 taut.
However, the amount of resistive force applied is only sufficient
to keep the cable 30 taut to ensure that the cable 30 does not bear
any of the load of the barbell 16. The cable 30 is made from any
suitable material that has sufficient strength to be able to
withstand a load of a barbell 16, preferably steel wire. For safety
reasons, the cable is preferably able to support several hundred
kilos.
[0027] The motor 26 in the preferred embodiment is a servomotor
though other forms of motor may be used. The motor 26 is enabled to
be able to provide sufficient power to lift the barbell 16, by
retracting the cable 30, which is preferably stored in the housing
of the motor 26. In the preferred embodiment, the motor 26 is
attached to the vertical support 18. In further embodiments (not
shown) the motor 26 may placed elsewhere, for example, below the
bench 12. A braking mechanism such as a drum type brake is
preferably provided within the motor 26. An additional brake 42 is
provided for additional safety.
[0028] The motor 26 therefore is enabled to reduce the net force
exert by the weights. Under normal use, the net force of the
weights will be the weight (i.e. mass times gravity). When the
motor 26 is engaged magnitude of the net force exerted by the
weights is reduced by an amount related to the strain taken by the
motor. For example, if a barbell 16 has 100 Kg of weight and the
cable 30 is taut but not bearing any weight the net force exerted
by the weight will be 100 Kg. If the motor 26 is engaged and
provides a force of 20 Kg then the net force exerted by the weights
is 80 Kg. Therefore, the magnitude of the net force exerted by the
weights can be varied by the motor.
[0029] The control panel 28, is enabled to allow the weightlifter
to input details regarding themselves e.g. height, weight, arm
reach etc., and/or the exercise they wish to undertake e.g. weight
of the barbell 16, number of repetitions, forced or negative
repetitions etc. Preferably the control panel 28 is a
self-contained unit of the class typically referred to as a Mobile
Data Terminal (MDT) It consists of a computer with storage,
interface cards and a touch screen. It will be operated through a
Graphical User Interface (GUI). This device is similar to those
found in-car GPS systems.
[0030] In a further embodiment the control panel 28 has other data
input means e.g. USB socket, mobile phone, voice input, swipe card,
key fob etc., which allow the user to identify themselves by some
form of external input.
[0031] The apparatus also contains a number of sensors 34, 40 for
calculation of speed and location of the barbell. In the preferred
embodiment there are one or more sensors on rack 14 and one or more
sensors 34 located in the groove 23. In the preferred embodiment
the sensors 34 in groove 23 are infrared sensors and sensors 40 are
infrared or ultrasonic distance measuring sensors. The sensors are
preferably contactless sensors, that is to say that they measure
the position. The strength of the signal between the sensors 34 and
40 allows for a calculation of the position of the barbell and
therefore barbell 16 relative to the vertical support 18.
Preferably to increase the accuracy of the positional determination
of the barbell 16 there at least two sensors 40 on the rack 14 and
at least one sensor in groove 23.
[0032] The sensors 34, 40 may also measure the speed of the cable
30. Preferably there is a barbell sensor 40. In the preferred
embodiment the sensor 34 on the horizontal support 22 and the
barbell sensor 40 are infrared sensors enabled to calculate the
distance between the sensors 34 and 40. As the sensor 34 is fixed
and barbell sensor 36 would move the position of the barbell 16 may
be calculated. Other suitable sensing means for detecting the
position of the barbell 16 with respect to the vertical support 18
may also be used.
[0033] All sensors are preferably contactless sensors, that is to
say that they measure the position of the bar in a 3-D environment
without the need for a physical connection between the measuring
sensor and the bar. The sensors can be used to measure the barbell
16, the weights lifted, the lifting arm etc. The sensors therefore
measure the position of an item (e.g. the barbell, the weights, a
reflective strip placed on the weights or barbell etc) which
provides an indication of the current position of the weights
during exercise. The sensors are preferably one or more of known
infra-red, ultrasonics or laser based sensors
[0034] The information from sensors 34, 40 is transmitted to
processor 38, which is preferably a suitable known microprocessor.
The processor 38 is preferably integrated into the control panel 28
and is enabled to calculate the position of the barbell 16 with
respect to the vertical support 18 from the strength of the signals
received from the sensors 34 and 40. To accurately measure the
position the sensors use triangulation techniques to accurately
measure the position of the barbell 16.
[0035] In a further embodiment, there are additional sensors in the
horizontal support (not shown in FIG. 1) which are used to increase
the accuracy of the positional measurement.
[0036] The processor 38, preferably, is linked to some form of
writeable memory so that it may store information regarding
multiple users. The writeable memory may also contain information
regarding the user and exercise programme that they are undertaking
therefore reducing the amount of information that needs to be
inputted at the control panel 28.
[0037] FIG. 2 is a side revelation of FIG. 1 and shows the features
as described with respect to FIG. 1. A brake 42 and a cable speed
sensor 44 on the vertical support 18.
[0038] A brake is preferably housed in the motor 26, but in a
preferred embodiment there is a further brake 42 on the horizontal
support 18. The brake 42 is preferably a drum brake, though other
types of brake may be used. The brake is enabled to stop the cable
30 and is able to support all the weight of the barbell 16.
[0039] FIG. 3 shows a schematic of the control system of the
spotter. There is shown the GUI 50, which inputs data to a
processor control 52. There is also shown position sensors 54 and
cable tension sensors 56 which inputs information to the processor
control 52, a brake control 60 which receives information from the
processor control 52 and an engine control 58 and memory 62 which
both receive and input data to the processor control 52.
[0040] As discussed previously, the control panel 28 is preferably
a GUI 50 which is enabled to display information and has a touchpad
means to allow a user to input further information. In a further
embodiment the information may be inputted remotely e.g. via a
wireless connection, or via some form of user identifier such as a
swipe card, key fob etc. The information inputted at the GUI 50 is
passed to the processor controller 52.
[0041] In a preferred embodiment the controller 52 accesses the
memory 62 for any relevant saved data, for example regarding the
user, the exercise to be undertaken. The processor control 52 is
preferably further enabled to write to the memory 62 so that any
information inputted at the GUI 50 may be stored for further
reference.
[0042] In the preferred embodiment, the processor control 52
receives information from the position sensors at least 10 times
per second, and preferably between 100-1000 times a second. The
information, in the form of signal strength allows the processor
control 52 to calculate the relative position of the barbell 16
(not shown in FIG. 3) at that particular moment. The processor
control 52 stores the different positional information over time
and therefore can also calculate the speed and acceleration of the
barbell 16. The position and speed of the barbell 16 are evaluated
and if they are outside the accepted tolerances and decision is
made as to whether the brake 42 and/or motor 26 should be engaged.
The decision as to whether the position and/or speed are outside
the accepted tolerances is discussed with reference to FIG. 4.
[0043] If processor control 52 determines the speed is above an
acceptable limit, the processor control sends a signal to the brake
control 60, which engages the brake 42 (not shown in FIG. 3).
[0044] If processor control 52 determines the motor 26 should be
engaged, the amount of load the motor should bear is calculated by
the processor control 52 (The calculation of the load born is
discussed with reference to FIG. 4) and a message is sent to the
engine control 58 to wind in the cable 30 to bear the correct
amount of load. The speed sensors 54 feedback to the controller 52
which in turn feeds back to the engine control 58 to either
increase or decrease the load on the cable. With such a feedback
loop it is desirable to use a servomotor as the motor 26.
[0045] In the preferred embodiment the cable 30 is kept taut at all
times to minimise the time for the motor 26 or brake 42 to be
properly engaged. In further embodiment the cable 30 is slack and a
cable tension sensor 56 is required. Such a sensor is required to
allow the processor control 52 to compensate for the slackness in
the cable 30. For example if a user drops the weighted barbell 16
the speed sensors 54 would register the increase in speed which
would be flagged as dangerous the controller 52 which would engage
the brake 42 via the brake control 60. If the cable 30 is slack the
barbell will fall further than if the cable 30 were taut. To
compensate the controller 52 would, for example, engage the engine
58 until such time as the tension sensor 56 would register the
cable 30 as being taut.
[0046] In the preferred embodiment the characteristics of freefall
will be programmed in, so releasing a weight altogether will
automatically apply the brake. Also, each site can set a minimum
height above the bench below which the weight will not be allowed
to go. These additional features are designed to increase the
safety of the user.
[0047] In use, a user inputs the details of the exercise they wish
to perform including the weight on the barbell 16 and number of
repetitions, and details regarding themselves e.g. height, arm
length into the control panel 28.
[0048] In a further embodiment the user inputs a unique ID, which
will identify the user, and retrieves previously inputted
information about the user from a writeable memory 62. The ID
preferably also identifies a training programme for the user and
displays the programme to the user at the control panel 28 via the
GUI 50. The user indicates via the control panel 28 if they wish to
accept the suggested exercise or another exercise. If the user does
not have an ID, the details of the user are preferably stored on
the memory 62 so that the information may be retrieved upon any
subsequent use.
[0049] In another embodiment the user does not input any
information into the control panel and the apparatus is calibrated
to the user at the start of the exercise. The calibration in
requires the user to perform a single or multiple presses, where
the sensors 34, 40 calculate the maximum height of the barbell 16
during the press which corresponds to a full extension of the
user's arms, and the speed of the lift (during both ascent and
descent). The sensors 34, 40 preferably also record information
regarding the height of the barbell 16 through the press, as well
as the time. This allows the processor to construct a model height
versus time graph for an individual press. The sensor information
would also be used to construct graphs of various parameters, e.g.
acceleration versus time. These graphs are discussed in further
detail with reference to FIGS. 4 to 6.
[0050] After input of the data and/or calibration the user performs
their exercise in the normal manner e.g. bench press. Sensors 34
and 40 measure the position of the barbell 16 and cable speed
sensor 44 measures the speed at which the barbell 16 is being
moved. The sensors 34, 40, 44 send their readings to the processor
38, which uses triangulation techniques to determine the relative
position of the barbell 16.
[0051] The speed and positional information is used to determine if
the processor control 52 is required in engage the brake control
60, to bear all the weight (i.e. the weights exert zero net force)
or engine control 58 so that the net force exerted by the weights
is reduced. The method and process of determining the course of
action and the response is discussed in further detail with respect
to FIGS. 4 to 6.
[0052] FIG. 4 shows an example of a typical height versus time
graph for a single lift.
[0053] There is shown the distance S, along the y-axis and time t
along the x-axis. The lift is divided into seven stages A,B,C, D,
E, F and G.
[0054] These seven stages represent, the lifter performing the
following actions: [0055] A. Accelerating the bar from rest to a
maximum velocity; [0056] B. Extending arms at maximum velocity;
[0057] C. Decelerating to lock position at full extension; [0058]
D. Holding the bar at full extension; [0059] E. Accelerating to a
maximum descent velocity; [0060] F. Holding the fixed velocity for
descent; and [0061] G. Decelerating to zero velocity at the rest
position.
[0062] The graph is constructed from the sensor information of the
various sensors 34, 36 placed on the apparatus. The processor 38 is
enabled to determine the position of the barbell 16 at various time
intervals. Therefore the processor 38 has position and time data
for the barbell 16, and the construction of the graph is
implemented using standard methods. In the preferred embodiment,
the graph is calculated with a relative position, the baseline
being the rest position assumed between reps.
[0063] From this graph and the associated velocity versus time and
acceleration versus time graphs the performance of the user, or
lifter, may be determined and a decision as to whether to the user
requires assistance, and the extent of assistance may be made.
[0064] The simplest measurement is distance (S). There is a minimum
value (S0) which is the rest position, which corresponds to the
lowest position of the barbell in a single press. Typically, in a
bench press this would be a couple of inches above the user's
chest.
[0065] There is also a maximum value (SMax), which represents the
position for the arms at maximum extension. The values of S0 and
SMax will differ according to each user and their lifting
styles.
[0066] The absolute detail of the shape will also vary between
lifters, and even varies between exercises for the same lifter,
however, the general shape and the seven stages are consistent
across all weightlifters.
[0067] As mentioned previously, there is, for a given lifter, a
`Calibration rep` which is stored in the system (this may, in fact,
be the average over a number of reps). This represents the optimum
performance of that user, carrying out a single lift when they are
unfatigued. Preferably, the calibration rep is performed at the
start of each session, as the performance of a user may change over
time. In further embodiments the Calibration rep is stored from
previous instances of the user.
[0068] The Calibration rep, is known to change between sessions,
and within one session represents the optimum behaviour of the
user. In an embodiment of the invention, the first rep of the user
is used as the calibration rep, and the user immediately commences
their exercise set.
[0069] The spotter detects the onset of fatigue (and hence decides
on the level of assistance) by comparing various parameters of the
Calibration rep with the actual performance on a given rep.
[0070] The parameters used can be grouped by measurement and stage,
where the measurement is either S (distance), V (Velocity) or A
(acceleration).
[0071] FIG. 5 shows a typical velocity vs. time graph for a single
rep. The seven stages A to G are equivalent to those described in
FIG. 4.
[0072] FIG. 6 shows a typical acceleration vs. time graph for a
single rep, with the same seven stages as described above.
[0073] From the graphs shown in FIGS. 4, 5 and 6 one or more of the
following parameters are determined by the processor 38.
[0074] SMax--full extension measured in StageD;
[0075] TMax--length of time weight is held at full extension in
Stage D, which are determined from the height versus time graph
(FIG. 4).
[0076] Vup--velocity achieved in Stage B; Vdown--Velocity achieved
in Stage F, from the velocity versus time graph (FIG. 5).
[0077] AA--acceleration to maximum lifting velocity (as measure in
stage A); AC--deceleration at end of lift (as measure in stage C;)
AE--acceleration to descent velocity (as measure in stage E);
AG--deceleration to rest (as measure in stage G), these are all
measured from the acceleration versus time graph (FIG. 6).
[0078] The system maintains two variables for the distance, which
describe permissible variation in the parameter, these are: [0079]
.DELTA.PN--the normal variation in this parameter which does not
indicate any fatigue; and [0080] .DELTA.PF--the failure variation
of the parameter which indicates that the lifter has passed their
limit.
[0081] An example of the use of .DELTA.PN and .DELTA.PF is given
using the velocity Vup, the measured velocity in stage B. From the
calibration lift a value of Vup, where the user is assumed to have
zero fatigue is calculated. This value of Vup is expected to
decreased during the exercise as the user becomes fatigued.
[0082] By comparing the actual value of Vup to the calibration
value of Vup a value of .DELTA.Vup may be determined. The preferred
method of determining .DELTA.Vup is:
.DELTA.Vup=(Vup.sub.calib-Vup.sub.actual)/Vup.sub.calib
[0083] where Vup.sub.calib is the speed of the press in the
calibration press and Vup.sub.actual is the speed during the
exercise. Other methods for determining .DELTA.Vup such as the
absolute difference between Vup.sub.calib and Vup.sub.actual may
also be used.
[0084] In the preferred embodiment the processor 38 uses look up
tables to determine a course of action based on the value of
.DELTA.Vup. For example if the value of .DELTA.Vup is 0.1 this
would indicate that the user is performing the lift 10% slower than
during the calibration rep. Such a value in the look up table would
be marked with .DELTA.VupN or .DELTA.PN i.e. that the user has not
reached failure. Accordingly the processor 38 would continue
monitoring the exercise and allow the user to continue as
normal.
[0085] If at a later time, say after the 10th rep, the value of
.DELTA.Vup is 0.66, this would indicate that the user is becoming
fatigued and may require assistance. In this example the look up
table for 0.66 would read .DELTA.VupF or .DELTA.PF i.e. the user
has reached failure and requires assistance. The process of
assisting the user is described below with reference to FIG. 7. The
above measurement of the variation between the model and the actual
behaviour and the monitoring of the values of .DELTA.P may be
applied to one or more the parameters listed above and not just
Vup. Additionally, the look-up tables may be tailored to the
individual user, depending on the extent of the exercise they wish
to do, with the values of .DELTA.PN and .DELTA.PF changing
accordingly.
[0086] In a further embodiment, the profiles that are stored in the
writeable memory 62 also contains a "problem pattern" library. The
library contains profiles which are indicative of current types of
"non-ideal" lifts. The term non-ideal relates to where a lift is
not performed in the idealised manner, for example, where one arm
is favoured over another arm, the barbell 16 may rotate slightly.
By analysing the performed exercises against the "problem library"
the invention is able to identify if any lifts are being performed
incorrectly. Preferably, the invention is able to communicate this
to the user by way of the GUI 50.
[0087] FIG. 7 is a flow chart of the process of the spotter
algorithm that the controller 52 uses to evaluate if a user
requires assistance. There is shown the monitoring the speed and
position at step S100, updating the various graphs at step S102,
calculating the value of .DELTA.PN and .DELTA.PF at step S104,
determining if the user requires assistance at step S106, engaging
the motor and or brake at step S108, The monitoring of the speed
and position of the barbell 16 at step S100 is performed using the
various sensors 34,40, 44 which inputs the data to the processor
38. The processor 38 determines the position of the barbell 16 as
well as the time. The information is stored in the processor during
the exercise.
[0088] The monitoring of the speed and position of the barbell
preferably occurs at least 10 times a second and preferably between
100-1000 times a second for safety reasons. This allows for any
potentially dangerous situation to be quickly identified, and the
apparatus to react to prevent any injury to the user.
[0089] Using the information recorded at step S100, the various
graphs are updated at step S102. In the preferred embodiment, the
graphs that are updated are the distance vs. time, velocity vs.
time and acceleration vs. time graphs. From the position and time
information the updating of the graphs is readily implemented by
the processor 38.
[0090] Using the updated graphs from step S102 the values of AP,
where P is parameter e.g .DELTA.Vup, are updated at step S104. The
determination of the values of .DELTA.P is as described above.
[0091] Once the values .DELTA.P has been determined it is compared
to the value of the look up table at step S106. If a value of
.DELTA.PF is returned it is an indication that the user has reached
muscle failure or is fatigued and therefore requires assistance,
the process goes to step S108. If .DELTA.PN is returned the user is
within the acceptable limits and the process returns to step S100
and repeats until failure has been reached or the exercise is
finished. By monitoring the speed and position several times a
second, values of .DELTA.P may be dynamically updated. i.e. they
are updated whenever a measurement is taken. Therefore, measures of
fatigue and failure may be dynamically determined during user
exercise. Preferably step S106 is performed upon each measurement
of the position of the weights by the one or more sensors, and
therefore occurs at least 10 times per second, preferably more.
Therefore the apparatus may be considered to be dynamically varying
the weight, in that the variations occur at a rate such that the
user is unable to notice a pause between operations.
[0092] If the user requires assistance the amount of assistance
required is calculated and the motor and/or brake is engaged at
step S108.
[0093] The amount of work performed by a user during a single lift
is proportional to the area under a distance versus time graph, as
shown in FIG. 4. Such work may be represented as a power curve for
the exercise. The power curve varies with the amount of power
required for the exercise at a given time. e.g. More power is
required at the start of a lift than say at the top of the lift.
Power curves will vary for each user and for the exercise
undertaken. In a further embodiment fatigue and muscle failure may
be measured using the power curve profile.
[0094] If the user requires assistance the speed of the lift is
below the accepted tolerance the amount of load to be taken by the
cable is calculated as being proportional to the weight on the
barbell 16 and the difference between the area under the graph of
the model graph and the actual graph. So if the actual relative
height of the barbell 16 is much lower than the expected height the
difference of the areas would be large and the processor control 52
would send a signal to the engine control 58 to increase the power
of the motor 26 thereby increasing the load on the cable and
reducing the net force exerted by the weights.
[0095] When the system detects fatigue it has the option depending
upon user preference, to engage one of four exercise regimes: 1
forced reps; 2 negative reps; 3 drop sets; 4 partial reps.
[0096] For all types of additional reps the user will have reached
the point of positive muscular fatigue.
[0097] Forced Reps;
[0098] Forced reps require a training partner to provide just
enough assistance to keep the weight moving. This continues for the
desired amount of repetitions.
[0099] The equivalent behaviour for the invention is as follows.
The invention tracks the behaviour of the user to determine if they
are in a fatigue zone (as described below). If they are fatigued
then the system lifts just sufficient weight from the bar to enable
the user to keep operating without entering the failure zone. The
invention continually monitors and re-calculates the required
assistance during the exercise thus keeping the user at the edge of
positive muscle failure. Therefore, the motor dynamically varies
the net force exerted by the weights through the motor until the
user is within the limit of positive muscle failure.
[0100] If the user is found to be in the failure zone the weight is
dynamically reduced until such time the user is able to lift the
weights and they are no longer considered to be failing. Once the
user has reached the fatigue zone (i.e. moved out of the failure
zone) the motor maintains the net force so that the user may
continue the exercise with weights exerting a reduced net
force.
[0101] This is continued until the desired number of reps are
completed.
[0102] Negative Reps;
[0103] Negative reps require a training partner to lift the weight
to the start position at maximum extension (SMax). The user simply
lowers the weight as slowly as possible. When the user reaches the
bottom of the movement, (SMin) the training partner will raise the
weight again. This continues for the desired amount of
repetitions.
[0104] The equivalent behaviour for the invention is as follows.
The invention automatically raises the weight to the maximum
extension (SMax) for this user by engaging the motor 26 to take the
full weight of the barbell 16. The user then takes the weight of
the barbell 16 and lowers it to their minimum position (SMin). The
invention tracks this behaviour and provides safety feature to lift
the weight if it is being lowered in an uncontrolled manner. At the
bottom of the rep it lifts the weight to the top and repeats until
the desired number of reps are completed.
[0105] During descent, as with the forced reps scenario, if the
user is found to be beyond the limit of positive muscle fatigue the
motor will dynamically reduce the net force exerted by the weights
until the user is determined to be within the fatigue zone. As with
the force reps once the user has moved back into the fatigue zone
the net force exerted is maintained.
[0106] Drop Sets;
[0107] For drop sets the user performs a set of any exercise to
failure or a point just short of failure. At this point the weight
is reduced and the user continues for more repetitions with the
reduced weight.
[0108] The equivalent behaviour for the invention is as follows.
The invention tracks the behaviour of the user until the fatigue
zone is entered. At this point it reduces the weight by a
pre-determined percentage and continues to track the user as with
normal reps. The pre-determined percentage may be user inputted
when initialising the apparatus or it may be a set percentage. The
dropped weight may be by either physically changing the weights on
the barbell 16 or using another barbell 16, or by engaging the
motor 26 to bear the pre-determined weight during the lift.
[0109] As with the forced rep scenario, if the user is unable to
maintain their exercise level with the dropped set (i.e. stay
within the limits of positive muscle failure) the motor will
dynamically reduce the net force exerted by the weight until the
user is able to perform their exercise at the predetermined
acceptable level.
[0110] Partial reps
[0111] Partial reps occur when the user intentionally completes
less than the full extension for a rep while using a given weight
on the bar. The partial is typically the top part or the bottom
part of the normal full rep. The user will decide how much of a rep
to complete and whether it is top or bottom. Typically, the partial
rep will be inputted into the control panel by the user at the
start of the exercise. In a further embodiment the partial rep to
be performed will be stored in the user's profile.
[0112] When performing a partial rep with a human spotter the
exercise occurs as follows. If the top part of the rep is to be
completed the training partner holds the bar at the starting
position. The user lifts from there to the top of the rep in an
unassisted manner, and then returns the weight to where it started,
at which point the training partner takes the weight from them. If
it is the lower part of the rep then the user starts from their
normal SMin and lifts until the spotter tells them that they have
reached their desired extension.
[0113] The equivalent behaviour for the invention is as follows.
The invention can be configured to provide either Upper or Lower
partial reps. The user must choose the type of rep and the range of
the rep (i.e. the distance between bottom and top of the rep).
[0114] For upper partial reps, the invention moves the weight to a
position which is below SMax by the value of range of the rep. The
user takes the weight, lifts it to the top and lowers it. When the
weight reaches the position which is below SMax by the value of
range, the invention takes the full weight.
[0115] For lower partials, the system treats the rep like a normal
rep, except that it takes range, rather than SMax to be the top of
the rep. In the preferred embodiment there is an auditory
confirmation, such as a siren, is used when this position is
reached.
[0116] In a further embodiment the look up tables are used to
determine the amount of assistance required. From the example of
.DELTA.Vup in FIG. 6, .DELTA.Vup was 0.66, the look-up table also
contains an indication of how much weight should be beared by the
cable 30 and motor 26. The value of 0.66 would indicate that whilst
the user is tired they still have not reached total muscle failure
and accordingly the motor 26 and cable 30 will take 10% of the
total weight of the bar. The higher the value of .DELTA.Vup, the
more fatigued the user and therefore the greater the weight born.
As a safety aspect if the value of .DELTA.Vup reached 80% the motor
and cable would take the entire weight of the barbell 16 as the
user would have reached a dangerous level of muscle failure and may
potentially lose control of the barbell 16. Again the value of the
percentage of weight to be taken by the motor as defined in the
look-up tables may be varied.
[0117] The power supplied by the motor 26 is, in a preferred
embodiment constantly adjusted, to take into account the user
performance when the engine is engaged. The values of .DELTA.PN and
.DELTA.PF are re-calculated whilst the assistance from the motor 26
occurs. If the value of .DELTA.PN is found to return to within the
acceptable limits it would indicate that the correct amount of
assistance is being provided and that level of assistance is
maintained. If the value of .DELTA.PF increases whilst the motor 26
is engaged, it would indicate that the user requires further
assistance and the processor control 52 would send a signal to the
engine control 58 to further increase the power supplied. The level
of assistance (i.e. reduction in net force) is increased until such
time that the user is within the pre-determined zone e.g. the
values of .DELTA.PN and .DELTA.PF are within the acceptable limits.
Once the user is within the acceptable limits then the present
level of assistance is maintained.
[0118] Drop Sets;
[0119] In yet another embodiment of the invention, if the user is
found to require assistance the apparatus may enter "drop weight"
mode. Once the user has reached failure on a particular weight set,
the rep is completed and the barbell 16 returned to the rack 14.
Weights are then removed from the barbell 16, and a further set of
reps are completed using the lower or dropped weight set.
[0120] In yet another embodiment of the invention, if the user is
found to require assistance the apparatus may enter "drop weight"
mode. Once the user has reached failure on a particular weight set,
the rep is completed and the barbell 16 returned to the rack 14.
Weights are then removed from the barbell 16, and a further set of
reps are completed using the lower or dropped weight set.
[0121] In a further embodiment, the motor 26 is used to simulate
the removal of the weight from the barbell 16, during the "drop
weight" mode. In this embodiment, the cable 30 is kept taut and the
motor 26 is engaged to bear some of the load of the barbell 16. For
instance, a user completes 20 reps using a 60 kg weight, and is
found that their value of .DELTA.PF indicates that they have
reached fail after 10 reps. The motor 26 is engaged and supplies
sufficient power to constantly lift 10 kg. Therefore the motor 26
has effectively reduced the weight on the barbell 16 to 50 kg. The
user continues with their reps and is found to fail, from their
measured value of .DELTA.PF after a further 5 reps at 50 kg. The
motor 26 increases the load born by a further 10 kg, effectively
making the weight on the barbell 40 kg. This allows the user to
complete their exercise without having to rack the barbell and
remove some weights, as would occur when normally performing
free-weight exercises. The setting of the drop weight mode is
preferentially preformed at the control panel 28, where the
increments in the reduction of weight may be set, though it may
also be activated as part of a user profile stored in the writeable
memory 62.
[0122] A further indicator of a user requiring assistance is if the
relative height of the barbell 16 begins to decrease before maximum
extension is reached. This indicates that the user has reached
muscle failure and the processor control 52 is required to engage
engine control 58 as a safety feature. The load that the cable 30
would bear in this situation in an embodiment is calculated by the
value of .DELTA.PF. In a further embodiment the power of the motor
26 and therefore the load beared is taken as being proportional to
the weight of the barbell 16 and the difference between maximum
height achieved and the maximum expected height. Again, if the
difference is large the processor control 52 increases the power of
the motor 26 thereby increasing the load on the cable and reduces
the net force exerted by the weights.
[0123] The motor 26 is engaged at step S108 winding in the cable 30
to take the load as required. Once the motor 26 is engaged the
speed and height of the barbell 16 are continually monitored. If,
in the case of the speed falling below a set tolerance, the
difference in the area between the model and actual graphs
increases, it would indicate that more assistance is required and
the motor 26 increases its load borne. If the speed increases to
above the expected speed the load bared by the motor 26 will
decrease, as it would indicate that the user requires less
assistance. Therefore, once the motor has been engaged to vary the
net force exerted by the weights, the process returns to step S106
to monitor the user's exercise. If the user is still found to
require assistance at step S106 the process repeats until the user
is found to be within an acceptable limit of the predetermined user
profile. Therefore, the power exerted by the motor 26, and
therefore the reduction in the net force, is continually varied
until such time the user is within an acceptable limit i.e. is
found not to require assistance as determined at step S106.
[0124] As a further safety mechanism, if the barbell 16 is
travelling downwards the speed at which it is travelling is checked
against a maximum safe speed and preferably acceleration. Given the
position and time information the processor is able to measure the
speed and acceleration of the barbell 16. If the barbell 16 exceeds
the maximum safe speed or acceleration it would indicate that the
user is unable to control the barbell 16 and the controller 52
engages the brake. Preferably as well as engaging the brake the
motor 26 will also be engage to lift the barbell 16.
[0125] In yet another embodiment, further monitoring of the user
may also occur by measuring the rise time, sections A, B and C of
FIG. 4, the fall time sections E, F and G of FIG. 4 and the pause
time which is simply the period of time between reps. As a user
completes more repetitions it is found that the pause time
increases as the user becomes fatigued. If the pause time is
measured to increase to a level greater than expected, this would
be taken as an indication that the user may require assistance. In
an embodiment of the invention there is a maximum pause time which
if exceeded would automatically engage the motor 26. The maximum
pause time may be set by the user at the control panel 28 when
initialising the invention or be a default setting of 20
seconds.
[0126] Other free-weight exercises will have different shaped
graphs, and the processor 38 would react according to these graph
shapes. In a further embodiment the graph shapes for the individual
users are stored on the writeable memory 62 allowing the processor
38 to compare the height and speed against previous user data
rather than model data. If a model height versus time graph is used
it would be stored in the memory 62 and preferably accessed by the
processor 38 during the initialising of the apparatus 10.
[0127] In a further embodiment of the invention the control panel
is enabled to accept voice commands. As well as monitoring the user
in the manner described above the invention may accept commands
from the user such as "Spot" or "Help" to engage the motor 26 and
"more" or "less" control the amount of load to be supported by the
motor. This embodiment relies on standard voice recognition
techniques to determine that assistance is required.
[0128] Whilst the present invention has been described with respect
to the bench press exercise as shown in FIG. 1, those skilled in
the art will understand that the present invention need not be
limited to the bench press but is also applicable to all other
forms of free weightlifting such as an inclined barbell press,
dumbbell flyes, standing barbell press, dead-lifts etc, as well as
stacked weight machines and physiotherapy equipment where the
weight taken by the invention is that of the users limb or body.
Other weight exercises and applications will have different shaped
graphs, but the processor 38 calculation of .DELTA.PF and .DELTA.PN
would be performed in an identical manner, of using a calibration
rep and comparing the actual data to the calibration data and
making decisions based on the comparison as described above.
[0129] FIGS. 8 shows a further embodiment of the apparatus. There
is shown the features of the apparatus as described in FIGS. 1 and
2.
[0130] In this embodiment there are two motors 26, each with
pulleys 20 and cable 30. The cables 30 are attached at opposite
ends of the barbell 16. In this embodiment, the motors 26 are
configured to provide different amounts of support on each side of
the barbell 16. This may be required when one of the user's arms
reaches fatigue or failure before the other. The method for
determining if a user is reaching fatigue or failure is as
described above.
[0131] In a preferred embodiment, the processor also places a limit
on the differential between the supporting forces provided by each
motor 26 thereby ensuring that the user does not preferentially use
one arm over another.
[0132] FIG. 9 shows yet another embodiment of the apparatus. There
is shown the features of the apparatus as described in FIGS. 1 and
2. There is also shown a track 51.
[0133] The vertical supports 18 are moveable along the tracks 51.
The supports 18 are moved using a pulley and cable system (not
shown) though other methods may be used. Depending on the exercise
to be performed the tracks 51 may be positioned to move the
vertical supports 18 in the direction of the exercise. For example,
in a "pullover" type exercise, the lifter lies on their back and
weights are moved from abdomen to above their head, the weights
move both vertically and horizontally, as opposed to a "bench
press" where the weights move vertically. The vertical supports 18
are moveable to ensure that the support is above the barbell 16
during the exercise. In further embodiments the supports 18 are
fully moveable in the x-y axis thus ensuring that the supports 18
are above the barbell 16 for all range of motions.
* * * * *