Development of wireless sensors for shake table and full - SERIES

S E R I E S SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR

EUROPEAN SYNERGIES

COMMISSION OF THE EUROPEAN COMMUNITIES

FP7- INFRASTRUCTURES-2008-1

SP4-Capacities

Development of wireless sensors for shake table and

full scale testing and health monitoring of structures

SERIES Concluding Workshop - Joint with US-NEES

“Earthquake Engineering Research Infrastructures”,

May 28-30, 2013 JRC, Ispra, Italy

Institute of Earthquake Engineering and Engineering Seismology (IZIIS) Skopje, R. Macedonia

Prof. Zoran Rakicevic, grad. CE

Igor Markovski, grad. EE

Dejan Filipovski, grad. EE

Slobodan Micajkov, grad. EE

Prof. Mihail Garevski, grad. CE

SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES

• The application of wireless technology to testing and monitoring of civil structures has been gaining considerable interest over the past decade or two.

INTRODUCTION


• Wireless sensors - autonomous data acquisition nodes to which traditional structural sensors (e.g. accelerometers) can be attached.

• Wireless sensors - a platform in which mobile computing and wireless communication elements converge with the sensing transducer.

• Wireless sensors rapidly evolving in multiple engineering disciplines, so there currently exist a large number of different academic and commercial wireless sensor platform.

INTRODUCTION


• At IZIIS, within the framework of the SERIES project, two types of wireless sensors have been developed:

• MIMRACS - Micro Integrated Measuring, Recording And Communication System.

• SAWARS – Standalone Wireless Acceleration Recording System using ZigBee protocol.

INTRODUCTION


INTRODUCTION

• Purpose ▫ Laboratory testing of physical model on shake table

▫ Ambient Vibration Measurements of full scale structures, and physical models in laboratory conditions

▫ multi point measuring system with high surface density of implementation for health monitoring of structures.


BASICS

• MIMRACS (Micro Integrated Measuring, Recording And Communication

System) sensor presents an intelligent self-controlled high integrated

GPS/GPRS/WEB based micro processing digital 3D measurement device,

with a possibility for power independence appropriate for measuring,

storing and transferring data with an exact time of their appearance.

• It is intended for establishment of multi point measuring system with

high surface density of implementation.

MIMRACS


Power supply : Adapter 220 VAC/12-24 VDC, 20 VA

• Accumulator battery (2x12 DVC) + solar panel

Consumption :

- Measuring : 0,1 W

- Communication : 7 W

Measure values : x/y/z accelerations (mm/sec2, %g)

• gyroscope - angle /E-W (o)

• inclination - angle in two axis (o)

• temperature(oC)

• battery status(h)

Controlled values : activity of process module

• real time

• power supply

• battery charging

• number of satellites (GPS)

• GSM/GPRS network

• memory

Operating mode event (activating)

preevent (continouosly cycle recording)

MIMRACS - Technical Characteristics


MIMRACS - Technical Characteristics

Measure range : +/- 2 g

Maximum acceleration : < 3000 g

Span : < 10 mg

Axis : x / y / z

Memory : FLASH RAM (3*4 Mbyte)

Time of recording : 27 minutes (100 samples/second)

Frequency range : DC-250 Hz

Sampling : 100/200/500/1000 samples/sec.

Dynamic range : ~140 dB

Amplifier : 70 – 1.000.000 programmable

A/D conversion : 24 bit

Trigger: x+y+z, programmable

Absolute time (UTP): GPS yyyy/mm/dd/hh/mm/ss,ss(ss)

Space coordinates : longitude/latitude/altitude

Inclination : -+ 90o deflection

Gyroscope : 0-360o (E-W)


MIMRACS - Components

MEMS sensor

Power supply (internal battery, 220VAC/12-24VDC converter, solar panel + accumulators)

Microprocessor

A/D converter

Amplifiers

Memory

GPS module

GPRS module

Gyroscope

Inclinometer

USB communication

LED signalization

LCD display 2 * 16 (optional)

CPU

GPS

GSM

POWER

Memory

Gyro

Accelerometer

Amplifier

A/D USB

Inclinometer

CPU

GPS

GSM

POWER

Memory

Gyro

Accelerometer

Amplifier

A/D USB

Inclinometer

Sensors

Communication

Power supply


MIMRACS - Hardware components - Microprocessor

• Model - MICROCHIP 18F4550

▫ 36 I/O

▫ USB Communication 12Mb/s

▫ Oscillator 8 MHz

▫ 10bit A/D

▫ 32 Кbytes Flash memory

▫ 2048 * 8 bytes RAM memory

▫ 256 bytes EEPROM memory

▫ SPI/I2C communication


MIMRACS - Sensors - Accelerometer

• Accelerometer

▫ Piezoresistive MEMS Model 3028

▫ Low Cost, DC Response, mV Output

▫ Range +/- 2 g

▫ Sensitivity 20 mV/g

▫ Frequency Response (Hz) 0-250 Hz

▫ Natural Frequency 700 Hz

▫ Damping Ratio 0.7

▫ Shock Limit 5000 g


MIMRACS - Sensors - Gyroscope

• Model ADXRS401 – Analog devices

▫ complete, angular rate-sensing gyroscope capable of measuring up to 75 degrees per second.

▫ low cost

▫ integrated with all of the required electronics on one chip.


MIMRACS - Sensors - Inclinometer

• Model ADIS16201 – Analog devices

▫ Programmable Dual-Axis Inclinometer

▫ 12-, 14-bit digital inclination/acceleration sensor outputs

▫ +1.7 g accelerometer measurement range

▫ +90° inclinometer measurement range, linear output

▫ 12-bit digital temperature sensor output


MIMRACS - GSM/GPS/GPRS Module

GE863-GPS


MIMRACS - Hardware components – Amplifier

• Model AD8556 – Analog devices

• Programmable Amplifier

• EMI filter on each input

• Work temp. -40 to+140оС

• Low noise 94dB min.

• Low pass filter

• Amplification 70-1,000,000 programmable


MIMRACS - Hardware components – A/D Converter


▫ 24 bit Sigma Delta

▫ Power Supply: 2.5 V to 5.25 V

▫ SPI communication

▫ Low RMS noise 1.5 μV

▫ Low consumption 75 μ А

▫ Simultaneous 50 Hz and 60 Hz rejection

▫ Work temp. -40 to 105°С


MIMRACS - Power Supply

• Adapter 220 VAC/12-24 VDC

• Solar panel + batteries

• Inner battery 3,6VDC, 3000 mAh


MIMRACS - Drawings

134 mm

95 mm

85 mm

Power

CPU, A/D, memory, gyroscope, inclinometer

MUX modul

Accelerometers Model 3028

Z

X Y

39 mm

46 mmGPS / GPRS modul

12-24 VDC

SIMUSB

GPS GPRSAntene Antene

Battery


MIMRACS - Photos


MIMRACS - Photos


Communication Network

Integrated Systems

Mobile

Users

GPRS

USB

DATABASE

S

M

M

S

S

M

M

S

S

M

M

S

S

M

M

S

S

M

M

S

S

M

M

S


MIMRACS - Software

• Data presentation application

• SQL data base

• Alarms

• Server Communication module

• Table presentation

• Chart presentation

• GIS presentation


MIMRACS - Software general

• Two software applications were developed

• One used for configuration of the device

• Second used as server application which collects the

data sent from the devices remotely through the

Internet.


MIMRACS - Software Configurator

• Divided in two sections:

• related to parameters concerning the measurements.

• related to GSM and GPRS settings



• Measurements parameters

▫ Sampling rate

▫ Pre-event

▫ Post-event

▫ Trigger level

▫ Low pass filter

▫ data for the current number of records in the device’s memory

▫ buttons for fetching or deleting records



• GSM and GPRS settings:

• setting the APNs (Access Point Name).

• setting PIN number of the SIM card

• field for a cell phone number


MIMRACS – Other parameters

• “Connection Interval”. The device is designed to

make connections to the server on predefined

intervals, sending its GPS coordinates, ambient

temperature, and its current settings, as well as

battery status.

• On this way the device “checks in” and informs the

server that it is “alive”


MIMRACS – Server application



• It purpose is to wait for connection from all devices which have its IP address set in their configuration and accept and store all the data received from the in local database.

• The server is designed to allow many concurrent connections and to manage the data sent from various sources simultaneously



• To visualize the received data a kind of a front panel application was also developed. This panel contains the data from all devices that made connections to the server, showing always the newly received information in real time.


MIMRACS – Test Results


SAWARS - Printed Board Design

Ongoing activities - Manufactured


SAWARS - Printed Board Design

Disposition of hardware components

Conditioner and amplifier low pass filter (programmable)

ZIGBEE RF MODULE

POWER SUPPLY SECTION

A/D

MEMORY 64Mbit

µP


SAWARS - Hardware components

• Microprocessor

▫ Model - MICROCHIP 18F4550

• Accelerometer

▫ Piezoresistive MEMS Model 3028

• Amplifier


• A/D Converter

▫ Model AD7789 – Analog devices


SAWARS - Hardware components-ZigBee RF Module

• Model MRF24J40MA – Microchip

• 2.4 GHz IEEE Std. 802.15.4

RF Transceiver Module

• Data Rate: 250 kbps

• Operating Voltage: 2.4-3.6V (3.3V typical)

• Work temp. -40 to+85оС

• Low-Current Consumption

• Up to 400 ft. Range


SAWARS-Hardware components–ZigBee performance

…………………………

The data is transferred in packets. These

have a maximum size of 128 bytes, allowing

for a maximum payload of 104 bytes.

Up to 6 Transmitters

1 Receiver

3 bytes/sample

At 2.4 GHz there are a total of sixteen different

channels available, and the maximum data rate

is 250 kbps.

250 kbits/8 = 31250 bytes

31250bytes/3bytes = 10416 samples / second

10416 samples/second / 6 transmitters = 1736 samples

6 * 1000 samples = 6000 samples * 3 bytes = 18000 bytes * 8 = 144 kbits/second

1 * 1000 samples = 1000 samples * 3 bytes = 3000 bytes * 8 = 24 kbits/second

144 kbits/second

24 kbits/second


SAWARS

acc f A/D A μP Zigbee

Dynamic Amplifying

Programmable filter

Pre – measurement

Principle of Operation

• Programmable low pass filter and the upper frequency have to be defined before each measurement.

• Programmable amplifier and it operates with dynamic amplification


SAWARS


Dynamic Amplifying

Programmable filter

Pre – measurement


• Before each A/D conversation, voltage analog output is measuring directly on analog input of microprocessor and according to the value it sets amplification factor of amplifier and signal is going trough filter, amplifier, A/D converter and stored in the memory.


SAWARS


Dynamic Amplifying

Programmable filter

Pre – measurement


• Signal is amplified always to be in the rank 2.5-3.3V before A/D converter in order to have more quality measurements (bigger resolution for small signals).

• Sampling rate is also predefined value. It can be set it from 10s/s – 1000s/s


SAWARS


Dynamic Amplifying

Programmable filter

Pre – measurement


• Microprocessor send data through Zigbee modem to Host Zigbee modem which is connected to PC for viewing results and advanced analyses.


SAWARS - Software

• For Communication and parameter settings

▫ Written in C#

• For online data presentation and data storage

• Written in NI LabView

• Streaming file format NI TDMS


SAWARS

Ongoing activities – Assembling

4 VNEG

1 Vdd

3 DIGIN

5VPOS

8Vss

6VCLAMP

2FILT/DIGOUT 7VOUT

4 CS

1 SI

3 RESET

2 SCK

5WP

8SO

6VCC

7GNDACC

Conditioner and amplifier low pass filter (programmable)

ZIGBEE RF MODULE

POWER SUPPLY SECTION

A/D

MEMORY 64Mbit

µP


SAWARS

Ongoing activities – testing

• Scheduled for mid June, 2013

• Shaker testing of indivudual SAWARS

• Shake table testing mounted on Physical model

• Comparison with high sensitive PCB accelerometes

in time and frequency domain


Acknowledgement

The research leading to this development has received funding from the European Community’s Seventh Framework Programme [FP7/2007-2013] under grant agreement n° 227887 - SERIES


Preface

• 1963 - Skopje Catastrophic Earthquake

DATE JULY 26 1963

TIME (GMT) 04:17:11

EPICENTRAL LATITUDE 42º 00.5' N

EPICENTRAL LONGITUDE 21º 27.3' E

HYPOCENTRAL DEPTH 5 km

MAGNITUDE (M) 6.2

EPICENTRAL INTENSITY (MCS) IX


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