A sensor transmitter and a voltage signal processing circuit thereof

Abstract

The application discloses a kind of sensing transducer and its voltage signal processing circuit, belong to the field of transducer, for using analog circuit to realize for sensor voltage signal segmented calibration, solved the problem that voltage signal is difficult to maintain higher signal accuracy under strong interference environment.Considering that the way of segmented calibration can improve the accuracy of sensor output voltage signal, and analog circuit has strong anti-interference ability, the segmented identification circuit of the application can deliver voltage signal to the segmented calibration circuit corresponding to the voltage value interval to which the voltage signal belongs, so that the segmented calibration circuit can multiply the received voltage signal by a predetermined slope and add a predetermined intercept, and output after signal conditioning circuit, so as to realize the segmented calibration of voltage signal, and each part of circuit is analog circuit, has strong anti-interference ability, so that voltage signal can maintain higher signal accuracy under strong interference environment, widen the application scenario of sensing transducer.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of transmitters, in particular to a sensing transmitter and a voltage signal processing circuit thereof. BACKGROUND

[0002] The sensing transmitter comprises a sensor and a voltage signal processing circuit, which can process the voltage signal output by the sensor to ensure accurate and stable transmission of the voltage signal. However, there is a lack of a mature voltage signal processing circuit in the related art, which makes it difficult for the voltage signal to maintain high signal accuracy in a strong interference environment (especially in a strong radiation environment such as a nuclear power field), thereby limiting the application scenarios of the sensing transmitter.

[0003] Therefore, how to provide a solution to the above technical problems is a problem that those skilled in the art need to solve at present. SUMMARY

[0004] The present application aims to provide a sensing transmitter and a voltage signal processing circuit thereof. The segmented identification circuit can transmit the voltage signal to the segmented calibration circuit corresponding to the voltage value interval to which the voltage signal belongs, so that the segmented calibration circuit can multiply the received voltage signal by a preset slope and add a preset intercept, and then output the voltage signal after being processed by the signal conditioning circuit, thereby realizing segmented calibration of the voltage signal. Each part of the circuit is an analog circuit, which has strong anti-interference ability, so that the voltage signal can maintain high signal accuracy in a strong interference environment, thereby widening the application scenarios of the sensing transmitter.

[0005] To solve the above technical problems, the present application provides a voltage signal processing circuit applied to a sensing transmitter, comprising:

[0006] A signal acquisition circuit is configured to acquire a voltage signal output by a sensor.

[0007] A segmented identification circuit is configured to transmit the voltage signal to a segmented calibration circuit corresponding to a voltage value interval to which the voltage signal belongs.

[0008] A plurality of segmented calibration circuits corresponding one-to-one to preset voltage value intervals are configured to multiply a received voltage signal by a preset slope and add a preset intercept to calibrate the voltage signal, wherein the preset parameters of each segmented calibration circuit are different, and the preset parameters include the preset slope and the preset intercept.

[0009] A signal conditioning circuit is configured to condition the voltage signal output by the segmented calibration circuit to facilitate signal transmission.

[0010] The signal acquisition circuit, the segmented identification circuit, the segmented calibration circuit, and the signal conditioning circuit are all analog circuits.

[0011] In another aspect, the segment identification circuit comprises:

[0012] a voltage threshold comparison unit having an input end connected to an output end of the signal acquisition circuit, configured to compare a voltage signal output by the signal acquisition circuit with a plurality of preset threshold voltages, and output a raw level signal reflecting a voltage value interval to which the voltage signal belongs;

[0013] a logic signal conversion unit having an input end connected to an output end of the voltage threshold comparison unit, configured to perform logic conversion on the raw level signal to generate a gating control signal;

[0014] a plurality of signal channels, each having an input end connected to an output end of the signal acquisition circuit, and each having an output end connected to an input end of the segment calibration circuit, and a channel gating unit having a control end connected to an output end of the logic signal conversion unit, configured to, under control of the gating control signal, open a signal channel corresponding to the voltage value interval to which the voltage signal belongs.

[0015] In another aspect, the voltage threshold comparison unit comprises:

[0016] a plurality of comparators having a same-phase input end or an opposite-phase input end connected to a preset threshold voltage, and having another input end commonly connected to an output end of the signal acquisition circuit, configured to output the raw level signal;

[0017] a threshold voltage generation circuit configured to generate a plurality of preset threshold voltages;

[0018] The threshold voltage generation circuit comprises a voltage dividing circuit, the number of threshold voltages is the same as the number of comparators, and the threshold voltages are set according to boundary values of preset voltage value intervals.

[0019] In another aspect, the logic signal conversion unit comprises:

[0020] a plurality of logic gate circuits having input ends connected to output ends of the voltage threshold comparison unit, configured to perform logic combination operations on the raw level signal to generate a gating control signal meeting a control rule of the channel gating unit.

[0021] In another aspect, the segment calibration circuit comprises a slope adjustment sub-circuit and an intercept adjustment sub-circuit:

[0022] The slope adjustment sub-circuit having an input end connected to the segment identification circuit, is configured to multiply a received voltage signal by a corresponding preset slope by adjusting resistance ratios of a resistance network;

[0023] The intercept adjustment sub-circuit comprises:

[0024] A reference voltage source is configured to output a reference voltage, which can be adjusted by a resistor or a potentiometer to set the preset intercept;

[0025] An input terminal of the adder is connected to the output terminal of the reference voltage source and the slope adjustment sub-circuit, respectively.

[0026] In another aspect, the slope adjustment sub-circuit comprises:

[0027] An operational amplifier connected to the segment identification circuit and the adjustable resistor network, respectively, is configured to multiply the received voltage signal by the corresponding preset slope.

[0028] The adjustable resistor network comprises at least one potentiometer or precision adjustable resistor, which is configured to adjust the preset slope by changing the resistance ratio.

[0029] In another aspect, the voltage signal processing circuit further comprises:

[0030] A temperature compensation circuit is configured to generate a temperature compensation voltage signal according to the deviation of the actual temperature from the standard temperature, and couple the temperature compensation voltage signal to the output of each segment calibration circuit.

[0031] In another aspect, the temperature compensation circuit comprises:

[0032] A temperature acquisition and processing unit is configured to acquire the actual temperature by a temperature sensor and convert it into a corresponding temperature electrical signal.

[0033] A temperature compensation value calculation unit connected to the temperature acquisition and processing unit is configured to compare the temperature electrical signal with a reference electrical signal corresponding to the standard temperature, and generate a compensation voltage signal reflecting the temperature deviation.

[0034] A signal coupling unit connected to the temperature compensation value calculation unit and the output terminal of each segment calibration circuit is configured to couple the compensation voltage signal to the output signal of the segment calibration circuit.

[0035] In another aspect, the temperature compensation value calculation unit comprises:

[0036] A comparator circuit is configured to determine whether the temperature electrical signal corresponding to the actual temperature is higher or lower than the reference electrical signal corresponding to the standard temperature.

[0037] An operational circuit, a subtracter and an adder.

[0038] The adder is configured to calculate the difference between the temperature electrical signal and the reference electrical signal.

[0039] The adder is used for converting the difference into a negative compensation voltage signal when the actual temperature is higher than the standard temperature, and converting the difference into a positive compensation voltage signal when the actual temperature is lower than the standard temperature.

[0040] To solve the above technical problems, the application further provides a sensing transmitter, comprising a sensor, and further comprising the voltage signal processing circuit as described above connected with the sensor.

[0041] Beneficial effects: the application provides a voltage signal processing circuit, which considers that (1) the precision of the sensor output voltage signal can be improved by adopting the segmented calibration mode, and (2) the analog circuit has strong anti-interference ability, so in the application, the segmented identification circuit can deliver the voltage signal to the segmented calibration circuit corresponding to the voltage value interval to which the voltage signal belongs, so that the segmented calibration circuit can multiply the received voltage signal by a preset slope and add a preset intercept, and then output after being processed by the signal conditioning circuit, thereby realizing the segmented calibration of the voltage signal, and each part of the circuit is an analog circuit, which has strong anti-interference ability, so that the voltage signal can maintain high signal precision in a strong interference environment, and the application scenarios of the sensing transmitter are widened.

[0042] The application further provides a sensing transmitter, which has the same beneficial effects as the voltage signal processing circuit described above. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the application, the related art and the drawings needed in the embodiments will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0044] Figure 1 a structure diagram of a first voltage signal processing circuit provided by the application;

[0045] Figure 2 a structure diagram of a segmented identification circuit provided by the application;

[0046] Figure 3 a structure diagram of a segmented calibration circuit provided by the application;

[0047] Figure 4 a structure diagram of a second voltage signal processing circuit provided by the application;

[0048] Figure 5 a structure diagram of a temperature compensation circuit provided by the application. DETAILED DESCRIPTION

[0049] The core of the present application is to provide a kind of sensing transmitter and voltage signal processing circuit thereof, segmented identification circuit can be sent to the voltage signal corresponding to the voltage value interval to which the voltage signal belongs Segmented calibration circuit, so that segmented calibration circuit can multiply the received voltage signal by preset slope and add preset intercept, and output after being conditioned by signal conditioning circuit, so as to realize the segmented calibration of voltage signal, and each part of circuit is analog circuit, with strong anti-interference ability, so that voltage signal can maintain high signal accuracy in strong interference environment, widen the application scenario of sensing transmitter.

[0050] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0051] Please refer to Figure 1 , Figure 1 The first voltage signal processing circuit provided by the present application is shown in the structural diagram, which is applied to sensing transmitter, comprising:

[0052] Signal acquisition circuit 1 is used for acquiring the voltage signal output by the sensor;

[0053] Segmented identification circuit 2 is used for sending the voltage signal to the segmented calibration circuit 3 corresponding to the voltage value interval to which the voltage signal belongs;

[0054] A plurality of segmented calibration circuits 3 corresponding to preset voltage value intervals one by one are used for multiplying the received voltage signal by preset slope and adding preset intercept, so as to realize the calibration of voltage signal, wherein the preset parameters of each segmented calibration circuit 3 are different, and the preset parameters include preset slope and preset intercept;

[0055] Signal conditioning circuit 4 is used for conditioning the voltage signal output by segmented calibration circuit 3, so as to transmit signal;

[0056] Among them, signal acquisition circuit 1, segmented identification circuit 2, segmented calibration circuit 3 and signal conditioning circuit 4 are analog circuits.

[0057] Specifically, considering the technical problems in the above background art, and in combination with the consideration that (1) the segmented calibration method can improve the accuracy of the sensor output voltage signal, and (2) the analog circuit has strong anti-interference ability, the embodiments of the present application aim to design a pure analog circuit to segmentally calibrate the voltage signal collected from the sensor of the sensing transmitter, thereby improving the signal accuracy transmitted by the sensing transmitter. For example, in order to enable the sensing transmitter to work stably in a nuclear radiation environment and improve the signal processing accuracy, the embodiments of the present application can use a pure analog circuit to realize the functions of voltage signal collection, interval identification, segmented calibration and conditioning, so as to avoid the timing violation problems of digital circuits in a radiation environment, and at the same time solve the defects of the lack of segmented calibration function in the existing similar devices.

[0058] For example, the voltage signal processing circuit can be applied to a nuclear level pressure sensing transmitter (ST, Sensing Transmitter). The signal acquisition circuit 1 acquires the mV level voltage signal output by the pressure sensor and filters out noise through an RC filter network; the segmented identification circuit 2 divides the signal into four intervals of 0-0.5V, 0.5-2V, 2-3V and 3-4V; the segmented calibration circuit 3 corresponding to each interval respectively adopts preset slopes 1.2, 1.5, 1.3 and 1.4 and preset intercepts 0.2V, 0.3V, 0.4V and 0.5V for calibration; and the signal conditioning circuit 4 amplifies the calibrated signal to 1-5V through an operational amplifier (OPAMP, Operational Amplifier). The above circuits are all composed of analog elements, without digital circuit modules.

[0059] Specifically, for the signal acquisition circuit 1, if the voltage signal processing circuit is applied to a nuclear level pressure sensing transmitter, the signal acquisition module and the signal amplification module both adopt pure analog circuits and anti-radiation design.

[0060] Signal acquisition module:

[0061] The core element includes a radiation-hardened operational amplifier (RHOP) as a signal buffer, the in-phase input end of which is connected to the output end of the pressure sensor to receive a weak voltage signal (including noise) of 0-40 mV output by the sensor; an RC filter network (RCFN) is configured, which is composed of a 2 kΩ precision metal film resistor and a 220 nF polytetrafluoroethylene capacitor and is connected in parallel between the output end of the operational amplifier and the ground, with a cutoff frequency of about 358 Hz, for filtering out high-frequency noise (such as signals above 1 MHz generated by electromagnetic interference) and 50 Hz power frequency interference; the circuit layout adopts close-range wiring of "sensor-filter network-buffer", and the surface is covered with a ground copper foil shielding layer (GND Shield) to isolate external radiation and electromagnetic interference, and ceramic packaging (CERDIP) is selected for the elements, which can withstand a total dose radiation of ≥30 kGy.

[0062] Signal amplification module:

[0063] A radiation-hardened instrumentation amplifier (RHIA) is adopted, the input end of which is connected to the output end of the signal acquisition module (i.e., the 0-40 mV signal output by the buffer); by adjusting the external precision resistor (Rg=100 Ω), the amplification factor is set to 100 times (amplification factor formula: G=1+49.4 kΩ / Rg), and the 0-40 mV signal is linearly amplified to 0-4 V, meeting the requirements of the subsequent segmented recognition circuit 2 for signal amplitude; the power supply end of the amplifier is connected in series with a 10 μH magnetic bead and a 100 nF decoupling capacitor to suppress power supply noise coupling; the circuit layout adopts differential wiring to reduce common-mode interference and ensure that the non-linear error of the amplified signal is ≤0.05% FS.

[0064] Working process of signal acquisition circuit 1: the 0-40 mV noise-containing signal output by the sensor is first filtered of noise by the RC filter network of the signal acquisition module, and then buffered and output by the radiation-hardened operational amplifier, and then enters the radiation-hardened instrumentation amplifier of the signal amplification module, which outputs a 0-4 V stable signal after 100 times amplification, and delivers the signal to the segmented recognition circuit 2.

[0065] Specifically, for the signal conditioning circuit 4, it can be various types, for example, it can be a voltage-to-current conversion circuit (VIC), which can convert the voltage value output by the segmented calibration circuit 3 into a 4-20mA current value (current is an analog signal, and has stronger anti-interference ability), and has a good linear proportional relationship.

[0066] Specifically, in order to better illustrate the embodiments of the present application, please refer to Figure 1 , Figure 1 A structural diagram of a voltage signal processing circuit provided by the present application, except for the sensor, each part in the diagram can be arranged on a circuit board, the sensor is independently arranged, the power module can supply power to each part, and the power module can supply power to the sensor in the sensor transmitter through a voltage regulating module with an isolation function, so as to avoid mutual interference between signals.

[0067] The present application provides a voltage signal processing circuit, considering that (1) the segmented calibration method can improve the accuracy of the sensor output voltage signal, and (2) the analog circuit has strong anti-interference ability, therefore, in the present application, the segmented identification circuit can deliver the voltage signal to the segmented calibration circuit corresponding to the voltage value interval to which the voltage signal belongs, so that the segmented calibration circuit can multiply the received voltage signal by a preset slope and add a preset intercept, and output after being conditioned by the signal conditioning circuit, thereby realizing segmented calibration of the voltage signal, and each part of the circuit is an analog circuit, which has strong anti-interference ability, so that the voltage signal can maintain high signal accuracy in a strong interference environment, and the application scenarios of the sensor transmitter are widened.

[0068] On the basis of the above embodiments:

[0069] As an optional embodiment, the segmented identification circuit 2 comprises:

[0070] A voltage threshold comparison unit connected to the output end of the signal acquisition circuit 1, for comparing the voltage signal output by the signal acquisition circuit 1 with a plurality of preset threshold voltages, and outputting an original level signal reflecting the voltage value interval to which the voltage signal belongs;

[0071] A logic signal conversion unit connected to the output end of the voltage threshold comparison unit, for performing logic conversion on the original level signal to generate a gating control signal;

[0072] The input ends of the plurality of signal channels are connected with the output end of the signal acquisition circuit 1, the output ends of the plurality of signal channels are connected with the input ends of the segmented calibration circuit 3 one by one, and the channel gating unit connected with the output end of the logic signal conversion unit at the control end is used for opening the signal channel corresponding to the voltage value interval to which the voltage signal belongs under the control of the gating control signal.

[0073] Specifically, to realize automatic identification of the voltage value interval to which the voltage signal belongs, in the embodiment of the application, a pure analog circuit combination of voltage comparison, logic conversion and channel gating is used to replace the interval judgment mode relying on a digital circuit, so that reliable interval division in a nuclear radiation environment is ensured, and a basis is provided for subsequent segmented calibration. The segmented identification circuit 2 is arranged in the embodiment of the application.

[0074] Specifically, for example, in the segmented identification circuit 2, the voltage threshold comparison unit adopts four comparators to compare the 1.1V signal output by the signal acquisition circuit 1 with threshold values of 0.5V, 2V, 3V and 4V, and outputs a raw level signal of “1, 0, 0, 0”; the logic signal conversion unit is composed of three NAND gates to convert the raw level signal into a gating control signal of “1, 0, 0”; and the channel gating unit adopts a multiplexed analog switch (MAS) to open the corresponding channel under the action of the gating control signal, so that the 1.1V signal is transmitted to the segmented calibration circuit 3 corresponding to the 0.5-2V interval.

[0075] Of course, in addition to the specific form as above, the segmented identification circuit 2 can also be in other forms, which are not limited in the embodiment of the application.

[0076] As an optional embodiment, the voltage threshold comparison unit comprises:

[0077] The same-phase input end or the opposite-phase input end is connected with a preset threshold voltage, and the other input end is commonly connected with a plurality of comparators of the output end of the signal acquisition circuit 1, and is used for outputting a raw level signal;

[0078] A threshold voltage generation circuit is used for generating a plurality of preset threshold voltages;

[0079] The threshold voltage generation circuit comprises a voltage dividing circuit, the number of threshold voltages is the same as that of the comparators, and the threshold voltages are set according to the boundary values of the preset voltage value intervals.

[0080] Specifically, to accurately judge the interval to which the voltage signal belongs, in the embodiment of the application, the signal is compared with a preset threshold voltage by a comparator, the threshold voltage is set according to the interval boundary value, and a pure analog comparator is used to realize direct output of the signal level, so that the problem of radiation sensitivity caused by digital circuit processing is avoided.

[0081] Specifically, to provide a stable threshold voltage supply interval identification, multiple accurate thresholds can be generated by a voltage dividing circuit in the embodiment of the present application, a pure analog resistance voltage dividing method is adopted to ensure that the threshold voltage can be flexibly set according to the interval requirement, and stable output is ensured in a radiation environment.

[0082] For example, the threshold voltage generating circuit is a voltage dividing circuit, which is composed of a 10V DC power supply and 1kΩ, 3kΩ, 5kΩ, 7kΩ precision resistors in series; 0.5V, 2V, 3V, and 4V threshold voltages are generated by resistance voltage division and output to the inverting input terminals of the comparators.

[0083] Of course, in addition to the specific form as above, the voltage threshold comparison unit can also be in other forms, which are not limited in the embodiment of the present application.

[0084] As an optional embodiment, the logic signal conversion unit includes:

[0085] The input end is connected with the output end of the voltage threshold comparison unit, and a plurality of logic gate circuits are used to perform logic combination operation on the original level signal to generate a gate control signal meeting the control rule of the channel gating unit.

[0086] Specifically, considering that the original level signal output by the voltage threshold comparison unit needs to be converted into a signal meeting the control logic of the channel gating unit, the embodiment of the present application realizes pure analog domain signal conversion through the combination operation of the logic gate circuit, ensuring the accuracy of channel gating and stability in a radiation environment.

[0087] Specifically, in order to better illustrate the embodiment of the present application, please refer to Figure 2 , Figure 2 A structure diagram of a segmented identification circuit 2 provided by the present application, the segmented identification circuit 2 in the figure is composed of a voltage threshold comparison unit, a logic signal conversion unit, a channel gating unit and supporting elements, and involves identification as follows:

[0088] (1) Circuit composition and identification analysis:

[0089] Core functional unit:

[0090] Voltage threshold comparison unit: operational amplifiers (comparators) U3A, U3B, U3C, U3D constitute (working in open loop comparison mode);

[0091] Logic signal conversion unit: logic gates U1A, U1B, U1C, U1D, U2D constitute;

[0092] Channel gating unit: multi-channel analog switch S1 constitutes.

[0093] Passive components and power supply: resistors: R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R16 (including threshold voltage, signal connection, pull-up / pull-down resistor);

[0094] Power supply: VSS 5V (low voltage power supply), VCC 5.5V (op-amp / logic gate power supply), ±5.5V VEE (multiplexing power supply).

[0095] (2) Signal flow and working mechanism:

[0096] Signal input:

[0097] The output signal of signal acquisition circuit 1 is connected through R16 and transmitted to the non-inverting input terminal (+) of U3A, U3B, U3C and U3D.

[0098] Threshold voltage generation:

[0099] VSS 5V is connected through a voltage divider network composed of R5, R1, R2, R3, R4, R10, R11 and R12 to provide different threshold voltages (such as interval boundary values) for the inverting input terminal (-) of U3A-U3D. Among them, through the independent voltage dividing resistors R11 and R12, a smaller and more precise voltage threshold can be generated to meet the precise voltage threshold requirement.

[0100] Threshold comparison operation:

[0101] U3A-U3D compares the "input signal (non-inverting terminal)" with the "threshold voltage (inverting terminal)" and outputs the original level signal (high / low level). R6-R9 is the pull-up resistor of the open-loop output of the op-amp to ensure the level compatibility of the subsequent logic gate.

[0102] Logic signal conversion:

[0103] The original level signal is input into the NOR gate logic network composed of U1A-U1D and U2D, and converted into the control signal (A0, A1, A2, EOS, etc. level) of S1.

[0104] Channel gating output:

[0105] After receiving the control signal, S1 selects the corresponding input channel (IN1-IN8) and outputs the signal to the subsequent segmented calibration circuit 3 through R13, completing the signal routing from "interval identification to channel gating".

[0106] (3) Key design features:

[0107] Radiation resistance adaptation: The operational amplifier (U3A-U3D) uses a radiation-resistant model that can withstand nuclear radiation environments and has an open-loop gain ≥100dB to ensure threshold comparison accuracy;

[0108] Analog domain implementation: the function is completed through pure analog circuit (op-amp comparison, logic gate operation, analog switch gating) throughout, avoiding the timing risk of digital circuit in the radiation environment;

[0109] The circuit realizes the functions of "voltage interval identification-logic conversion-channel gating" through hierarchical analog circuit design, provides a reliable signal path for subsequent segmented calibration, and meets the stable operation demand in the nuclear radiation environment.

[0110] Of course, in addition to the specific form as above, the logic signal conversion unit can also be other forms, which are not limited in the embodiments of the present application.

[0111] As an optional embodiment, the segmented calibration circuit 3 includes a slope adjustment sub-circuit and an intercept adjustment sub-circuit:

[0112] The slope adjustment sub-circuit connected with the segmented identification circuit 2 at the input end multiplies the received voltage signal by the corresponding preset slope by adjusting the resistance value ratio of the resistance network;

[0113] The intercept adjustment sub-circuit includes:

[0114] The reference voltage source is used to output a reference voltage, which can be adjusted by a resistor or a potentiometer to set a preset intercept;

[0115] The input end is connected with the reference voltage source and the output end of the slope adjustment sub-circuit respectively, and the output end is connected with the addition operation circuit of the signal conditioning circuit 4, which is used to superimpose the output signal of the slope adjustment sub-circuit and the reference voltage.

[0116] Specifically, considering that the actual voltage signal presents nonlinear characteristics in different intervals, accurate calibration can be achieved through segmented adjustment of slope and intercept, therefore, in the embodiments of the present application, a pure analog method of adjusting slope by resistance network and adjusting intercept by superimposing reference voltage is adopted, avoiding the unreliability of digital calibration in the radiation environment.

[0117] Of course, in addition to the specific form as above, the segmented calibration circuit 3 can also be other forms, which are not limited in the embodiments of the present application.

[0118] As an optional embodiment, the slope adjustment sub-circuit includes:

[0119] The operational amplifier connected with the segmented identification circuit 2 and the adjustable resistance network respectively is used to multiply the received voltage signal by the corresponding preset slope;

[0120] The adjustable resistance network including at least one potentiometer or precision adjustable resistor is used to adjust the preset slope by changing the resistance value ratio.

[0121] Specifically, to accurately adjust the preset slope of the segmented calibration, in the embodiment of the application, continuous adjustment of the resistance ratio in the analog domain can be realized by the combination of the operational amplifier and the adjustable resistance network, so that the slope parameters of different intervals can be flexibly set, and the calibration accuracy is improved.

[0122] Specifically, in order to better illustrate the embodiment of the application, please refer to Figure 3 , Figure 3 A structure diagram of a segmented calibration circuit 3 provided by the application is shown in the figure, the segmented calibration circuit 3 is composed of a slope adjustment sub-circuit, an intercept adjustment sub-circuit and supporting elements, and involves the following identification:

[0123] (1) Circuit composition and identification analysis:

[0124] Core functional unit:

[0125] The slope adjustment sub-circuit is composed of an operational amplifier U30;

[0126] The intercept adjustment sub-circuit is composed of a voltage follower U32 and a voltage dividing circuit (corresponding to a reference voltage source) and an operational amplifier U31 (corresponding to an addition operation circuit).

[0127] Passive elements and power supply:

[0128] Resistors: R83, R84, R85, R86, R87, R88, R89, R90, R91 (including feedback adjustment, voltage division, current limiting resistors);

[0129] Capacitors: C57, C58, C59, C60, C61 (power decoupling, signal filtering capacitors);

[0130] Power supply: 5V (operational amplifier power supply), VEF2.5 (2.5V reference voltage, used for intercept adjustment).

[0131] Signal interface:

[0132] Input: VIN (output voltage of the segmented identification circuit 2);

[0133] Output: pin 1 of U31 (output terminal of the segmented calibration circuit 3, delivered to the subsequent signal conditioning circuit 4).

[0134] (2) Signal flow and working mechanism:

[0135] Slope adjustment sub-circuit (U30 module):

[0136] Signal input: Vin is connected to the non-inverting terminal (pin 3) of U30;

[0137] Feedback network: the inverting terminal (pin 4) of U30 is connected to the adjustable feedback network composed of R84, R85 and R83:

[0138] R85 is a precision potentiometer, adjusting its resistance value can change the feedback coefficient, and then adjust the amplification of U30 (i.e. "preset slope", such as 1.2~1.5 slope adjustment by resistance matching);

[0139] R83, R84 are fixed resistors, which cooperate with R85 to build a closed-loop feedback to ensure linear amplification.

[0140] Power filter: C57 is connected in parallel with the 5V power supply terminal of U30, to filter out power supply noise and improve slope adjustment stability.

[0141] Reference voltage source:

[0142] Reference voltage: VEF2.5 provides a 2.5V stable reference, connected to the IN+ terminal (pin 3) of U32;

[0143] Voltage division adjustment: R90, R91 form an adjustable voltage division circuit (R91 is a potentiometer), which divides the 2.5V reference voltage and outputs an intercept compensation voltage (connected to the non-inverting terminal of U31, corresponding to "preset intercept", such as 0.2~0.5V intercept adjustment);

[0144] Filtering and voltage stabilizing: C60 is connected in parallel with the output terminal of the voltage division circuit to filter out voltage division noise; C59 is the power decoupling capacitor of U32 to ensure the accuracy of the reference buffer.

[0145] Addition operation circuit (U31 module):

[0146] Signal input:

[0147] The output of U30 (slope-adjusted signal) is connected to the non-inverting terminal (pin 3) of U31 through R88;

[0148] The intercept compensation voltage is connected to the non-inverting terminal (pin 3) of U31 through R86;

[0149] Operation feedback: R87, R89 form a feedback network to build an addition operation model (set the slope and intercept weight by resistance matching), realizing the linear superposition of "slope-adjusted signal + intercept compensation voltage";

[0150] Power filter: C58 is connected in parallel with the 5V power supply terminal of U31 to suppress the interference of power fluctuations on the output.

[0151] (3) Key design features

[0152] Pure analog calibration: the whole process is realized through operational amplifier, resistance network, and reference source to achieve "slope adjustment-intercept compensation-signal superposition", which is consistent with the design of "pure analog circuit" and avoids the radiation sensitivity of digital calibration;

[0153] Parameter adjustability: continuous parameter adjustment is realized through R85 (slope) and R91 (intercept) to adapt to the nonlinear compensation requirements of different intervals (such as 0-0.5V interval slope 1.2, intercept 0.2V, 2-3V interval slope 1.3, intercept 0.4V, etc.);

[0154] Anti-interference design: decoupling capacitors (C57, C58, C59) are configured at the power supply end, and filter capacitors (C60, C61) are used in the signal path to suppress noise coupling in the radiation environment and ensure calibration accuracy.

[0155] The circuit realizes precise calibration of "slope linear amplification + intercept voltage compensation" through hierarchical analog circuit design, and provides stable and adjustable segmented compensation capability for voltage signal processing in a nuclear radiation environment.

[0156] As an optional embodiment, the voltage signal processing circuit further comprises:

[0157] A temperature compensation circuit 5 is configured to generate a temperature compensation voltage signal according to the deviation of the actual temperature from the standard temperature, and couple the temperature compensation voltage signal to the output of each segmented calibration circuit 3.

[0158] Specifically, in order to better illustrate the embodiments of the present application, please refer to Figure 4 , Figure 4 The second voltage signal processing circuit provided by the present application is shown in the structure diagram, and the temperature compensation circuit 5 is introduced; considering that temperature change will cause the output signal of the sensor to drift, therefore, in the embodiments of the present application, a temperature compensation voltage can be generated by an analog circuit and coupled to the calibration signal (the output of each segmented calibration circuit 3) to eliminate temperature error and solve the problem of inadaptability of related equipment in a radiation environment relying on digital circuit to realize temperature compensation.

[0159] For example, when the actual temperature of the temperature compensation circuit 5 is 50℃ (standard temperature 25℃), a temperature compensation voltage signal of-0.15V is generated; the signal is coupled to the 1.65V signal output by the segmented calibration circuit 3, and finally a 1.5V compensated signal is output, eliminating the signal deviation caused by temperature rise.

[0160] As an optional embodiment, the temperature compensation circuit 5 comprises:

[0161] A temperature acquisition and processing unit is configured to acquire the actual temperature through a temperature sensor and convert it into a corresponding temperature electrical signal;

[0162] A temperature compensation value calculation unit connected to the temperature acquisition and processing unit is configured to compare the temperature electrical signal with a reference electrical signal corresponding to the standard temperature, and generate a compensation voltage signal reflecting the temperature deviation;

[0163] The signal coupling unit, which connects the temperature compensation numerical calculation unit and the output terminals of each segment calibration circuit 3, is used to couple the compensation voltage signal to the output signal of the segment calibration circuit 3.

[0164] Specifically, for a better explanation of the embodiments of the present invention, please refer to... Figure 5 , Figure 5 This is a schematic diagram of the structure of a temperature compensation circuit 5 provided by the present invention. In order to realize a complete temperature compensation process, the embodiments of the present invention can use a pure analog circuit chain of temperature acquisition and processing unit, compensation value calculation unit and signal coupling unit to avoid digital processing from temperature signal acquisition to compensation implementation, thereby ensuring the stability of temperature compensation under nuclear radiation environment.

[0165] Specifically, for example, the temperature acquisition and processing unit acquires the ambient temperature of 50℃ through a thermistor and converts it into a 0.8V temperature electrical signal; the temperature compensation numerical calculation unit compares this signal with the 0.5V reference electrical signal corresponding to 25℃ and generates a -0.15V compensation voltage; the signal coupling unit couples the -0.15V to the output signal of the segmented calibration circuit 3 through an operational amplifier adder circuit.

[0166] As an optional embodiment, the temperature compensation numerical calculation unit includes:

[0167] The comparator circuit is used to determine whether the temperature signal corresponding to the actual temperature is higher or lower than the reference signal corresponding to the standard temperature.

[0168] Operational circuits, including subtractors and adders;

[0169] An adder is used to calculate the difference between the temperature electrical signal and the reference electrical signal;

[0170] The adder is used to convert the difference into a negative compensation voltage signal when the actual temperature is higher than the standard temperature, and to convert the difference into a positive compensation voltage signal when the actual temperature is lower than the standard temperature.

[0171] Specifically, in order to accurately determine the direction of temperature deviation and calculate the corresponding compensation value, in this embodiment of the invention, a comparator circuit can be used to determine the temperature level, and by combining the operations of a subtractor and an adder, positive and negative compensation voltage signals in the analog domain can be generated to ensure that the compensation value matches the temperature deviation.

[0172] The comparator circuit of the temperature compensation value calculation unit compares 0.8V corresponding to 50 DEG C with 0.5V corresponding to 25 DEG C, and outputs a high level to indicate that the actual temperature is higher than the standard temperature; in the operation circuit, the subtracter calculates 0.8V-0.5V=0.3V deviation, and the adder converts 0.3V into -0.15V negative compensation voltage; if the actual temperature is 10 DEG C (corresponding to 0.3V), the adder converts 0.5V-0.3V=0.2V into +0.1V positive compensation voltage.

[0173] In addition, as an optional embodiment, the channel gating unit comprises a multiplexing analog switch.

[0174] The input ends of the plurality of signal channels of the multiplexing analog switch are connected to the output ends of the signal acquisition circuit 1 respectively, and the output ends of the plurality of signal channels are connected to the input ends of the corresponding segmented calibration circuits 3 respectively.

[0175] The multiplexing analog switch is used for gating the corresponding signal channel according to the gating control signal received from the control end.

[0176] Specifically, in order to switch the signal channel according to the interval identification result, the multiplexing analog switch can be used as the channel gating unit in the embodiment of the present application, and the channel switching is realized through the analog control signal, so that the accurate selection of the signal path in the pure analog circuit is ensured, and the demand of the radiation environment is adapted.

[0177] Specifically, for example, the channel gating unit adopts the multiplexing analog switch, the input ends of the eight signal channels of the multiplexing analog switch are connected to the 1.1V signal output by the signal acquisition circuit 1, and the output ends are connected to the four segmented calibration circuits 3 respectively; the control end A0, A1 and A2 are connected to the "1, 0, 0" level output by the logic signal conversion unit, the second channel is gated, and the 1.1V signal is transmitted to the segmented calibration circuit 3 corresponding to the 0.5-2V interval.

[0178] The present application also provides a sensing transmitter, which comprises a sensor and a voltage signal processing circuit as in the foregoing embodiments connected to the sensor.

[0179] For the sensing transmitter provided by the embodiment of the present application, please refer to the foregoing embodiments of the voltage signal processing circuit, and the embodiment of the present application will not be described here.

[0180] Embodiments of the present application are described herein with reference to the drawings, wherein: The embodiments are described in progressively greater detail throughout the present specification. Each embodiment is directed to the differences between itself and other embodiments. Each embodiment shares the features of the other embodiments as described throughout the present specification. It is also to be noted that, as used in the specification, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise. As used herein, the expression "and / or" includes combinations of one or more of the associated items, and can be interpreted in the same way as "one or more of the items" or "at least one of the items" unless the context clearly dictates otherwise. The terms "comprises", "comprising", "includes", "including" or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises... a", "has... a", "includes... a", "contains... a", or "followed by... a" does not, without more constraints, foreclose the existence of additional identical elements.

[0181] The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A voltage signal processing circuit, characterized in that, Applications in sensor transmitters include: The signal acquisition circuit is used to acquire the voltage signal output by the sensor. The segmented identification circuit is used to transmit the voltage signal to the segmented calibration circuit corresponding to the voltage value range to which the voltage signal belongs; Multiple segmented calibration circuits, each corresponding to a preset voltage value range, are used to multiply the received voltage signal by a preset slope and add a preset intercept to calibrate the voltage signal. The preset parameters of each segmented calibration circuit are different, including a preset slope and a preset intercept. The signal conditioning circuit is used to condition the voltage signal output by the segmented calibration circuit in order to enable signal transmission. Among them, the signal acquisition circuit, segment recognition circuit, segment calibration circuit and signal conditioning circuit are all analog circuits; The segmentation identification circuit includes: The voltage threshold comparison unit, whose input terminal is connected to the output terminal of the signal acquisition circuit, is used to compare the voltage signal output by the signal acquisition circuit with multiple preset threshold voltages and output the original level signal reflecting the voltage value range to which the voltage signal belongs. The logic signal conversion unit, whose input terminal is connected to the output terminal of the voltage threshold comparison unit, is used to perform logic conversion on the original level signal to generate a gating control signal. The input terminals of multiple signal channels are all connected to the output terminals of the signal acquisition circuit, and the output terminals of multiple signal channels are connected one-to-one to the input terminals of the segmented calibration circuit. The channel selection unit, whose control terminal is connected to the output terminal of the logic signal conversion unit, is used to open the signal channel corresponding to the voltage value range to which the voltage signal belongs under the control of the selection control signal.

2. The voltage signal processing circuit according to claim 1, characterized in that, The voltage threshold comparison unit includes: The non-inverting or inverting input terminal is connected to a preset threshold voltage, and the other input terminal is connected to multiple comparators at the output terminal of the signal acquisition circuit to output the original level signal; Threshold voltage generation circuit, used to generate multiple preset threshold voltages; The threshold voltage generation circuit includes a voltage divider circuit, the number of threshold voltages is the same as the number of comparators, and the threshold voltage is set according to the boundary value of a preset voltage value range.

3. The voltage signal processing circuit according to claim 1, characterized in that, The logic signal conversion unit includes: The input terminal is connected to the output terminal of the voltage threshold comparison unit, which is used to perform logical combination operations on the original level signal to generate a gating control signal that conforms to the control rules of the channel gating unit.

4. The voltage signal processing circuit according to claim 1, characterized in that, The segmented calibration circuit includes a slope adjustment sub-circuit and an intercept adjustment sub-circuit: The slope adjustment sub-circuit connected to the input terminal of the segment recognition circuit multiplies the received voltage signal by the corresponding preset slope by adjusting the resistance ratio of the resistor network. The intercept adjustment sub-circuit includes: A reference voltage source is used to output a reference voltage, which can be adjusted by a resistor or potentiometer to set the preset intercept. The input terminal is connected to the reference voltage source and the output terminal of the slope adjustment sub-circuit, respectively. The output terminal is connected to the signal conditioning circuit via an adder circuit, which is used to superimpose the output signal of the slope adjustment sub-circuit with the reference voltage.

5. The voltage signal processing circuit according to claim 4, characterized in that, The slope adjustment sub-circuit includes: An operational amplifier connected to the segmented identification circuit and the adjustable resistor network is used to multiply the received voltage signal by a corresponding preset slope. An adjustable resistor network, including at least one potentiometer or precision adjustable resistor, is used to adjust the preset slope by changing the resistance ratio.

6. The voltage signal processing circuit according to any one of claims 1 to 5, characterized in that, The voltage signal processing circuit further includes: The temperature compensation circuit is used to generate a temperature compensation voltage signal based on the deviation of the actual temperature from the standard temperature, and couples the temperature compensation voltage signal to the output of each segment calibration circuit.

7. The voltage signal processing circuit according to claim 6, characterized in that, The temperature compensation circuit includes: The temperature acquisition and processing unit is used to acquire the actual temperature through a temperature sensor and convert it into a corresponding temperature electrical signal. The temperature compensation numerical calculation unit connected to the temperature acquisition and processing unit is used to compare the temperature electrical signal with the reference electrical signal corresponding to the standard temperature and generate a compensation voltage signal that reflects the temperature deviation. A signal coupling unit connecting the temperature compensation numerical calculation unit and the output terminals of each segment calibration circuit is used to couple the compensation voltage signal to the output signal of the segment calibration circuit.

8. The voltage signal processing circuit according to claim 7, characterized in that, The temperature compensation numerical calculation unit includes: The comparator circuit is used to determine whether the temperature signal corresponding to the actual temperature is higher or lower than the reference signal corresponding to the standard temperature. Operational circuits, including subtractors and adders; The subtractor is used to calculate the difference between the temperature electrical signal and the reference electrical signal; The adder is used to convert the difference into a negative compensation voltage signal when the actual temperature is higher than the standard temperature, and to convert the difference into a positive compensation voltage signal when the actual temperature is lower than the standard temperature.

9. A sensor transmitter, characterized in that, It includes a sensor, and also includes a voltage signal processing circuit as described in any one of claims 1 to 8 connected to the sensor.

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