Tracking Sound and Vibration Levels Using RFID

Transcription

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2 Tracking Sound and Vibration Levels Using RFID Dr. Ravi N. Margasahayam Safety and Mission Assurance Engineer Kennedy Space Center Florida, USA 2

3 Active RFID Application Highlights Goal: Record launch-induced Sound and Vibration Existing: Extensive Wired systems/ no Wireless Microstrain: Embedded sensors showed promise RFID type: Active - signals over extended range Wireless : Monitors large area/complex situations Issues: RFI affecting People, Systems, Mission Deployment: Battery, Line-of-Sight, Large Data Environmental: Weather, Power, Far-field Inception to data: 3-6 months; Shuttle launch Phase II: Near-field data, High Sample Rate 3

4 Space Shuttle Discovery Lift-off 4

5 Why measure Rocket Noise? KSC s role as a premier rocket launch site, dictates reliability of ground equipment and structures Structural vibration is a consequence of launchinduced acoustics, both air- and structure-borne Launch of Shuttle generates in excess of 188 decibels, largest man-made continuous sound Sound affects Astronauts, payload, wildlife, community, and helps define explosive blast zones Resonance primarily attributable to the generated sound; study of sound and vibration is vital to structural design, safety and mission assurance Sound or unwanted Noise - leads to Structural Vibration, which results in partial or full Resonance 5

6 Natural Frequencies & Modes 6

7 Structures : Natural Frequencies Eyeball, Intraocular Structure (20-90 Hz) Head (axial mode) (20-30 Hz) Shoulder Girdle (4-5 Hz) Chest wall ( Hz) Arm (5-10 Hz) Hand (30-50 Hz) Abdominal Mass (4-8 Hz) Spinal column (axial mode) (10-12 Hz) Abdominal mass mode (around 5 Hz) Space Shuttle Astronauts 3-4 G s 7

8 Astronauts: Natural Frequencies Eyeball, Intraocular Structure (20-90 Hz) Head (axial mode) (20-30 Hz) Shoulder Girdle (4-5 Hz) Chest wall ( Hz) Arm (5-10 Hz) Hand (30-50 Hz) Abdominal Mass (4-8 Hz) Spinal column (axial mode) (10-12 Hz) Abdominal mass mode (around 5 Hz) Space Shuttle Astronauts 3-4 G s 8

9 Resonance: Due To High Pitch Noise 9

10 Resonance: Due to Gear Vibration 10

11 Resonance: Caused By Wind Loads 11

12 Resonance: Due to Ocean Waves 12

13 Noise: Deforms Rocket Structures 13

14 Noise: Leads To Structural Vibration 14

15 Noise: Affects KSC Wild Life 15

16 Noise +Vibration =Vibroacoustics Input Forces + System Response (Mobility) = Vibration Forces caused by Imbalance Shock Friction Noise Structural Parameters: Mass Stiffness Damping Vibration Parameters: Acceleration Velocity Displacement Frequency 16

17 Noise: Max Q - Aerodynamics 17

18 Noise: Measurement Challenges Sensors affected by noise levels over 180 db Excessive Vibration over 100 g s for 6-8 seconds Thermal environment in excess of 4000 degree F and plume heat rate of over 5000 BTU/Ft2-sec Total Shuttle Thrust Million pounds Daily environment - moist salt air, UV radiation System Dynamics sensors must be designed to withstand resonant effects Near-field Sensors typically cooled, shielded, wires have thermal tape, terminated inside Pad Traditionally sensors are limited by cabling, cannot measure all locations, cannot instrument critical locations due to access issues 18

19 RF Controls: Manned Space Flight The Radio Frequency (RF) environment is managed to avoid RFI issues that could harm People, Systems or the expensive and critical Mission. RF emitter evaluation is based on device frequency, power and distance relative to RF sensitive systems pyrotechnics, communications and control systems. Direct and harmonic frequencies as well as the potential to swamp the receive circuits of existing devices using a close frequency. frequency manager reviews frequency utilization for license requirements from the FCC 19

20 900 MHz: Wing Leading Edge 20

21 900 MHz: Orbiter Stinger Issue 21

22 2400 MHz: Holding Pond Water Level 22

23 Microstrain Active RFID Sensors Founded in 1987 in Vermont ; wireless sensors since 1996 Has COTS systems for strain, pressure, load, displacement, acceleration, tilt, etc Developing the next generation of cutting-edge wireless systems for Navy and Army helicopters and fixed wing aircraft Used in automotive, aerospace, industrial manufacturing, semiconductor, alternative energy, environmental monitoring, oil & gas, power generation, civil structures and defense markets. Customers: Bell Helicopter, Sikorsky, Boeing, Caterpillar, Motorola, Johnson & Johnson, general Electric, Pratt & Whitney, Rolls Royce, Lockheed Martin, Ford, Intel, IBM,, US Navy, US Army These are Active RFID sensors, with internal battery power and ability to transmit data during rocket launches 23

24 What is a Wireless Node? Sensor Inputs Lithium thionyl chloride battery Radio Frequency (RF) transceiver Sensor signal conditioning low power, microcontroller Flash EEPROM for sensor logging 12, 16 or 24 bit A/D converter multiplexer, PG instrumentation amplifier 24

25 Microstrain -Wireless System Sensor Nodes Node Commander - GUI Base Station Cloud Computing 25

26 Deployed Wireless Technology 2.4 GHz active RFID tags with built-in sensors and signal conditioning for external sensors Easy to configure/deploy using Node Commander GUI Scalable network support hundreds of synchronized wireless nodes Comprised of G-Link accelerometer nodes, a SG- Link strain node, a Wireless Sensor Data Aggregator base Station(WSDA-Base), and SensorCloud, a web data management platform SensorCloud -Tool to remotely visualize and manage data and to isolate and interpret launch event data - key for test analysis correlation. Qualifies and meets requirements for use at 26

27 Active RFID: Health Monitoring 27

28 Active RFID: Aerospace Applications 28

29 Plume-induced Vibroacoustics 29

30 Test Article and Test Design Issues Pad 39B location far-field, historical data exists, linear acoustics laws, SVETA (test article) Accessibility of test site 24 hours prior to launch Plate dynamics - easy to model and build Plate weight does not affect modal behavior Wireless systems would not affect sensitive Shuttle communications during pad clear to launch Sensor installation access, support, environment Base station inside building, line-of-sight issues Computer location, Ethernet, remote access Launch issues access, pad closeout, safety 30

31 FE, Modal for Launch Validation 31

32 SVETA: Laboratory Calibration KSC 32

33 SVETA: Pad 39B Camera Mount 33

34 Space Shuttles on Pads 39 A & B 34

35 SVETA on Pad B (Launch from A) 35

36 SVETA Line of Sight - WSDA 36

37 SVETA- Field Setup -WSDA 37

38 Endeavour Final and Historic Lift-off 38

39 Space Shuttle Lift-off Sequence 39

40 Test Analysis Correlation Method TOA, Shape, Frequency, Magnitude (PSI Load) Time of Arrival (TOA) tells us when the Rocket lifted off at Pad 39A; how and when SVETA experiences the sound load (magnitude and speed of sound) Shape Acoustics and Vibration signature be similar in shape (less in magnitude distance effect) Frequency Modal (Static test), FE computer Analysis, Shuttle Lift-off should be same from all 3 methods Magnitude of Vibration actually measured g s and then backtracked PSI and db load (it would have been easier to measure acoustics) Pressure load (PSI) is converted to db and compared with historical data from Master Planning 40

41 Shuttle Acoustic and Vibration

42 LaunchVibration: TOA and Shape

43 SVETA :Modal Test Frequencies

44 SVETA: Launch Frequencies

45 SVETA : Frequency and Modes Modal Test and FE Analysis (Hz) Lift-off (Hz)and Mode Shape BENDING TORSION TORSION 45

46 SVETA : Lift-off G s and db Levels G loads on lift-off at SVETA Equivalent PSI and db level 0.5 g s psi (128.2 db) 0.6 g s psi (129.5 db) 0.7 g s psi (130.8 db) 0.8 g s psi (132.2 db) 46

47 Shuttle Acoustics- Analysis & Test

48 Acoustic Levels Historical Data

49 Future Wireless Application- Hypers 49

50 Future Wireless Application- GUCP 50

51 Future Wireless Application - COPV

52 Conclusions & Observations 2.4 GHz RFID tags with built-in sensors from Microstrain were used to measure launch vibrations First use of ACTIVE RFID in the Space Shuttle program and rocket launches Verified time of arrival of rocket noise data and Vibroacoustics implications of a rocket launch Launch Vibration data is used to assess loads/stresses imposed by rocket noise on structures/useful life Test data is vital to study safety and operational readiness and to predict impending failures of GSE Helps monitor pressurized, hazardous systems operating at high temperatures with access issues Developed a tool to evaluate Safety, Reliability, and Maintainability of structures via condition/health monitoring 52

53 Time for Questions? 53

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