Structural Health Monitoring Using Smart Sensors - ideals ...

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Sender Send parameters • Sender sends parameters to the receiver. (e.g. data length, sensitivity, offset, data type, message ID, etc.) • Sender keeps sending the parameters until acknowledgement packet is received. Data • Sender sends series of data packets End of data • Sender notifies the receiver that all the data is sent. This message is repeatedly sent until acknowledgement is received. Missing packets? yes Send missing data • Sender reply to the request. no Receiver Acknowledge • Receiver saves received parameters and return acknowledgement packet Receive data • Receiver saves received data and keeps track of missing packets. Acknowledgement/Request missing packets • Receiver acknowledges. If receiver missed packets, request sender resend the missing packets. Receive data • Receiver saves received data and keeps track of missing packets. Done • Sender tells the receiver that the data transfer is complete. Sender keeps sending packets until an acknowledgement packet is received. Acknowledge • Receiver acknowledges. Figure 5.12. Simple block diagram of the reliable unicast protocol for long data records. data; data processing results on Imote2s can be directly compared with those on a PC, which are most likely in double precision format. Transfer of 64-bit double precision data is supported based on such needs. Unicast In the unicast protocol, the sender seeks to reliably deliver long data records to the receiver utilizing acknowledgment messages. Figure 5.12 shows a simple flowchart of this protocol.The details of the protocol are explained in the following paragraphs as well as in the block diagram in Figure 5.13. On start-up, the communication protocol requests that the main application assign a buffer space to keep data to be transferred. This buffer needs to be large enough to hold the entire data record. When 11,264 data points in 16-bit integer format are transferred, this buffer size is about 22.5 kB. The main application returns the pointer to this buffer. The need for this large buffer size is a drawback of this approach. However, with knowledge of the application, the main application can utilize this memory space for other purposes when communication is not expected to take place. This buffer is allocated in the main application and only the pointer is given to the communication program. When the application is ready to send data, the sender informs the receiver of the necessary parameters (e.g., data length, data type, message ID, destination node ID, source node ID, etc.). If the data is in integer format, the sensitivity and offset of the data are also conveyed to the receiver. A packet containing these parameters is sent to the receiver. 65
Sender SendLData.send() Pack parameters (e.g., Destination, message ID, data length, sensitivity, etc. ) SendNoticeSubTask() SendNoticeMsg.sendDone() call TimerNotice.start() Receiver ReceiveNoticeMsg.receive() Receiver stores received parameters. Afterward, message ID and sender’s address will be used to rejects packets for other communication request. TimerNotice.fired() if acknowledged, post SendDataTask() else post SendNoticeSubTask() ReceiveNoticeMsg.receive() set flag as acknowledged SendAckMsg() SendNoticeSubTask() SendDataTask() Pack a packet with data TimerData.start TimerData.fired SendDataMsg.sendDone if all the data is sent post SendNoticeEnd else post SendDataTask ReceiveDataMsg.receive Receiver stores received data SendNoticeEnd() Pack a packet. Notification that sender has sent all the data SendNoticeSubTask SendNoticeMsg.sendDone() call TimerNotice.start() TimerNotice.fired() if acknowledged, post Comment3CheckUnicast() else post SendNoticeSubTask() Comment3CheckUnicast() if there are missing packets post SendDataTask else pack a packet with ‘Done’ message post SendNoticeSubTask SendNoticeSubTask SendNoticeMsg.sendDone() call TimerNotice.start() ReceiveNoticeMsg.receive() set flag as acknowledged check request for resending ReceiveNoticeMsg.receive() Receiver checks for missing packets and report to the sender. SendAckMsg() SendNoticeSubTask() ReceiveNoticeMsg.receive() Acknowledge the sender Signal received() TimerNotice.fired() if acknowledged, signal sendDone() else post SendNoticeSubTask() ReceiveNoticeMsg.receive() set flag as acknowledged SendAckMsg() SendNoticeSubTask() Figure 5.13. Detailed block diagram of the reliable unicast protocol for long data records. 66
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NSEL Report Series Report No. NSEL-
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The Newmark Structural Engineering
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Contents Page CHAPTER 1 INTRODUCTIO
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9.2.3 Power harvesting . . . . . .
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damage/deterioration is intrinsical
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scalability to a large number of sm
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logic circuit. However, FPGAs are m
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easons, smart sensors spatially dis
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Figure 2.1. EYES project sensor pro
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Table 2.1. Smart Sensor Specificati
Page 21 and 22: While a number of sensor boards for
Page 23 and 24: need to be within the coordinator's
Page 25 and 26: eing examined (Moore et al., 2001).
Page 27 and 28: structural damage, the analysis to
Page 29 and 30: that sensor installation cost inclu
Page 31 and 32: (2004) indicated that this accelero
Page 33 and 34: different type of sensors connected
Page 35 and 36: Chapter 3 SHM ARCHITECTURE This cha
Page 37 and 38: Modal operation Several modal opera
Page 39 and 40: its spatial gradient, which is clai
Page 41 and 42: Manager node Cluster head node Leaf
Page 43 and 44: commands; execution timing cannot b
Page 45 and 46: Table 3.2. Desirable Characteristic
Page 47 and 48: Table 3.2. Desirable Characteristic
Page 49 and 50: Figure 4.1. Foil strain gage. strai
Page 51 and 52: dB A s Figure 4.4. AA filter design
Page 53 and 54: 8.32F 3V 3.45F 3V Input 1K 1K 1K 1K
Page 55 and 56: Strain ( ) 80 w/o Digital Filter 60
Page 57 and 58: performance was experimentally vali
Page 59 and 60: anges from 10 to 20. If 50 percent
Page 61 and 62: Node 1 x1 i =1,2,…,ns E x 1
Page 63 and 64: Correlation function estimate (m 2
Page 65 and 66: Figure 5.5. Effect of data loss and
Page 67 and 68: Frobenius norm. Because only a limi
Page 69 and 70: 90 80 70 60 50 Node1 Node2 Node3 No
Page 71: On reception of a NACK, the sender
Page 75 and 76: If there are missing packets, the r
Page 77 and 78: Sender SendLData.bcast() Pack param
Page 79 and 80: Sender Send a packet • Sender sen
Page 81 and 82: utilized in SHM applications follow
Page 83 and 84: where R xxref is a vector consistin
Page 85 and 86: Time (sec) 80 60 40 20 0 -20 -40 -6
Page 87 and 88: Difficulties encountered in realizi
Page 89 and 90: 1.8715 x10 5 #ofdatablocks 1.871 me
Page 91 and 92: Before this decimation is applied,
Page 93 and 94: where xn is the original signal,
Page 95 and 96: Timer firing every T3 110 data poin
Page 97 and 98: locks before or after the current b
Page 99 and 100: Chapter 6 ALGORITHMS In this chapte
Page 101 and 102: The eigenproblem of the system matr
Page 103 and 104: where M 0 is the mass matrix of the
Page 105 and 106: same community, eliminating the nee
Page 107 and 108: measurement or mass perturbation ca
Page 109 and 110: these algorithms are implemented on
Page 111 and 112: 10 0 10 -2 10 -4 0 500 1000 1500 20
Page 113 and 114: Table 7.1. SVD Accuracy Check on Ma
Page 115 and 116: 7.1.4 Complex matrix inverse A comp
Page 117 and 118: Figure 7.9. Details of the joint (G
Page 119 and 120: Figure 7.13. Amplifier (Gao, 2005).
Page 121 and 122: 0.08 0.2 Acceleration (g) 0.04 0 -0
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3 Imote2_2/Imote2_1 Imote2_1/Siglab
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200 3 Phase of spectral densities (
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1.5 x10-17 Time (sec) Difference in
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input forces applied at nodes in th
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CH1 CH2 CH3 …. CHn-1 CHn Initiali
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1 2 Node ID 102 RETAKE 1 3 4 INCONS
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Initialization: within local sensor
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PC Base station Manager sensor Clus
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Table 7.7. Instructions in DCS Code
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EXPERIMENTAL VERIFICATION Chapter 8
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8 x10-3 Time (sec) Correlation func
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Table 8.2. Mass Normalization Const
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1 2 Node ID 67 RETAKE 0 3 4 ID 67 #
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for a SHM strategy does not necessa
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are saved. The 420 seconds listed a
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1 1 Normalized accumulated stress m
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Page 161 and 162:
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Table 8.5. Summary of False Damage
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Table 8.7. Summary of False Damage
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e scalability, autonomous distribut
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The lowest frequencies of interest
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structural vibration is considered
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REFERENCES Actis, R. L. & Dimarogon
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Casciati, F., Faravelli, L, Borghet
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Feldman, M. & Braun, S. (1995). “
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Kling, R. (2003). “Intel Mote: an
Page 181 and 182:
Mufti, A. A. (2003). “Integration
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Sazonov, E., Janoyan, K., & Jha, R.
Page 185 and 186:
Yi, J.-H. & Yun, C.-B. (2004). “C
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