Performance Evaluation of a Distributed Reconfigurable Controller Architecture for Robotic Applications

Recent research in controller architecture has had some focus on reconfigurability and associated concepts such as modularity and openness. These paradigms advocate non-proprietary components such as commercial off-the-shelves (COTS) with standard interconnection interfaces. The tradeoffs of such a controller architecture are performance challenges such as network-induced delays and synchronization problems, especially where non-real time entities such as Ethernet are involved. In our quest to address some of these challenges we have developed a modular control architecture for machine and robotic control as a test platform. The advantage of this architecture is cost-effectiveness and openness, achieved through the use of COTS components. Each machine axis is controlled by a real-time Java micro-controller and all the controllers communicate through a switched-Ethernet communication network. The architecture is designed to support reconfiguration of both hardware and software resources by the use of modularity and service-discovery protocols in the software and hardware design. Therefore devices such as axes and sensors may be reorganized, removed or added easily. Our research presents performance results and applications typical of industrial or real life for our control architecture. The performance criteria analyzed include network delays, synchronization resolutions and error analyses.