A trend is emerging in the fields of ambient intelligence (AmI) and autonomous robotics, which points in the direction of a merger between these two fields. The inclusion of robotic devices in AmI system, sometimes named ubiquitous robotics, makes one of the hard problems in this field even harder: how can we provide a comfortable, natural interface between the everyday user and a complex system which consists of a large multitude of highly heterogeneous devices? In this paper, we address a specific, important aspect of this problem: to monitor the state of the ubiquitous system by the user of the system. The solution that we propose is based on two mechanisms: an expression-based semantics to represent in a uniform way the status of heterogeneous devices; and a common interface point to aggregate the information from all devices into a summary status presented to the user. For both mechanisms, we propose to use the tools of fuzzy logic. We justify this choice by arguments grounded in the semantics and formal properties of fuzzy logic. We also illustrate our approach on a specific type of ubiquitous robotic system called Ecology of Physically Embedded Intelligent Systems, or PEIS-Ecology.