Evolution of the concept
From the point of view of the IT technologies, system integration and system interoperability are two main concepts supporting the intelligent building concept.
Figure 8.4, derived from the views of the European Intelligent Building Group (EIBG), shows different levels of integration normally identified within the intelligent building concept (named as “Computer Integrated Building”).
It as to be noted that the timeframes associated with each of the market development periods (in the right hand side of the figure) have been up-dated along the last decade, in the sense that the top-level is something to reach in the near future; as an example, during early nineties, it was foreseen to reach the full “Computer Integrated Building” concept after 1995; although before the end of the last century, the expectation was shifted to 2005.
Figure 4 Evolution of the " Computer Integrated Building " concept.
Figure 4 clearly presents several integration levels associated with building systems, from isolated systems to completely integrated solutions. At the top level, the “Computer Integrated Building” is the result of the integration of the “Building Automation Systems” and the “Integrated Communication Systems”.
Building Automation Systems
During the early 60’s, specific automation systems were introduced inside buildings. Due to technology availability, automation systems start to be based on electro-mechanical devices and wired logic controllers, and during 70’s programmable logic controllers were introduced.
From the control point of view, the automation system was conceived as a centralized controlled system, which means that the controller is the heart of the system and is connected to a set of input/outputs of sensors and actuators through a complex cabling system. The level of autonomy/decision of those systems is low, and it is common to find large synoptic and specialized personnel for their operation.
Next step in the automation area led to the usage of specialized systems. So, before the 90’s, the different types of automation systems, from access control to HVAC (heating, ventilation and air conditioning), including security and other energy management, were considered as separated islands within the building.
At the same time, a shift was produced from centralised to hierarchical distributed control systems. This change had severe impacts at different levels:
- In terms of the cabling necessary for connecting all devices;
- In terms of the introduction of local control that allows the usage of specific controllers associated with a specific set of local sensors and actuators.
Afterwards, the granularity of the system integration becomes larger, and nowadays is possible to find integrated solutions or, at least, solutions where interoperability among systems from different vendors is possible.
Integrated Communication Systems
For the communication systems point of view, the evolution towards integration is similar to the one presented for the building automation systems, where the existence of the web can be considered as the revolutionary concept of the current state of the art.
From the early autonomous systems for voice, text and video transmission, we can find nowadays the internet as the support for voice transmission (VoIP – voice over IP), text transmission (email) and video transmission (video streaming, video broadcast and video conference).
Interestingly, it is also the web and the internet that can allow the merging of the two worlds of automation and communication into the computer integrated building.
Interoperability needed
Several efforts have been done by companies and academia towards the intelligent building concept implementation (which should be considered always as on-going development). Although, the driving force of such developments has been the industry and market opportunities.
This had a severe impact in the evolution of the intelligent building concept implementation, in the sense that most solutions are proprietary and the open systems and open source strategies have had a “limited” impact on those home and building systems.
Anyway, from the communication protocol infrastructure point of view, there are several standards available, some of them already approved inside standardization boards, others approved inside companies’ ad-hoc coalitions as de-facto standards (where the market is the driving force), as already presented in previous chapters. So, interoperability of equipments and systems provided by different companies is limited and a push towards the effective adoption of open protocols in this area of intelligent homes and intelligent buildings is welcomed (from the user’s point of view).