Nice robot! Getting me inspired already!
Big-B, actually my robot NINA was supposed to do something very similar to this like help carry in the groceries in a tub or wagon and use a line sensor to move them back into the house. Along with vacuuming the rug (which doesn't work too great with thick treads), fetch canned beverages, put out fires, and night-guard the house. Looking back on those ambitions I don't think NINA will fullfil half those roles.
But I did learn a lot about robots, mechanics, electronics, and physics along the way. Right now, I'm making NINA's primary role to be a "social machine." Meaning, it's going to interact with people and help me solve problems on how my robot might teach people who have trouble communicating or relating to others (like those with autism or Asperger Syndrome). It may take a while before NINA can do this professionally, but you got to start somewhere. Also, NINA may still night-guard the house
. I think I'll build a second robot using NINA's left over parts to help carry in the groceries.
Personally, my conviction is robots ought to help people by doing what a human being cannot do, or going ahead of humans on dangerous work. I think a robotics setup like this would be great, however, for someone who hypothetically might have very severe cerebral palsy. Such a robot could cover for (or work with) a human care provider. Think of the kinds of robots with a house-hold-helper set-up that we could benefit from!