Different GPS speeds on different computers

Albertus
Posts: 3
Joined: Thu Jun 26, 2008 12:29 pm

Different GPS speeds on different computers

Postby Albertus » Thu Jun 26, 2008 12:50 pm

I have some DL's and IMU6. We did some tests yesterday and i have loaded the (same .RUN) data (from one DL2 with IMU6) into 3 different computers. Computer 1 gave me a speed of 127 km/h, computer 2 a speed of 131 km/h and computer 3, 140.2 km/h. How is that possible? Computer 1 RT software version 6, computer 2, version 7 and computer 3 version 7,2,68. I've exported the data on the 3 computers to an Excel file and have the same results. Changing the analysis mapping option into'" not combining data"gives (after re-calculations) a better result. Computer 1 128, computer 2 and 3 131 km/h. But, there is still a difference. What im I doing wrong?

Greetings Albertus
Holland

faraday
Posts: 284
Joined: Sun Feb 25, 2007 1:18 am

Postby faraday » Thu Jun 26, 2008 1:43 pm

:shock:

The mind boggles!

:roll:

What manner of testing are you doing?

Are the position maps clean and believable?

If you have the old setup executables, uninstall each version with the 'Other' > Uninstall utility, install again and see if issue persists.

Regards from Australia.

Albertus
Posts: 3
Joined: Thu Jun 26, 2008 12:29 pm

Postby Albertus » Fri Jun 27, 2008 8:17 am

Hello Australia!
thanks for your reply.

We did some motorcycle tests on a open race track. What do you mean with "position map"?

The protocol was: 10 laps on the trach with the gps on the back of the MC.
Then we imported the .RUN data in computer one. The top speed at one place at the track was in computer one (with RT V6) 127 km/h. Because the battery was empty I,ve loaded the same data in computer 2 with RT V7 software. This computer gives a topspeed of 140.1 km/h. I did not trusted the data anymore and imported the same file in my Home computer with the latest RT software. Topspeed 131..
Another problem is my IMU6 sensor. On the V6 and V7 software the scaling is in "g", on the latest software I see scaling from 0 to 120. Is there somewere a "superbug"? Next week I will re-install the old V6 software and replace it for the latest version. Then I try to do some validation tests in a car.
Thanks again. (sorry for the bad english. Not my second language)

Albertus

faraday
Posts: 284
Joined: Sun Feb 25, 2007 1:18 am

Postby faraday » Fri Jun 27, 2008 5:02 pm

Your English is fine :)

Is the logger mounted with isolation from harsh engine vibration?
Was the circuit a smooth road surface?

Vibration can upset GPS componentry.

Email me some data if you like: rotoflow at optusnet dot com dot au. Maybe I can spot something. Perhaps the bike application is tricking something - it shouldn't, as long as accelerometer assistance is turned off.

Did you buy the IMU specifically for bike testing?
I don't imagine too many have been sold. I have no experience of such a beast.

By "position map" I mean a "Track Map", which shows the GPS position solution, as opposed to the speed solution that you have focussed on.

Does the path displayed appear to be accurate, with a good overlay lap-by-lap and smooth curves, or is the trace jumpy or discontinuous?

I have experienced some very strange bugs in many versions of R-T software that only occur rarely. It is complicated stuff and with a relatively small user population, the nastiest seldom occur.
I gather R-T is a small and very lean enterprise. Most of the product is very keenly priced. Thus, in-house testing is probably not as extensive as some might expect.
More often than not, the problem will not repeat, or a re-install fixes it. I might suffer such an inconvenience every six weeks or so, but I use the product almost every day.

:)

Albertus
Posts: 3
Joined: Thu Jun 26, 2008 12:29 pm

Postby Albertus » Mon Jun 30, 2008 7:05 am

Is the logger mounted with isolation from harsh engine vibration?
Yes, we use a kind of "pillow" on the MC
Was the circuit a smooth road surface?
Yes, but the test was done by a professional racing driver on a Ducati 1098S so there was off course some vibration ans high lean angles
Does the path displayed appear to be accurate, with a good overlay lap-by-lap and smooth curves, or is the trace jumpy or discontinuous?
Yes
In fact, the DL2 works fine. Ik think it is not a data gathering problem. It seems to me that the whole problem is a softwareproblem.
I'm starting today with some validationtests. You'll here from me.

Support

Postby Support » Mon Jun 30, 2008 1:50 pm

Hi Albertus,

If you have any doubts then please email me the run file at:

andrew@(then the normal RT-URL)

and I would be very happy to look at it for you.

BR,

Andy


Return to “GPS-specific questions”

Who is online

Users browsing this forum: No registered users and 2 guests