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G meter discrepancy
Posted: Fri Jun 02, 2017 5:22 am
by boggie1688
Some of you may have seen the video I posted from my recent Autox event. I was looking over the video and notice the g meter seems off. Particularly in the 180 turn towards the end if the run.
I've attached a raw datalog and was hoping someone could help. Is it the datalog? Meaning the RCP needs to be recalibrated? Or does it have something to do with how racerender is calculating the g?
https://drive.google.com/file/d/0B-Udn3 ... p=drivesdk
Posted: Fri Jun 02, 2017 3:26 pm
by boggie1688
I did a basic Pythagorean calculation on x and y; g= ( x^2+y^2 ) ^ (1/2). Created a column in the log, and loaded it into the app. The calculated G seem more in line with what is expected.
Anyone have the formula for calculating G with x,y,z with yaw, pitch, and roll??
I figure it would be best to calculate this, then compare with race render.
Posted: Fri Jun 02, 2017 4:57 pm
by brentp
How do you have the unit oriented during mounting? is it different than natural orientation (flat, upright, connector facing forward) ?
Also, did not see the video. Got a link?
Posted: Fri Jun 02, 2017 5:42 pm
by boggie1688
Hey Brent,
Natural orientation. It is not on the center of rotation, but mounted under the driver seat. It has the 24 pin connector facing forward and the sd,led,usb connector facing the rear.
Here is a copy of the video:
https://drive.google.com/file/d/0B-Udn3 ... sp=sharing
Posted: Fri Jun 02, 2017 5:54 pm
by brentp
I watched the video, and the 180 degree section around 0:53. What were you expecting to see in the video? Looks like in the 180 degree section you had some consistent lateral G's.
Posted: Fri Jun 02, 2017 6:07 pm
by boggie1688
The actual value seems low.
I admit, I'm red/green color blind. Given the size of the g meter, and the color, I'm having a hard time seeing the tenths place. But to my eyes, it says 0.0X mid turn.
Am I seeing this wrong?
Posted: Fri Jun 02, 2017 6:15 pm
by brentp
Did you check out the data in the app?
Looks like you were pulling about 1G in that turn-around.
Agree, RaceRender seems to be doing something with the actual g-force calculation.
Posted: Fri Jun 02, 2017 6:41 pm
by boggie1688
Thanks for confirming Brent.
I did check the data, but I wasn't 100% sure what I was looking at. The data log seemed correct, but I was trying to figure out where, if any, errors were being introduced.
I'll post on the racerender forum.
Your help is always appreciated.