SMART ROCK TECHNOLOGY FOR REAL-TIME MONITORING

Transcription

1 SMART ROCK TECHNOLOGY FOR REAL-TIME MONITORING OF BRIDGE SCOUR AND RIPRAP EFFECTIVENESS GUIDELINES AND VISUALIZATION TOOLS Genda Chen, P.E., Ph.D., F.ASCE, F.SEI Professor and Robert W. Abbett Distinguished Chair in Civil Engineering Director, System and Process Assessment Research Laboratory (SPAR Lab) Associate Director, Mid-America Transportation Center (MATC) Missouri University of Science and Technology (Missouri S&T) 3 rd Technical Advisory Council Meeting on April 1,

2 OUTLINE OF THIS PRESENTATION The Smart Rock Monitoring Concept Design and Prototyping Localization and Effectiveness Field Test Demonstration Concluding Remarks 2

3 THE SMART ROCK MONITORING CONCEPT Two Application Scenarios Scour Depth Deposits at a bridge pier or abutment are washed away to form a scour hole with unknown location and depth. Countermeasure Effectiveness Move of rocks leads to the loss of a rip-rap countermeasure for bridge scour protection. Multiple measurement stations using one magnetometer Bridge deck Pier River bank Current flow Water Natural rocks Smart rocks Scour hole Piles Soil deposits Fig. 2 Scour Countermeasure Monitoring 3

4 DESIGN AND PROTOTYPING Arbitrarily Oriented System (AOS) Monitored along the river bank or on the bridge deck Most complicated in smart rock localization AOS Model of Smart Rocks 4

5 DESIGN AND PROTOTYPING Automatically Pointing-South System (APSS) Monitored along the river bank Measurement station located in South or North pole of the magnet Rapid convergence and high accuracy of APSS location However, easily affected by ferromagnetic substances R=11cm r=10cm Level Bubble 10.16cm N S 5.08cm (a) Schematic View Copper Beeds Propylene Glycol APSS Model of Smart Rocks (b) Prototype Smart Rock 5

6 DESIGN AND PROTOTYPING Automatically Pointing-Up System (APUS) Automatically Pointing to Upward System (APUS) Measurement apparatus set on the bridge deck Gravity-orientated direction, reduces the degree of freedom, less effect by ferromagnetic substance R=14cm r=12.5cm R=14cm r=12.5cm 5.05cm Level Bubble S N Propylene Glycol Copper Beeds 10.16cm Level Bubble S N Propylene Glycol Copper Beeds 15.24cm (a) One N45 Magnet 10.16cm (b) Two N42 Magnets (b) Prototype Smart Rock 6

7 DESIGN AND PROTOTYPING Concrete Encasement and Fabrication cm-diameter mold with a concrete density of 1495 kg/m 3 Fabrication process One N45 Magnet R2=14.0cm R3=18.415cm R1=12.5cm Level Bubble S R2=14.0cm R3=18.415cm R1=12.5cm Level Bubble S Two Stacked N42 Magnet N N 1. Mix fiber concrete 2. Place APUS inside a mold 3. Fill the mold with concrete 4. Cure the concrete in water for 14 days 7

8 LOCALIZATION AND EFFECTIVENESS Ambient Magnetic Field at Q Station in Absolute XYZ Coordinate System Ambient Ferromagnetic Substances B A, Ambient Magnetic Field Vector at a Measurement station, Q (X,Y,Z) Three components of B A : B XA B A cos cos B B YA ZA B A B A cos sin sin B A, measured by magnetometer θ (0, π) and φ θ (0, 2π) measured by an orientation device 8

9 LOCALIZATION AND EFFECTIVENESS Total Magnetic Field at Q Station in Absolute XYZ Coordinate System Total Magnetic field intensity: B ( B B ) ( B B ) ( B B ) XM XA YM YA ZM ZA B = B (B A, θ, φ, k, X M, Y M, Z M, α, β, γ, X, Y, Z) at a Measurement station, Q (X,Y,Z) Given k, θ, φ and B A at each (X, Y, Z), B = B (X M, Y M, Z M, α, β, γ) Magnet s effect: k3 xy/ r 5 BXM BYM T k(2 y x z ) / r 5 B 3 / ZM k zy r cos cos cos sin sin T sin sin cos cos sin sin sin sin cos cos sin cos cos sin cos sin sin cos sin sin sin cos cos cos 9

10 LOCALIZATION AND EFFECTIVENESS Localization Algorithm Unknown Orientation ( P) ( SRSS error between predicted intensity B and the measured intensity M ), n ( P) ( M) 2 M M M i i i 1 J( X, Y,Z,,, ) [ B B ] J( XM, YM,Z M,,, ) 0 X M J( XM, YM,Z M,,, ) 0 Z M J( XM, YM,Z M,,, ) 0 Y Known Orientation (α=0, β=0, and γ=0) M J( XM, YM,Z M,,, ) 0 J( XM, YM,Z M,,, ) J( XM, YM,Z M,,, ) 0 0 n ( P) ( M) 2 M M M i i i 1 J( X, Y,Z ) [ B B ] i B i J( XM, YM,Z M) 0 Y M J( XM, YM,Z M) 0 Z M J( XM, YM,Z M) 0 X M 10

11 LOCALIZATION AND EFFECTIVENESS Experimental Validation Procedure Before a smart rock is deployed, the ambient magnetic field of the Earth and environmental effects was evaluated at each measurement point either by a scalar magnetometer and an orientation device or by a threecomponent magnetometer. After the smart rock is deployed, the total magnetic field of the magnet and the ambient field was measured with the same magnetometer at various points around the smart rock. The coordinates of measurement points were surveyed by a total station a survey instrument. The intensity and coordinate measurements at six or more stations allowed the determination of the smart rock s location. 11

12 LOCALIZATION AND EFFECTIVENESS Experimental Validation Test Setup A scour experienced pier Three Locations M1, M2, and M3 for AOS and APSS Total 34 measurement points Total Station at Point B to survey coordinates of three smart rocks' locations and 34 sensor positions MFDD was set at the 34 points to measure the angles of θ and φ B Y(S) X(W) M M M Pi er 19 C A 12

13 LOCALIZATION AND EFFECTIVENESS Experimental Validation Test Results (M3 APSS ) Location of Sensor Head X(m) Y(m) Z(m) B (M) i (nt) P P P P P P P P P Predicted APSS Location M3 APSS Measured APSS Location M3 APSS Location Prediction Error for M3 APSS SRSS Error in Coordinate 0.085m N/A 13

14 LOCALIZATION AND EFFECTIVENESS Experimental Validation Test Results (M3 AOS ) Location of Sensor Head X(m) Y(m) Z(m) B (M) i (nt) P P P P P P P P P Predicted AOS Location M3 AOS Measured AOS Location M3 AOS N/A Location Prediction Error for M3 AOS SRSS Error in Coordinate 0.093m 14

15 Test Crane Design Lightweight, easy installation, rapid assembling, and cost effectiveness Minimal wind-induced disturbance Non-magnetic materials in proximity to the sensor Comp. 3 Comp. 4 Comp. 5 Prism 1 Prism 2 x z y Comp. 2 Sensor Prism 3 Comp. 1 15

16 Test Crane Prototype/Product 16

17 Three-axis Flux Digital Magnetometer (STL) Manufactured by Systemtechnic Ludwig GmBH, Konstanz, Germany STL DM050: measure X-, Y- and Z- component and total field 50 meters Coax cable for power and data transmission Interface : Coax Ethernet Hub for connection of up to 3 magnetometers STL GradMag software installed in a Notebook for full controlling of measurement, data acquisition and viewer Field range: ±1,000,000nT Resolution: 0.002nT Maximum sample rate: 10 khz 17

18 HWY1 Waddell Creek Bridge, CA 18

19 Setup and Layout on Bridge Deck Test Procedure Set a Cartesian Coordinate System Ambient Magnetic Field Measurement Deployment of Smart Rocks Measurement of the Total Magnetic Field Results from Bridge Deck Measurements 19

20 Measurement Station Layout on Bridge Deck Santa Cruz San Fransisco Y1Y2Y3Y4 Y1 Y2Y3Y4Y5 Bridge Deck Z7 Z6 Z5 Z4 Z3 Z2 Z1 Z7 Z6 Z5 Z4 Z3 Z2 Z1 Z SR3 SR2 Abutment 1 Bent 2 SR1 Y Total Station Y1 Y2 SR3 Y3Y4 Mesh 4 Mesh 3 X4 X3 X2 X1 X4 X3 X2 X1 Y1Y2 Y3Y4Y5 SR2 SR1 Mesh 2 Mesh 1 Y X Total Station 20

21 Test Setup and Layout Prism 1 Prism 2 Sensor Prism 3 21

22 Test Set up and Layout Measurement Points Layout on the Bridge Deck 22

23 Test Procedure Set a Cartesian coordinate system O-XY Point A- Permanent Benchmark Total station at Point A to set coordinate system as A-xy Survey Point B and O under A-xy coordinate system Set up total station at Point O to determine the final coordinate O-XY River Flow y Y A-Benchmark Abutment1 B C Bent 2 x Bent 3 Bent 4 Santa Cruz San Fransisco O Total Station Abutment 5 X 23

24 Test Procedure Measure the Ambient Magnetic Field Magnetic field from Earth and ambient ferromagnetic constructions Conduct before deployment of the smart rock Abutment 1 Measurement: Y1, Y2, Y3 along Y axis, X1, X2, X3, X4 along X axis, and Z1,Z2,..., Z7 along Z axis, total 84 points. Bent 2 Measurement: Y1, Y3, Y5 along Y axis, X1, X2, X3, X4 along X axis, and Z1,Z2,..., Z7 along Z axis, total 84 points. Measurement points sequence: X1 Z1 to Z7 X1 Z1 to Z7 X1 Z1 to Z7 Y1 X2 X3 Z7 to Z1 Z1 to Z7 Y2 or Y3 X2 X3 Z7 to Z1 Z1 to Z7 Y3 or Y5 X2 X3 Z7 to Z1 Z1 to Z7 X4 Z7 to Z1 X4 Z7 to Z1 X4 Z7 to Z1 24

25 Test Procedure Deploy Three Smart Rocks Smart Rock 1 (SR1) & Smart Rock 2 (SR2) around Bent 2 Smart Rock 3 (SR3) around Abutment 1 Y Abutment1 B SR3 SR2 Bent 2 Santa Cruz SR3 River Flow SR1 Bent 3 Bent 4 San Fransisco Total Station Abutment 5 X 25

26 Test Procedure Deploy Three Smart Rocks SR1 SR2 26

27 Test Procedure Measure the Total Magnetic Field Intensity Magnetic field from both smart rock and AMF. Abutment 1 Measurement: Y1, Y2, Y3 along Y axis, X1, X2, X3, X4 along X axis, and Z1,Z2,..., Z6 along Z axis, total 72 points. Bent 2 Measurement: Y1, Y3, Y5 along Y axis, X1, X2, X3, X4 along X axis, and Z1,Z2,..., Z7 along Z axis, total 84 points. Measurement points sequence same as that of AMF. SR3 Y1X1Z7 SR3 Y1X4Z1 27

28 Test Results FIELD TEST DEMONSTRATION Coordinates and Intensities at Measurement Points around Abutment 1 Y1X2 Y1X3 Measurement Points Coordinate (m) N42 Magnet Factor (nt.m 3 ) AMF Intensity (nt) SR3 & AMF Intensity (nt) X i Y i Z i K B XA B YA B ZA B A B X B Y B Z B Z Z Z Z Z Y1X4 Z Y2X2 Y2X3 Y2X4 Y3X2 Y3X3 Y3X4 28

29 Test Results FIELD TEST DEMONSTRATION Localization of SR3 Point Name Measurement Points Coordinate (m) N42 Magnet Factor (nt.m 3 ) AMF Intensity (nt) SR3 & AMF Intensity (nt) Y1X2 Y1X3 X i Y i Z i K B XA B YA B ZA B Z Z Z Z Z Y1X4 Z Predicted SR3 Location Measured SR3 Location Location Prediction Error for SR SRSS Error in Coordinate NA 29

30 I-44 Roubidoux Ceek Bridge, MO (Bent 7 downstream) 30

31 Measurement Station Layout on Bridge Deck Rolla Y1 Y2 Y3 Springfield Bridge Deck Z7 Z6 Z5 Z4 Z3 Z2 Z1 SR1 Z7 Z6 Z5 Z4 Z3 Z2 Z1 Bent 8 Bent 7 Z Z7 Z6 Z5 Z4 Z3 Z2 Z1 Bent 6 Total Station O Y Y1 X2 X1 Y2 Y3 1.8m Mesh 2 O Total Station X Y X2 X1 SR1 6.0m 0.4m 1.8m 2.3m Mesh 1 31

32 Test Setup and Layout 32

33 Test Set up and Layout Measurement Points Layout on the Bridge Deck 33

34 Test Procedure Set a Cartesian coordinate system O-XY Y Bent 6 B Springfield River Flow Bent 7 Rolla O Total Station X Bent 8 A-Benchmark 34

35 Test Procedure Ambient Magnetic Field Measurement Magnetic field from Earth and ambient ferromagnetic constructions Conduct before deployment of the smart rock Bent 7 Measurement: Y1, Y2, Y3 along Y axis, X1, X2 along X axis, and Z1,Z2,..., Z7 along Z axis, total 42 points. Measurement points sequence: Y1 X1 X2 Z1 to Z7 Z7 to Z1 Y2 X1 X2 Z1 to Z7 Z7 to Z1 Y3 X1 X2 Z1 to Z7 Z7 to Z1 35

36 Test Procedure Deployment of Smart Rocks Smart Rock 1(SR1) around Bent 7 Y Bent 6 B Springfield River Flow SR1 Bent 7 Rolla O Total Station X Bent 8 A-Benchmark 36

37 Test Procedure Measure the Total Magnetic Field Intensity Magnetic field from both smart rock and AMF. Bent 7 Measurement: Y1, Y2, Y3 along Y axis, X1, X2, along X axis, and Z1,Z2,..., Z7 along Z axis, total 42 points. Measurement points sequence same as that of AMF. 37

38 Test Results FIELD TEST DEMONSTRATION Coordinates and Intensities at Measurement Points around Bent 7 Y1X1 Measurement Points Coordinate (m) N42 Magnet Factor (nt.m 3 ) AMF Intensity (nt) SR3 & AMF Intensity (nt) X i Y i Z i K B XA B YA B ZA B A B X B Y B Z B Z Z Z Y1X2 Z Y2X1 Y2X2 Y3X1 Y3X2 38

39 Test Results FIELD TEST DEMONSTRATION Localization of SR1 X M /m Y M /m Z M /m Predicted SR1 Location Measured SR1 Location Location Prediction Error for SR SRSS Error in Coordinate 0.258m 39

40 US63 Gasconade River Bridge, MO (Bent 4 upstream) 40

41 Measurement Station Layout on Bridge Deck Jefferson City Y1 Y2 Y3 Rolla Bridge Deck Z Bent 2 Z7 Z6 Z5 Z4 Z3 Z2 Z1 Z7 Z6 Z5 Z4 Z3 Z2 Z1 Z7 Z6 Z5 Z4 Z3 Z2 Z1 O Y Total Station Bent 3 Bent 4 Bent 5 O X Y Total Station Y1 X2 X1 X2 X1 Y2 9.0m SR1 Y3 2.0m 0.4m 2.0m 1.8m Mesh 2 Mesh 1 41

42 Test Setup and Layout 42

43 Test Set up and Layout Measurement Points Layout on the Bridge Deck 43

44 Test Procedure Set a Cartesian coordinate system O-XY Y Rolla Bent 5 River Flow Jefferson city Bent 4 B Bent 3 Bent 2 A-Benchmark O X 44

45 Test Procedure Ambient Magnetic Field Measurement Magnetic field from Earth and ambient ferromagnetic constructions Conduct before deployment of the smart rock Bent 4 Measurement: Y1, Y2, Y3 along Y axis, X1, X2 along X axis, and Z1,Z2,..., Z7 along Z axis, total 42 points. Measurement points sequence: X2 Y3 Y2 Y1 Z1 to Z7 Z1 to Z7 Z1 to Z7 X1 Y1 Y2 Y3 Z1 to Z7 Z1 to Z7 Z1 to Z7 45

46 Test Procedure Deployment of Smart Rocks Smart Rock 1(SR1) around Bent 4 Y Rolla Bent 5 SR1 River Flow Jefferson city Bent 4 B Bent 3 Bent 2 A-Benchmark O X 46

47 Test Procedure Measure the Total Magnetic Field Intensity Magnetic field from both smart rock and AMF. Bent 7 Measurement: Y1, Y2, Y3 along Y axis, X1, X2, along X axis, and Z1,Z2,..., Z7 along Z axis, total 42 points. Measurement points sequence same as that of AMF. X1 Y1 Y2 Y3 Z1 to Z7 Z1 to Z7 Z1 to Z7 X2 Y1 Y2 Y3 Z1 to Z7 Z1 to Z7 Z1 to Z7 47

48 Test Results FIELD TEST DEMONSTRATION Coordinates and Intensities at Measurement Points around Bent 7 Measurement Points Coordinate (m) N45 Magnet Factor (nt.m 3 ) AMF Intensity (nt) SR3 & AMF Intensity (nt) X i Y i Z i K B XA B YA B ZA B A B X B Y B Z B Z Y1X1 Z Z Y1X2 Z Y2X1 Y2X2 Y3X1 Y3X2 48

49 Test Results FIELD TEST DEMONSTRATION Localization of SR1 The ground truth of the coordinate is SR1 was not measured due to the fast water current. The predicted location is reasonable according to the relative position to the measurement points. X M /m Y M /m Z M /m Predicted SR1 Location

50 CONCLUDING REMARKS The APUS smart rocks have been deployed at three sites of the Waddell Creek Bridge, CA, the Roubidoux Creek Bridge, MO, and the Gasconade River Bridge, MO. The AOS, APSS, and APUS smart rock localization algorithms without and with knowing the magnet polarization in a priori have been validated at the three sites, all giving satisfactory results (<< 0.5 m). The test crane can be set on a trailer and moved as needed in application. 50

51 ACKNOWLEDGEMENTS Financial support for this study was provided by the U.S. Department of Transportation Office of the Assistant Secretary for Research and Technology (USDOT/OST-R) under Cooperative Agreement No. OASRTRS-14-H-MST and by Missouri Department of Transportation (in-kind). The views, opinions, findings and conclusions reflected in this presentation are the responsibility of the presenter only and do not represent the official policy or position of the USDOT/OST-R or any State or other entity. Thanks are due to California and Missouri Departments of Transportation for their assistance in traffic control during field tests. Thanks are also due to graduate students (Yan Tang, Zhaochao Li, Yizheng Chen, Steve Guo, Fan Liang), senior specialist (Jason Cox), and engineering technicians (John Bullock, Greg Leckrone, Gary Abbott, and Brian Swift). 51