Layered control of a practical AUV

Following a brief explanation of ISER´s layered control theory, the author gives working examples of layered control on the existing ARCS vehicle. In the process of implementing a control system for the ARCS vehicle, ISER has incorporated hierarchical and cooperative elements into the subsumption architecture. Vehicle control functions are defined as independent behaviors that share the use of actuators by a mechanism called cooperation and subsumption. Cooperation means that behaviors on the same layer combine their outputs, and subsumption means that behaviors on one layer substitute those on another. Layering is also extended to combining data from redundant sensors, finding discrepancies between sensors and predictions of an analytic model, and using these discrepancies in fault diagnostics. This layered control system has been implemented on the ARCS vehicle in preparation for Arctic sea trials in 1993