Day 8

1. Reorganize px4-firmware repo:
   • Forked sitl-Gazebo and added as submodule, in order to create bambi world and models.
2. Set up simulation to develop and test obstacle avoidance:
   • Add iris_rplidar model in bambi world. N.B to make the lidar works properly we had to change rayGPU plugin to the standard ray plugin which instead uses CPU. Moreove we notice strange outputs when the drone is in flight (random short distances,less then 35cm, outputs) so we increase the minimum detected distance to 40cm which is a bit more than the iris frame dimension.
   • Disabled down-facing lidar as suggested in https://github.com/PX4/Firmware/issues/9156 otherwise Gazebo crashes reporting segmentation fault.
3. Added first non-working implementation of Repulsive Force Field Obstacle Avoidance in px4 mc_pose_control_main.cpp:
   • Subscribed to uORB topic obstacle_distance and injected obstacle repulsive thrust vector summing it with setpoint thrust computed by velocity controller. The resulting thrust is then sent to mc_attitude_controller.