The real difference is that the environment for Shopper is a simulation . My own work focuses on building intelligent robots to function in everyday environments. Navigation - Progressively more complex behavior as Shopper adapts and learns the structure of a store. The use of simulators of real environments for doing Artificial Intelligence work is fairly commonplace. Typically, researchers want to take out nasty things that happen in the real world - things like uncertainty and humans.
Simulators also allow researchers to ignore huge problems like making a robot see.
The simulator allows me to ignore problems like wheel slippage, hardware failures, etc., and instead concentrate on a different set of problems. This simulator gives images as if you were actually there. It's limited in that you can only face four directions, but you can move around the store. In total, the laserdisc which holds all the images can output about 75,000 images of the store. Other than the images, the simulator provides sonar and sign information .