Navigation is the ability to get to the right place at the right time. Localization is the robot’s ability to know where it is in space at any given time

Surrogate landmarks refer to reflectors, induction magnets and wires, painted lines, or other artificial environmental decorations for localization. It means additional infrastructure to install and maintain as it wears out. AGVs require these landmarks to be visible and identical to continuously verify that they are still on track, otherwise the robot will stop.

In contrast, AMRs rely on natural features for localization (static things in the environment, such as walls or pillars). The quality of the map representing the static natural environment is directly related to the quality of the fixed path navigation. Usually this is the case only with the highly structured environments.

Most real-world environments can be described as semi-structured at best. This means that they have both static and dynamic features that come and go and ideally need to be handled autonomously by the robot. This requires the introduction of a path planning engine that intelligently avoids obstacles while maintaining the optimal path. In this approach, localization accuracy is allowed to vary, but it must increase as the robot gets closer to a target (usually a material handling point).