hello,
I want to know that how can i force a predefined package to subscribe a particular topic, for an instance, i have a package named "executive_usarsim" by makokal which acts as an interface between usarsim and ROS and currently it is not subscribing to cmd_vel topic, i want this package to subscribe to "cmd_vel" topic.
Thank you.
I suppose you have no access to the code of the package "executive_usarsim". (in that case it would be really strightforward)
If you have no access then you could remap the output of a specific topic to your desired topic (/cmd_vel) in your launch file.
Here is an example which coudl be helpful to you. Your keyword shuld be "remap". Since the documentatin in ROS is not so good I suggest to look in existing codes in the Q&A.
Regards