Wireless Condition Monitoring with Self-sufficient Sensor Nodes Hannover Messe 2011: Innovation for Industry Forum Session: Energy Harvesting & Wireless Sensor Network Dr.-Ing. Dr. rer. oec. Michael Niedermayer Fraunhofer-Institute for Reliability and Microintegration Department: System Design & Integration
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)
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
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 Measured variable Ambient energy Sensor Light Temperature gradients Kinetic energy Power-supply Signal- and dataprocessing Communication interface Communicating system Energy demand Standby-mode (timer only) Intermittent operation (duty-cycle) Continuous operation (functional components all active) µw mw P
Approach of Model-based Design Profiles of Ambient Energy Sources & Energy Sinks Parameterized Sub-Models System-level Simulations Characterized System Components Prototype Developement
Selection of the Ambient Energy Source
Input Profiles - Ambient Conditions in Paper Mill Modul2_T_cooler Modul2_T_machine C 60.0 58.0 56.0 54.0 52.0 50.0 48.0 46.0 44.0 42.0 40.0 38.0 36.0 Temperature Hotside Temperature Coldside 0:00 0:30 1:00 1:30 0 Tage h:m C 57.0 56.0 55.0 54.0 53.0 52.0 51.0 50.0 49.0 T_M2_Ambient_Pt100_b T_M2_UM_19 T_M2_OM_18 Operating Point: T=10K 48.0 47.0 46.0 0 20 40 60 80 100 s
Characterization of Thermoelectric Converter Serial Inner Resistance vs. Temperature Inner Resistance [Ohm] 5,0 4,5 4,0 3,5 20 40 60 80 100 Temperature [ C] Seebeck.Coefficient [mv/k] Seebeck-Coefficient vs. Temperature 54 20 40 60 80 100 Temperature [ C] 68 66 64 62 60 58 56
Conversion Chain Characterization DC/DC Converter 1400 1200 1200 1000 I_out [ A] 1000 800 600 Iout [µa] 800 400 200 600 400 200 500 400 300 Uin[mV] 100 200 300 400 500 U_in [mv] Efficiency [%] 0 0 0 1 2 Uout [V] 3 4 5 0 200 100 5 10 15 20 Source: EnOcean
Simulink-Model: Source Conversion Sink
Simulation Results I load [ma] 50 40 30 20 10 Measurements can be done every 20 minutes! I load [ma ] 40 20 0 0 1 2 3 4 5 6 7 8 9 10 11 12 t [h] 4 0 0 2 4 6 8 10 t [s] U cap [V] 3 2 1 Ultra cap Voltage drops just below 3.4 V making appliances with the need of 3.3 V input possible! 0 0 1 2 3 4 5 6 7 8 9 10 11 12 t [h]
Overall System Performance Efficiency thermoelectric conversion <1% Electric output TE converter 4,9 mw Losses at DC/DC converter (Step-up) 3,8 mw 10 µw Leakage ultracap 340µW Losses at DC/DC converter (step-down) 795 µw Regulated output voltage V 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 0 Tage, 0h 0 Tage, 4h 0 Tage, 8h ; U. Kagelmarker et al. (IMC) Tage, h
Piezoelectric Transducer PCT ceramics Utilization of the transversal piezoelectric effect High energy-efficiency only for excitations near resonant frequency => complicates a universal applicability ; J. Hefer et al. (Dept. SDI)
Resonant Frequency of Vibration Transducers Prin- Prinzip ciple* F [Hz] Bandbreite Bandwidth [Hz] M [g] V [cm³] P [µw] P-Density P-Dichte [µw/cm³] Perpetuum PMG 17 EM 50,60, 100,120 >±20Hz 655 130 13000 (250mg) 99,5 AdaptiveEnergy Joule-Tief Module PZ 60? 43 34,5 ~250 (200mg) 7,3 Cedrat APA400M-MD PZ 110? 270 35,2 95000 (max.) 2699 Volture PEH25W (V25W) PZ 40 3 85 40,5 931 (250mg) 23 Baumer Piezo PZ 265 10 500 140 3000 (250mg) 21,5 Baumer Stack8 PZ 300-800 500 1836 464 420 (200mg) <1 *EM: Electromagnetic; PZ: Piezo 04.04.2011 B. Hiller et al. (Baumer-Hübner)
Universal Piezoelectric Transducer Stack of 8 piezoelectric transducer with different resonant frequencies Increased bandwidth of 300-800Hz Power between 94 420µW at 2m/s² Frequency [Hz] 04.04.2011 B. Hiller et al. (Baumer-Hübner)
Next Steps 2nd Prototype Generation (Miniaturized) 1st Prototype Generation Paper Mill: 664 Nodes 04.04.2011
Further Activities: Wafer-Level Batteries & Fuel Cells Wafer level batteries (silicon cavity battery) 04.04.2011 Robert Hahn et al. (Dept. HDI.WLP) Hydrogene fuel cell, 0.1 cm² active area (Pulse power of 200mW/cm² achieved)
Thank you for your attention!
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 The project ECoMoS is funded by the German Federal Ministry of Education and Research. 04.04.2011