Hi,
I was flying at approx. 120m for a range test and looking at the log, the bottom distance/altitude measurements reported by different sensors is quite different
I am not sure how to approach this because the altitude reported via the telemetry data is also wrong at times (it might state that the drone is 30m or more higher or lower than it actually is). Therefore, when initiating return to land procedure, the drone will try to climb to what it thinks the actual safe altitude is and then it will not land (very low speed in coming down).
I am not understanding why that is. I thought it happens when the range finder (bottom facing distance sensor) conflicts with GNSS based height measurements, but it also happens when the EKF2_RNG_CTRL is disabled…
What shall I look at to see of the data from the range finder is actually being used? Is it just if the data is being fused?
On another note, it is pretty weird that the max distance reported by the sensor is around 25m, but the datasheet states it is rated for 50m.
Btw, this adds to the issue that the altitude seems unstable at times: there are some low frequency oscillations along the z axis of 3m to 5m. I am guessing that is either related to PID tuning or to the wrong altitude being reported and the drone trying to adjust for it (?).
Can it instead be something related to the EKF2 filters mentioned here: MC Filter Tuning & Control Latency | PX4 Guide (v1.15)
Thanks in advance,
Nick
PS: this is the log