Intelligent agents embedded in physical environments need the ability to connect, or anchor, the symbols used to perform abstract reasoning to the physical entities which these symbols refer to. Anchoring must deal with indexical and objective references, definite and indefinite identifiers, and a temporary impossibility to perceive physical entities. Furthermore it needs to rely on sensor data which is inherently affected by uncertainty, and to deal with ambiguities. In this thesis, we outline the concept of anchoring and its functionalities. Moreover we define the general structure for an anchoring module and we present an implementation of the anchoring functionalities in two different domains: an autonomous airborne vehicle for traffic surveillance and a mobile ground vehicle performing navigation.