wireless sensor developments for physical prototype...

Wireless sensor developments for physical prototype testingtesting

SAS 2008, Atlanta, Georgia, USA, 12 February – 14 February 2008Edgar Moya, Tom Torfs, Bart Peeters, Antonio Vecchio, Herman Van der Auweraer, Walter De RaedtLMS International - IMEC

Outline

Scenarios and objectivesSensors

MEMSMEMS3D stacking technologyInterface

Wireless linkCompromisesRadio LinkWireless receiver

Interface with the acquisition systemData acquisition system requirementsBlock diagramInterface with the systemInterface with the system Physical implementationResults

Future research and conclusions

2 copyright LMS International - 2008

Scenarios

Measurement systemSensors (Accelerometers)PC & data-acquisition front-end q

(2-1000 channels)Data acquisition

Signature testingE i t l M d l A l iExperimental Modal AnalysisVibration analysis

Excitationshakers or hammershakers or hammerforce cell


Scenarios

AutomotiveCivil Engineering

Aerospace


Scenarios


Objective: short term

ConceptIntegration of the MEMS sensors and radio transmittersWired analogue sensors combined with wireless digital sensorsWired analogue sensors combined with wireless digital sensorsTraditional sensors combined with MEMS sensors

RFModule

Data Acquisition

system

Sensor 3

Sensor 4

system


Sensor 5

Objective: long term

Complete Wireless MEMS sensor networkIntegration of the radio receiver in the acquisition system (New Generation Acquisition systems)syste s)

Data Acquisition

system


Challenges

Multichannel data acquisitionMulti axes sensorsMulti-axes sensorsVibration analysis: DC … 20kHz (High sampling frequency)Synchronized data neededNoise level limited and high dynamic range (contrary to some biomedic and car o se e e ted a d g dy a c a ge (co t a y to so e b o ed c a d casensors)Size: 1 cm3

Covering large measuring area Range: 300 mM i l Ti d tMeasuring analog Time dataAnalog to digital conversionNo high cost wiringReduce installation costs MEMS sensorsMEMS sensorsReduce installation costs SizeSize

Radio (Bw Radio (Bw –– Range)Range)SynchronizationSynchronizationA tA t


AutonomyAutonomy

Outline







MEMS Sensors

Micro Electro Mechanical SystemPlus:Plus:

Small sizeLow cost (25 $)Easy integration with electronicsasy teg at o t e ect o csLow power supply (1v – 3v)Multi-axes sensor

Minus:Low sensitivity (power supply / measurement range)Higher noise levelNormally not designed for modal analysisNot massive market Slow developmentNot massive market Slow development


3D Stacking

It is a layered, modular system containing: Bottom layer Power management (voltage regulation and switch on/off)S d l S f ti litiSecond layer Sensor functionalitiesThird layer low power microcontrollerTop layer low-power radio with integrated antennaLi-ion battery (25 mm x 20 mm x 4 mm 3 7 g)Li ion battery (25 mm x 20 mm x 4 mm, 3.7 g)

The prototype system uses connectors for the vertical interconnectA more compact implementation can be made using solder ball interconnect technology

Radio Chip

Microcontroller

Antenna

MEMS sensor

Switch

Recharger

Power


Battery

MEMS Sensor Interfaces

Automotive – Aerospace applications: 2D accelerometer was selected. F 3D A dditi l ti l b d i th tFor 3D An additional vertical board in the systemAnalog output Internal 12-bit ADC on the microcontroller layer

•FREESCALE MMA6233Q (High measurement range)

• Measurement 10 g

• Sensitivity 120 mV/g

• Frequency range 0.9 KHz

• Voltage supplier 3 v

• Noise 30 ug/√Hz

•2 axis


MEMS Sensor Interfaces

Environment – Civil applications: 3D accelerometer which also includes the analog-to-digital converter (ADC) ADC included in the sensor: 12 bits

• KIONIX KXP84-2050 (Low measurement range) ( g )

• Measurement 2 g

• Sensitivity 819 counts/g, 12 bits

• Frequency range 1.7 KHzq y g

• Voltage supplier 3 v

• Current supplier 1 mA

• Noise 175 ug/√Hz

• 3 axis


Outline







Wireless Compromises

1.- Size Vs Autonomy Longer autonomy on time Bigger batteries.Bigger size More distortion in the measure

2.- Power Vs SensitivitySensitivity Power / RangeLower power Lower sensitivity

3.- Distance Vs Power Longer distance Higher consumptionHigher consumption Shorter autonomy

4.- Sampling FrequencyVs

Higher Sampling Freq per sensor Broader Bandwidth per sensor

Number of Sensors Broader Bw per sensor less # sensors

5 - # Axes Vs # Sensors Higher # Axes Broader Bw less # sensors


5.- # Axes Vs # Sensors Higher # Axes Broader Bw less # sensors

Radio link

Current design:The Nordic Semiconductor nRF2401A ultralow power 2 4GHz transceiverThe Nordic Semiconductor nRF2401A ultralow power 2.4GHz transceiverSampling Frequency: 2.5 KHz X 3 axis = 7.5 KHz x 12 bits = 90 Kbps (DATA)Data info + Control info + Error info + Radio info = 250 Kbps (Max. good quality) Distance = few meters ( < 8 m)( )Battery = around 8 hours

Bandwidth is the Bottleneck for online measurements 2.5 KHz max sampling freq.Less Sampling Freq per sensorLess Sampling Freq per sensorReduced number of sensorsDifficulties for online measurements


Wireless receiver

USB stick or Wire connectionUART output dataSynchronization:Synchronization:

Periodic beacons every 25.6 msSensor network get synchronized (µs)Between beacons, sensors transmit

Sampling momentsSampling moments

time

ti

Sampling moments

Radio communication:time

ti

Sampling moments

Radio communication:

time

Beacon: receiver transmits; sensor nodes receive

Data frames: sensor nodes transmit;i i

time

Beacon: receiver transmits; sensor nodes receive

Data frames: sensor nodes transmit;i i


receiver receivesreceiver receives

Outline







Data acquisition system requirements

Communication via the audio QDA port:Audio format: SPDIFAudio format: SPDIFMinimum Sampling Frequency: 6.4 KHzNo synchronization

Interface between Receiver and data acquisition system:

Format conversion: UART SPDIFU li 2 5KH 6 4 KHUpsampling: 2.5KHz 6.4 KHz

RadioReceiver

SCADAS III(QDA)

INTERFACE

UART SPDIF


2.5KHz 6.4 KHz

Block diagram

Fixed Input Sampling Frequencies. Minimum 6.5 KHz

IMEC LMSInstLMS

FPGASPARTAN3XC3S1500

ResamplerAD1896Receiver UART SCADASSPDIFSPDIF

Fs=2.5 KHz Fs=6.5 KHz


Interface with the system

Concept validation Validation of the receiver and the interface to the SCADASVerification with shaker testVerification with shaker test


Physical implementation

Test.Lab

Power Source

FPGA

SCADAS



FPGAFPGA


Results: Time domain

0.40 1.16

Rea

lg

Rea

lg

F Time Point1B Time Point5

0.03 0.27s

-0.37 0.860.11690.0462 1.79

Rea

lg

R

F Time Point5B Time Point1


57.02 57.09s1.18

Results: Frequency domain

-40.00 -50.00

dB( g2 /H

z)

dB ( g2 /H

z)

0 00 1100 00H

-90.00 -100.00

F PSD Point1F PSD Point2B PSD Point5

-47.64 -57.64

0.00 1100.00 HzdBg2 /H

z)

dB g2 /Hz)

( (

F PSD Point1F PSD Point2B PSD Point5


0.00 100.00 Hz

-70.92 -80.92 14.81

Outline







Future Research

Study the degradation of the signal at high frequencies

Multiple wireless sensor nodes operating in a network New architectures

Synchronization and networking wired and wireless sensorsSynchronization and networking wired and wireless sensors

Use of repeaters must be studied

New radio technologies broader bandwidth

MEMS reduce noise level

Focus the platform to the application


Conclusions

Wireless sensor network combines measurement precision low powermeasurement precision, low power consumption, wireless communication and low cost equipment.First approach has been developed for physical prototyping testingphysical prototyping testing.The performance of the WSN was compared with the classical wired monitoring systemAccurate modal testing can be carried out with standard wireless technology and MEMS sensors.


Acknowledgement

This work was carried out in the frame of the MEDEA+ project 2A204 SWANS “Silicon platforms for Wireless Advanced Networks of Sensors”platforms for Wireless Advanced Networks of Sensors . The financial support of the Institute for the Promotion of Innovation by Science and technology in Flanders (IWT) is gratefully acknowledged.


Thank you for your attention

SAS 2008, Atlanta, Georgia, USA, 12 February – 14 February 2008Edgar Moya, Tom Torfs, Bart Peeters, Antonio Vecchio, Herman Van der Auweraer, Walter De RaedtLMS International - IMEC

Outline

SWANS Scenarios and DemonstratorSensorsSensors

Piezo-electric sensorsMEMSInterface

Wireless linkCompromisesRadio Link

I t f ith SCADASInterface with SCADASSCADAS LimitationsBlock diagramComponentsComponentsPhysical implementationResults

Dissemination


Future activities

Dissemination

1. - Papers accepted at conferences.“Wireless sensor network for bridge vibration monitoring – design and results” TWireless sensor network for bridge vibration monitoring – design and results , T. Uhl, A. Hanc, K. Mendrok & P. Kurowski, B. Peeters, E. Moya & H. Van der Auweraer. EVACES07. Porto, Portugal. October 2007“Bridge monitoring system using wireless sensor network – hardware solution and preliminary tests”. T. Uhl, A. Hanc, B. Peeters, E. Moya, H. Van der Auweraer. p e a y tests U , a c, eete s, oya, a de u e aeInternational Workshop on Structural Health Monitoring, Stanford University, Stanford (CA), USA. September 2007“Wireless sensor developments for physical prototype testing”. E. Moya, T. Torfs, B. Peeters, A. Vecchio, H. Van der Auweraer, W. De Raedt. IEEE Sensor Application Symposium, Atlanta, Georgia, USA. February 2008.

2.- Demonstration during MEDEA+ forum3.- University lecture + demo: Bart Peeters, "Wireless sensing for civil engineering Structural Health Monitoring", Dept. Structural Engineering, Università di Pisa, 20 November 2007.


Cooperation with SWANS partners

Block Diagram

SignalS Conditioning RF Receiver

SCA

SENSO SCADAS

LPF LNAADC

NetworkRF Transmitter

Battery

ADAS

R Interface

SPI - SPDIF

Resampler3D-Stacking S

SENSOR LEVEL RECEIVER LEVEL

LMS Automotive demonstrator

Resampler


S uto ot e de o st ato

Cooperation with SWANS partners

IMEC

Nordic nRF2401AIMEC

LMSBlock Diagram

SignalS

IMEC

Conditioning RF ReceiverSCA

SENSO SCADAS

LPF LNAADC

FREESCALE

Kyonix

NetworkRF Transmitter

Battery

ADAS

R Interface

SPI - SPDIF

ResamplerNordic nRF2401A

3D-Stacking S

SENSOR LEVEL RECEIVER LEVEL

LMS Automotive demonstrator

Resampler

VARTA LPP 402025CE


S uto ot e de o st ato

IMEC FPGA XILINX EVL1500 Analog devices

AD1896EB

Cooperation partners

IMEC : Automotive and Environmental Scenario3D StackingInterfacing with the sensorgRadio managingMicrocontroller managing

Energocontrol: Environmental Scenario (WP5)Possibility of integrating their own wireless systemPossibility of integrating their own wireless system with the LMS measurement system SCADAS

Verhaert: Common platform for the environmental sensor

AnSem: ADC designed with according to the LMS requirements


AnSem: ADC designed with according to the LMS requirements

Outline

SWANS Scenarios and DemonstratorSensorsSensors

Piezo-electric sensorsMEMSInterface

Wireless linkCompromisesRadio Link

I t f ith SCADASInterface with SCADASSCADAS LimitationsBlock diagramComponentsComponentsPhysical implementationResults

Dissemination


Future activities

Future activities - civil engineering

Wireless Sensor Network will be tested in a modeled bridge (5 meters long).Civil scenarioCivil scenarioComparison between 4 wireless sensors and 4 traditional sensorsData acquisition (IMEC software) + data analysis (test.lab LMS software)


Future activities – automotive engineering

Comparison results with a wireless and a wire sensor over a rotary machineF lt Si l t S t (MFS2004)Fault Simulator System (MFS2004)Data acquisition (IMEC software) + data analysis (test.lab LMS software)


Piezo-electric Sensors

PIEZO Wired

MEMS Wireless


Radio link: nRF2401A Transceiver.

The Nordic Semiconductor nRF2401A ultralow power 2.4GHz transceiver

FEATURES

True single chip GFSK transceiver in a small 24-pin package (QFN24 5x5mm) Data rate 0 to1Mbps Only 2 external components y pMulti Channel operation 125 channelsSupport frequency hopping Channel switching time <200µs. Power supply range: 1.9 to 3.6 V Add d CRC t tiAddress and CRC computation Shock Burst mode for ultra-low power operation and relaxed MCU performance DuoCeiver for simultaneous dual receiver topology Low supply current (TX), typical 10.5mA peak @ -5dBm output power Data slicer / clock recovery of data 100% RF tested100% RF tested No need for external SAW filter World wide use Low supply current (RX), typical 18mA peak in receive mode "Green" lead free alternative


Hardware tools: SPARTAN3 XC3S200, XC3S400

• XILINX Spartan – 3 Evaluation Kit


Hardware tools: Resampler AD1896


Sensor level: Battery


Interface Block Diagram

FPGAFPGA ResamplerInput

RESAMPLERRESAMPLERBOARDBOARD

X,Y (2.5 KHz)X,Y

Extracting dataA (X Y Z)

p BOARDBOARD

ResamplerI t

RESAMPLERRESAMPLERZZ (2.5 KHz)

Axes (X,Y,Z)

X,Y,Z

Input BOARDBOARD

SPDIFZ (20 KHz)

Uart Decoder SPDIFencoder

X,Y (20 KHz)

encoder

Data SCADAS IIISCADAS III

(QDA)(QDA)X,Y (20 KHz)

X,Y,Z


ataReceiver(2.5 KHz)

(QDA)(QDA)Z (20 KHz)


AD UpsamplerFPGA p pFPGA


Interface Definition and components

SENSOR LEVEL: MEM sensor (Kionix KXP84-2050, Freescale MMA6233Q), Battery (VARTA LPP 402025CE), Radio (Nordic nRF2401A), 3D Stacking and microcontroller (IMEC technology) RECEIVER LEVEL: Radio (Nordic nRF2401A), FPGA (XILINX EVL1500), resampler (AD1896EB), measurement system (LMS SCADAS)y ( )

RF communicationRF communicationNordic nRF2401A Nordic nRF2401A

3D StackingBattery

XILINX EVL1500

SCDAS: SPDIF Module

Analog devices AD1896EB

Freescale: MMA6233QKIONIX: KXP84-2050


Receiver LevelSensor Level

SCDAS: SPDIF Module

wireless sensor developments for physical prototype...

Documents