ISEE Part IIThe Application Protocol Approach

K.J. Wang, S.J. Wang, W.C. Cheng, Y.S. Yang, K.C. TsaiNational Center for Research on Earthquake Engineering

Joint NCREE/JRC WorkshopInternational Collaboration on Earthquake Disaster Mitigation Research

October 18, 2003

Outline• Demands• Platform for Networked Structural

Experiments (PNSE)• Networked Structural Experiment Protocol

(NSEP)• Experimental Validation• Networked Pseudo Dynamic Tests on 3-story

CFT/BRB Frame• Conclusions

Demands

• Environment independent - Different facility controllers, control programs, OS, computer hardware

• Event reflective - Change of running state:

READY, RUNNING, HOLDING, INTERRUPTED_TEMP, INTERRUPTED, FINISHED

- Lab events: specimen adjustment, control problems, … etc. (worthy recorded) - Human conversation (not worthy recorded)

• Efficient transmission

• Data security

• Friendly individual participation

PNSE (Platform for Networked Structural Experiments)

ServerCGMDB

server

Viewer

PNSE

CameraFCM #1 FCM #2

CGM: Command Generation ModuleFCM: Facility Control Module

NSEP data packets

based on TCP/IP

commandsresponses

Video server

Webserver

NSEP (Networked Structural Experiment Protocol)

• SD_ERROR• SD_LOGIN• SD_PRJINFO• SD_SIGNALINF

O• SD_PRJSTATE• SD_CLNSTATE• SD_CPSCMD• SD_IDVCMD• SD_IDVRSP• SD_CPSRSP• SD_SIGNAL• SD_DISCUSS

Length Type Data

2 bytes 1 byte n bytes

Packet composition

Server Client

packet

packet

• Command cycle - SD_CPSCMD, SD_IDVCMD - SD_IDVRSP, SD_CPSRSP - SD_SIGNAL

• Active notification (Event trigger) - To save networked resources - To enhance overall efficiency - To accommodate more complex interactions in the future

Experimental Validation

NCREE Lab NTU Lab

6.0 m2.

37 m C1 C2

X

Y

X

Y

concrete infilled

double tube• 3 Tests - Test A: Domestic - Test B: Transnational (CGM at Stanford) - Test C: Transnational (Server at Stanford)

• Test results: displacement historiesTest C, NTU, Y dir, TCU 082, PGA=9.13gal, M=235.6ton, =2%

-6

-3

0

3

6

0 5 10 15 20Time (sec)

Dis

p.

(mm

)

Analysis Test S F

C

F

F

F

C S

F

FC SA

B

C

(US)

(TW)

(TW)

(US)

(TW)

Experimental Validation (cont.)

85%

10% 1%3%

0%

1%6%

1%

1%21%

0%

71% 58%

16%

16%1%

4%

5%

S FC

F

F

FC SF

FC S Test A (domestic) Test B (CGM Stanford) Test C (server Stanford)

Internet (CGM ⇔ Server)

Internet (FCM ⇔ Server)

Server works

CGM works

FCM works (actuator control)

FCM works (miscellaneous)

Communication Program Test A Test B Test C

CGM ⇔ ServerPNSE 0.000

8 0.1661 0.1693

Ping <0.01 0.1628 0.1653

NTU ⇔ ServerPNSE 0.003

7 0.0056 0.1651

Ping <0.01 <0.01 0.1625

NCREE ⇔ ServerPNSE 0.004

6 0.0039 0.1701

Ping <0.01 <0.01 0.1608

Experimental Validation (cont.)

Test C (Time consumed in network)

0

0.4

0.8

1.2

0 200 400 600 800 1000Step

Tim

e (s

ec)

Time consumed in internet between Analysis and Server per stepTime consumed in internet between Server and Facility Control in NTU per stepTime consumed in internet between Server and Facility Control in NCREE per step

• Time consumed in data transferring over the Internet is quite stable

PDT on 3-story CFT/BRB Frame

FCM, Windows XP

CGM, FreeBSD

PNSE server, Windows XP

Database serverMS SQL ServerWindows 2003

Web serverWindows 2003

Web guest

Web guest

Web guest

Conclusions• All data including command and lab feedback

can be transmitted correctly on PNSE.

• Efficiency of PNSE is satisfactory. Less than 0.1701 seconds is needed for a packet to make a round trip between Taiwan and Stanford.

• Running states of the whole project and of all PNSE clients can be reflected accurately and promptly on PNSE.

• The proposed PNSE and NSEP has preliminarily achieved the goal of networked collaborative experiments.

PDT on 3-story CFT/BRB Frame

i step 0 1 2Scan no.

1 2 3

THS

FCM

Server+

CGMSend initial condition to

FCM

Actuator control

Trigger (i=1)

Trigger (i=2)

Get scanned data (i=0)

Get scan data (i=1)

Send calculated

responses to FCM

Send calculated

responses to FCM

Sleep

Send scanned data to server

(i=0)

Ramp

Send force to server

Write to DatabaseScan Scan

Send scanned data to server

(i=1)

Sleep

Send force to server