Both are fine and there's almost no difference in meaning. When my wife says "take out the trash," "the trash" means one particular collection of trash--the trash in our house today. If you say "Robots may help clean up the trash," the picture in my mind is dozens of homes, each with its own robot, each one cleaning up "the" trash in its own house. If you say "Robots may help clean up trash," I think of the abstract idea of robots with the capability of recognizing trash and collecting it.

Both are grammatically ok. Robots may help clean up the trash. (more specific trash) Robots may help clean up trash (Trash in general) :)