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Emergency Exit Detector Team Kelly PDR Presentation Team Members Leonardo Mascarenhas Ernald Nicolas Krystina Pysz David Vega. Motivation. September 11, 2001 South Tower four civilians escaped on Stairwell A from 80 th floor or above
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Emergency Exit Detector Team Kelly PDR Presentation Team Members Leonardo Mascarenhas Ernald Nicolas Krystina Pysz David Vega
Motivation September 11, 2001 South Tower • four civilians escaped on Stairwell A from 80th floor or above • one specific evacuee switched from one impassable staircase to a clear one North Tower • one group below the fire repeatedly called 911 asking for the fire’s location • this group is presumed dead because 911 advised them to remain on the 83rd floor
Development Original Idea • Imaging sensors, cameras or radar, monitor stairwells and return information on blockage. • This data feeds a processing unit that shows its result on displays near the corresponding sensors. Structural Engineering Consultation Dr. Scott Civjan University of Massachusetts Amherst • emphasized that sensors must have no potential of harm • noted that power supply often fails during such emergencies • said that the current concern in high-rise safety is risk of fire
Today Heat Sensor Input • monitor temperature and its rate of rise • wireless sensors avoid dependence on building power grid • commercially available system relieves the need to design sensor network Flashing Light Output National Electrical Manufacturer’s Associationarticle • uniqueness of each individual fire • need to alert victims of the current emergency • importance of providing as much information as possible
Block Diagram Wireless Heat Sensors Exit Warning Devices Device 1 out 1 FSK Receiver FSM (A/D) Light Displays Digital Logic Computer with Routing Algorithm 2 Device 2 Commercial Sensor Receiver and Fire Control Panel out 3 FSK Receiver FSM (A/D) Digital Logic Light Displays FSK Transmitter 4 Device 3 out 5 FSK Receiver Digital Logic Light Displays 6 Wireless Wire
Monitoring / data collection • Wireless Heat Sensors will be placed inside stairwells • Monitoring and data collection will be performed by commercially available fire control panels • Ours system input data will be retrieved from the fire control panel Wireless Heat Sensors 1 2 Commercial Sensor Receiver and Fire Control Panel 3 4 5 6
User Interface and Routing Algorithm • User interface has to be user friendly and secure • Will retrieve the data from a fire control panel • Will analyze the data to identify which stairwells are clear • If fire gets into a stairwell, it will send a warning signal to the transmitter • Will be able to prioritize best exit route Computer with Routing Algorithm
FSK Transmitter • FSK Transceiver • Advantages • Uses Unlicensed band (433MHz) • Bandwidth of 140kHz to 800 kHz • Frequency Hopping Capability • We are sending very small messages • Low Power • Transmission range of 50m • Will require some logic before it • Will require backup power (Battery) FSK Transmitter
Exit Warning Device • Must be compact • Will be placed above the stairwell door • Requires Backup Power • Will display a Green or a Red light • Receiver • FSK Transceiver • Same motives as transmitter • Each receiver will be tuned to different frequencies • Output will be directed to a Digital Logic Circuitry Device 1 FSK Receiver FSM (A/D) Digital Logic Light Displays
Cont’d, Exit Warning Device • Digital Logic • Will use a FSM • Necessary to control Light displays • Will have 3 main states • Idle, Green, and Red • Will count the number of high inputs during a small period of time to decide its output. • Light Display • Has to be intuitive • Display either Green orRed • Must be as visible as possible through smoke Device 1 FSK Receiver FSM (A/D) Digital Logic Light Displays
Design Alternatives Options exist in our choice of: Sensors Warning displays Wireless Transmission
Wireless Heat Sensors 1 2 Commercial Sensor Receiver and Fire Control Panel 3 4 5 6 Design Alternatives: Sensors • The following were considered for the main sensing unit: • 1. Optical/Infrared cross-referenced with images – to measure stairwell aggregation and/or structural integrity • X Lighting is poor during emergencies, and infrared could give false information • 2. Wires embedded in wall - measure structural integrity • X Fires pose more common and more serious threat than structural collapse • 3. RFID - for measuring stairwell aggregation and detecting heat/temperature rise • X RFID scanners are too expensive • Why we chose Heat/Smoke Detectors – • Commercially available • Focus is on fire emergencies • Wireless
Design Alternatives: Warning Displays The following are currently under consideration: • Visual: Flashing Lights • Red = unsafe exit, Green = safe exit • Visual: Mapping Display • Show optimal route of exit • Sounds: Speakers/Voice - Including information such as location, time frame, severity, and likelihood of hazard, source of warning Device 1 FSK Receiver FSM (A/D) Light Displays Digital Logic Device 2 FSK Receiver FSM (A/D) Digital Logic Light Displays Device 3 FSK Receiver Light Displays Digital Logic
Computer with Routing Algorithm FSK Transmitter Design Alternatives: Wireless Transmission • ASK (Amplitude Shift Keying) – for sending binary data X More susceptible to noise than FSK 2. Amplitude Modulation (AM) X Subject to amplitude noise • Bandwidth efficient = good if large numbers of signals are to be multiplexed 3. Frequency Modulation (FM) X Bandwidth inefficient, complex receiver • Good sound quality 4. Frequency Division Multiplex (FDM) - Need for bandpass filters = tough to build - good for limited amount of receivers with lots of information to send, too many could cause interference
MDR Deliverables Transmitter Capable of sending a specific message In our case, we would like to send a 1 or nothing. Able to sweep through an entire sequences of desirable frequencies Outputs with sufficient signal strength Transmission without overlap to adjacent frequency bands
(cont’d) MDR Deliverables Receiver • Equipped with bandpass filter attuned to specific frequency band • Extract message from signal and apply the instruction to the LED display • Full digital logic unit will not be included for MDR • LED array of red/green lights with diodes in reverse polarity
Deliverables • Generated output files from heat sensor system as input to algorithm • Interface of algorithm with transmitter • 6 output receivers (2 floors) receiving wireless signals at unique frequencies • Effective output display device