Wireless Condition Monitoring with Self-sufficient Sensor Nodes

(1)

Hannover Messe 2011: „Innovation for Industry“ Forum

Session: Energy Harvesting & Wireless Sensor Network

Wireless Condition Monitoring with

Self-sufficient Sensor Nodes

Dr.-Ing. Dr. rer. oec. Michael Niedermayer

Fraunhofer-Institute for Reliability and Microintegration

Department: System Design & Integration

(2)

04.04.2011 Dr-Ing. Dr. rer. oec. Michael Niedermayer

Application: Condition Monitoring of Paper Mills



Problem:



Sudden failures of critical machine components lead to unpredicted maintenance

intervals



High costs during shut-down (EUR 5000 €/h)

(3)

Application: Condition Monitoring of Paper Mills



Solution:



Self-sufficient sensor nodes form a network for wireless condition

monitoring



Early detection of failures through measurement of critical parameters, e.g.

vibrations

(4)

Components of the self-sufficient radio sensors



Principle Schematic of the Sensor System



Acceleration sensor

attached to vibrating machine surface



AD-Converter



DSP for FFT and analysis of characteristic spectrum



Proprietary communication standard



Energy Harvesting device

Sensor

Signal- and

data-processing

Measured

variable

Communi-cation

interface

Power-supply

Ambient

energy

Light

Temperature gradients

Kinetic energy

Communi-cating

system



Energy demand



Standby-mode

(timer only)



Intermittent operation

(duty-cycle)



Continuous operation

(functional components

all active)

mW

P‘

µW

(5)

Approach of Model-based Design

System-level Simulations

Parameterized

Sub-Models

Characterized

System Components

Profiles of

Ambient Energy Sources

& Energy Sinks

Prototype

Developement

(6)

Selection of the Ambient Energy Source

(7)

Input Profiles -

Ambient Conditions in Paper Mill

Modul2_T_cooler Modul2_T_machine 36.0 38.0 40.0 42.0 44.0 46.0 48.0 50.0 52.0 54.0 56.0 58.0 60.0 °C 0:00 0:30 1:00 1:30 0 Tage h:m T_M2_Ambient_Pt100_b T_M2_OM_18 T_M2_UM_19 46.0 47.0 48.0 49.0 50.0 51.0 52.0 53.0 54.0 55.0 56.0 57.0 °C 0 20 40 60 80 100 s

Operating

Point:

∆T=10K

Te

m

pe

ra

tu

re

H

ot

si

de

Tem

per

atu

re

Co

lds

ide

(8)

Characterization of Thermoelectric Converter

Seebeck-Coefficient vs. Temperature

Serial Inner Resistance vs. Temperature

20

40

60

80

100 3,5

4,0

4,5

5,0

Inner R

e

sist

ance [

O

hm]

Temperature [°C]

20

40

60

80

100

54

56

58

60

62

64

66

68 See

beck.

Coef

fici

en

t [

m

V

/K]

Temperature [°C]

(9)

Conversion Chain –

Characterization DC/DC Converter

100 200 300 400 500 200 400 600 800 1000 1200 U_in [mV] I_o u t [  A]

0

1

2

3

4

5

0

200

400

600

800 1000

1200

1400

0

100

200

300

400

500 Iout [µA]

Uin[mV]

Uout [V]

0 5 10 15 20

Efficiency [%]

Source: EnOcean

(10)

Simulink-Model: Source –

Conversion –

Sink

(11)

Simulation Results

0

1

2

3

4

5

6

7

8

9

10

11

12

0

1

2

3

4 U

cap

[V

]



Ultra cap Voltage drops just below

3.4 V –



making appliances with the need of

3.3 V input possible !



Measurements can be done

every 20 minutes !

0

1

2

3

4

5

6

7

8

9

10

11

12

0

10

20

30

40

50 t [h]

I

lo

a

d

[m

A

]

0 2 4 6 8 10 0 20 40 t [s] Iload [m A ]

(12)

Overall System Performance

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 V

0 Tage, 0h 0 Tage, 4h 0 Tage, 8h

Tage, h

Electric

output

TE converter

4,9 mW

Regulated

output voltage

10 µW

Leakage

ultracap

3,8 mW

340µW

Losses at

DC/DC

converter

(step-down)

795 µW

Losses at

DC/DC

converter

(Step-up)

Efficiency

thermoelectric

conversion

<1%

(13)

Piezoelectric Transducer



PCT ceramics



Utilization of the transversal

piezoelectric effect



High energy-efficiency only

for excitations near resonant

frequency => complicates

a universal applicability

(14)

Resonant Frequency of Vibration Transducers

500

10

3 ?

?

>±20Hz

Bandbreite

[Hz]

21,5

3000

(250mg)

140

500

265 PZ

Baumer Piezo

<1

420 (200mg)

464 1836

300-800

PZ

Baumer Stack8

23

931 (250mg)

40,5

85

40 PZ

Volture PEH25W

(V25W)

2699

95000

(max.)

35,2

270

110 PZ

Cedrat APA400M-MD

7,3

~250

(200mg)

34,5

43

60 PZ

AdaptiveEnergy

Joule-Tief Module

99,5

13000

(250mg)

130

655 50,60,

100,120

EM

Perpetuum PMG 17

P-Dichte

[µW/cm³]

P

[µW]

V

[cm³]

M

[g]

F

[Hz]

Prinzip

_ciple*

Prin-

Bandwidth

P-Density

*EM: Electromagnetic; PZ: Piezo

(15)

Universal Piezoelectric Transducer

Frequency [Hz]



Stack of 8 piezoelectric transducer with different resonant frequencies



Increased bandwidth of 300-800Hz

(16)

Next Steps

1st Prototype

Generation

2nd Prototype

Generation

(Miniaturized)

(17)

Further Activities: Wafer-Level Batteries & Fuel Cells

Hydrogene fuel cell, 0.1 cm² active area

Wafer level batteries

(18)

(19)

Impressum



Dr.-Ing. Dr. rer. oec. Michael Niedermayer



Email: michael.niedermayer@izm.fraunhofer.de



Telefon: +49 30 64603 -185



Dipl.-Ing. Stephan Benecke



Email: stephan.benecke@izm.fraunhofer.de



Telefon: +49 30 64603 -748



Dipl.-Ing. Eduard Kravcenko



Email: eduard.kravcenko@izm.fraunhofer.de



Telefon: +49 30 64603 -780