On the Use of Reconfigurable Hardware in Sensor System Integration for Airliner Cabin Environment Research Sin Ming Loo FAA Center of Excellence for Airliner Cabin Environment Research Boise State University Boise, Idaho 83725
Outline • Airliner Cabin Environment • Health Issues and Airliner • CoE Airliner Cabin Environment Research • Reconfigurable Sensor System Backbone • Challenges • Conclusions & On-going Work
Cabin Environment • Airline passengers encounter environmental factors that include • Potential exposure to contaminants • O3, CO, CO2 • Pesticides • Various organic chemicals • Biological agents • Close proximity • Low humidity • Reduced air pressure • Health effects? • Ticket to ride Spreading germs a mile high
Health Issues and Airliner • Many reported sickness after flying • Including passengers and flight crew • Is there a link? • No data collected can conclusively says that there is a link • Due to technique used to collect and interpret data • NRC’s 2002 report - “The Airliner Cabin Environment and the Health of Passengers and Crew” • Concludes that more systematic long-term airliner cabin monitoring and research are required
So, why don’t I feel right after flying? • Close proximity • Sardine! • Humidity • 10% to 20% • Temperature • < 20 C • Pressurization • Cabin pressure at altitude up to 8000 ft (2,440 m) • Partial oxygen level • Stress of flying
Operating Environment • Taxiing Takeoff Cruise Descent • Temperature • -55C to 50C • Pressure • 10.1 kPa to 101 kPa • Altitude • Sea level to 36,000 ft (typical cruising altitude) • Extreme range of operating environments • So, how am I being kept alive? • Environmental Control System - provide a suitable indoor environment
Environmental Control Systems • Role • Ventilate and pressurize the cabin • Prevent rapid changes in cabin pressure • Minimize concentrations of contaminants • Typically, large commercial aircraft (>100 passengers) re-circulate about 50% of cabin air • Re-circulated air passes through high efficiency particulate air (HEPA) filters • Not mandated by FAA • 85% of aircraft (>100 passengers) are equipped with HEPA filters
Bleed Air Reference: United States General Accounting Office, Aviation Safety: More Research Needed to the Effects of Air Quality on Airliner Cabin Occupants, GAO-04-54, January 2005.
Source of Contaminants • At cruising altitude, the air is quite pure • Source of contaminants • You and I! • Industrial and urban sources • Air supply systems • Leaking hydraulic fluid • Spilled fuel • Deicing fluid • Intentional agent release
CoE ACER • FAA established the Center of Excellence for Airliner Cabin Environment Research (http://acer-coe.org) in 2004 • ACER consists of an eight-institution team: • Auburn University • Purdue University • Harvard University • Boise State University • Kansas State University • Lawrence Berkeley National Laboratory • The University of California Berkeley • The University of Medicine and Dentistry of New Jersey • ACER conducts a comprehensive and integrated program of research and development on the cabin environment
Airliner Cabin & FPGA? Why does the FPGA have anything to do with airliner cabin environment research?
ACER Needs a… • Sensor backbone: • Flexible • Scalable • Interfaceable to analog- and digital-based sensors • Removable storage • Wireless • Solution • Combination of FPGA and microcontroller
Remote Station Base Station S0 S0 S1 S1 S2 S2 S3 S3 Wireless Wireless RH RH/C RH . . . Interface Wireless S4 S4 Sn-3 Sn-3 Sn-2 Sn-2 Sn-1 Sn-1 Indicator SD Flash Sensor Peripheral Board Wireless Sensor Network • Base stations with m remote stations • Remote station interface to n sensors • Sensor peripheral unit • Analog • Digital
RH/C Interface Wireless Indicator SD Flash Base Station • Xilinx FPGA with Microblaze core • 802.11b compatible Wireless Transceiver • Secure digital flash memory • Extra I/O for future interface • Real-time clock • Battery power
4.5” S0 S0 S1 S1 S2 S2 S3 S3 Wireless Wireless RH RH . . . S4 S4 Sn-3 Sn-3 Sn-2 Sn-2 Sn-1 Sn-1 3” Remote Station • Xilinx FPGA with Microblaze core • 802.11b compatible wireless transceiver • Lots of I/Os for sensors • Real-time clock • Battery power • I2C
Sensor Peripheral Board • Low cost microcontroller is used to ease the task of interfacing to analog or digital sensor • This board: • Microcontroller • Analog ports • Digital ports • Small prototype area
Wireless Transceiver • WiFi to be used for data collection by base station • 802.11b, 2.4GHz • Check out http://ww.connexion.com • Wireless module • Aerocomm AC5124C-10A
Sensor Interface Prototype • Sensors • National Temperature Sensor • Humirel Relative Humidity Sensor • Motorola Pressure Sensor • FIS Gas Sensor VOCs • FIS Gas Sensor Carbon Monoxide • FIS Ozone Sensor • FIS Gas Sensor Combustion Gas
Challenges • Analog/digital sensor interface • Data storage • Raw data? • Scalable number of sensors • Minimize the electronic characterization (certification) required for in-cabin usage • FCC and FAA standards • Power consumption/interface
Conclusions & On-going Work • Provided an introduction to airliner cabin environment research • Presented a design of an Ad-hoc wireless sensor network with backbone capable of interfacing with large numbers of sensors • Analysis of the quality of wireless signals in the aircraft cabin
Acknowledgement This work is funded by FAA Cooperative Agreement No. 04-C-ACE-BSU. Disclaimer Although the FAA has sponsored this project, it neither endorses nor rejects the findings of this research. The presentation of this information is in the interest of invoking technical community comment on the results and conclusions of the research.