ELECTRICAL CAPACITANCE TOMOGRAPH

Transcription

1 2 nd Forum Białystok-Białowieża ELECTRICAL CAPACITANCE TOMOGRAPH Nuclear and Medical Electronics Division Institute of Radioeletronics Warsaw University of Technology Projekt współfinansowany przez Unię Europejską w ramach Europejskiego Funduszu Społecznego

2 Tomography Tomography process consist of: aquisition of tomography data (projections) by measurement of radiation propagation through the object, creating images from projections applying tomographic reconstruction algorithms. The quality of images depands on several factors: application of the radiation or field, detection of the signals, measurement and processing of analog signals (projections), reconstruction images from projections, visualisation.

3 Tomography process in Electrical Capacitance Tomography - ECT Tomography process in ECT consist of: applying electrical signal on transmitting electrode; receiving charges from all receiving electrodes; amplifying analog signals, converting to digital data and transmitting to computer; image reconstruction from projections; visualisation and archiving results.

4 Charge-Discharge method in ECT Charging C X RFB Q FB = U T C X U T U A = + U T 0 V Virtual Ground C FB U A S1 S3 U T S2 C X S4 Q x = + U T C x A1 U 1 = U T C X / C FB Discharging C X V1 - f U T Cx Rf V2 f U T Cx Rf U A = U T 0 V Virtual Ground Q FB = + U T C X R FB U A S1 S3 C FB S2 C X S4 Q X = U T C X A2 U 2 = + U T C X / C FB

5 Electrical Capacitance Tomograph ET1 ET1-12 elctrode modular ECT - (May 2002)

6 ET1/ET3 Flow Chart

7 ET3-32 channel ECT Jednostka sterująca + ADC Karty pomiarowe (sygnałowe) Płyta - matka Stages of ET3 mountage

8 Disprsion and dynamic of measured signals 0,6 Pojemność (pf) 0,4 0, Numer elektrody We have manage in ECT with very small capacitance and dispersion of them is from ~0.005 pf (few femtofarad!) to 0.5 pf for different couple of electrod.

9 Signal Card Flow Chart +12 V 3 x ADG409 R FB MUX R FB MUX TK1 2 x ADG442 EN RS3 RS1 RS0 EN RS3 RS1 RS0 2 x PGA206 PROG. GAIN PROG. GAIN TK3 RK3 RK4 R FB MUX R FB MUX KK3 KK2 KK1 KK0 EN EN +12 V RS2 RS1 RS0 C FB MUX RS2 RS1 RS0 C FB MUX TK2 EN EN CS1 CS0 CS1 CS0 TK4 RK1 RK2 AD8620 EL 1 EL 2 Input from Electrodes TK1..TK4 RK1..RK4 RS0..RS3 CS0..CS1 KK0.. KK3 ANALOG OUT Output to MUX & ADC CONTROL LOGIC EPM7064A TA TB RA RB clocks SA SB SC SD selects MD0.. MD4 data Adjustable signal channel for capacitance tomograph. Local control PLD reduces the number of external connections.

10 Adjustable signal channel printed circuit board

11 Output from ET3 signal card a), b) - Output from dual, fixed charge amplifier visible U characteristic c), d) - Output from dual charge amplifier circuit with adjustable parameters Significant improvement in signal to ripple and noise ratio is evident!

12 Runtime mode of ET3 Flexibility and user hardware configuration of ET3 is possible by applying PLD. Depends on number of electrods run-time mode of ET3 is: 1 x 8 1 x 12 1 x 16 1 x 20 1 x 24 1 x 32 2 x 8 2 x 12 2 x 16 4 x 8

13 RESULTS 16 electrode probe, 9 elements phantom (plexi rods diam. 20 mm) Modified pictures Normalised distance from measured data LBP meth. 100%

14 RESULTS 10 th elements phantom (8 plexi diam. 20 mm) Obrazy po rekonstrukcji Normalised distance from measured data LBP meth. 100%

15 RESULTS 16 electrode probe, 10 elements phantom (plexi rods diam. 20 mm) Modified pictures Normalised distance from measured data LBP meth. 100%

16 Two Plane version of ET3 2x12 electrod A B A B sonda 2 płaszczyznowa z granulatem PCV

17 Electrical capacitance tomography system in Centre for Bulk Solids and Particulate Technologies, University of Newcastle, Australia Data Acquisition System (DAS) - Constructed by the ECT design team located at the Institute of Radio Electronics, Warsaw University of Technology, Poland Sensors Control Computer BULK EUROPE - Prague

18 ECT Attachment BULK EUROPE - Prague

19 Velocity profile test 1 Pixel number - Average velocity across the pulse -Distinct Velocity profile (max 3.5 m/s) Velocity [m/s] Pixel number Mˆ Solids flow rate at each pixel T 1 = ρ sv( i, j, t) α s ( i, j, t i j t T s ) 0 M s = 0.31 kg/s (70% total mass flow kg/s) BULK EUROPE - Prague

20 Process Tomography in Computer Engineering Department Technical University of Lodz

21 3D IMAGING of plexi PHANTOMS in Computer Engineering Department Technical University of Lodz Chair prof. Dominik Sankowski

22 TOMOGRAF IREna

23 One-Channel ECT TOMOGRAPH IREna

24 Two ET3 tomographs with 2x12 electrod sensor and 1x32 electrod sensor

25 ET3 and three plane sensor (3x12 electrod) for flowing parameters measurement Installation for investigation of gas-liquid flow

26 Publications Jacek Mirkowski, Waldemar T. Smolik, Member, IEEE, M. Yang, T. Olszewski, Roman Szabatin, Dariusz S. Radomski, and Wuqiang Q. Yang, Senior Member, IEEE, A New Forward-Problem Solver Based on a Capacitor-Mesh Model for Electrical Capacitance Tomograph, IEEE Transactions on Instrumentation and Measurement, vol.57, No.5, May 2008, T.Olszewski, W.Smolik, J. Mirkowski R.Szabatin, D.Radomski, P.Brzeski, Electrical Capacitance Tomograph ET3, Elektronika nr4/2008, K.Williams, T. Olszewski, M. Jones and B. Singh, Electrical Capacitance Tomography of Dense Phase Pneumatic Conveying of Flyash Powder, Proceedings, BulkEurope 2008, Prague, P. Czarnecki, Hardware Implementation Of Iterative Image Reconstruction Algorithm For Capacitance Tomography, Proceedings 5th International Symposium on Process Tomography, , Zakopane B. Radzik, R. Szabatin, J Mirkowski, W. Smolik, Tomasz Olszewski, Elektryczny tomograf pojemnościowy IREna, Elektronika 2009 (przyjęty do druku) P.Czarnecki, Ł. Dańko, R. Szabatin, One channel capacitance tomography with hardware implementation of image reconstruction algorithm, Proceedings, 2009 IEEE Workshop on Imaging Systems and Techniques (IST2009), Shenzen, China (artykuł przyjęty na konferencję) Projekt współfinansowany przez Unię Europejską w ramach Europejskiego Funduszu Społecznego