Naturally, helpless and homeless are different things. However, homeless robots project helplessness as an aspect of their being.
Dirk the Homeless Robot (by Fred Abels, 2004 onward) pushes forward a shopping cart, and operates among unsuspecting people. These folks are typically annoyed, then suspicious, inquisitive and finally appreciative of Dirk's true robot nature.
By its maker, Dirk is mainly contextualized as a social experiment. He also notes that the work plays with tension between wanting to look away from homeless people and wanting to satisfy your curiosity about it being a robot.
For pictures of Dirk, visit this page.
"Anti-homeless robot"
Oddly, in 2017 interaction between robots and homeless (real) people made headlines. An animal shelter in San Francisco deployed a commercial security robot to protect its grounds after several prior incidents. However, nearby homeless people turned against it, claiming it to be an "anti-homeless robot". Reputedly they tipped it over and smeared it with barbecue sauce. After widespread outrage on social media the robot was fired from its job.