|
Smart Home System: a comprehensive Review Arindom Chakraborty, monirul Islam, Fahim ShahriyarBog'liq Smart Home System A Comprehensive Review6. Sensors Utilized
Sensors play a signifcant role in the development of SHSs.
Te application of multiple types of sensors was identifed in
the literature review stage conducted previously. Te fol-
lowing section presents the details of the sensors used to
design, develop, and implement SHSs.
6.1. Infrared (IR) Sensor.
Teoretically, all the objects and life
forms that have a minimum amount of temperature emit IR
radiation. An IR sensor is an electronic device that is capable
of detecting and measuring the IR radiation in its sur-
rounding environment. Te main reason for using IR
sensors is motion detection and temperature measurement.
Tere are two types of IR sensors available: active infrared
sensors and passive infrared (PIR) sensors. Among these
two, PIR is the most frequently used IR sensor.
A PIR sensor detects the change in electromagnetic
radiation levels in its surrounding environment. It does not
actively emit IR radiation like an active IR sensor. Te main
application of PIR is motion detection. When an object
comes in the range of a PIR sensor, it measures the diference
in IR levels and detects the object. In SHSs, PIR is used for
intruder alert [31, 78, 92], detecting the occupant activity in
an SHS [24, 35, 103], and creating an elderly healthcare
system [51, 79]. However, PIR sensors are usually used inside
of a house because they are afected by environmental
changes such as snow and rain.
6.2. Temperature Sensor.
A temperature sensor by sensing
the temperature of its surrounding environment can ensure
comfortable living. Multiple types of temperature sensors
have been used in the development of SHSs, and the most
popular is LM35 [77]. Temperature sensors are used for
measuring room temperatures based on which other ap-
pliances are controlled such as fans, air conditioners, and
heaters [25, 70].
6.3. Humidity Sensor.
Humidity sensors detect and measure
the change in the amount of water vapor or moisture in the
air surrounding them. Te most popular humidity sensor
used by SHS researchers is DHT11, which can measure
temperature as well. In SHSs, a humidity sensor is generally
used for monitoring room moisture levels [26, 78], home
automation [75], and early warning systems [52].
6.4. Gas Sensor.
Gas sensors detect the presence of certain
gases in the air in their range. Tey are used for detecting
harmful or dangerous gases such as LPG, propane, methane,
carbon monoxide, I-butane, and alcohol and are particularly
important in the development of SHSs because they give
a warning about harmful gases in the house [24, 34, 57, 93].
6.5. Smoke Sensor.
A smoke sensor is an electronic device
that detects smoke in its vicinity and triggers an alarm.
Smoke sensors are used as a precautionary measure of an
early fre warning system. In SHSs, a smoke sensor is
generally programmed to trigger an alarm or send a warning
signal to the home occupants via a GSM message or app
[22, 95, 104, 105].
6.6. Ultrasonic Sensor.
An ultrasonic sensor emits and re-
ceives ultrasonic sound waves and measures the distance of
a certain object by emitting sound waves and receiving the
refected sound wave from that object which the sensor
transforms into an electronic signal. In SHSs, an ultrasonic
sensor is used for implementing an automatic door system
[78], water level monitoring [104], and basic smart home
automation [24].
6.7. Flame Sensor.
A fame sensor is an electronic device
designed to detect the presence of fre in its operating range
and respond by triggering an alarm or other warning
mechanism. Any security-centric smart home system usually
employs fame sensors for early detection and warning of
fame in the house [65, 70, 97].
|
| |
