Twitchy/Unstable flight in position control mode (External Vision Estimator + PX4Flow)

Hello everyone,

Problem: Twitchy and unstable flight in position control mode. For local position on the drone I am feeding Marvelmind(Pose data published to /vision_pose/pose in MAVROS) and PX4Flow.

Previously, I had Toilet bowl effect when I used just external vision estimator without PX4Flow. I am still stuck with this problem. Copter moving in circle in POSCTL mode (external position estimate). To move forward I tried using combination of PX4Flow and Marvelmind, which seems to solve the TBE issue.

In the log even though I am not touching the remote control, the x and y setpoints seems to be changing. I don’t understand why.

When I flew the copter just with PX4flow to debug the issue, the setpoint is one straight line. Please see the logs below.


  1. IRIS drone with Pixhawk 2.1
  2. Marvelmind position system- publishing data over /vision_pose/pose
  3. PX4Flow
  4. Teraranger for height


  1. EKF_AID_MASK = 26
  2. HGT_MODE = Teraranger


  1. Can anyone explain reason for twitchy/unstable flight ?
  2. Is there any reason for the XY setpoint to be changing even when I am not touching the RC controller.
  3. Other than using external vision estimator is there any way to integrate marvelmind to pixhawk with a PX4 1.9.2

Any help will be much appreciated.