Abstract
A core chassis for a mobile robot assembly includes: a housing to enclose one or more electric motors; first wheel mounts to receive first wheels to be driven by the electric motor(s); one or more extension plate mounts to receive one or more extension plates to longitudinally displace second wheels relative to the housing and the first wheels. A flipper plate is rotatably driven when mounted to a main body of the robot. The flipper plate is bent to align a first flipper wheel mounted on the inner side of the flipper plate with a second flipper wheel mounted on the outer side of the flipper plate. The flipper plate has a first part proximate to the first flipper wheel, and a second part proximate to the second flipper wheel, and has a first link, a second link, and a middle link each of which rigidly connects the first part to the second part.