Smart Houses can be divided into several categories that are presented in a graph below.
As it can be seen on the graph above, Smart Houses can be divided into three main categories:
We have made a classification of existing smart house projects according the taxonomy proposed above. The classified projects have been chosen based on their visibility and we accept that the list is non-exhaustive.
- Controllable Houses is the first category. This type deals with the improvement of the way, in which different equipment in the house is being controlled. It is a house, where an inhabitant can control different devices in more advanced and more efficient ways than it is done in normal contemporary houses. We have identified three distinct classes of such houses:
- Houses with one integrated remote control. In such a house a number of subsystems and appliances can be controlled from one remote control or a panel. There are no technical challenges in implementation of such an infrastructure. Simple remote or wired communication has to establish between devices and the control unit. An example of this technology is an integrated remote controller for the VCR and TV or a Bang & Olufsen Master Controller.
- Houses with interconnected devices. Different electronic devices like TV sets, VCRs, radios, computers and additional speakers, displays, microphones or cameras are connected with each other. Such infrastructure allows for media exchange between those devices and allows for more accessible entertainment or easy communications between people in different rooms in the house. There is a broadband network required within the house, but both wired and wireless technologies are commonly available for this purpose. Also the functionalities of previous type of houses are required, as there is a need for an easy control over all interconnected devices. Examples of this technology are KiSS DivX/DVD players that gives the possibility to play movies in DivX format that are stored on the computer or streamed from the Internet. They also allow for wireless connections between the TV screen and players.
- Houses controlled by voice, gesture or movement. Such infrastructure could be similar to the house from the first subgroup. The only difference is that a visible controlling unit is replaced with an invisible one that reacts on people voice, movement or gesture. There is no problem with the hardware to support such type of house, opposite to the software, which is a difficult part. The reason for that are the voice or gesture recognition capabilities, which need to be really reliable. Described here technologies would be similar to the voice dial functionality of modern phones or communication with the computer on the star ship Enterprise from the TV series Star Trek.
- The Programmable Houses are the second category of Smart Houses. Such infrastructure allows programming the house so it would switch on, switch of or adjust some devices in particular conditions. We have identified two subclasses:
- First group are Programmable Houses reacting to time and simple sensor input. Time allows some devices to be turned on or off at a particular time, another example of sensor input is a simple thermostat, which switches on or off when the temperature somewhere in the house reaches a certain level or a dusk sensor that switches on the lights when it gets dark outside the house. Basically it is a data from one reliable sensor that triggers other devices to change their state. There are no technical problems with an implementation as different sensors with high reliability are commonly available on a market.
- Programmable Houses assessing and recognising situations. Such houses have a possibility to recognize simultaneous input from several sensors as a particular scenario. For example the inhabitant, tired after long hard work, returns home and lies down on a couch to take a nap. Then the house could turn off the lights and play some soft music for a while. Such scenario has to be defined and programmed in advance. The house does not react to the changing environment and has to be reprogrammed every time some changes occur. With the functionalities of the programmable house, there is a need for reliable software that would analyze the situation correctly. Additionally there is a need for the careful programming of the house so the scenarios stored in the processing unit would be identical to the real ones.
- The Intelligent Houses belongs to the last category of Smart Houses. Such a group is very similar to the previous one, with one small exception – there would be no need to program any functionalities as the house would do it by itself. The ambient intelligence in the house would observe the inhabitants in their everyday life, searching for repeated actions. After a pattern has been identified the house will program itself, so that the next time the scenario is recognized, the house automatically switches on or off certain equipment. There are two subcategories that are identical to those of Programmable Houses. Those that are reacting to simple sensor inputs and those that are assessing and recognising situations or scenarios. Their properties and requirements are identical to the ones in the Programmable Houses group.
The elements of the Taxonomy can be reorganized to form a logical sequence presented on the evolution model below.
This model was created focusing on the improvement that each type of house brings to people’s life. For example it is very easy and convenient to control various devices using voice, but it is even easier to program the house once, so there would be no need to control any devices, as they would be controlled automatically by the house.