An Application Framework for Loosely Coupled Networked Cyber-Physical Systems

Networked Cyber-Physical Systems (NCPSs) present many challenges since they require a tight combination with the physical world as well as a balance between autonomous operation and coordination among heterogeneous nodes. These fundamental challenges range from how NCPSs are architected, implemented, composed, and programmed to how they can be validated. In this paper, we describe a new paradigm for programming an NCPS that enables users to specify their needs and nodes to contribute capabilities and resources. This new paradigm is based on the partially ordered knowledge-sharing model that makes explicit the abstract structure of a computation in space and time. Based on this model, we propose an application framework that provides a uniform abstraction for a wide range of NCPS applications, especially those concerned with distributed sensing, optimization, and control. The proposed framework provides a generic service to represent, manipulate, and share knowledge across the network under minimal assumptions on connectivity. Our framework is tested on a new distributed version of an evolutionary optimization algorithm that runs on a computing cluster and is also used to solve a dynamic distributed optimization problem in a simulated NCPS that uses mobile robots as controllable data mules.