CN202255549U - Signal processing circuit component for radar liquidometer - Google Patents
Signal processing circuit component for radar liquidometer Download PDFInfo
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- CN202255549U CN202255549U CN2011203783787U CN201120378378U CN202255549U CN 202255549 U CN202255549 U CN 202255549U CN 2011203783787 U CN2011203783787 U CN 2011203783787U CN 201120378378 U CN201120378378 U CN 201120378378U CN 202255549 U CN202255549 U CN 202255549U
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Abstract
The utility model discloses a signal processing circuit component for a radar liquidometer, which comprises a power supply circuit and a signal processing circuit, wherein the power supply circuit comprises an input protection circuit, a filter circuit and a voltage conversion circuit; a direct current is sent into the filter circuit through the input protection circuit so as to be filtered, and is processed by the voltage conversion circuit to generate a multichannel power source; the signal processing circuit comprises an automatic gain control circuit, a voltage-limit filter circuit, a low-frequency cut-off circuit, an analog-to-digital conversion circuit, a central processing circuit and a serial interface circuit; an input intermediate-frequency signal is subjected to amplitude adjustment by the automatic gain control circuit, subjected to clutter filtration by the voltage-limit filter circuit and the low-frequency cut-off circuit, subjected to digital-to-analog conversion by the analog-to-digital conversion circuit, and subjected to calculation by the central processing circuit to obtain the measured distance. The utility model has the advantages of wide measuring range, high precision and the like, is slightly influenced by the environment, and can solve the problems of short action distance, high susceptibility to jamming, and incapability of adapting to great temperature change range in the existing liquid level measuring equipment.
Description
Technical field
The utility model belongs to the Radar Technology field, particularly a kind of signal processing circuit assembly that is used for radar level gauge.
Background technology
Radar level gauge is the new type measuring instrument device of a kind of advanced person's measurement face of land water level, and its adopts CW with frequency modulation mode of operation, has that range is big, precision is high, receives environment etc. to influence characteristics such as little.
Present existing radar level gauge majority is the radar wave float type level gauge, can only in oil tank, basin, use, and dynamic range of signals is narrow, and operating distance is limited; Serviceability temperature is single, and precision is lower in the bigger environment of range of temperature.
The utility model content
The utility model provides a kind of signal processing circuit assembly that is used for radar level gauge, solves existing fluid level measuring device operating distance weak point, is subject to disturb and can't adapts to the problem of temperature variation in a big way.
Realize that the concrete technical scheme that the utility model purpose is adopted is:
A kind of signal processing circuit assembly that is used for radar level gauge comprises power circuit and signal processing circuit two parts, it is characterized in that:
Said power circuit comprises input protection circuit, filtering circuit and the voltage conversion circuit that connects successively; Direct current is sent into filtering circuit through said input protection circuit and is carried out filtering; Generate multiple power supplies through said voltage conversion circuit again, be respectively applied for T/R assembly power supply to said signal processing circuit and radar level gauge;
Said signal processing circuit comprises that the automatic gain control circuit, pressure limiting filtering circuit, the low frequency that connect successively cut off circuit, analog to digital conversion circuit, central processing circuit and serial interface circuit; The intermediate-freuqncy signal of the T/R assembly input of radar level gauge after said automatic gain control circuit carries out the amplitude adjustment, gets into said pressure limiting filtering circuit and low frequency cuts off circuit filtering clutter; Filtered signal is sent into analog to digital conversion circuit and is carried out digital-to-analog conversion; Digital signal after the conversion is sent into central processing circuit; Calculate find range and leave, measurement result is seen off through said serial interface circuit.
Further; Also comprise waveform generating circuit, temperature-compensation circuit and first temperature sensor in this signal processing circuit; Said central processing circuit produces the triangular wave periodic signal through this waveform generating circuit of control, and sends into the T/R assembly and carry out linear frequency modulation, and said first temperature sensor is sent into central processing circuit with survey signal circuit temperature with the form of digital signal; As the input of said temperature-compensation circuit, be used for said triangular wave periodic signal is carried out the amplitude adjustment.
Further; Also comprise enable circuits, second temperature sensor and relay in the said power circuit, this enable circuits is used to control the work and the cut-out of voltage transitions electricity, and relay is used to control the power supply break-make of T/R assembly; Said second temperature sensor detects the central temperature of power circuit; And detected temperature sent into central processing circuit with the form of digital signal, as the input of said temperature-compensation circuit, be used for said triangular wave periodic signal is carried out the amplitude adjustment.
Further; Said automatic gain control circuit comprises variable gain amplifier and backfeed loop; This backfeed loop comprises a multiplier and an amplifier, and the said intermediate-freuqncy signal of input is sent into multiplier and obtained a DC level after this variable gain amplifier amplifies, and sends into said variable gain amplifier adjustment signal enlargement range after amplifying through this amplifier again; Thereby make the input signal amplitude of sending into late-class circuit remain a steady state value, leave to increase the survey rise.
Further; Said pressure limiting filtering circuit comprises second order active low-pass filter, second order active high-pass filter, limiter and amplifier; Input signal is respectively through this second order active low-pass filter and second order active high-pass filter filtering clutter, again through exporting through the amplifier amplification behind this limiter amplitude limit.
Further; Analog-digital conversion circuit as described comprises comparer and level translator; Input signal and DC reference voltage carry out amplitude relatively through comparer; It then is 1 that input signal amplitude is higher than reference voltage, and it then is 0 that input signal amplitude is lower than reference voltage, obtains the digital signal identical with frequency input signal thus.
The invention also discloses a kind of radar level gauge that comprises said signal processing circuit assembly
The utility model utilizes CW with frequency modulation (LFMCW) Radar Technology, can cooperate T/R assembly and antenna system, under contactless situation, realizes the accurate measurement to the water surface, liquid level relative height.Because it adopts automatic gain control, FPGA double frequency counting algorithm and temperature-compensation circuit; Reduce system cost and realized difficulty, improved operating distance and distance accuracy, and had in the full temperature scope function such as altimetry precision compensation; Simple in structure, operating distance is far away, altimetry precision is high.
Description of drawings
Fig. 1 forms synoptic diagram for an embodiment of the utility model;
Fig. 2 is temperature-compensation circuit figure;
Fig. 3 is automatic gain control circuit figure;
Fig. 4 is D/A converting circuit figure.
Embodiment
Below in conjunction with accompanying drawing and specific embodiment the utility model is further described:
As shown in Figure 1, the signal processing circuit assembly of the radar level gauge of an embodiment of the utility model comprises power circuit and signal processing circuit.
Said power circuit comprises input protection circuit 1, filtering circuit 2, voltage conversion circuit 3, enable circuits 13, temperature sensor 14 and relay 15.Input protection circuit 1 adopts Surface Mount fuse 0451002.HL and transient current rejector P6KE 22A to realize; Filtering circuit 2 adopts wave filter BNX005-01 to realize; Voltage conversion circuit 3 adopts power module DPB10-12D5Q and DPB10-12D12Q to realize; Temperature sensor 14 adopts DS1621S to realize, relay 15 adopts the JZC-078M hermetically-sealed superminiature electromagnetic relay to realize.
Said signal processing circuit comprises that automatic gain control circuit 4, pressure limiting filtering circuit 5, low frequency cut off circuit 6, analog to digital conversion circuit 7, central processing circuit 8, waveform generating circuit 10, temperature-compensation circuit 11, serial interface circuit 9 and temperature sensor 12.Automatic gain control circuit 4 adopts variable gain amplifier AD604AR, multiplier AD835AR and amplifier AD711AQ to realize; Pressure limiting filtering circuit 5 adopts operational amplifier SE5532AD8 to realize; Low frequency cuts off circuit 6 and adopts triode 2N4391 to realize; Analog to digital conversion circuit 7 adopts comparer MAX9201ESE to realize; Central processing circuit 8 adopts fpga chip to realize; Waveform generating circuit 10 adopts DA chip MAX5441AEUA to realize; Temperature-compensation circuit 11 adopts numerical control adjustable attenuator AD7533LP to realize; Serial interface circuit 9 adopts serial port chip IL422 to realize.
The whole signal processing component course of work is following:
18V～36V direct current is imported from the outside; Through input protection circuit 1 and filtering circuit 2 supply power change-over circuits 3, power-switching circuit 3 work when enable signal is low level, generations ± 5V and ± the 12V four-way power supply; Wherein ± 5V supplies with signal processing circuit with ± 12V; ± 5V supplies with the T/R assembly through relay 15, and relay 15 original states are closed condition, and the T/R assembly is not worked.
After powering on, central processing circuit 8 carries out system reset; The end that resets is back to be provided with the DA chip; Through amplitude being added up or successively decreasing generation amplitude and the certain periodicity triangular wave of frequency; According to the temperature information of two temperature sensor passbacks on power circuit and the signal processing circuit, finely tune again through 11 pairs of triangular wave amplitudes of temperature-compensation circuit.Temperature-compensation circuit 11 adopts numerical control adjustable attenuator AD7533 to realize that as shown in Figure 2, DB1～DB10 is the control pin of AD7533, when DB1～DB10 be complete 1 the time signal unattenuated, signal was a maximum attenuation for complete 0 o'clock.FPGA utilizes the temperature information of two temperature sensor passbacks to calculate corresponding temperature compensation value, and DB1～DB10 is configured the amplitude fading with the control triangular wave, thereby realizes the temperature compensation of complete machine.Triangular wave through after the temperature compensation exports the T/R assembly to, carries out linear frequency modulation with control T/R assembly.
Intermediate-freuqncy signal is cut off circuit 6 filtering clutter and pressure limitings through pressure limiting filtering circuit 5 and low frequency after the automatic gain adjustment, send into analog to digital conversion circuit 7.The high algorithm of the survey of the utility model only needs the frequency information of intermediate-freuqncy signal; Therefore analog to digital conversion circuit 7 adopts comparer to realize; As shown in Figure 4, the DC reference voltage of an input signal and a 0V carries out amplitude relatively through comparer, and it then is 1 that input signal amplitude is higher than reference voltage; It then is 0 that input signal amplitude is lower than reference voltage; The digital signal that obtains thus is identical with frequency input signal, and because of input signal is not pure sine wave, near the fluctuation reference voltage can cause digital signal to have an impulse disturbances; Series connection one 10k Ω resistance can effectively be removed impulse disturbances between comparator output terminal and signal input part, is to send into central processing circuit 8 behind the 3.3V to handle through level translator with voltage transitions again.
The high algorithm use double frequency of the survey of the utility model counting algorithm.The double frequency counting algorithm is the conventional technology in this area; Precision is superior to fft algorithm in the measurement of low clearance; Error depends on the multiple of reference clock frequency and intermediate-freuqncy signal frequency, if reference clock frequency is K times of IF-FRE, then error is the 1/K of frequency counting error; Therefore under the certain prerequisite of IF-FRE, improve reference clock frequency and can effectively improve altimetry precision.In order to reduce the interference in the printed board, external clock generally uses the crystal oscillator of 20MHz or 40MHz, and precision is not high.The utility model FPGA inner use the DCM resource with the clock signal frequency multiplication of 20MHz to 200MHz clock as a reference, can effectively reduce theoretical error; In addition, the triangular wave turning point linearity is lower, and the intermediate-freuqncy signal that nonlinear frequency modulation produces can cause error to counting; The utility model can also generate a square wave identical with the triangular wave cycle in central processing circuit; Intermediate-freuqncy signal to producing at the triangular wave spike is cut off, and can avoid non-linear section to surveying high influence, when counting, carries out intermediate-freuqncy signal is carried out the accumulation in 1024 cycles; Ask average at last, can effectively improve altimetry precision.Added that the triangular wave spike cuts off, can avoid spike to disturb the counting error that causes, carried out after the multistage stored counts on average again, reduced the error that the monocycle counting causes;
Common central processing circuit is made of single-chip microcomputer; The counting reference clock depends on the frequency of external crystal-controlled oscillation; General maximum to about the 40MHz; The utility model uses FPGA to do central processing circuit, can use inner DCM resource will count the reference clock frequency multiplication to MHz to 1 GHz of hundreds of, can significantly improve counting precision.
Claims (6)
1. a signal processing circuit assembly that is used for radar level gauge comprises power circuit and signal processing circuit two parts, it is characterized in that:
Said power circuit comprises input protection circuit (1), filtering circuit (2) and the voltage conversion circuit (3) that connects successively; Direct current is sent into filtering circuit (2) through said input protection circuit (1) and is carried out filtering; Generate multiple power supplies through said voltage conversion circuit (3) again, be respectively applied for T/R assembly power supply to said signal processing circuit and radar level gauge;
Said signal processing circuit comprises that the automatic gain control circuit (4), pressure limiting filtering circuit (5), the low frequency that connect successively cut off circuit (6), analog to digital conversion circuit (7), central processing circuit (8) and serial interface circuit (9); The intermediate-freuqncy signal of the T/R assembly input of radar level gauge after said automatic gain control circuit (4) carries out the amplitude adjustment, gets into said pressure limiting filtering circuit (5) and low frequency cuts off circuit (6) filtering clutter; Filtered signal is sent into analog to digital conversion circuit (7) and is carried out digital-to-analog conversion; Digital signal after the conversion is sent into central processing circuit (8); Calculate find range and leave, measurement result is seen off through said serial interface circuit (9).
2. signal processing circuit assembly according to claim 1; It is characterized in that; Also comprise the waveform generating circuit (10), temperature-compensation circuit (11) and first temperature sensor (12) that are connected with central processing circuit (8) respectively in this signal processing circuit; Said central processing circuit (8) produces the triangular wave periodic signal through this waveform generating circuit of control (10), and sends into the T/R assembly and carry out linear frequency modulation, and said first temperature sensor (12) is sent into central processing circuit (8) with the temperature of survey signal circuit with the form of digital signal; As the input of said temperature-compensation circuit (11), be used for said triangular wave periodic signal is carried out the amplitude adjustment.
3. signal processing circuit assembly according to claim 1 and 2; It is characterized in that; Also comprise enable circuits (13), second temperature sensor (14) and relay (15) in the said power circuit, this enable circuits is used to control the work and the cut-out of voltage conversion circuit (3), and relay (15) is used to control the power supply break-make of T/R assembly; Said second temperature sensor (14) detects the central temperature of power circuit; And detected temperature sent into central processing circuit (8) with the form of digital signal, as the input of said temperature-compensation circuit (11), be used for said triangular wave periodic signal is carried out the amplitude adjustment.
4. signal processing circuit assembly according to claim 1 and 2; It is characterized in that; Said automatic gain control circuit (4) comprises variable gain amplifier and backfeed loop; This backfeed loop comprises a multiplier and an amplifier, and the said intermediate-freuqncy signal of input is sent into multiplier and obtained a DC level after this variable gain amplifier amplifies, and sends into said variable gain amplifier adjustment signal enlargement range after amplifying through this amplifier again; Thereby make the input signal amplitude of sending into late-class circuit remain a steady state value, leave to increase the survey rise.
5. signal processing circuit assembly according to claim 1 and 2; It is characterized in that; Said pressure limiting filtering circuit (5) comprises second order active low-pass filter, second order active high-pass filter, limiter and amplifier; Input signal is respectively through this second order active low-pass filter and second order active high-pass filter filtering clutter, again through exporting through the amplifier amplification behind this limiter amplitude limit.
6. signal processing circuit assembly according to claim 1 and 2; It is characterized in that; Analog-digital conversion circuit as described (7) comprises comparer and level translator, and input signal and DC reference voltage carry out amplitude relatively through comparer, and it then is 1 that input signal amplitude is higher than reference voltage; It then is 0 that input signal amplitude is lower than reference voltage, obtains the digital signal identical with frequency input signal thus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011203783787U CN202255549U (en) | 2011-09-28 | 2011-09-28 | Signal processing circuit component for radar liquidometer |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011203783787U CN202255549U (en) | 2011-09-28 | 2011-09-28 | Signal processing circuit component for radar liquidometer |
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| CN202255549U true CN202255549U (en) | 2012-05-30 |
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| CN2011203783787U Expired - Fee Related CN202255549U (en) | 2011-09-28 | 2011-09-28 | Signal processing circuit component for radar liquidometer |
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103490781A (en) * | 2013-09-14 | 2014-01-01 | 西安奇维科技股份有限公司 | High-accuracy analog signal acquisition circuit with temperature self-correcting function |
| CN104006865A (en) * | 2014-06-11 | 2014-08-27 | 中国科学院电子学研究所 | Processing system for radar liquid level measurement data |
| CN104101404A (en) * | 2014-04-25 | 2014-10-15 | 西安德创电气科技有限公司 | Radar level meter |
| CN104132713A (en) * | 2014-05-22 | 2014-11-05 | 深圳万讯自控股份有限公司 | Method and device for processing echo signals of guided wave radar liquid level meter |
| CN106840310A (en) * | 2017-02-17 | 2017-06-13 | 水利部南京水利水文自动化研究所 | A kind of CW/FM continuous wave/frequency modulated modulated indicator water gage measuring method |
| CN107395148A (en) * | 2017-07-31 | 2017-11-24 | 中国电子科技集团公司第二十九研究所 | A kind of temperature compensation equalizing circuit of TR components |
| CN108445485A (en) * | 2018-02-02 | 2018-08-24 | 哈尔滨工程大学 | MIMO radar transceiving integrated device based on FMCW signal |
| WO2020108270A1 (en) * | 2018-11-30 | 2020-06-04 | 华为技术有限公司 | Radar and target detection method |
| CN111913170A (en) * | 2020-08-12 | 2020-11-10 | 南京英锐创电子科技有限公司 | Signal transmitting apparatus |
-
2011
- 2011-09-28 CN CN2011203783787U patent/CN202255549U/en not_active Expired - Fee Related
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103490781A (en) * | 2013-09-14 | 2014-01-01 | 西安奇维科技股份有限公司 | High-accuracy analog signal acquisition circuit with temperature self-correcting function |
| CN104101404A (en) * | 2014-04-25 | 2014-10-15 | 西安德创电气科技有限公司 | Radar level meter |
| CN104132713A (en) * | 2014-05-22 | 2014-11-05 | 深圳万讯自控股份有限公司 | Method and device for processing echo signals of guided wave radar liquid level meter |
| CN104132713B (en) * | 2014-05-22 | 2017-08-22 | 深圳万讯自控股份有限公司 | A kind of guide wave radar liquid level gauge echo signal processing method and device |
| CN104006865A (en) * | 2014-06-11 | 2014-08-27 | 中国科学院电子学研究所 | Processing system for radar liquid level measurement data |
| CN106840310B (en) * | 2017-02-17 | 2020-06-26 | 水利部南京水利水文自动化研究所 | Continuous frequency modulation wave radar level gauge measuring method |
| CN106840310A (en) * | 2017-02-17 | 2017-06-13 | 水利部南京水利水文自动化研究所 | A kind of CW/FM continuous wave/frequency modulated modulated indicator water gage measuring method |
| CN107395148A (en) * | 2017-07-31 | 2017-11-24 | 中国电子科技集团公司第二十九研究所 | A kind of temperature compensation equalizing circuit of TR components |
| CN107395148B (en) * | 2017-07-31 | 2020-06-09 | 中国电子科技集团公司第二十九研究所 | Temperature compensation equalizing circuit of TR (transmitter-receiver) component |
| CN108445485A (en) * | 2018-02-02 | 2018-08-24 | 哈尔滨工程大学 | MIMO radar transceiving integrated device based on FMCW signal |
| WO2020108270A1 (en) * | 2018-11-30 | 2020-06-04 | 华为技术有限公司 | Radar and target detection method |
| CN111913170A (en) * | 2020-08-12 | 2020-11-10 | 南京英锐创电子科技有限公司 | Signal transmitting apparatus |
| CN111913170B (en) * | 2020-08-12 | 2023-08-08 | 南京英锐创电子科技有限公司 | Signal transmitting device |
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| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120530 Termination date: 20150928 |
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| EXPY | Termination of patent right or utility model |