Custom Data Tracks

by old_man_biking

Downloads: 1,792 (5) • Reviews: 0

Version:

3.0.5980

Updated:

May 15, 2016

Custom Data Tracks; AEPF for left/right leg

Custom Data Tracks; AEPF for left/right leg

Postby tndmbkr » Sun Aug 10, 2014 11:24 am

I think calculated tracks are a wonderful new feature of this plugin.
Unfortunately my first calculations do not give plausible results.

Because of an injury on my left leg, I want to have better information about the distribution of the pedalforce between left and right leg when the load and the cadence are higher.

The concept of Average Effective Pedal Force was introduced to me with the plugin Quadrant Analysis.
When Power= 180W, and Cadence= 100 rpm, the AEPF is about = 100N (crank length=170mm).
When both legs do their job equally, the AEPF for left and right should be 100 N

But I cannot reproduce these findings with the Calculated Tracks feature of the CDTplugin

My procedure.
I create a calculated track for the AEPF of the left leg.
Part 1 of the formula divides the power between both legs
(100-Datapoint PowerBalance) * Datapoint Power / 100
In part 2 the cadence, and the crank length come into play. The cranklength = 170 mm
(Part1 * 60)/( Datapoint Cadence * 2 * 3.141593 * 170 / 1000 )

I think the results of part 1 of the formula are false
When the Average Power for the activity = 180W, and the Avg Power Balance = 60%, one expects 72W for the left leg, and 108W for the right leg.
But part1 of my formula gets to something like 89W left and 91W right.

I do not understand.
Does anyone have a clue?
Last edited by tndmbkr on Mon Aug 11, 2014 1:05 am, edited 1 time in total.
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Re: Custom Data Tracks; AEPF for left/right leg

Postby old_man_biking » Sun Aug 10, 2014 1:42 pm

Can you attach the .FIT file of this activity to your post?
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Re: Custom Data Tracks; AEPF for left/right leg

Postby tndmbkr » Mon Aug 11, 2014 2:34 am

tndmbkr20140809_vsAB.rar
(244.83 KiB) Downloaded 243 times
When I prepared my reply, I tried to split my activity.
Then I noticed there had to be someting wrong with the recorded laps.

In the attached file you will find the fitlogex of the original activity with recorde laps (version A)
And you will find a fitlogex of a part of the original activity without recorded laps Iversion B)

The avarege values of the calculated power for the left/right leg in version B make more sense to me.
Last edited by tndmbkr on Mon Aug 11, 2014 3:54 am, edited 1 time in total.
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Re: Custom Data Tracks; AEPF for left/right leg

Postby tndmbkr » Mon Aug 11, 2014 2:41 am

Here is the .FITfile you asked for
Attachments
2014-08-09-15-40-43.fit
(227.5 KiB) Downloaded 235 times
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Re: Custom Data Tracks; AEPF for left/right leg

Postby old_man_biking » Mon Aug 11, 2014 5:00 am

When I tried to reproduce you issue, I found a bug in Garmin FIT Devices plugin.
When you import with GFD plugin (I assume you did), INVALID power balance values (e.g. when cadence = 0) are reported as 100% right.
I'll fix that for the next version. If you want to try out a beta version, please send me a PM with your email address.

Besides that, I could not find any flaws in your calculation formula, the resulting values look reasonable for my eyes.

Cheers,
OMB
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Re: Custom Data Tracks; AEPF for left/right leg

Postby tndmbkr » Wed Oct 01, 2014 3:21 pm

Thank you for the improved GFDplugin.
I get reliable results for the NEWly imported activities.

But the improved version of the plugin does not help me with the analysis of OLDer activities.
Question: Do I have to import the older activities again?

That means extra work for some activities.
For instance when I have added splits, when I have changed datatracks, etc
Maybe there is a more sophisticated procedure ????
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Re: Custom Data Tracks; AEPF for left/right leg

Postby old_man_biking » Thu Oct 02, 2014 7:50 am

tndmbkr wrote:Thank you for the improved GFDplugin.
I get reliable results for the NEWly imported activities.

But the improved version of the plugin does not help me with the analysis of OLDer activities.
Question: Do I have to import the older activities again?

That means extra work for some activities.
For instance when I have added splits, when I have changed datatracks, etc
Maybe there is a more sophisticated procedure ????

Sorry, but basically you'll have to reimport the activities. The AEPF tracks were wrecked during import and can't be healed.
There might a way to avoid that changes of activities get lost:
1. Import the .FIT files into NEW activities, using the current version of GFD plugin
2. Use Custom Data Tracks plugin to export the AEPF tracks of these newly imported activities to CSV files ...
Note that you can select multiple activities (best in "Reports" view) and use Export:CDT:... to export all CSV files with just one click.
... and import them into the original activities
This needs to be done one by one, but the file names equal the start time, so it's easy to match activities and files.

Cheers,
OMB
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Re: Custom Data Tracks; AEPF for left/right leg

Postby tndmbkr » Mon Oct 06, 2014 3:05 pm

In the Settings page I can define the type of a calculated custom data track; Power, HR, Custom, etc

Question: Why do the values of my calculated AEPF for left/right leg change, when I change the type of these calculated custom data tracks from Power into Custom.

When I assign type Power to these tracks, I get realistic values.
But in the chart the unit is Watt, instead of Newton.

When I assign type Custom to these tracks, the values are way too low.
But in the chart the unit is Newton.
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