First of all, clone it to your ros workspace source file then go to your root workspace and type catkin_make and after that source it. Now you can follow the steps to view the navigation course!
In order to start the simulation go to your terminal and hit roslaunch demo_navi mybot_world.launch. Now we want our robot to move as we want, for that hit rosrun teleop_twist_keyboard teleop_twist_keyboard.py.
Because we have two LiDAR we must somehow merge their scan's so launch
roslaunch ira_laser_tools laserscan_multi_merger.launch.
Now that we started the simulation we want it to map the area, to do that we will use gmapping as our SLAM algorithm so hit roslaunch gmapping slam_gmapping_dn.launch after that go your terminal that you runned the teleop_twist_keyboard and navigate the area to map it seeing it from rviz.
After you finish mapping the area, now we must save it, for that open a new terminal and hit rosrun map_server map_server -f /"ENTER YOUR UNIQUE PATH"/navigation/amcl/maps/test_map. If you have problems doing that don't panic, I have already saved a map just in case.If so you can skip this step and close all terminals.
Finally we can see our robot moving autonomously. To begin, do again the step one without running teleop_twist_keyboard and step two after that we can launch amcl roslaunch amcl amcl_omni.launch.
Thank you! ❤️