Off-center Yaw Rotation

System Overview:

  • Vision System: Stereo Camera - VIO

  • Calibration: Extrinsic calibration between PX4 IMU and Vision IMU performed using Kalibr - i do visualise of the result and its lock good

  • Flight Mode: Position Slow Mode (tested at low speeds to observe behavior).

  • Frame: 7 inch

The Problem: I am experiencing significant Yaw-Induced Translation (often referred to as “orbital yaw” ). When I command a pure yaw via the RC, the drone does not rotate around its Center of Mass or the IMU center. Instead, it travels in a circle with a radius of approximately 1 meter.

Testing & Observations:

  • Static Bench Test: I tested the vision system’s stability on a robotic arm and a rotating chair to simulate pure yaw. In these controlled environments, the position estimate remains stable and does not diverge.

  • In-Flight: As soon as the drone is airborne in Position Mode, any yaw input results in the drone “orbiting” a central point rather than spinning on its axis.

  • Calibration: I have used Kalibr to find the transformation between the PX4 IMU and the camera. I believe my extrinsics are mathematically sound, but the translation coupling persists during flight.

thanks for helping