Updated documentation

README.md

@@ -169,6 +169,11 @@ Compile the workspace:
 ```
 catkin_make
 ```
+## Diagnostics
+
+This node has the following diagnostics:
+* A HeartBeat to know that the node is alive.
+* A subscriber diagnostic to check that imu, lasers and odometry data is received with the desired frequency.
 
 ## How to use it