add slam_gmapping

slam_gmapping/README.md

@@ -0,0 +1,17 @@
+# SLAM_GMAPPING
+
+SLAM(Simultaneous Localization and Mapping) is the computational problem of constructing or updating a map of an unknown environment while simultaneously keeping track of an agent's location within it.
+
+This contains package ```openslam_gmapping``` and ```slam_gmapping``` which is a ROS2 wrapper for OpenSlam's Gmapping. Using slam_gmapping, you can create a 2-D occupancy grid map (like a building floorplan) from laser and pose data collected by a mobile robot.
+
+## Launch:
+
+```bash
+ros2 launch slam_gmapping slam_gmapping.launch.py
+```
+
+The node slam_gmapping subscribes to sensor_msgs/LaserScan on ros2 topic ``scan``. It also expects appropriate TF to be available.
+
+It publishes the nav_msgs/OccupancyGrid on ``map``. 
+
+Map Meta Data and Entropy is published on ``map_metadata`` and ``entropy`` respectively.