I use the arbotixgui to control /cmdvel very good.

But I want to change the topic from /cmdvel to /myrobotcmd_vel?

I want to use the .launch file.

but I don't know the pkg and type and others?

Now I have more questions about launch?

<!-- Launch the OpenNI drivers -->

<!-- Run the depthimagetolaserscan node -->

How can I know the imformation like " "?

I can use rospack list to list the pkg, but I can not know that the package have (so many name or type or output).

Thanks for your help!