In this paper, we demonstrate the use of qualitative spatial modelling as the foundation for the conceptual representation of route instructions, to enable robust humanrobot interaction on navigation tasks. Our conceptual model is motivated by empirical studies on route navigation, and combines Qualitative Orientation Calculi for spatial reasoning using directional orientation information and topological maps for structuring route segments and routes. Moreover, we present a formal definition of the conceptual model using the algebraic specification language CASL for syntactic and semantic checking, consistency checking and verification. Finally, we introduce a generic route graph concept and its formalThe instantiation of the generic route graph at different abstraction levels provides a formal foundation for linking the conceptual model to a global environment map used by an intelligent robot, e.g., a semi-autonomous wheelchair, to carry out human navigation tasks. Key words: qualitat...