Learning Robotics using Python - Second Edition

Depth image to laser scan conversion

The depth sensor on the robot provides the 3D coordinates of the environment. To achieve autonomous navigation, we can use this data to create a 3D map. There are different techniques for creating a map of the environment. One of the algorithms that we are using for this robot is called gmapping (http://wiki.ros.org/gmapping). The gmapping algorithm mainly use a laser scan for creating the map, but in our case, we get an entire 3D point cloud from the sensor. We can convert the 3D depth data from a laser scan by taking a slice of the depth data. The following nodelet (http://wiki.ros.org/nodelet) in this launch file is able to receive the depth data and convert it to laser scan data:

 <node pkg="nodelet" ...