I submitted a paper to a IEEE journal. During the submission, I acknowledged a person who helped me in experiments. Now I am getting minor revision. Is it possible to include him now?
Yes, you can update the author list. Depending on the system, you might be able to update the authors in the submission system directly, or you may have to contact the editor to have them do it.
One caveat, there is the possibility that a new author changes the people conflicted with reviewing it. For a minor revision, which probably only goes back to an associate editor, this may not matter much. Plus, it's already essentially accepted. If it were a major revision that would get reviewed again, it's possible someone who should reread it is now conflicted. (More likely if the new author is with another institution, but even if it were a student, a summer internship could have that effect.)