https://www.sciencedaily.com/releases/2019/11/191104141700.htm

Standard approaches for robotic navigation involve mapping an area ahead of time, then using algorithms to guide a robot toward a specific goal or GPS coordinate on the map. While this approach might make sense for exploring specific environments, such as the layout of a particular building or planned obstacle course, it can become unwieldy in the context of last-mile delivery.

Imagine, for instance, having to map in advance every single neighborhood within a robot's delivery zone, including the configuration of each house within that neighborhood along with the specific coordinates of each house's front door. Such a task can be difficult to scale to an entire city, particularly as the exteriors of houses often change with the seasons. Mapping every single house could also run into issues of security and privacy.