Building Automation Service Middleware

As part of the Building as a Service (BaaS) research project, the goal of my Bachelor’s thesis was the development of a service-oriented middleware for building automation systems.

The middleware provides a three-layer approach:

  1. Automation devices run on the field bus (BACnet, KNX, LON, etc.) in the Field Layer.
  2. The Midleware connects to the field layer via technology-specific gateway services, that discover the field device data points (inputs, outputs, data) and provides an abstraction layer for access through other parties.
  3. Building Automation System services are deployed atop the middleware and can access data and controls from field devices in a techonlogy-agnostic manner.

The middleware manages the data point abstractions and provides unified interfaces to interact with devices from different vendors and automation protocols. All accessible data points are stored in the Data Point Registry. The Event Service and Subscription Service make it possible for BAS services to subscribe to events on the field layer to implement interactive and adaptive automation applications.

The system is based on the service-oriented OSGi Java framework to make it easy to develop and deploy services on different nodes to create a distributed and dependable system.

Automation Services

OSGi services can be developed and deployed to implement intelligent and dependable automation functionality. Prototype applications developed on top of the middleware are, for instance:

  • Lighting and window blinds control
  • Presence detection
  • Reconfigurable room controls for rooms with removable walls
  • Daylight detection and room light output adjustments

For demonstration, testing and evaluation purposes, we even build a small-scale model house! Populated by Playmobil office workers, we added miniature LED fixtures, motorized window blinds and a whole TV as a window backdrop for night-day-cycle simulation. All devices are hooked up to commercial field bus devices from Kieback & Peter.

 

Field Bus

Field devices from Kieback & Peter provide data point connections on the BACnet field bus.