An activity description language for activity recognition

Activity recognition aims at recognizing and understanding the movements, actions, and objectives of mobile objects. These objects can be humans, animals, or simple artefacts. Many important and critical applications such as surveillance or health care require some form of (human) activity recognition. Existing languages can be used to describe models of activities, but they are difficult to master by non computer scientists (ex: doctors). In this paper, we present a new language dedicated to end users, to describe their activities. We call it ADeL (Activity Description Language). This language is intended to be part of a complete recognition system. Such a system has to be real time, reactive, correct, and dependable. We choose the synchronous approach because it respects these characteristics, it ensures determinism and safe parallel composition, and it allows verification of systems using model-checking. Relying on the synchronous approach, we supply our language with two complementary formal semantics and we provide it with two formats: textual and graphical. This paper focuses on the description of the ADeL language.