Operative Platform Applied to Building Automation

Abstract

This article introduces an advanced control structure to be applied to building automation. This structure is composed by three inter-related levels: the Operational-level – where the field equipment is controlled, the Inter-Active level - where inhabitants communicate the building their preferences regarding control variables (lights, temperature, etc) and the higher-level control, the Overall Building Well-Being Model, which manages the global building, taking into account the optimization of the inhabitants preferences, constrained by the available resources. At this third level the inter-building communication is available. Each building has the capability to communicate with its neighbours, informing about fires, floods, security problems, power consumption expectations, etc. This article implements one of the three above referred inter-related control levels: the Operational-level control. This operative platform is structured over a cascade hierarchical control architecture where inner-loops are performed by local PLCs (Programmable Logic Controllers), and the outer-loop is managed by a centralized SCADA system (Supervisory Control and Data Acquisition) that interacts with the entire PLC network. The lower level control loop assures high processing velocity tasks, the upper level control loop updates the local references, knowing the complete system state. This operative model is tested on two prototypes, where all instrumentation in place is controlled by the industrial PLC network. Both prototypes worked perfectly showing the huge potential of communication systems between distributed processes. These communication systems allow intelligent centralized algorithms to manage decision making problems in real-time environments. The system presented in this paper combines several technologies (local PLCs, SCADA systems and network communications) to reach the goal of efficient management of intelligent buildings.