Omnibusf4sd runs PX4: reject position control

No matter what my GPS count is, it doesn’t switch position mode, it tells me to reject position control."

Usually, when position control is rejected, it means that the local position is not valid yet. It’s usually because the GPS doesn’t pass the EKF’s checks.
To check if the local position is valid, go to the Mavlink Console and enter ekf2 status. You can also have more details on the GPS state by entering gps status in the console.

This board does not have MAG.Is it because of this?

Oh, that could be the problem. The EKF can’t run without mag data.

@bresch

Hello, I am using Holybro Pixhawk 4 Mini, and Pixhawk 4 GPS Module, and the Pixhawk 4 Mini has ◦Accel/Gyro: ICM-20689◦Accel/Gyro: BMI055◦Magnetometer: IST8310
◦Barometer: MS5611.

I am till getting this error, how to solve this issue? Please help?

Thank You
Ganesh.

@Ganesh I would need a log to tell you what’s the problem, but it is most likely related to the location of the GPS module. It could be that the GNSS data is jammed by an embedded device (camera, companion computer, …) or that the compass is affected by changing magnetic fields.
First thing would be to check the quality of the GNSS data (gps status) and the mag data (sensors status).

1 Like

Hello all, @bresch hank you for your support, I have uploaded my log http://logs.px4.io.
Please see the log dated 2019-12-16 Description: Critical Reject Position Control.

Trust_Weight ratio as per the eCalc is 5.2.
I am trying to build a endurance quad, so I have to reduce the weight as much as possible.

Your help will be very much appreciated. Thank You.

Hi @Ganesh , this plot shows a big issue on your drone and is most likely closely related to the problem you’re reporting: https://logs.px4.io/plot_app?log=f7fb28d0-572c-4830-8e87-1eb50ba0f957#Nav-Thrust-and-Magnetic-Field

Side remark about

Trust_Weight ratio as per the eCalc is 5.2.
I am trying to build a endurance quad, so I have to reduce the weight as much as possible.

A thrust-to-weight of 5.2 is good for a drone that needs a lot of acceleration such as a racer but is usually not a good idea for an efficient multirotor as it will most likely hover at an inefficient RPM for this motor. (Except if this is for empty weight and the usual takeoff weight will bring down the thrust/weight ratio to ~2)