GPS data jumps (same spot, every lap)

MichaelDrost
Posts: 4
Joined: Thu Sep 14, 2017 1:11 pm

GPS data jumps (same spot, every lap)

Postby MichaelDrost » Sun Oct 01, 2017 2:01 pm

Hello all,

I recently acquired a DL1 mk3 and immediately got going on a full day test. While reviewing the data afterwards, I ran into a few things I can't get my head around. In short: on every recorded lap, the GPS trace seems to jump in the same spots, every lap (see the screenshot).

I've switched around with all sorts of settings, but suspect (and hope) that the GPS data is raw (and therefore unmolested by the Analysis software).
Which leads me to the following question: is this a loose GPS antenna I am looking at?

The (bigger) problem I have is that (even though I thought I had prepped the logger correctly) the sensor measured AccLong and AccLat have been switched around. That makes the option to combine GPS with the accelerometers yield even more suspicious data.

So my second question is: how do I (correctly) re-assign the measured accelerometer data? - update: found it, tried it, failed : the graph still says G_long is G_lat and vice versa -

Thank you in advance for any and all efforts to anyone who can help me here!

Regards,

Michael
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Support
Posts: 399
Joined: Mon Nov 21, 2005 4:09 pm

Re: GPS data jumps (same spot, every lap)

Postby Support » Mon Oct 02, 2017 8:29 am

Hi Michael,

the jumps in the GPS data are due to the wrong mounting orientation being selected in the DL1 configuration software, compared with how you have it mounted in the vehicle. In analysis, we combine GPS with the accelerometer data, as this, when orientations are set correctly, give a much smoother, more precise track map.

Read the configuration back from your unit in the configuraiton software, make a note of your logger orienation in the vehicle, and change this to suit.

Obviously, this will not help for the data already recorded, but will help in the future. Please feel free to send over your run file to me, and I will look at ways to improve this for you.

Kind regards,
RT Support (SK)
Attachments
accelorientation.JPG
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______________________________
Posted by Race Technology Support

MichaelDrost
Posts: 4
Joined: Thu Sep 14, 2017 1:11 pm

Re: GPS data jumps (same spot, every lap)

Postby MichaelDrost » Wed Oct 04, 2017 6:31 pm

Thank you for your assistance!

And I will gladly take up your offer to look at the existing files.

With regards and gratefulness,

Michael Drost

Support
Posts: 399
Joined: Mon Nov 21, 2005 4:09 pm

Re: GPS data jumps (same spot, every lap)

Postby Support » Thu Oct 05, 2017 8:01 am

Hi Michael,

No problem at all.

Please send any run files to sam@race-technology.com. I'll take a look at them for you.

Kind Regards,
RT Support (SK)
______________________________
Posted by Race Technology Support

MichaelDrost
Posts: 4
Joined: Thu Sep 14, 2017 1:11 pm

Re: GPS data jumps (same spot, every lap)

Postby MichaelDrost » Thu Oct 05, 2017 7:55 pm

Yabba dabba doo!

Sam, I followed your lead and fiddled around with the settings (those related to orientation mostly). Had to reload everything, after changing a lot of things, so I am a bit fuzzy on which particular setting it actually was that did the trick.

Now everything is where it should be and I am beginning to get to grips with what Analysis can do: a lot!

Sheer fun just looking at the balance of the car being affected by a gear change, never mind now really seeing just how nervous the car is in some places. The trackmap is now as it should be!! Though this isn't my first analysis tool experience, after the earlier struggles, I can definitely feel the joy of seeing everything fall into place.

Some things are still a bit counter-intuitive (having to use pageUP to go to the next window in the list (which progresses downwards) and vice versa), but I am having a lot of fun now!

So next thing on my playlist: math channels!

Oh and time slip ... how do I zero it on the fastest lap? I now have the fastest lap moving along with the others, when I want to use it as a baseline (ie the red line as a horizontal line, with the other ones doing their delta thingy) - see attachment with all possible options displayed

Or should I repost this question as a new post for the benefit of everyone else?

So, all in all, very, very, very happy with your support and very grateful for your efforts!

With highest regards,

Michael Drost
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924RACR
Posts: 113
Joined: Tue Jul 13, 2010 5:34 pm
Location: Royal Oak, MI
Contact:

Re: GPS data jumps (same spot, every lap)

Postby 924RACR » Fri Oct 06, 2017 12:20 pm

Time slip is based on whichever lap has the "radio button" selected in the lap/sector/best lap time display... so by default it's the theoretical best selected... you can switch to the best Continuous lap, or any individual lap, by clicking on the circle next to the appropriate lap... it will recalculate when you do so...

Make sense?

MichaelDrost
Posts: 4
Joined: Thu Sep 14, 2017 1:11 pm

Re: GPS data jumps (same spot, every lap)

Postby MichaelDrost » Sun Oct 08, 2017 6:10 pm

Absolutely!

Thank you for that!

With regards,

Michael

thokes82
Posts: 38
Joined: Wed Oct 24, 2012 4:11 pm

Re: GPS data jumps (same spot, every lap)

Postby thokes82 » Tue May 28, 2019 1:11 pm

Same Problem here. But with RTLive I am not able to solve it the way you describe. I can change the orientations settings in the analysis only as the RTLive config software doesn't provide these options. The "back" setting should normally be the correct one for my setup. I tried different other settings too.
The back setting has these bumps and I can't explain what is wrong.
Thomas

racetec
Site Admin
Posts: 326
Joined: Thu Oct 27, 2005 12:02 pm

Re: GPS data jumps (same spot, every lap)

Postby racetec » Tue May 28, 2019 1:29 pm

Hello Thomas

The jumps are there as you've not got the mounting orientation correct, and you have the option set to combine GPS+accelerations.

thokes82
Posts: 38
Joined: Wed Oct 24, 2012 4:11 pm

Re: GPS data jumps (same spot, every lap)

Postby thokes82 » Mon Jun 03, 2019 10:25 am

Sorry, I cannot figure it out. Can the problem be linked to the fact that RTLive is not really using the accelerometers but the calculated GPS based values for display? Mounting is correct and setting in Analysis is correct too. Please also confirm that there is not option in RTLive config software for orientation that I am overseeing.
regards, Thomas

racetec
Site Admin
Posts: 326
Joined: Thu Oct 27, 2005 12:02 pm

Re: GPS data jumps (same spot, every lap)

Postby racetec » Tue Jun 11, 2019 12:03 pm

The orientation is not correct, this can be changed in analysis options


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