Connectivity of Thetis, a Distributed Hybrid Simulator, with a Mixed Control Architecture

The purpose of this paper is to present the linkage of Thetis (a real time multi-vehicles hybrid simulator for heterogeneous vehicles) with a control architecture for the management of contextual tasks on AUVs (autonomous underwater vehicle), both developed at LIRMM (France). An AUV is mainly composed of an onboard informatics system and a set of sensors and actuators. We design a 3-layer control architecture (global supervisor, local supervisors, and a set of management modules which are in charge of the means of perception and actions), allowing for facing Hardware (embedded instrumentation) and software evolutions. Due to the complexity and the sophistication of the control of actual underwater systems, it is necessary to check the embedded robot controller, i.e. all its constitutive hardware and software sub-systems before beginning any real mission. To achieve this goal its possible to call upon simulation, thus avoiding heavy and numerous experimentations. Thetis is able to provide the necessary environment to test real robots and their interactions (communication and collision detection). Indeed this simulator allows hardware in loop simulations with the support of virtual sensors. The paper first describes the architecture and functionalities of Thetis, then the control architecture of our AUVs is briefly presented. We conclude with the advantages of connecting the 2 systems together.