Computer-aided design of a generic robot controller handling reactivity and real-time control issues

An original system, Open Robot Controller Computer-Aided Design (ORCCAD), for the computer-aided design of robot controllers is described. Accessed by three different user levels (system, control, and application), it provides a coherent approach from a high-level specification down to its implementation, and offers several tools for design, display, and test. Following a critical study of the main architectures reported in the literature, the basic principles and underlying concepts of ORCCAD are presented. The main entity considered is the robot task, an elementary control action associated with a local behavior controlled by a set of observers and modeled by a finite-state automaton. It is made of a set of real-time communicating tasks, called module tasks. The module task which handles the behavior of the robot task, is described using the synchronous language ESTEREL. The application level is defined as a set of synchronized robot tasks, also described using ESTEREL. Two detailed examples are discussed.>