SF20A Height measurement sudden jumps!

[Margus_A (Margus)]

Pixhawk FW 3.4.2
Pixy IR LOCK
SF10/A

Terrain Following - Disabled
WPNAW_RFND_USE - Disabled
Rangefinder max 25m

The problem is that the sf10/a is giving some kind of jumps. Copter loses altitud 2-4m when turning yaw.

Only in loiter.
Other modes like Auto and Guided etc. are all fine.

Is it possible to turn of rangefinder on other alt. hold modes.
We only need it to precision landing.(RTL)

There is no spikes on Takeoff and Landing also.

The log shows on the start Stabilize but it actually is in loiter.

[OXINARF (Francisco Ferreira)]

Hi Margus,

@Margus_A

Is it possible to turn of rangefinder on other alt. hold modes.

Look at my answer in another topic:

SF11 Lidar use to -1

Ah sorry, as you referred to EKF I forgot about that part. There are different settings, the EKF one just prevents the EKF to use it as a height reference, but it doesn’t disable Copter to use it for surface tracking or landing - to do that you need to use an aux switch (in low position) set to the rangefinder option: http://ardupilot.org/copter/docs/channel-7-and-8-options.html (it’s called sonar in this page).

@Margus_A

The log shows on the start Stabilize but it actually is in loiter.

If the log says Stabilize, it was in Stabilize.

Regarding those big jumps in the end, it looks like you are out of range. Have you configured your rangefinder with the proper max range?

[Margus_A (Margus)]

1. So is the rangefinder primary height measurement if you are under 25 m ?
   If rangefinder is getting bad readings the aircraft is going to that height and not switching to baro ?

2. Loiter is behind the Stabilize.
   Rangefinder is connected to serial and max height is 25m and in the end of the log we went up to 60m to be sure it is rangefinder fault. 60m we didn’t have any height loses.

Im not 100% sure but i think we didn’t had this problem with 3.4.2FW