An Architecture for Autonomy

International audienceAn autonomous robot offers a challenging and ideal field for the study of intelligent architectures. Autonomy within a rational behavior could be evaluated by the robot's effectiveness and robustness in carrying out tasks in different and ill-known environments_ It raises major requirements on the control architecture. Furthermore, a robot as a programmable machine brings up other architectural needs, such as the ease and quality of its speci_cation and programming. This paper describes an integrated architecture allowing a mobile robot to plan its tasks, taking into account temporal and domain constraints, to perform corresponding actions and to control their execution in real_time, while being reactive to possible events. The general architecture is composed of three levels : a decision level, an execution level and a functional level. The later is composed of modules that embed the functions achieving sensor data processing and effector control. The decision level is goal and event driven, it may have several layers, according to the application ; their basic structure is a planner/supervisor pair that enables to integrate deliberation and reaction. The proposed architecture relies naturally on several representations, programming paradigms and processing approaches meeting the precise requirements specified for each level. We developed proper tools to meet these specifications and implement each level of the architecture : IxTeT a temporal planner, PRS a procedural system for task refinement and supervision, Kheops for the reactive control of the functional level, and GenoM for the specification and integration of modules at that level. Validation of temporal and logical properties of the reactive parts of the system, through these tools, are presented. Instances of the proposed architecture have been already integrated into several indoor and outdoor robots. Examples from real world experimentations are provided and analyzed