Home automation

1) Introduction: what is meant by home automation

Home automation is a new way of conceiving and designing home systems.  
Home automation is the result of an evolution of technological systems: in the houses of the past the systems were mainly made up of a light point and therefore a home automation system would have been useless. But with the passage of time and following the improvements in the field of systems and technology (automatic shutters, air conditioning systems, burglar alarms, video surveillance methods, audio systems ...) it was possible to introduce the use of home automation.
The most particular aspect is the interdisciplinarity, because the topic in question deals with very different themes, from networks to security systems, lighting, air conditioning and even photovoltaics. The problem is to understand all these different aspects and merge them into a single system: this is the operation on which home automation as a technique is based; in fact, nowadays more and more credit and importance is given to the professional figure of the system integrator, who deals with the home automation system.
The term domotics refers to a “computerized home”, which can be managed through technological tools.
At a technical level, home automation is a digital system for managing domestic systems. It controls all systems: electrical, air conditioning, security, acoustics, lighting, etc. The characteristics that distinguish a home automation system are control, integration and digitalization. Control because the system, in itself, has no autonomous function, it is simply independent. Integration allows the different subsystems to communicate with each other; finally, digitalization allows the various systems to interact in the form of bits.

2) Costs, advantages and problems of the home automation system

Home automation therefore appears to be something well defined and brings numerous benefits. For example, it allows to rationalize energy consumption related to electricity and gas, increases the safety of the electrical system and the entire house, and overall allows to give an active response to any emergencies, allows an improvement in comfort, through centralized control and not of the system in all its subsystems, through computer control via the internet.

In the past, each device had its own remote control and this created a lot of confusion. Home automation avoids these problems also thanks to the ever-increasing use of tablets and smartphones through which everything can be controlled. In this way, everything is more easily and rationally manageable.

The system is easy to use and is not dangerous. It always works, even in the presence of possible failures, and is immune to malfunctions.

Of course, costs should not be underestimated, since it is necessary to consider how much the home automation system affects the total cost of the systems. There are various methods with which a home automation system can be created. For example, a system that is limited to controlling lights and loads (basic level) affects about 10-20%; if the system is larger, the cost will also be higher. The cost also changes depending on the type of system adopted, given that there are various technologies for creating a home automation system. A complete system inside a standard-sized apartment of 120 m50 can affect up to XNUMX% of the total cost.

3) General structure of a home automation system

A home automation system always consists of three elements:

• commands: transmit the order to perform an action, such as buttons to turn on a lamp;
• actuators: they perform a specific function, such as turning on a light;
• transmission media: These are physical means through which orders pass from the control to the actuator.

The controls play a fundamental role of direct control, since most of the functions are set through a control configuration. Some systems simply use home automation buttons, while others use specific interfaces that use traditional buttons to transform them into home automation buttons. Nowadays, keypads with touch technologies are used, which also have a design more suitable for many modern homes. But in addition to an aesthetic motivation, the use of keypads is preferable to traditional buttons because they allow for better programming and integration of functions.

Actuators are also called outputs; many of these have more complex functions than simply turning on a light bulb. They are distinguished according to the function they perform:

• digital actuators are used mostly to control lights;
• dimmer actuators have the task of regulating the light intensity of the light points;
• roller shutter/venetian blind actuators control the roller shutter motors;
• Analog actuators direct current intensity, but are mostly used for industrial buildings;
• Special function actuators are specifically designed to perform particular functions, such as an actuator that sends infrared light to another device.

Transmission media ensure communication between controls and actuators. There are three transmission media:

• a cable that allows communication between home automation components;
• the radio waves;
• a power cord.

The most used method is the data transmission cable, called BUS cable.
The different components of the system are not all on a single circuit but are physically distant from each other and connected by a single channel that puts them in communication.

Block diagram of the operation of the HOME AUTOMATION CONTROLLER network

The integration of the systems into the structure is essential, since the goal is to make the different systems compatible with each other.
An integrated system requires, first of all, coordination between the system designer and the architectural designer, in order to use some elements of the building to create earthing systems, to define the most suitable spaces for passing electrical and water pipes, etc., to find the most suitable spaces for the technical rooms.

The design of a home automation system consists of several phases:

1) investigation of user needs
2) forecast of the required systems
3) definition of functions
4) Control system selection
5) study of the system diagrams with the layout of the signals, commands and connections
6) analysis of the specific structures of the system

In the very first phase, you need to analyze the characteristics of the place, the type of building (single dwelling, condominium, size of the rooms) and understand the real needs of the users. This is an important phase because following this evaluation you understand whether or not it is necessary to install some elements or if it is preferable to study a certain type of system instead of another.

The second point involves an evaluation of the systems, and therefore deciding on all the systems to be installed. The different functions of the systems are studied, such as the motorization of gates, shutters, doors and windows, ... and this analysis has the task of highlighting the various possible ways to control the devices present and avoid inconsistencies between the numerous systems. Naturally, the positioning of the control devices must be done based on the proximity of the user and the distance between the load and the actuator must be minimal.

We then move on to defining the functions, that is, we choose the operating modes of the security, air conditioning, lighting, motorization of doors, windows, etc., acoustics, telephony systems.

The next step involves selecting the control system and therefore the components that need to be integrated. The control unit, the various sensors to manage the systems, the controls for the lights and motorization systems, the devices for the various commands, the control elements for household appliances and various services such as video surveillance are chosen.

They follow the study of the system diagrams with the drafting of signals, commands and connections. During this delicate moment the components of the required systems are transcribed at a graphic and computer level, for example through CAD; in this way we have precise and schematic drawings of the electrical systems, acoustic systems, lighting devices, motors for windows, etc., and all the home automation devices such as inputs, outputs, power supplies, couplers, etc., which will then be used during the manual installation phase of the systems themselves.

At this stage, the spaces for installing the various systems are identified; this representation is identified by IS4 (general switchboard), IS5 (junction box in the room) and IS6 (plug-in boxes, inside which the light control devices will be installed). The controls must be clear and identified precisely, using alphanumeric codes; for example for the buttons Pl.0, Pl.1,Pl.2,…, for the sensors Sn.0, Sn.1, Sn.2, etc.

5) Examples of implementation

The field of application of home automation is very wide, and it adapts to the different needs of the users, starting from the single dwelling in a condominium, to the independent villa. As already mentioned, basic home automation includes anti-intrusion, environmental security, and environmental comfort.

For example, when designing a home automation system for a ground floor apartment of about 100 square meters, some specifications must be considered. As regards anti-intrusion security, a double perimeter protection can be installed, on the roller shutters and on the grates, which use sensors to activate the alarm. For environmental security, gas and water sensors are positioned. Finally, for environmental comfort, the air conditioners are automatically turned on and off.

Other systems are also considered, such as the management of roller shutters, which can be lowered or raised according to needs, even in predefined intervals to avoid power loads; the management of external and internal lights allows all lights to be connected and controlled by traditional buttons or more complex systems.
The best time to install a system of this type is right at the design stage of the apartment itself, or during a renovation. A home automation system in the house makes the domestic environment intelligent and guarantees excellent control.

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USEFUL LINKS
http://it.wikipedia.org/wiki/Domotica
http://www.domotica.it/
http://www.ceiweb.it