How to convert raw xyz in a diff coordinate frame to Pixhawks NED frame.

[ajithmaniac]

Hey I'm using a rf based indoor navigation system which spits the xyz of the UAV. The frame is actually fixed but at a yaw angle of 40 degrees with the Earth Fixed NED frame. I'm trying to convert it to Pixhawk frame. I just send the XYZ values from the indoor navigation system, after compensating for the yaw angle, to the Pixhawk thru the vision_pose/pose topic. I tested the setup by moving the quad using hand, the local xyz and vision_estimate did sync very well. So I tried testing the quad in manual posctl mode. The quad rises up, turns in the yaw axis and keeps drifting. I don't know what the issue is. I'm not sending any roll pitch yaw information thru the vision_pose topic. Do you think that is an issue ?? Can you brief on what data I should send to Pixhawk thru vision_pose/pose topic in order to sync the fixed coordinate frame and Pixhawk body frame.

[edkoch]

When you say it is drifting do you mean that the position is drifting or that the yaw angle is drifting? Yes you should send orientation information through the vision_pose topic. This is how it gets the correct yaw angle.

[edkoch]

BTW one might be tempted to just keep feeding back whatever position or orientation you get from the vehicle thinking that it should hold it stable, but in fact what it will do is slowly drift.