Security Systems Vital and Versatile To Home Automation
L Y Chiu, Director and Founder, Cytech Technology
There is not yet a universally accepted definition of Home Automation, or Domotics as it is also referred to. It has been perceived to be anything from high speed networks, computer controlled homes, universal remote controls, touchscreens, lighting and sound systems, and even household robots.
My personal definition of home automation is the ability to intelligently coordinate and monitor the operation and behaviour of appliances, lighting and subsystems in the home to achieve comfort, security, convenience and energy saving. I would not consider the ability to use a remote control or touchscreen or a designer keypad to switch lights on and off to be an example of useful home automation. They are just examples of expensive light switches. The ideal automated home would require very little direct intervention from the occupants except to make changes to its preferred behaviour from time to time, although this ideal does not fully exist at present.
The most common component of a home automation system is lighting, where one of more lights can be controlled by electronic switches, keypads or remote controls. Such lighting systems may be bus-based like KNX (www.knx.org) or C-Bus (by Schneider) where electronic low voltage switches are connected in a bus throughout the house, and the lighting loads are connected directly to relays or actuators rather than through electrical light switches. Bus lighting systems are very reliable and have very extensive functionality. However they will probably not be found in the average home due to the cost and the fact that the typical electrician is unfamiliar with the wiring scheme. Lights and appliances can also be connected via the AC outlets using Power Line Technology like X10 and its variants, although this is more suitable for non-essential items like plug-in devices because of the problems caused by noise on the power line.. Other lighting products communicate by wireless means like Infrared and RF signals.
Wireless technologies used in Home Automation, including products complying to the Zigbee and Zwave standards, are expected to be more widely available at a lower cost in the near future. It should be understood that it is not necessary to be able to control every light in the house, or to have expensive dimming systems to have a practical home automation system.
Sound and Entertainment multi-room systems controlled by touchscreens and keypads that also control lighting with mood scenes and underfloor heating are a typical part of home automation for high end homes in the UK. The cost of such systems ranges from tens of thousands of pounds, to more than 5 figures.
However home automation is not just for the very rich with million-pound homes, expensive sound in every room and lighting systems controlling every lighting point. Any reasonably sized house can be a candidate for automation .
A security system, or more accurately, an Intruder alarm system is an essential part of most homes in most developed countries. Alarm systems typically have one or more keypads, magnetic sensors on external doors and windows and one or more motion sensors or Passive Infrared Detectors (PIRs) within the house. When the alarm system is armed, any intrusion detected by the sensors causes the sounders to be activated, and perhaps the alarm monitoring company to be notified. When the alarm system is connected to a central home automation controller, or plays the part of the controller, the opportunity to create an intelligent home is presented.
A basic means of integrating security with lighting is the signalling of events from the former to the latter. Most simple alarm systems have a few outputs that are triggered by say, an intruder alarm or the system being armed and disarmed. In this manner, the lights can be made to switch on in the event of an alarm or to switch off when the system is armed. In a practical home automation system, it is only necessary to control strategic lights so that they can respond to predefined events.
More sophisticated security systems are available that are well suited to act as the main controller in a home system or to communicate with another controller. Such systems have many programmable outputs as well as the ability to communicate via a serial interface like RS232 or Ethernet to lighting and other third party products. Events like the arming and disarming of the security system, movement in any zone, opening and closing of doors and windows and the occurrence of specific alarms like Intruder, Fire, and Power Failure can be linked to lighting and other subsystems in the home. This allows the security sensors to play a larger role in the intelligent home than just detecting intruders. Various sensors in the home including Motion, doors, windows, temperature and light act as eyes and ears for the intelligent home.
When the security system is armed to Away or Holiday Mode, lights and music can be switched on at suitable times in the day or night to give the impression that the house is occupied.
Automatic garage doors and gates can be opened or closed with a single control which arms and disarms the security system at the same time.
Schedules or Time Programmes allow automatic control of security, lighting and other appliances. These can be used to automatically arm the security system and switch off selected lights at night, and, for example, to water the garden
The heating in the home can be automatically switched on or off or turned up or down in response to the security system being armed to Away or Night mode or by Time Programs.
In summary, it is not necessary to add full lighting and entertainment systems and to have touchscreens in every room to have a ‘smart’ home. The key to practical and affordable automation is to link together strategic appliances, lights, security and other subsystems in the to create an intelligent home which provides comfort, convenience and energy savings for the occupants. I believe there is large untapped opportunity to bring affordable home automation to a much wider market.