Interactive forces

This short article is devoted to the dynamics of controlled (and, therefore, open) systems. The internal forces, which appear only in the presence of external free controls and depend explicitely on them, are considered. Such interactive forces may be regarded as feedbacks generated in the system by the external free controls. In particular, one is able to interpret the interactive controls as couplings of free controls with the action of interactive forces; such dynamical approach to the interactive systems often simplifies their analysis and allows to perform their synthesis on a systematic level. The field theoretic counterparts of interactive forces, the fields of interactive forces, are also considered.