Sensing in Smart Homes
Sensors play an important role in smart home systems. A Smart Home can provide people with a comfortable, safe, power-saving and convenient life by enabling intercommunication amongst all household appliances. This includes lights, HVAC (Heating, Ventilation and Air Conditioning), TVs, computers, entertainment system, and security system. They can be controlled by a smart home control panel installed in house or through GSM/CDMA, Internet, and PSTN networks. Smart home systems are also called home automation, electronic home/e-home, or intelligent home.
The following sensors can be used for different purposes in contribution to making a smart house. Temperature, humidity, light, and air pressure sensors constitute an intelligent environment monitoring network. This network works with HVAC, electric windows, and lighting system to control indoors temperature, humidity, and lighting intensity so as to make a comfortable environment.
To build a security system, various devices such as cameras, reed sensors, smoke detectors, PIR (Passive Infrared) sensors, and IR sensors are required. You can also include sounders in security systems. Alarm sounder is a low current consumption device suitable for close proximity signaling in fire and security applications. Cameras are made based on image sensors which are the core devices implement real-time video capture. Reed sensors can be installed on doors and windows to detect intrusion. Smoke sensors are used to detect if there is fire accident. PIR sensors are a kind of motion sensor, responsible for detecting intruder’s motion in a specified area. When any of these devices detects something unexpected, an alarm is triggered and is reported to the property owner and management staff.
PIR sensors are used as human body detectors for the purpose to turn on and turn off lights based on presence and absence of people. Light sensors detect intensity of natural light based on which lights in home will be turned off in daytime and turned on at night. The combination of PIR and light sensors can provide an intelligent lighting control.
As sensing and wireless communication technologies evolve continuously, MEMS sensors of smaller size and wireless sensor network have already been introduced into smart home systems.