Allan Bennett wrote:
In article .com, Tinkerntom
wrote:

Why not measure the HR of the engine? I've read that the well trained
athelete can output something in the neighborhood of 1/4 HP. All the
variables of measuring the work accomplished would not change the power
rating of the motor, if it is power you are after! TnT


HR is a measure of sympathetic stimulation and oxygen demand by the working
muscles. It will not give an accurate assessment of power, esp when
anaerobic fibres become significantly invloved... Those who have used a HRM
will also have noticed that HR can remain high even when the workload is
reduced to plodding pace or slower, plus weekly or daily variations.

Allan Bennett
Not a fan of horse-sense


The P.I. I'm working with is actually a systems physiologist, and
currently uses metabolic estimates of power and economy (HR + O2
consumption) for kayaking. We want a more direct measurement.

-Kieran

"Kieran" schrieb im Newsbeitrag
news:nK2Ud.65307$8a6.4571@trndny09...
Hey there, sorry for the cross-post!

I might be taking on a project where we try to determine the power
(force and velocity) developed by a kayaker while paddling. I'm
wondering if anyone out there knows of any research that's been done
like this. I know that it is a fairly common thing for rowing crews to
be "instrumented" with strain guages on the oars, and potentiometers on
the oarlocks, to get force/time curves for on-water rowing. So, I'm
wondering if anyone is aware of this sort of study having been done on
kayaking or canoeing.

The obvious problem with kayaking and canoeing, is that the paddle has
no fixed pivot point, like a rowing shell does. So most likely some
sort of video kinematic analysis will be necessary. We have the
capability to set this up, although I think the physics will be
complicated (i.e. statically indeterminant problem). I've done a search
of the scientific journal literature (Medline) and haven't found any
published papers on this topic, but that doesn't mean the work hasn't
been done at some National training center, or product development
center somewhere... or that it's in a very obscure journal that Medline
doesn't cover.

I'd appreciate any thoughts or hints on who might have done this sort of
work in the past. I'd rather not re-invent the wheel, if I can maybe
work on just improving it! :-)

Thanks,
Kieran Coghlan

Look for

http://www.fes-sport.de/kanu.htm

But I am not sure how much of their work is published

Eberhard

Might be worth looking at the reaction forces on the boat - ie/
footrests/seat, as these would be relatively easy to measure, and with
a bit of meathematical modelling could probably give you a fair amount
of information about paddle force & direction.

In article nK2Ud.65307$8a6.4571@trndny09, Kieran
wrote:
Hey there, sorry for the cross-post!

I might be taking on a project where we try to determine the power
(force and velocity) developed by a kayaker while paddling. I'm
wondering if anyone out there knows of any research that's been done
like this. I know that it is a fairly common thing for rowing crews to
be "instrumented" with strain guages on the oars, and potentiometers on
the oarlocks, to get force/time curves for on-water rowing. So, I'm
wondering if anyone is aware of this sort of study having been done on
kayaking or canoeing.

The obvious problem with kayaking and canoeing, is that the paddle has
no fixed pivot point, like a rowing shell does. So most likely some
sort of video kinematic analysis will be necessary. We have the
capability to set this up, although I think the physics will be
complicated (i.e. statically indeterminant problem). I've done a search
of the scientific journal literature (Medline) and haven't found any
published papers on this topic, but that doesn't mean the work hasn't
been done at some National training center, or product development
center somewhere... or that it's in a very obscure journal that Medline
doesn't cover.

I'd appreciate any thoughts or hints on who might have done this sort of
work in the past. I'd rather not re-invent the wheel, if I can maybe
work on just improving it! :-)


There has been some tensiometric analysis carried out with strain gauges on
the shaft (see The Canadian Canoe Association Coaching Manual; The Science of
Canoeing, Richard Cox, ISBN 0 95118931 14). The work has
been repeated from time to time (I've just dismantled my own kit, sorry).
All the results are similar, but the usefulness is negligible, IMO.

However, I suggest you set up a paddling ergometer which can give you the
data you require w/o the vagaries of water and weather conditions.


Allan Bennett
Not a fan of square wheels



--

Allan Bennett wrote:
In article nK2Ud.65307$8a6.4571@trndny09, Kieran
wrote:
Hey there, sorry for the cross-post!

I might be taking on a project where we try to determine the power
(force and velocity) developed by a kayaker while paddling. I'm
wondering if anyone out there knows of any research that's been
done
like this. I know that it is a fairly common thing for rowing
crews to
be "instrumented" with strain guages on the oars, and
potentiometers on
the oarlocks, to get force/time curves for on-water rowing. So,
I'm
wondering if anyone is aware of this sort of study having been done
on
kayaking or canoeing.

The obvious problem with kayaking and canoeing, is that the paddle
has
no fixed pivot point, like a rowing shell does. So most likely
some
sort of video kinematic analysis will be necessary. We have the
capability to set this up, although I think the physics will be
complicated (i.e. statically indeterminant problem). I've done a
search
of the scientific journal literature (Medline) and haven't found
any
published papers on this topic, but that doesn't mean the work
hasn't
been done at some National training center, or product development
center somewhere... or that it's in a very obscure journal that
Medline
doesn't cover.

I'd appreciate any thoughts or hints on who might have done this
sort of
work in the past. I'd rather not re-invent the wheel, if I can
maybe
work on just improving it! :-)


There has been some tensiometric analysis carried out with strain
gauges on
the shaft (see The Canadian Canoe Association Coaching Manual; The
Science of
Canoeing, Richard Cox, ISBN 0 95118931 14). The work has
been repeated from time to time (I've just dismantled my own kit,
sorry).
All the results are similar, but the usefulness is negligible, IMO.

However, I suggest you set up a paddling ergometer which can give you
the
data you require w/o the vagaries of water and weather conditions.


Allan Bennett
Not a fan of square wheels



--

On 3/2, I posted describing the paddle as a large torque wrench. I have
a background in mechanics and have used torgure wrenches. Is this what
you are mentioning for strain gauges?

You say the usefulness of of the measurements are negligible, can you
expound? TnT

Tinkerntom wrote:
Allan Bennett wrote:

All the results are similar, but the usefulness is negligible, IMO.

However, I suggest you set up a paddling ergometer which can give you

the

data you require w/o the vagaries of water and weather conditions.


Allan Bennett
Not a fan of square wheels

--

On 3/2, I posted describing the paddle as a large torque wrench. I have
a background in mechanics and have used torgure wrenches. Is this what
you are mentioning for strain gauges?

Yes, your idea of using a torque wrench is essentially the same thing
that a strain guage would give. Except the strain guage would be much
more precise, and more accurate.


You say the usefulness of of the measurements are negligible, can you
expound? TnT

I too wonder what Allan meant by this comment.

-Kieran

Allan Bennett wrote:

There has been some tensiometric analysis carried out with strain gauges on
the shaft (see The Canadian Canoe Association Coaching Manual; The Science of
Canoeing, Richard Cox, ISBN 0 95118931 14). The work has
been repeated from time to time (I've just dismantled my own kit, sorry).
All the results are similar, but the usefulness is negligible, IMO.

However, I suggest you set up a paddling ergometer which can give you the
data you require w/o the vagaries of water and weather conditions.

Our lab actually has a very large annular pool where this experiment
would take place, so it would be a fairly controlled environment. I'll
check out the Coaching Manual you referenced above, thanks.

Allan Bennett
Not a fan of square wheels

Yeah, neither am I!

-Kieran

I have another simplistic thought on this subject. How about towing the boat
with a load equivalent to the weight of a the paddler measuring the towing
force versus speed. Then all you have to do is measure the speed to know
what force is being applied.

If you want motive power or P = {F}*{V} then you would wish to measure
either the reaction forces of the Kayaker against the boat and/or the
tractive force of the boat (use a line with constant tension and measure the
velocity.)

If you want the forces on the paddle to generate force vs position and/or
time it will get much more complicated but not impossible. Try using strain
gages on the paddle shaft with the data synchronized with video. You can
(with much labor) get position, force and velocity.

There is software already in use that can provide many of the tools you
need. You may need to spend $$ for it though and the learning curve is
probably steep.

"Kieran" wrote in message
news:nK2Ud.65307$8a6.4571@trndny09...
Hey there, sorry for the cross-post!

I might be taking on a project where we try to determine the power
(force and velocity) developed by a kayaker while paddling. I'm
wondering if anyone out there knows of any research that's been done
like this. I know that it is a fairly common thing for rowing crews to
be "instrumented" with strain guages on the oars, and potentiometers on
the oarlocks, to get force/time curves for on-water rowing. So, I'm
wondering if anyone is aware of this sort of study having been done on
kayaking or canoeing.

The obvious problem with kayaking and canoeing, is that the paddle has
no fixed pivot point, like a rowing shell does. So most likely some
sort of video kinematic analysis will be necessary. We have the
capability to set this up, although I think the physics will be
complicated (i.e. statically indeterminant problem). I've done a search
of the scientific journal literature (Medline) and haven't found any
published papers on this topic, but that doesn't mean the work hasn't
been done at some National training center, or product development
center somewhere... or that it's in a very obscure journal that Medline
doesn't cover.

I'd appreciate any thoughts or hints on who might have done this sort of
work in the past. I'd rather not re-invent the wheel, if I can maybe
work on just improving it! :-)

Thanks,
Kieran Coghlan

Anthony Garcia wrote:
If you want motive power or P = {F}*{V} then you would wish to measure
either the reaction forces of the Kayaker against the boat and/or the
tractive force of the boat (use a line with constant tension and measure the
velocity.)

If you want the forces on the paddle to generate force vs position and/or
time it will get much more complicated but not impossible. Try using strain
gages on the paddle shaft with the data synchronized with video. You can
(with much labor) get position, force and velocity.

Yes, this is exactly what I assumed needs to be done. We have the
hardware and software to do 3D kinematic video analysis, but I was
wondering if there was ever a simpler method devised.


There is software already in use that can provide many of the tools you
need. You may need to spend $$ for it though and the learning curve is
probably steep.

Which software is this? I'd appreciate a link or reference. There is
money to be spent on this... not infinite amounts, but some....

thanks,
Kieran