Plan execution monitoring and control architecture for mobile robots

This paper deals with the architecture and control structure of mobile robots. The authors decompose robot functions into modules organized according to their predefined interactions: sensor modules that accomplish various processings on data from physical sensors, effector modules that issue commands to effectors, servo-processes that establish links between perception and action to achieve closed-loop behaviors, and functional units that provide specific functionalities. These modules, and hence the robot system itself, are controlled by a control system that also enables the robot to execute missions (plans) expressed in a command language. The authors introduce and discuss a generic control system structure, composed of a supervisor that interprets the plan and oversees its execution, an executive for operating and managing robot modules and resources, a surveillance manager for detecting and reacting to asynchronous events, and an error recovery module for local plan mending and correction. Several experimental examples are given