I am working on UAV project for GPS denied environments.
The drone should be able to follow a fairly simple pre-defined waypoint path on very moderate speed.
In this sense, I would like to have your input on the location tracking system.
I am very inclined for the Ultrawideband(UWB) system from Marvelmind Robotics (http://www.marvelmind.com).
It can be directly connected to the PXFmini board (that I already have), it has ROS compatibility and Python dedicated library - basicaly, all the features want.
The question is/are:
1) What is the absolute minimum coordinate update rate (Hz) that I need to achieve in order to obtain a fairly stable UAV? On the marvelmind website I have read the position calculation is updated with a 16Hz rate - I am not sure this value is up to date though. Would this rate value make it possible? If not, what other position tracking strategies would you recommend?
2) In order to obtain a autonomous flight, I am planning to use a PID controller, in order to guide the drone by velocity commands. For this, I need to know, at a certain moment, stay "t",the values of pitch/roll/yaw (from the PXFmini IMU) and the concomitant x,y,z coordinates (from the UWB tracking system). Considering the output rates of the IMU and the UWB are different, can this be a problem? Say, can this produce a certain "offset" between the IMU data and the UWB data?
Thanks a lot for any input - anything helps!