Guardian Home Security System

Transcription

1 Guardian Home Security System Project Proposal Bryce Woodland Western Washington University Fall

2 I. Summary The Guardian Home Security System is an integrated security solution designed to be used in apartments, houses, or office buildings. It has the ability to monitor doors, windows, and even detect motion within the building, in order to provide maximum security. The system uses magnetic relays to monitor doors, laser grids to monitor windows, and laser based motion sensors to detect motion inside the building. II. Description This system is designed to be implemented into a building during construction, as it is completely hard wired. All of the devices within the system will be powered off of same power lines that already run through the walls of a standard house. The system that I am building will be implemented inside of a simple four wall model house, and will include four security elements: a motion sensor, two laser grids, and a magnetic relay switch. The motion sensor will be located inside of the house, the two laser grids will be placed over two windows, and the relay switch will be mounted above the door. All of the security elements will be wired to, and monitored by, a central microcontroller (MCU). 2

3 Figure 1: Block diagram of the Guardian Security System. The laser grids will consist of five to six laser diodes each, which will all have their beams directed into phototransistors. The laser diodes will be multiplexed, so that only one laser is active at a time, which will save a considerable amount of power. When each laser is active, the output voltage of its respective phototransistor will be checked by the MCU, to ensure that the beam has not been broken by a potential intruder. The magnetic relay will have an output voltage that will also be monitored by the MCU. The relay will be mounted parallel to a permanent magnet, which is mounted on the door. When the door is closed, the relay will be closed, when the door is open, the relay will be open. The motion sensor will be a laser based device 3

4 that will simply detect the presence of motion inside the house, and send that data as a digital voltage (one or zero) to the MCU. The MCU will be attached to a keypad and a display, which will serve as the user interface portion of the security system. Through this user interface module, the user will be able to select which elements of the system they wish to be active, set a security code that is used to disarm the system, arm the system, and power the system on or off. The display will be a monochrome LCD, with a blue backlight. It will show the current time, as well as other information about whether the system is armed, and what mode it is operating in. If an alarm is triggered, the display will show what time the break in occurred, and prompt the user to enter their security code, in order to turn off the alarm. The entire security system will be attached to a power adapter that will plug into a wall outlet and supply each of the security elements, as well as the MCU, with the necessary voltage and current. III. Benefits The primary benefits of this system are its power efficiency and reliability. Everything is hard wired to the power supply, which means that there are no batteries, so there is almost no chance that any part of the system will fail. With battery powered security systems, there is always the chance that one device may run out of power, which could result in an undetected security breach. Also, the fact that this system doesn t use batteries means that the user doesn t have to replace 4

5 batteries, which makes it much cheaper and more efficient in the long run than a wireless security solution. Additionally, most current wireless security systems on the market today have an MCU inside of each security element, as well as in the central user interface hub. In the Guardian Home Security System, there is only one MCU, which drastically reduces the cost of the system as a whole, and makes each security element much smaller in size. However, because the Guardian Security System is powered entirely off of the house s power grid, if power to the house was lost or turned off, this system would fail. This problem is avoided by using an uninterruptable power supply that connects the house power grid to the security system power adapter. Also, most current security systems don t use lasers to monitor windows, and instead simply monitor whether the glass has been broken or not. This requires that the windows are closed for the system to be effective. By using lasers, the windows can be monitored all the time, regardless of whether they are open or closed. Also, by multiplexing the lasers across the windows, their power consumption is kept to a minimum. IV. Similar Product The security company ADT provides several different home security system options. Their systems are almost all wireless and consist of individual components, such as motion sensors, magnetic relays, and trip lasers. All of these components are rather bulky and require batteries. They provide much of the same features that I 5

6 hope to implement in my security system. However, all of these systems are ones that the user buys, and then installs themselves. The Guardian Home Security System will be hard wired, and installed into the house during construction. This makes it much simpler for the user, more reliable, and also reduces the overall cost. V. Societal & Global Impacts Considering that almost all security systems currently on the market are primarily wireless, and are not implemented during building construction, I believe that the Guardian Home Security System will have vast global impacts. It will save cost to the end user by eliminating batteries, and by making integration much simpler. In developing areas, this system will be extremely beneficial, because it will allow people to buy houses that have fully integrated and incredibly reliable security systems at very little additional cost. This will give an extra sense of security to those people who have just bought a new home. Also, on the developer side, this system will be a lucrative option, because it adds another selling point for when they are putting a house on the market. However, there is the added cost of wiring during integration. This is made to be minimal, though, because each component of the system is a just a single module, with a small bundle of wires coming out. All the construction crew has to do is bolt the module in place, and plug in the wires. But there is always the situation where the customer wishes that a change be made to the system after integration. In this scenario, there could be significant costs (depending on the location of the desired change) because someone may have to drill into the wall to access the security component. Even with this type of expense 6

7 in mind, though, I still believe that this system will be much cheaper than a completely wireless alternative. VI. Development & Demonstration This system, as well as the model home that will house it, will be developed over the next three quarters. During fall and winter quarter I will be primarily focusing on high level design and hardware testing and development. Most of the software will be written during late winter, as well as spring quarter. To demonstrate the feasibility of this system, I will use realistically sized windows, power it from a wall socket, and include several different modes of operation. 7