Exercise 3.1 The arm swings up


I just met a problem. In exercise 3.1, could someone can tell me why the arm can swing up when I don’t publish any command through the hardware or rqt_gui? Thanks!

Could you send a video or something showing the issue?

Hi @youngyangcs,

when the course is started, the controllers are not yet enabled, that is why you see the arms moving randomly.

Once the controllers are enabled, the arms will only move when instructed to do so.

Please let us know in case I misunderstand your question.