Computer control of robot vehicles of operation in unstructured environment typically involves both symbolic reasoning and numerical computation. Based on earlier experiences of the authors and others, this paper proposes a three level architecture for control software for such vehicles. From the top down, the three levels are called the strategic level, the tactical level, and the execution level. This paper argues that a multiple paradigm multi-lingual approach facilitates the realization of such a scheme with logic programming, object-oriented/functional programming, and imperative programming respectively being used in the successive levels. Experiments are reported in which Prolog is used at the strategic level, Lisp or C++ at the tactical level, and Pascal or C at the execution level. Experience with control of a large six legged walking machine and an autonomous submarine has led the authors to the belief that the proposed software architecture greatly facilitates the development and utilization of such vehicles through the isolation of a concise operational doctrine expressed horn clause form at the strategic level of control. ROBOT VEHICLE, CONTROL, SOFTWARE ARCHITECTURE, CONTROL SOFTWARE, ASV, AUV.