The phrase "Big Brother is watching you" is more relevant today than ever: of course, we have not yet reached total surveillance, but the interaction of engineering systems can be seen firsthand. A huge number of sensors connected to the controllers ensures the safety of property, personal safety, comfort in a smart office, home, car or public building.
Sensors for "Smart Home" are conventionally divided into two categories: motion sensors and sensors for monitoring environmental parameters.
Motion sensors
They are part of the security systems of intelligent lighting. Sensors that track the movement of objects are classified as intelligent. They scan several zones at the same time, determining the volume, mass of the object and the distance to it. A security system with a connected computer and installed software monitors the movement of an object in a building and determines its exact location.
Two types of sensitive elements used in security systems do not belong to the category of followers - an acoustic detector of broken glass and a reed switch.
Acoustic Detector and Reed Switch
The operation of the reed switch - an electromechanical device - occurs when the contacts open. This is accompanied by activation of the alarm and sending a message to the rapid response service. Reed switches are wireless and wired. They provide a high level of security.
Acoustic detectors are sensors for the Smart Home that respond to sound when glass is broken. In case of hacking, the recorded signal is sent to the control panel of the security system.
Motion and presence sensors
The principle of operation of motion sensors is based on technology for tracking changes in ultrasonic and infrared fields. Such sensors are widely used in security systems and automatic light control. The infrared sensors used in lighting systems are equipped with light sensors. Some models of sensors for the "Smart Home" have the functionality of remote IR receivers.
The presence sensors work similarly to motion sensors, but are more sensitive to changes in parameters. In addition to infrared, capacitive and inductive models are distinguished. The functionality of the latter allows you to track metal objects in the service areas. The high sensitivity of the presence indicators makes it impossible to use them in security systems - instead, they are installed in home appliances and lighting control systems.
Sensor Features
Despite all its advantages, the main disadvantage of sensors for Smart Home is the ability to bypass them. For example, infrared sensors that respond to changes in body temperature can be easily fooled.
For this reason, to ensure full protection, security officers recommend installing several sensors of different spectrum of activity on the entrusted objects.
It is almost impossible to build a full-fledged Smart Home control system only on presence and movement sensors. The signal does not come if the object does not move for a long time, respectively, there is no certainty that the room is empty.
The software of the Smart Home system records the number of people in the room and saves the received data. Photoelectric sensors installed in the corridor or opening determine whether a person has exited or has entered. Such sensors detect the movement of objects only in a narrow beam spectrum.
Similar sensors are installed on barriers, garage and entrance automatic gates. The equipment for the Smart Home records whether someone passed through the gate or not, automatically closing or opening them.
Photoelectric sensors are replaced by laser sensors at specially guarded facilities due to unlimited budget. Their main difference from optical analogs is high sensitivity and the absence of errors when reading data. They work at a great distance and react even to small objects.
Temperature devices
These are sets of sensors for the Smart Home, designed for the functioning of engineering systems. Modern heaters are equipped with various types of temperature devices.
Outdoor sensors monitor the outdoor temperature. The information received from them and the home weather station, allows you to set the optimal mode of operation of ventilation and heating system.
The smart home room temperature sensors installed on the return and flow lines of the coolant maintain the optimum room temperature.
Environmental sensors
Gas leak sensors indicate a leak with a piercing signal. Fuel will be stopped if there is a stopcock with an electromagnetic valve at the inlet.
Fire detectors detect smoky air in the room or an increase in temperature in excess of the established norm.
Leakage sensors block valves embedded in the water supply system when water enters the tracking elements.
Water pressure sensors monitor the pressure in the pipeline. The Smart Home system automatically decides to shut off water during critical pressure changes.
A damp sensor detects the level of humidity in the room and reports leaks. He can notify of problems with heating or open windows.
Rain sensors built into the system record the readings and send them to the home weather station, monitoring the operation of other systems, including automatic watering of the home area.
Criterias of choice
The method of connecting the sensor is one of the main criteria for its selection. There are two options: wired and wireless, but the first is considered technically and morally obsolete and is not used in modern systems.
For wireless connection can be used:
- Radio channel It is used extremely rarely, since it has a large number of shortcomings, as a result of which it loses its relevance.
- Channel Z-Wave. Combines up to 232 devices. The best low-cost option to connect a small number of devices.
- ZigBee Channel Connects up to 6,500 gadgets. This is the most common Smart Home technology, which is considered standard.
- Wi-fi Not the most convenient way to connect sensors, since signals from different devices can overlap each other.
Modern technologies of Smart Home support several options for connecting sensors, but it is preferable to choose a specific one.
The second selection criterion is the range of settings. Sensors before operation are set to normal and critical data boundaries - the response range. The setting is important for sensors that are responsible for the climate and security of the territory.
When choosing sensors for "Smart Home", the manufacturer is taken into account. The modern market offers a wide range of equipment, there are clear leaders whose products are highly reliable.
Installation options
Wiring accessories for "Smart Home" are available not only in the form of standard sensors, but also in the form of sensors for installation in suspended ceilings. This installation method allows you to place the sensors flush: externally they do not differ from halogen lamps.
Installation itself can be carried out in two ways: wall and ceiling. The first is often resorted to when installing the system in rooms with high ceilings. The optimal height of the sensors is 2-3 meters.
During installation, the maximum load is taken into account - the number of devices simultaneously activated by the sensor command. The presence sensors may burn out due to the high load exerted on them by fluorescent and LED lamps. The optimal load on the dimmers and sensors connected to the LED lamps should be 2-3 times lower than the rated load power.
Customization
Sensors before installation are adjusted using the controls located on the housing. In this way, threshold values are set: sensitivity levels, illumination, delay time and special operating modes.
In a similar way, the viewing angle of the sensor is adjusted. This is done with the help of plastic overhead curtains that come with the kit - they are called signal cut-off filters. The viewing angle is adjusted by breaking out a part of the plastic curtain along the notches.
How much is a "smart home"
The total cost of the project is affected by the quantity and reliability of equipment, a set of modules, acquired multimedia devices, features of engineering systems and wiring in the house.
The price may also vary depending on the number of utility and residential premises, the total area of the building, the number of windows and the size of the bathrooms.
No less important is the number of functions, equipment modification, manufacturer, and the specifics of the work performed. For this reason, there is no upper price limit.
Some sensors are required to install - for example, security systems and fire extinguishing systems. Some can be abandoned without loss of quality and convenience of the system.
A lot depends on individual needs. The technology may include various functions, among which remote turning on and off lighting, heating the Smart Home, turning on the music automatically, opening and closing curtains are not very popular. Their exclusion from the project allows you to save from 20 to 80 thousand rubles.
The situation is similar with other subsystems. For the installation of equipment you will have to pay 10-20% of its cost. The average price for the Smart Home system is 400 thousand rubles, but the maximum cost can be much higher. Luxury technology kits can cost millions.