NEXUS: a flexible, efficient and robust framework for integrating software components of a robotic system

We present NEXUS, a framework for integrating the software elements (routines, modules, etc.) of a robotic system in a modular, robust and efficient way. It is based on the use of some modular and object-oriented programming techniques. It achieves a desirable decoupling between the programs designed for a given task and the software facilities required in most of the robotic systems, making the software less sensitive to changes than monolithic applications. Another important features of NEXUS are its distributed nature, its hierarchical error recovery system, and the real-time capabilities. NEXUS has been developed for mobile robots but its design has been done generic enough for implementing other robotic systems, such as manipulators, teleoperation systems, etc. We describe the components and features of NEXUS and a real software application implemented for our mobile robot RAM-2