Introduction

This ROS package implements a state dependent LQR controller for high accuracy trajectory tracking. It was tested with PX4_SITL and Gazebo before being flown in an agile racing quad with a Raspberry Pi 3B companion computer.

Commands

Runs PX4, VRPN (VICON mocap), and relay pose data.

roslaunch lqr_controller mavros_vrpn.launch

Runs main controller and loads param.yaml file.

roslaunch lqr_controller lqr_euler.launch

Future Plans

Working on developing a learning algorithm for inflight thrust mapping. Strain gauges are attached to a quadrotor to collect thrust measurements in flight and how the mapping of normalized motor input [0,1] to thrust changes as a result of voltage decrement, ground effects, and propeller downwash.

Videos:

<img src="https://img.youtube.com/vi/MLneSW5LoOI/hqdefault.jpg" alt="VINS" width="320" height="240" border="10" />

<img src="https://img.youtube.com/vi/oX6Q640imiw/hqdefault.jpg" alt="VINS" width="320" height="240" border="10" />

<img src="https://img.youtube.com/vi/GEzpsT8T1fg/hqdefault.jpg" alt="VINS" width="320" height="240" border="10" />

<img src="https://img.youtube.com/vi/aMhNqe3vxsc/hqdefault.jpg" alt="VINS" width="320" height="240" border="10" />

<img src="https://img.youtube.com/vi/phKAAQSkkjc/hqdefault.jpg" alt="VINS" width="320" height="240" border="10" />

<img src="https://img.youtube.com/vi/Arlwatxqgfo/hqdefault.jpg" alt="VINS" width="320" height="240" border="10" />

Acknowledgements:

This state dependent LQR controller is an extension of [1] for euler angles and quaternions.

References:

[1] Foehn, Philipp & Scaramuzza, Davide. (2018). Onboard State Dependent LQR for Agile Quadrotors. 10.1109/ICRA.2018.8460885.