How to add automatically keyword to taxonomies when a post published, and assign them to the post

How to add automatically keyword to taxonomies when a post published, and assign them to the post
for example i have in my post edition, a custom meta box, when you complete this input, a function should generate a group of keywords in background , and i want these keywords are automatically adding to a specific custom taxonomy in that post when it published,
this is possible?
i try with