PaddleWise by thread

From: <rebyl_kayak_at_energysustained.com>
subject: RE: [Paddlewise] RE: bracing and power
Date: Sun, 25 Jul 2010 12:02:25 +0000
MATT MARINER BROZE wrote:
.........It appears to be nearly exactly how I envisioned it needed to be with strain gauges out near each blade on the shaft and three rotational accelerometers to position its orientation exactly in space at all times. The rotation sensors I felt would be a needed to prove the paddle was being used in a consistent manner during trials of different boats. I've already e-mailed Chris at Sea Kayaker the link in the hopes that they can get one to review ASAP. ........

G'Day Matt,

Hope you enjoy your break.

We talked about this kind of paddle abut five years ago and the role of gyroscopic measurement as well as three axis accelerometers. It looks as if the Talon software has come a long way since then. A paddle restricted to just accelerometers would probably require a double integration in three axes to solve the relevant equations and consequently a deal of calibration and the data could be quite noisy. Hence the potential for gyroscopic measurement. These transducers are now small enough and with fast enough response times to be used in this application and I suspect they have been incorporated. Its a topic Andrew Eddy (an erstwhile Paddlewiser) and I have been discussing at some length as the techniques involved are similar to some that we use in vibration testing of transportation systems. 
 
Margi at Canberra University is likely also working with the Australian Institute of Sport who train athletes for the Olympics. As its a locally built product I'll try contacting her and see if I can get some feedback for Paddlewise and my own interest in the algorithms used.

All the best, PeterO
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From: PeterO <rebyl_kayak_at_energysustained.com>
subject: [Paddlewise] Electronic paddle - was bracing and power
Date: Mon, 26 Jul 2010 18:19:33 +1000
Peter wrote
>We talked about this kind of paddle abut five years ago and the role of
gyroscopic measurement 
>as well as three axis accelerometers. It looks as if the Talon software has
come a long way since then. 
>A paddle restricted to just accelerometers would probably require a double
integration in three axes 
>to solve the relevant equations and consequently a deal of calibration and
the data could be quite noisy. 
>Hence the potential for gyroscopic measurement. These transducers are now
small enough and with fast 
>enough response times to be used in this application and I suspect they
have been incorporated. Its a 
>topic Andrew Eddy (an erstwhile Paddlewiser) and I have been discussing at
some length as the techniques 
>involved are similar to some that we use in vibration testing of
transportation systems. 
 
>Margi at Canberra University is likely also working with the Australian
Institute of Sport who train 
>athletes for the Olympics. As its a locally built product I'll try
contacting her and see if I can get 
>some feedback for Paddlewise and my own interest in the algorithms used.



G'day Matt, Richard and Paddle wise,

Talon Technology, the manufacturers of the kayak data acquisition paddle,
are located fairly close to Stiffies, where I store a boat, so I gave them a
call. We talked briefly about the issues of measuring blade trajectory as
well as rotation and they have gone some way towards this with their kayak
paddle, using three axis accelerometers. However, they thought there would
be some difficulty in measuring kayak paddle sweep strokes with the present
system. If I've understood correctly it looks as if the paddle is good for
analysing racing paddle strokes as intended, including paddle blade angles
in the water, but not adequate yet for analysing rolls, sculling or sweep
strokes. However, Talon do have an experimental version embedded in their
rowing oars, which is not only fitted with accelerometers but also gyro's
and magnetometers. This shows promise, to me at any rate, for being adapted
to analysing kayak paddle movement during rolling, bracing, sweeping etc and
they seemed quite interested in the ideas Andrew Eddy and I were discussing.
We will visit them in the next few days to see if these ideas make sense and
how they might be developed further. Their paddles can be readily configured
to supply the raw data from the transducers so it might be a viable
proposition to get a special made with gyro and magnetometers fitted, for
kayaking applications beyond forward stroke.

As anticipated Talon's collaborators are working with the Australian
Institute of Sport. Richard Smith at Sydney University is also carrying out
research in this area, while Margi Bohm of Canberra University wrote the
review in the 'Canoe and Kayak Racing' Magazine.

I for one will look forward to Matt's formal analysis and review, and to
talking with Talon engineers about how the paddle might be developed
further. 

All the best, PeterO
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From: Craig Jungers <crjungers_at_gmail.com>
subject: Re: [Paddlewise] Electronic paddle - was bracing and power
Date: Mon, 26 Jul 2010 07:02:44 -0700
On Mon, Jul 26, 2010 at 1:19 AM, PeterO <rebyl_kayak_at_energysustained.com>wrote:

>
> Talon Technology, the manufacturers of the kayak data acquisition paddle,
> are located fairly close to Stiffies, where I store a boat, so I gave them
> a
> call. We talked briefly about the issues of measuring blade trajectory as
> well as rotation and they have gone some way towards this with their kayak
> paddle, using three axis accelerometers.
>

Just mulling through the ideas made me wonder whether they will integrate
their paddle data with instant boat speed. I would imagine that a
paddlewheel device would be more likely to tell you whether a given paddle
stroke actually accelerated the boat. A GPS would be too slow. Have they
given this any thought or are they simply interested in paddle dynamics?


Craig
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From: MATT MARINER BROZE <marinerkayaks_at_msn.com>
subject: RE: [Paddlewise] Electronic paddle - was bracing and power
Date: Mon, 26 Jul 2010 13:46:03 -0700
That is what I'm hoping can be done somehow. Add the imput from a knotmeter ro
the data at the same time. That is what will be needed to measure the drag on
different kayak hulls at  various speeds (plus a lot of other variables
controlled).



Date: Mon, 26 Jul 2010 07:02:44 -0700
Subject: Re: [Paddlewise] Electronic paddle - was bracing and power
From: crjungers_at_gmail.com
To: rebyl_kayak_at_energysustained.com
CC: marinerkayaks_at_msn.com; culpeper_at_tbaytel.net; paddlewise_at_paddlewise.net

On Mon, Jul 26, 2010 at 1:19 AM, PeterO <rebyl_kayak_at_energysustained.com>
wrote:



Talon Technology, the manufacturers of the kayak data acquisition paddle,
are located fairly close to Stiffies, where I store a boat, so I gave them a
call. We talked briefly about the issues of measuring blade trajectory as
well as rotation and they have gone some way towards this with their kayak
paddle, using three axis accelerometers.


Just mulling through the ideas made me wonder whether they will integrate
their paddle data with instant boat speed. I would imagine that a paddlewheel
device would be more likely to tell you whether a given paddle stroke actually
accelerated the boat. A GPS would be too slow. Have they given this any
thought or are they simply interested in paddle dynamics?


Craig
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From: Carey Parks <carey_at_jimparksfamily.com>
subject: RE: [Paddlewise] Electronic paddle - was bracing and power
Date: Mon, 2 Aug 2010 11:01:58 -0400
---------- Forwarded message ----------
From: Carey Parks <carey_at_jimparksfamily.com>
Date: Mon, Aug 2, 2010 at 11:01 AM
Subject: Re: [Paddlewise] RE: Electronic paddle - was bracing and power
To: PeterO <rebyl_kayak_at_energysustained.com>


Peter et al,

I was stumbling around in the Android Marketplace looking for cool stuff for
my phone (and I use that term "phone" loosely) and I ran across an app for
rowing that displays and records the boat acceleration and also infers
stroke rate, and some other things by using the "phone's" integrated GPS and
three axis accelerometer. It's pretty good. Both the app and my device.

http://nargila.org/trac/robostroke/wiki

It of course does not integrate paddle dynamics, but to my mind they can be
separated and still be useful. Maybe not optimal, but useful, and the cost
is zero since I own the phone. The system (given boat, paddle, paddler,
water) has an input, the paddlers stroke, and an output, the boat
acceleration. I can think of two distinct scenarios where the optimal paddle
stroke could be different. One is a sprint, when the goal is maximum boat
speed, and the other is a cruise where the goal is maximum boat speed at a
maximum heart rate, or a minimum heart rate for a given boat speed.

I don't have the electronic paddle, but I do have a heart rate monitor and
now this thingy to display and record boat acceleration. I'm going to go
have a play with them both and see how the instant feedback on the
effectiveness of a paddle stroke helps me adjust my stroke (GP) to get the
most effect on the boat.

Lots of things might come into play, like how much of the power developed by
the paddle is absorbed by my body and not transmitted to the boat? I will
try things like feet on and off the pegs, tight back band, different paddle
grips. (I only have one paddle so I'm going to leave paddle length
alone!!!)

Best,

Carey



-- 
http://parkswhistles.com/
http://www.facebook.com/carey.parks
http://twitter.com/LuthierCarey
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From: Carey Parks <carey_at_jimparksfamily.com>
subject: RE: [Paddlewise] Electronic paddle - was bracing and power
Date: Tue, 3 Aug 2010 10:44:43 -0400
Hi Peter,

No, I don't have anything to send BlueTooth to the device other than my
computer, which is not going paddling. The software will accept Bluetooth
input from a heart rate monitor, but only one model as it is interfaced to
it's output stream. I guess XML has not arrived on the scene yet. ;->  The
take-away point from that is if there were a BlueTooth data stream available
someone could write code to grab it an I would think log it along with the
accelerometer data.

Today I went looking and I have found several other free apps that will plot
and log the accelerometer data. One converts to m/s^2 and logs that value. I
can create a log with timestamps in ms from Jan 1, 1970 so it should be easy
to correlate multiple logs provided they have their clocks set the same
and/or as you suggest there is some sync pulse. It might work to strap the
device to the paddle shaft and swing the paddle around a couple times then
move the device to it's logging position for the trials.

Sadly, these later apps require post processing. I would like to have a
display that would give me instant feedback (that I could see in the
sunlight) of the effect of my strokes. I'm thinking that a ten second
integration might be good to allow me to alter some aspect of my stroke and
see what effect that has on the boat speed. The key is accuracy. GPS speed
is quick enough but not precise enough to know if the change is me or just
noise.

I think gathering the data is quite possible given these tools, and the
challenge will be knowing what data corresponds to what changes in form or
other application of the paddle to the water. There are two approaches that
might have merit for different purposes. Prerecorded instructions to the
paddler and live recording of paddler audio. I've tested both of these
techniques sitting here in my office and the device seems to handle both of
them just fine.

One thing I don't know, is if the logged values
are instantaneous acceleration values or averages for the time interval. If
it were averaged then it would be more useful for positional calculations,
but I expect it is instantaneous, and average acceleration will have to be
assumed, which is OK if the sample rate is high enough compared to the
acceleration of the vehicle.

The mp3 player comes with the device.

Here are links to the apps I'm looking at. No connection to any of them
other than I'm trying them out:

Auto mic gain audio recorder:
http://tapemachine.samalyse.com/

Accelerometer logs:
http://www.androlib.com/android.application.org-nargila-robostroke-android-app-jzCFp.aspx
http://www.androlib.com/android.application.pt-acoelhosantos-android-acc-nFwm.aspx
http://www.androlib.com/android.application.com-freshprogramming-sensortive-xDwB.aspx
http://www.androlib.com/android.application.com-ohisamallc-ohiapp29-jwDCF.aspx
http://www.androlib.com/android.application.abs-sensor-ADpA.aspx

I probably won't go paddling to try these ideas until Thursday (GMT -4) and
will continue to think about the issues and/or play with spreadsheets to
convert the data into speed values or other relative numbers that could be
used to compare techniques for better or for worse.

As in any other investigation, it's important to know what one is try to
achieve, and in my case I would like to know what is my most efficient
paddle stroke for A) steady state cruise, and B) burst acceleration.

Carey
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From: PeterO <rebyl_kayak_at_energysustained.com>
subject: RE: [Paddlewise] Electronic paddle - was bracing and power
Date: Thu, 5 Aug 2010 22:36:58 +1000
Carey wrote:
...................I've uploaded some of the data I collected today to
Box.net and sent you an
invite to share the folder..................................

G'Day

Thanks Carey your paddling data came through nicely and I'll start working
through it on Saturday.

All the best, PeterO 
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