The merchandising information is typically well known along with product taxonomy, but the mapping of this relative information to a physical layout isn't always cleanly implemented or available.

A typical scenario is sku 85111 is grouped in a product hierarchy (family > sub category > subdepartment > department or the retailer equivalent) and that sku is assigned to a planogram or set of planograms associated with a display fixture (which sometimes have a hierarchy of their own (e.g. peg > shelf > section > aisle) with mixed relative distancing. There's generally a departmental divide between who manages product and merchandising information.

Many of these robots to my knowledge use the products or special tags as unique identifiers as opposed to an indoor-positioning system that ties back to an exact product location. So it's frequently easy to say that a product is in aisle 20 section 2 shelf 1 it's not easy to say from your current location go down 8 aisle and up half an aisle, look on your left.