Hi all,
In testing the DIMU I ran into what seems like the same problem several times, except now I finally was able to log it (first time forgot SD card, 2nd time SD card didn't work).
First time: Had been flying a bit in manual, position hold, RTH, and waypoint modes. Then changed batteries and sent a mission with an autonomous take-off. Throttle to 30% in manual, then switch to mission mode and throttle to 50%. The copter starts to rise but at about 10m it suddenly starts a steep bank to the right and increases throttle audibly and loses control. Before I have time to go to manual it makes a semi-circle and crashes into a building (no worries, empty warehouse). Had to replace a Recom and some props etc.
Second time: Tried a take-off in PH. Throttle to 30% or so in manual, then PH on and throttle quickly to 85-90%. Copter takes off and rises but has some slight drift. Then it seems to lose its position and drift faster and then steep pitch and goes off in forward direction very fast. I switch back to manual and land without issues. Without turning the copter off I take off again in manual and switch to PH. Now there seems to be no problem, position is quite stable and I fly around for a while. Unfortunately the SD card logging was not working this time.
Third time (10-15 minutes after 2nd time): I got the SD card logging again and replaced battery. I try to reproduce the issue with success. I take off in PH like before and it rises with some slight drifting when suddenly the motors seem to go full power and the copter rises fast and tilts forward. I switch back to manual and recover. After reboot I fly with manual take-off and PH works like normal.
I reviewed the log (attached) and my tentative conclusion is an issue with the GPS. The GPS altitude suddenly drops right before the motor throttle goes through the roof.
So several questions:
1. Do you agree that this is a GPS glitch or is there something else happening?
2. Why does the UKF_PRES_ALT also show the same dip at 7.2secs while ADC_PRESSURE1 is showing normal behaviour?
3. Any suggestions on what can be done to prevent this?
4. Are the vibrations too high?
Here some additional info:
- AQ 6.1 with R372-DIMU 1.1 FW
- Quad-X setup with ESC32 and Tiger Motor U3
- AQ GPS and ground plane
- Statically balanced TM 12" props
- Total weight around 2.5kgs
Sorry for the long story, but this is puzzling me. Hope that someone can help me.
Cheers,
Richard