CN205679561U - Standing tree carrying out flaw detection device based on resistance tomography technology - Google Patents
Standing tree carrying out flaw detection device based on resistance tomography technology Download PDFInfo
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- CN205679561U CN205679561U CN201620575312.XU CN201620575312U CN205679561U CN 205679561 U CN205679561 U CN 205679561U CN 201620575312 U CN201620575312 U CN 201620575312U CN 205679561 U CN205679561 U CN 205679561U
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Abstract
A kind of standing tree carrying out flaw detection device based on resistance tomography technology.Traditional microwave, ultrasonic wave nuclear magnetic resonance and x-ray imaging technology have application in wood nondestructive testing field, but are also all clearly present some shortcomings.A kind of standing tree carrying out flaw detection device based on resistance tomography technology, its composition includes: device body, device body (8) is internal has analog signal conditioner circuit (6), driving source Acquisition Circuit (2), signal selection module circuit and variable connector control circuit (1), variable connector control circuit passes through wire (7) electrode electrically connected (4), and electrode is connected on standing tree cross section (5)；Analog signal conditioner circuit includes again low-pass filter circuit (6 1), demodulator circuit (6 2), exchange second amplifying circuit (6 3), differential one-level amplifying circuit (6 4) and high-pass filtering circuit (6 5).The utility model application is applied to the standing tree carrying out flaw detection device based on resistance tomography technology.
Description
Technical field:
The utility model relates to a kind of carrying out flaw detection field, particularly relates to a kind of standing tree based on resistance tomography technology
Carrying out flaw detection device.
Background technology:
At present, the technology such as microwave, ultrasonic wave and nuclear magnetic resonance and X radial imaging in wood nondestructive testing field all
Some have been had to attempt and application；It although these technology differ from one another in wood nondestructive testing, but is also all clearly present some not
Foot；When defects in timber and physical property thereof are detected by applied microwave method, suffer from the impact of moisture content situation,
The resolution ratio of standing tree detection is all had much room for improvement with adaptability；Sufficiently complex additionally, due to wood structure, utilize ultrasonic technology
When carrying out flaw detection is carried out to timber, can there is certain contact gap between timber and ultrasonic probe, need quality preferable
Couplant carry out adhesion and could realize effectively connection；Although and utilize the character Application comparison of X-ray detection timber extensive, but
Owing to its equipment cost is higher, therefore current also in the experimental study stage；In addition, said method also all exist not portable,
The problems such as operation inconvenience, it is often more important that, these methods are typically only capable to detect the rotten situation of standing tree middle and advanced stage, and right
The diagnosis performance of the early stage rotten discoloration of standing tree is not good.
Content of the invention:
The purpose of this utility model is to provide a kind of standing tree carrying out flaw detection device based on resistance tomography technology.
Above-mentioned purpose is realized by following technical scheme:
A kind of standing tree carrying out flaw detection device based on resistance tomography technology, its composition includes: device body, described
There is inside device body analog signal conditioner circuit, driving source Acquisition Circuit, signal selection module circuit and variable connector control
Circuit processed, described variable connector control circuit is by wire electrode electrically connected, and described electrode is connected on standing tree cross section；Institute
The analog signal conditioner circuit stated includes that again low-pass filter circuit, demodulator circuit, exchange second amplifying circuit, differential one-level are amplified
Circuit and high-pass filtering circuit, described low-pass filter circuit electrical connection demodulator circuit, described demodulator circuit electrical connection exchange
Second amplifying circuit, the described differential one-level amplifying circuit of exchange second amplifying circuit electrical connection, described differential one-level is amplified
Circuit electrically connects high-pass filtering circuit；Described driving source Acquisition Circuit includes again AD9850 signal generator, voltage-controlled current source
Circuit, cpu controller, data sampling circuit, amplitude control circuitry and serial communication circuit, described AD9850 signal generator
It is electrically connected cpu controller, described data sampling circuit and described serial communication with described voltage controlled current source circuit
Circuit is also electrically connected cpu controller, and described amplitude control circuitry is electrically connected to voltage controlled current source circuit.
The described standing tree carrying out flaw detection device based on resistance tomography technology, described serial communication circuit electrical connection
In tomography computer, described variable connector control circuit electricity is connected to described high-pass filtering circuit, described high-pass filtering electricity
Road is in turn, electrically connected to described differential one-level amplifying circuit and the described second amplifying circuit that exchanges, described data sampling electricity
Road is electrically connected to described low-pass filter circuit, and described amplitude control circuitry is electrically connected to described demodulator circuit, described
The described voltage controlled current source circuit of AD9850 signal generator electrical connection, described voltage controlled current source circuit is electrically connected to described
Signal selection module circuit.
The described standing tree carrying out flaw detection device based on resistance tomography technology, described electrically connecting as is done by wire
For connecting medium.
The beneficial effects of the utility model:
1. standing tree carrying out flaw detection device of the present utility model, can effectively detect the early stage rotten discoloration of standing tree,
The survival rate improving standing tree reduces timber loss, and simultaneously easy to operate, simple in construction is easy to carry.
Standing tree carrying out flaw detection device of the present utility model, the scheme of institute's foundation is resistance fault imaging (ERT) technology, profit
The standing tree cross section distribution of resistance obtaining with measurement builds two-dimensional section image, and then analyzes standing tree internal feature.
Standing tree carrying out flaw detection device of the present utility model, the working method of ERT is current excitation, voltage measurement；Alternation electricity
Stream is applied on tested standing tree surface by pair of electrodes, and when the resistivity changes in distribution in standing tree, the distribution of current field is also
Can change therewith, the measurement voltage on standing tree periphery correspondingly can be caused also to change；That is standing tree periphery measurement
The change of voltage can reflect the change of standing tree internal resistance rate；Measurement voltage according to standing tree periphery, by certain one-tenth
As algorithm, the distribution of impedance in standing tree cross section can be reconstructed, and thus set up the two dimensional image in standing tree cross section.
Standing tree carrying out flaw detection device of the present utility model, due in electric impedance imaging system, sensor electrode and standing tree
Surface has certain contact resistance, and in order to eliminate the impact of this resistance, this device uses the very big constant-current source of internal resistance and makees
For pumping signal.
Standing tree carrying out flaw detection device of the present utility model, the signal strength signal intensity recording due to standing tree surface differs, and device needs
The weak voltage signal obtaining under these measurement electrodes is nursed one's health.
Standing tree carrying out flaw detection device of the present utility model, uses signal gating module, is responsible for processing each different excitation electricity
Switched conductive between pole and measurement electrode；Device uses the Review of Electrical Impedance Tomography of 16 electrodes, it is therefore desirable to four 16 tunnels
Analog switch is circulated conducting excitation input and voltage measurement.
Standing tree carrying out flaw detection device of the present utility model, the described standing tree carrying out flaw detection based on resistance tomography technology
In system, in equipotential line backprojection algorithm, the determination of weight coefficient uses and is proportional to view field's size method reciprocal,
Can effectively reduce the impact of star artifact, improve image resolution ratio further.
Brief description:
Accompanying drawing 1 is standing tree carrying out flaw detection apparatus structure schematic diagram of the present utility model.
Accompanying drawing 2 is standing tree carrying out flaw detection plant system drawing of the present utility model.
Accompanying drawing 3 is detection device electrical impedance tomography schematic diagram of the present utility model.
Accompanying drawing 4 is the constant-current source pumping signal generation module schematic diagram of detection device of the present utility model.
Accompanying drawing 5 is the low-pass filter circuit schematic diagram of detection device of the present utility model.
Accompanying drawing 6 is the sinusoidal excitation signal generation module circuit theory diagrams of detection device of the present utility model.
Accompanying drawing 7 is the Detection of Weak Signals module differential signal input circuit schematic diagram of detection device of the present utility model.
Accompanying drawing 8 is the Detection of Weak Signals module differential signal programming amplifying schematic diagram of detection device of the present utility model.
Accompanying drawing 9 is the Detection of Weak Signals modular circuit schematic diagram of detection device of the present utility model.
Accompanying drawing 10 is the signal gating modular circuit schematic diagram of detection device of the present utility model.
Accompanying drawing 11 is the main control module circuit theory diagrams of detection device of the present utility model.
Accompanying drawing 12 is the communication module circuit theory diagrams of detection device of the present utility model.
Accompanying drawing 13 is the power module circuitry schematic diagram of detection device of the present utility model.
In figure: 1 variable connector, signal gating modular circuit；2 driving source acquisition module circuit；2-1 is voltage-controlled
Current source circuit；2-2 AD9850 signal generator；2-3 cpu controller；2-4 amplitude control circuitry；2-5 —
Data sampling circuit；2-6 serial communication circuit；3 tomography computers；4 electrodes；5 standing tree cross sections；6 simulations
Signal-regulated kinase circuit；6-1 low-pass filter circuit；6-2 demodulator circuit；6-3 exchanges second amplifying circuit；6-4
Differential one-level amplifying circuit；6-5 high-pass filtering circuit；7 wires；8 housings；
Detailed description of the invention:
Embodiment 1:
A kind of standing tree carrying out flaw detection device based on resistance tomography technology, its composition includes: device body, described
Device body 8 is internal has analog signal conditioner circuit the 6th, driving source Acquisition Circuit the 2nd, signal selection module circuit and variable connector
Control circuit 1, described variable connector control circuit is by wire 7 electrode electrically connected 4, and described electrode is connected to standing tree cross section
On 5；Described analog signal conditioner circuit includes again low-pass filter circuit 6-1, demodulator circuit 6-2, exchange second amplifying circuit
6-3, differential one-level amplifying circuit 6-4 and high-pass filtering circuit 6-5, described low-pass filter circuit electrical connection demodulator circuit, institute
The demodulator circuit electrical connection exchange second amplifying circuit stated, the described differential one-level of exchange second amplifying circuit electrical connection amplifies electricity
Road, described differential one-level amplifying circuit electrical connection high-pass filtering circuit；Described driving source Acquisition Circuit includes again AD9850
Signal generator 2-2, voltage controlled current source circuit 2-1, cpu controller 2-3, data sampling circuit 2-5, amplitude control circuitry 2-4
With serial communication circuit 2-6, described AD9850 signal generator and described voltage controlled current source circuit are electrically connected CPU control
Device processed, described data sampling circuit and described serial communication circuit are also electrically connected cpu controller, described amplitude control
Circuit processed is electrically connected to voltage controlled current source circuit.
Embodiment 2:
The standing tree carrying out flaw detection device based on resistance tomography technology according to embodiment 1, described serial ports leads to
News circuit is electrically connected to tomography computer 3, and described variable connector control circuit electricity is connected to described high-pass filtering circuit, described
High-pass filtering circuit be in turn, electrically connected to described differential one-level amplifying circuit and the described second amplifying circuit that exchanges, described
Data sampling circuit be electrically connected to described low-pass filter circuit, described amplitude control circuitry is electrically connected to described demodulation
Circuit, the described voltage controlled current source circuit of described AD9850 signal generator electrical connection, described voltage controlled current source circuit electricity
It is connected to described signal selection module circuit.
Embodiment 3:
The standing tree carrying out flaw detection device based on resistance tomography technology according to embodiment 2, described electrical connection
For by wire as connect medium.
Embodiment 4:
The standing tree carrying out flaw detection device based on resistance tomography technology according to embodiment 2, uses one
Electric current injects, voltage measurement method, injects alternating excitation electric current on a pair adjacent electrode, and on other all adjacent electrodes
Measurement voltage difference, obtains one group of image that can reflect that standing tree internal resistance is distributed, and this measuring method is referred to as adjacent to；As
Measured standing tree surface surrounding places N=16 electrode, and electric current injects so each time, just has one group of N-1=15 independence
Voltage measurements (removes adjacent two to drive between electrode)；It yet with the existence of contact impedance, is being total to driving electrode
Therefore the measurement voltage obtaining on the measurement electrode of electrode can cannot function as rebuilding the data of resistance view picture containing bigger error
Source；So, the independence measurement voltage number of times under electric current injects each time just becomes N-3=13；More only in order to obtain
Vertical voltage measurement data, the utility model needs to use endless form to be implanted sequentially electric current on all adjacent electrodes, carries out N altogether
=16 times, every primary current all can obtain N-3=13 voltage measurements under injecting, and such one has N* (N-3)=208 independence
Voltage measurement.
Embodiment 5:
The standing tree carrying out flaw detection device based on resistance tomography technology according to embodiment 2, including pumping signal
Input module, adjacent driven electrode that this module is gated by signal gating module (16 to) is double to the alternation applying 0.5 milliampere
Polarity current, produces electrostatic field on standing tree cross section, then utilizes small-signal acquisition module to refer to according to signal gating module
16*13=208 the voltage signal collected, to circle collection (13) voltage signal, is then passed through RS-by fixed measurement electrode
232 serial ports are delivered to host computer and are carried out image reconstruction and follow-up analyzing and processing, and the logic control of all modules here is all by leading
Control unit module provides.
Embodiment 6:
The standing tree carrying out flaw detection device based on resistance tomography technology according to embodiment 2, as shown in Figure 4,
Being AD9850 sinusoidal signal generator circuit theory diagrams in pumping signal generation module, wherein AD9850 is as supply voltage 5V,
Can external 125M crystal oscillator, maximum can export the sinusoidal signal of 62.5MHZ.Having the adjustment frequency position of 32, resolution ratio is
0.0291HZ；5 bit digital phase places are reconciled, it is possible to provide the output signal of out of phase；AD9850 output is current signal, passes through
Current signal is converted to voltage signal by outer meeting resistance；Wherein current strength is controlled by outer meeting resistance R8, exports as R8=3.9K
Current value size is 10.24 milliamperes, wherein；AD9850 chip provides parallel and serial two kinds of interface modes；AD9850 configuration is adopted
40 bit registers, low 32 is frequency control word, and most-significant byte is input mode and phase control words；In order to save master control
The I/O mouth of module end, the utility model uses serial interface mode, it should be noted that AD9850 is parallel port when initializing
Input, parallel port mode is the most-significant byte i.e. W32-W40 in first input 40；So, initialization has only to W_CLK when powering on
Control word can be write with FQ_UD rising edge, AD9850 is configured to serial input pattern；When using serial mode input,
Different from parallel input mode, it is high-order rear at front MSB that input sequence in 40 control words is LSB low level；Wherein AD9850
The 9th pin accesses is the input of extraneous clock signal, i.e. crystal oscillator output；The output of 21 pin (IOUT) port is certain frequency
Current signal, what 22 pin exported is the current signal of the same frequency becoming 180 degree of phase differences with 21 pin, the resistance in external 250 Europe,
Generate the double of Vpp=2.5v after 5 rank Butterworth LPF that cut-off frequency is 40KHZ and AD620 are subtracted each other simultaneously
Polar voltages signal；Wherein AD620 be common-mode rejection ratio be 100db(G=10) carry a width of 120KHZ (G=100), input imbalance drift
Move 0.6uV/ DEG C only need the low cost of outer meeting resistance adjustable gain, the instrument amplifier of low power consumption high-precision；Wherein AD620
The bipolar voltage signal of 6 pin outputs enters in double operational VCCS module, and wherein main control end employing is program control
PGA203 chip, voltage follower uses the operational amplifier OP602 that TI company produces, and what the 12nd pin output exported is
0.5,1,2 milliampere of adjustable constant-flow signal.
Embodiment 7:
The standing tree carrying out flaw detection device based on resistance tomography technology according to embodiment 2, as shown in Figure 7,
Being Detection of Weak Signals module, the differential signal of measurement electrode pair is coupled to AD620 differential input end by RC high-pass filtering, can
Being prevented effectively from the direct current signal that polarity effect produces, AD620 can effectively remove input common mode voltage, differential voltage signal energy simultaneously
Pass through AD620 module；The 1 of AD620 chip, when 8 pin connect 50K ohm, gain factor is 2, and when unsettled, gain factor is 1；
AD620 output is input to programmable amplifier PGA202+PGA203, and gain control end is respectively 1,10,100,1000 and 1,
2,4,8；Suitably can regulate according to the amplitude of input signal, signal carries out real effective through being amplified into AD637
Extracting, the TCL2543 being then input to 12 is AD converted, and recently enters main control module.
Embodiment 8:
The standing tree carrying out flaw detection device based on resistance tomography technology according to embodiment 2, as shown in Figure 10,
For signal gating module, what the gating of the driving electrode pair of pumping signal input utilized is ADG1406 chip, conducting resistance 9.5
Ohm, track to track cmos analog switch；The common port of one of them ADG1406 accesses the signal output part of constant-current source, another
ADG1406 common port is directly grounded；By controlling 4 logic control element input circulation gating phases of each chip
A pair adjacent driving electrode is as the input of pumping signal；Measurement electrode tip uses two CD4067CMOS simulations and opens
Close, conducting resistance 125 ohm, owing to signal output part is instrument amplifier, the impact of the very big therefore conducting resistance of input impedance
Negligible.
Embodiment 9:
The standing tree carrying out flaw detection device based on resistance tomography technology according to embodiment 2, as shown in Figure 11,
For main control module and periphery communication and memory module, and vibration, reset circuit is, and indicator lamp and single input through keyboard list
Unit, wherein main control module is STC89C52RC, 512 bytes RAM, 8K bytes Flash, and communication interface is RS232 serial ports, it is achieved with
Upper machine communication；Memory module uses AT24C16,2048 bytes, the EEPROM of serial i IC EBI；Wherein power supply
Power, be converted into positive and negative 5v voltage by after 7805 and 7905 voltage stabilizing chips for positive and negative 12 volts of module employing, it is achieved system is different
The power supply of unit；Wherein digitally realize that modulus is isolated with using to be connected at power import by 0 Ohmic resistance with simulating.
Embodiment 10:
A kind of flaw detection of the standing tree carrying out flaw detection device based on resistance tomography technology utilizing described in embodiment 1 to 9
Detection method, its workflow is as follows: the control centre of native system sends acquisition instructions to slave computer, the CPU control of slave computer
After device receives order, utilizing signal gating module, circulation selects adjacent two electrodes as current input terminal, remaining electrode
To as voltage measurement end；According to electrostatic field theory, when between any pair of adjacent electrode at standing tree cross section during input current
A field domain will be set up in inside, as the point of the same potential in field domain is connected into line, just become a series of equipotential line；
The equipotential line wherein originating in boundary node can terminate between two electrodes of input current；On standing tree cross section any two
After individual interelectrode voltage removes flip-flop interference by high-pass filtering, enter high-impedance differential amplifier, then through two grades
Differential amplification, utilizes AD637 module to carry out the calculating of real effective, and the direct current signal of final output is entered by TCL2543 chip
Row AD conversion is saved in slave computer E2PROM；After slave computer gathers all of independent voltage measured value, by RS232 mouth
It is uploaded to control centre；Control centre utilizes equi-potential back-projection algorithm process analyze these data and utilize imaging mode to show
The change in resistance situation of tested standing tree cross section content；Wherein the basic thought of equi-potential back-projection algorithm is, it is assumed that internal
Resistivity change after equipotential lines distribution in the case of do not change, the change of internal resistance rate influences whether and its phase
The boundary voltage value closed changes；First the boundary node magnitude of voltage that these collectors are caught is entered column criterion by control centre
Change process, according to affecting accordingly the situation of change to the resistivity of internal element for relation (equipotential line view field) back projection,
And by 1 circulation input, these feedback result are overlapped, ultimately generate one and can reflect that content element resistivity becomes
The image changed；Wherein the method for standardization be by under the magnitude of voltage collecting and uniform resistivity distribution situation by just asking
Topic solves after calculated boundary voltage subtracts each other is divided by again, to eliminate dimension impact；Affect relation and then can pass through back projection's square
Battle array is expressed；In addition, tradition equi-potential back-projection algorithm utilization is to influence whether limit when internal element resistivity changes
This principle of the change of boundary's node voltage, and this change is all fed back in view field in the algorithm equably, therefore can
Cause actually unchanged unit to be mistaken as too according to projection matrix there occurs change；To this end, native system passes through
Set influence area weight parameter, the impact on unit for the boundary voltage big for view field is reduced, to reduce star artifact
Impact；The value of the unit resistivity tried to achieve is converted into color value and carries out standing tree cross section resistivity imaging by final system
Display.
Claims (3)
1. the standing tree carrying out flaw detection device based on resistance tomography technology, its composition includes: device body, its feature
It is: there is inside described device body analog signal conditioner circuit, driving source Acquisition Circuit, signal selection module circuit and many
Way switch control circuit, described variable connector control circuit is by wire electrode electrically connected, and described electrode is connected to standing tree
On cross section；Described analog signal conditioner circuit includes again low-pass filter circuit, demodulator circuit, exchange second amplifying circuit, difference
Dynamic one-level amplifying circuit and high-pass filtering circuit, described low-pass filter circuit electrical connection demodulator circuit, described demodulator circuit
Electrical connection exchange second amplifying circuit, the described differential one-level amplifying circuit of exchange second amplifying circuit electrical connection, described difference
Dynamic one-level amplifying circuit electrical connection high-pass filtering circuit；Described driving source Acquisition Circuit include again AD9850 signal generator,
Voltage controlled current source circuit, cpu controller, data sampling circuit, amplitude control circuitry and serial communication circuit, described AD9850
Signal generator and described voltage controlled current source circuit are electrically connected cpu controller, described data sampling circuit and described
Serial communication circuit be also electrically connected cpu controller, described amplitude control circuitry is electrically connected to voltage controlled current source circuit.
2. the standing tree carrying out flaw detection device based on resistance tomography technology according to claim 1, is characterized in that: described
Serial communication circuit be electrically connected to tomography computer, described variable connector control circuit electricity is connected to described high-pass filtering electricity
Road, described high-pass filtering circuit is in turn, electrically connected to described differential one-level amplifying circuit and exchanges two grades of amplification electricity with described
Road, described data sampling circuit is electrically connected to described low-pass filter circuit, and described amplitude control circuitry is electrically connected to institute
The demodulator circuit stated, the described voltage controlled current source circuit of described AD9850 signal generator electrical connection, described voltage controlled current
Source circuit is electrically connected to described signal selection module circuit.
3. the standing tree carrying out flaw detection device based on resistance tomography technology according to claim 2, is characterized in that: described
Electrically connect as by wire as connect medium.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105911107A (en) * | 2016-06-15 | 2016-08-31 | 东北林业大学 | Standing tree crack detecting device and method based on resistance tomography |
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2016
- 2016-06-15 CN CN201620575312.XU patent/CN205679561U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105911107A (en) * | 2016-06-15 | 2016-08-31 | 东北林业大学 | Standing tree crack detecting device and method based on resistance tomography |
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