1. Sensor modeling in Gazebo can be done using Gazebo plugins. The sensor model can be written using C++, which can be plugged in to the Gazebo simulator.
2. ROS is interfaced to Gazebo using Gazebo ROS plugin. When we load this plugin into Gazebo, we can able to control Gazebo through ROS interface.
3. The important tags are <inertia>, <collision>, and <gazebo>.
4. The Gmapping package in ROS is an implementation of Fast SLAM algorithm, which can be used in robot to map the environment and localizing on it. Using Gmapping in ROS is a straightforward process, including the gmapping node with necessary parameters and topics such as odometry and laser scan.
5. The Move_base node has a provision to handle various navigation subsystem in a robot. It is having a provision to handle global and local planner, also the map of the robot. Once the node receives the goal position, which feed to the navigation subsystem in order to reach to that goal position.
6. AMCL stands for Adaptive Monte Carlo Localization, which is an algorithm to localize a robot on a given map. There is a ROS package in ROS for deploying AMCL in our robot. We can launch the amcl node with proper input and necessary parameters.