Consecutive laps do not overlay

MotoKinetic
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Joined: Tue Jan 15, 2008 10:30 pm
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Consecutive laps do not overlay

Postby MotoKinetic » Tue Jan 15, 2008 10:55 pm

A client of mine has a DL1 Mk2 installed and is getting less than acceptable GPS lap-data. The unit is well installed, the standard GPS antenna is being used and is correctly mounted on the centre of the roof and has a full 360' view. The unit appears to get a good GPS lock but when reviewing data, there is a significant "drift" in track position. In some instances, more than 17m in a corner.

We have tried analysing the data in V6 and V7 of the Analysis software and I have ensured all of the Analysis and Vehicle options are set correctly.

To add to this, we have seen the same results at more than one circuit.

The most recent data file he has sent me is located here :
http://www.motokinetic.com.au/support/OPRUN01MR.RUN

tristancliffe
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Joined: Thu Mar 15, 2007 3:41 pm
Location: Norwich, UK
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Postby tristancliffe » Wed Jan 16, 2008 9:38 am

Downloaded and loaded. Played a bit. Tried every combination of options, and every trick I know.

And I can't get it to line up any more. You have good GPS signals throughout, and your accelerometer data doesn't change it. But that's the only thing I can think of - is your DL1 mounted forwards (card slot towards the rear of the car), and accurately square to the centre line? It has to be level too, else it'll be confused. And is it mounted securely - i.e. not on foam or rubber feet, but directly to the chassis (via velcro perhaps)?
Monoposto 2000 - Reynard 883 Toyota

Maxx
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Joined: Tue Jan 09, 2007 10:25 am
Location: Nottingham, UK
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Postby Maxx » Wed Jan 16, 2008 1:10 pm

Most Odd. I also downloaded and tried various different settings in order to try make it line up better but pretty much every variation gives a similar result.

It's not just a DRIFT situation either, the corner shapes are also significantly different in places, see the example below. I assume the actual driven line was not this variable? Was it track or loose surface?

Image

Maxx

MotoKinetic
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Joined: Tue Jan 15, 2008 10:30 pm
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Postby MotoKinetic » Wed Jan 16, 2008 10:00 pm

tristancliffe yes the logger is mounted forward, square to centre-line and level. The installation is similar to all other installations I've worked with and they have worked fine and have been accurate.

Maxx It's a bitumen/hotmix circuit and the driving line would have been within a car width off (or thereabouts) each lap. It's bizzare that this happens at more than one circuit.

I read another forum entry on here about someone getting interference from external sources. This particular car does have a lot of 3rd party electronic control devices installed (boost controllers, ems controller etc). Has anyone ever seen a situation where those type of devices have caused interference on a DL1 ?

Does anyone from RT have any input?

Greg Amy
Posts: 25
Joined: Sun Dec 11, 2005 2:59 pm

Postby Greg Amy » Thu Jan 17, 2008 6:15 pm

MotoKinetic wrote:tristancliffeThis particular car does have a lot of 3rd party electronic control devices installed (boost controllers, ems controller etc). Has anyone ever seen a situation where those type of devices have caused interference on a DL1 ?

I've read that the GPS signal from satellites can be akin to seeing a candle on a bright day from 5 miles away.

So, absolutely. Trying turning off some of the electrical noise and see what happens.
Greg Amy
FastTech Limited, http://www.fasttechlimited.com/
Data Acquisition, Driver Consultation

boxheadmr
Posts: 22
Joined: Sat Sep 22, 2007 8:41 am
Location: Sydney Australia

Postby boxheadmr » Mon Feb 04, 2008 8:53 am

hi,
i am the owner with the above problem and am geting a little frustrated, it does not seem to be an electrical issue as the unit is mounted away from any electrical items under the passenger side glove compartment.
Would be good if i could use the unit for it's intended purpose after the 3 months i have had it for.
Anyone want to buy a $1500 paperweight?

Matt

Support

Postby Support » Mon Feb 04, 2008 1:42 pm

Hi,

We've arranged an exchange on this unit - it does appear to have a problem with the GPS unit.

Thanks

Andy (UK support)


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