Hello!
We bought an OTOS when they were first released. We had it working during the summer before the OTOS got added to the most recent SDK. We are trying to calibrate it to our new robot (now using the newest SDK) and the OTOS is reading consistently wrong on the FTC mats. We calculated the angular scalar and that seems to be working. Then for the linear scalar we had the robot drive straight 96in but the OTOS consistently read 70in. We found that we couldn’t change the linear scalar to compensate for error more than 10-15%. We tried changing the height but it’s already at 11mm. We also bought another OTOS and we tested that one as well with the sample code and we still got inaccurate readings. We tried on our field tiles, as well as clean ties, and the floor.
Do you have any suggestions on what we could do to fix this?
Try these SparkFun Optical Tracking Odometry Sensor (OTOS) Accuracy - #2 by Jason_DeBruler
and High drift with Optical Tracking Odometry Sensor - #12 by SparkFro
The product notes say 10-27mm is best, maybe also try moving it higher to see it that helps or hurts (I presume it would hurt, though!)
Hi there,
I assume you’re using this for FTC, correct? For the FTC foam tiles, the optimal height for the OTOS is 10mm.
When you first used the OTOS and had it working, did it have good accuracy? If so, then something has changed to cause worse tracking. If you switch back to that code, does the accuracy improve?
I’d also suggest testing with the sample OpMode without modification. Some users have reported tracking issues when it was actually a code problem.
Also, please try the sensor on white printer paper, that should rule out any problems with the surface you’re using. If performance is good on the paper, then the problem is something with your field tiles. If it performs poorly on the paper, then it’s something else.
Also, please ensure that you’re using standard foam tiles from AndyMark that are clean. Other tiles have different optical properties that can degrade tracking performance.
And please check that the optical sensor is clean. You can clean it with some isopropyl alcohol and a cotton swab.
Hope this helps!
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We tried all of the above and it was still was not accurate.
We figured out the problem, the hole at the bottom of the box with the OTOS in it was too small. We used the Sparkfun CAD design but it must not have had the 30 degree clearance from the sensor area recommended in the datasheet. We widened the hole and it works much better!
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Thanks for sharing this, I’ll add that to my list of debugging suggestions! Glad you got it working!
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