Feedbacks from @bresch for visibility:
it’s unfortunate but normal that the height estimate is affected by the range finder when range aid is enabled. Range aid is something we didn’t like and this is why I removed it in 1.14
Some reference documents:
- v1.14 Range finder documentation
- PR that introduced new height sensor configuration architecture: EKF2 multiple height sources fusion by bresch · Pull Request #19944 · PX4/PX4-Autopilot · GitHub
- Another PR that emphasized importance of not using Range Aid completely?!: Use range finder for height control instead of height aiding by bresch · Pull Request #18864 · PX4/PX4-Autopilot · GitHub
My further questions
After some investigation, it seems that range aiding isn’t really removed (as it’s still ‘conditional’, and those conditions are the same, except for the influence from terrain estimator in regards to kinematic consistency check).
Thus, wouldn’t the system from v1.11 with EKF2_RNG_AID = 1, act the same with v1.14 with EKF2_RNG_CTRL = 1 (Conditional), regarding the disruption of height estimation? (Except for the cases where kinematic consistency check is failing)
Answers
Hi, not exactly. You can have the same behavior if
EKF2_HGT_REFis set to “range”. Otherwise, if set to baro or GNSS, the conditional range finder fusion shouldn’t affect too much the height estimate if bad. In 1.11, when range fusion was active (through range aid), it automatically became the reference. Now it isn’t the case anymore, the reference doesn’t change.
Follow up questions
Ahhh gotcha, there’s a difference between being the reference vs just aiding on the side (since v1.14)