Anti-interference aerostat differential pressure sensor acquisition conditioning circuit

Abstract

The invention provides an anti-interference aerostat differential pressure sensor acquisition conditioning circuit, which relates to the technical field of aerostats and comprises a lightning protection unit, a filtering unit, an I / V conversion unit, an RF protection unit and a clamping unit. The input end of the lightning protection unit is connected with the output end of the differential pressure sensor; the filtering unit is connected in parallel with the lightning protection unit; the input end of the filtering unit is connected with the output end of the differential pressure sensor; the I / V conversion unit is connected to the output end of the filtering unit and is used for converting a current signal output by the differential pressure sensor into a voltage signal; the RF protection unit is connected with the output end of the I / V conversion unit; and the clamping unit is connected with the output end of the RF protection unit and used for carrying out amplitude clamping on the converted voltage signals and providing voltage signals meeting operational amplification requirements for subsequent circuits, and the output end of the clamping unit is connected with the AD acquisition circuit. According to the invention, high-reliability acquisition of signals of the differential pressure sensor is realized, and the safety of an aerostat pressure regulating system is improved.

Description

Technical Field

[0001] The invention relates to the technical field of airborne computer interfaces for aerostats, and in particular to an anti-interference aerostat differential pressure sensor acquisition and conditioning circuit. Background Art

[0002] Aerostats are a large class of floating aircraft that rely on light gas filled into the airbag to generate buoyancy. Common floating aircraft include airships, tethered balloons, etc. Usually, the light gas inside is helium. In order to maintain the rigidity and aerodynamic shape of the sphere, the differential pressure of the airbag must be within the expected range. Therefore, the collection of the differential pressure of the airbag is the key data for the flight safety of the aerostat. The aerostat has a long time in the air, is likely to be struck by lightning, and has no metal skin, and has a harsh electromagnetic environment. The traditional differential pressure sensor acquisition circuit lacks a self-checking function. When the circuit fails, it may report erroneous data and cannot be recognized by the system. At the same time, it has no corresponding suppression function for interference caused by lightning induction and radio frequency. Summary of the invention

[0003] In view of this, an embodiment of the present application provides an anti-interference aerostat differential pressure sensor acquisition and conditioning circuit, which is used to protect, condition, and filter the pressure signal of the differential pressure sensor on the aerostat, and designs an interface self-detection circuit, thereby achieving high-reliability acquisition of the differential pressure sensor signal and improving the safety of the aerostat pressure regulation system.

[0004] The embodiment of the present application provides the following technical solutions: an anti-interference aerostat differential pressure sensor acquisition and conditioning circuit, including a lightning protection unit, a filter unit, an I / V conversion unit, an RF protection unit and a clamping unit;

[0005] Among them, the input end of the lightning protection unit is connected to the output end of the differential pressure sensor, which is used to protect the output signal of the differential pressure sensor from lightning interference; the filtering unit is connected in parallel with the lightning protection unit, and the input end of the filtering unit is connected to the output end of the differential pressure sensor, which is used to filter out noise and interference signals in the output signal of the differential pressure sensor; the I / V conversion unit is connected to the output end of the filtering unit, which is used to convert the current signal output by the differential pressure sensor into a voltage signal; the RF protection unit is connected to the output end of the I / V conversion unit, which is used to perform radio frequency protection on the voltage signal; the clamping unit is connected to the output end of the RF protection unit, which is used to clamp the amplitude of the converted voltage signal, and provide a voltage signal that meets the requirements of the operational amplifier for the subsequent circuit, and the output end of the clamping unit is connected to the AD acquisition circuit.

[0006] According to an embodiment of the present application, the circuit further includes a self-test unit, which is connected to the output end of the filter unit through a switch and is used to simulate a sensor current signal according to a control command to provide a reference excitation source for subsequent circuits.

[0007] According to an embodiment of the present application, the circuit further includes a processor, which is connected to the AD acquisition circuit and is used to compare the acquired voltage signal with the reference excitation source to verify the amplitude of the voltage signal.

[0008] According to an embodiment of the present application, the lightning protection unit includes a TVS tube V1 and a TVS tube V2, one end of the TVS tube V1 and one end of the TVS tube V2 are respectively connected in parallel to the output end of the differential pressure sensor, and the other end of the TVS tube V1 and the other end of the TVS tube V2 are both connected to the casing shielding ground.

[0009] According to an embodiment of the present application, the filtering unit includes a filter capacitor C1, a filter capacitor C2 and an inductor L1 connected to the output side of the TVS tube V1, the inductor L1 is connected in series in the circuit, one end of the filter capacitor C1 and one end of the filter capacitor C2 are respectively connected in parallel with the two ends of the inductor L1, and the other end of the filter capacitor C1 and the other end of the filter capacitor C2 are respectively connected to AGND; the filtering unit also includes a filter capacitor C3, a filter capacitor C4 and an inductor L2 connected to the output side of the TVS tube V2, the inductor L2 is connected in series in the circuit, one end of the filter capacitor C3 and one end of the filter capacitor C4 are respectively connected in parallel with the two ends of the inductor L2, and the other end of the filter capacitor C3 and the other end of the filter capacitor C4 are respectively connected to AGND.

[0010] According to an embodiment of the present application, the I / V conversion unit includes a resistor R2; the self-test unit includes a single-pole double-throw switch K1, a single-pole double-throw switch K2, a resistor R1, a resistor R3 and a current source circuit, the single-pole double-throw switch K1 is respectively connected to the rear end of the inductor L1, pin 1 of the resistor R1 and pin 1 of the resistor R2; the single-pole double-throw switch K2 is respectively connected to the rear end of the inductor L2, pin 2 of the resistor R2 and pin 1 of the resistor R3; pin 2 of the resistor R1 is connected to the current source circuit, and pin 2 of the resistor R3 is connected to AGND.

[0011] According to an embodiment of the present application, the RF protection unit includes an x2y capacitor C5, pin 1 of the x2y capacitor C5 is connected to pin 1 of the resistor R2, pin 2 of the x2y capacitor C5 is connected to pin 2 of the resistor R2, and pins 3 and 4 of the x2y capacitor C5 are respectively connected to the system AGND.

[0012] According to an embodiment of the present application, the clamping unit includes a diode V3, a diode V4, a diode V5 and a diode V6, the negative end of the diode V3 and the positive end of the diode V4 are connected to pin 2 of the x2y capacitor C5, the positive end of the diode V3 is connected to +10V, and the negative end of the diode V4 is connected to -10V; the negative end of the diode V5 and the positive end of the diode V6 are connected to pin 1 of the x2y capacitor C5, the positive end of the diode V5 is connected to +10V, and the negative end of the diode V6 is connected to -10V.

[0013] According to one embodiment of the present application, the circuit also includes an operational amplifier D2, the negative end of the diode V3 and the positive end of the diode V4 are connected to the A+ phase of the operational amplifier D2, the negative end of the diode V5 and the positive end of the diode V6 are connected to the A- phase of the operational amplifier D2, and the output end of the operational amplifier D2 is connected to the AD acquisition circuit.

[0014] Compared with the prior art, the beneficial effects that can be achieved by at least one of the above-mentioned technical solutions adopted in the embodiments of this specification include at least the following: the embodiments of the present invention improve the reliability and testability of the acquisition circuit by designing a lightning protection unit, a filtering unit, and a self-test unit, etc., and can safely and reliably protect and condition the output signal of the differential pressure sensor, thereby greatly improving the accuracy and safety of the airship pressure system. The circuit also has a strong anti-electromagnetic interference capability, can effectively eliminate environmental interference, provide accurate and reliable differential pressure data, and improve the safety and reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 This is a schematic diagram of the overall structure of the anti-interference aerostat differential pressure sensor data acquisition and conditioning circuit according to an embodiment of the present invention;

[0017] Figure 2 The figure is a connection diagram of the data collection and conditioning circuit of the anti-interference aerostat differential pressure sensor according to an embodiment of the present invention. DETAILED DESCRIPTION

[0018] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0019] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0020] like Figure 1 As shown, an embodiment of the present invention provides an anti-interference aerostat differential pressure sensor acquisition and conditioning circuit, including a lightning protection unit, a filtering unit, an I / V conversion unit, an RF protection unit and a clamping unit; wherein the input end of the lightning protection unit is connected to the output end of the differential pressure sensor, for performing lightning interference protection on the output signal of the differential pressure sensor; the filtering unit is connected in parallel with the lightning protection unit, and the input end of the filtering unit is connected to the output end of the differential pressure sensor, for filtering out noise and interference signals in the output signal of the differential pressure sensor; the I / V conversion unit is connected to the output end of the filtering unit, for converting the current signal output by the differential pressure sensor into a voltage signal; the RF protection unit is connected to the output end of the I / V conversion unit, for performing radio frequency protection on the voltage signal; the clamping unit is connected to the output end of the RF protection unit, for performing amplitude clamping on the converted voltage signal, and providing a voltage signal that meets the requirements of the operational amplifier for the subsequent circuit, and the output end of the clamping unit is connected to the AD acquisition circuit.

[0021] Among them, the lightning protection unit performs lightning interference protection on the output signal of the differential pressure sensor, suppresses direct or indirect interference caused by external lightning, and prevents damage to subsequent circuits; the RF protection unit performs radio frequency protection on the voltage signal, improves signal quality, and reduces radio frequency interference.

[0022] In an embodiment of the present invention, the circuit also includes a self-test unit, which is connected to the output end of the filtering unit through a switch, and is used to simulate the sensor current signal according to the control command, provide a reference excitation source for the subsequent circuit, and verify the integrity and accuracy of the acquisition function of the subsequent circuit through the reference excitation source.

[0023] In an embodiment of the present invention, the circuit further includes a processor, which is connected to the AD acquisition circuit and is used to compare the acquired voltage signal with the reference excitation source to verify the amplitude of the voltage signal.

[0024] In a specific implementation of the embodiment of the present invention, the lightning protection unit includes a TVS tube V1 and a TVS tube V2, one end of the TVS tube V1 and one end of the TVS tube V2 are respectively connected in parallel to the output end of the differential pressure sensor, and the other end of the TVS tube V1 and the other end of the TVS tube V2 are both connected to the casing shielding ground.

[0025] The filtering unit includes a filter capacitor C1, a filter capacitor C2 and an inductor L1 connected to the output side of the TVS tube V1, the inductor L1 is connected in series in the circuit, one end of the filter capacitor C1 and one end of the filter capacitor C2 are respectively connected in parallel with the two ends of the inductor L1, and the other end of the filter capacitor C1 and the other end of the filter capacitor C2 are respectively connected to AGND; the filtering unit also includes a filter capacitor C3, a filter capacitor C4 and an inductor L2 connected to the output side of the TVS tube V2, the inductor L2 is connected in series in the circuit, one end of the filter capacitor C3 and one end of the filter capacitor C4 are respectively connected in parallel with the two ends of the inductor L2, and the other end of the filter capacitor C3 and the other end of the filter capacitor C4 are respectively connected to AGND.

[0026] The I / V conversion unit includes a resistor R2; the self-test unit includes a single-pole double-throw switch K1, a single-pole double-throw switch K2, resistors R1 and R3 and a current source circuit, the single-pole double-throw switch K1 is respectively connected to the rear end of the inductor L1, pin 1 of the resistor R1 and pin 1 of the resistor R2; the single-pole double-throw switch K2 is respectively connected to the rear end of the inductor L2, pin 2 of the resistor R2 and pin 1 of the resistor R3; pin 2 of the resistor R1 is connected to the current source circuit, and pin 2 of the resistor R3 is connected to AGND.

[0027] The RF protection unit includes an x2y capacitor C5, wherein pin 1 of the x2y capacitor C5 is connected to pin 1 of the resistor R2, pin 2 of the x2y capacitor C5 is connected to pin 2 of the resistor R2, and pins 3 and 4 of the x2y capacitor C5 are respectively connected to the system AGND.

[0028] The clamping unit includes a diode V3, a diode V4, a diode V5 and a diode V6. The negative end of the diode V3 and the positive end of the diode V4 are connected to pin 2 of the x2y capacitor C5, the positive end of the diode V3 is connected to +10V, and the negative end of the diode V4 is connected to -10V; the negative end of the diode V5 and the positive end of the diode V6 are connected to pin 1 of the x2y capacitor C5, the positive end of the diode V5 is connected to +10V, and the negative end of the diode V6 is connected to -10V.

[0029] In an embodiment of the present invention, the circuit further includes an operational amplifier D2, the negative end of the diode V3 and the positive end of the diode V4 are connected to the A+ phase of the operational amplifier D2, the negative end of the diode V5 and the positive end of the diode V6 are connected to the A- phase of the operational amplifier D2, and the output end of the operational amplifier D2 is connected to the AD acquisition circuit.

[0030] The embodiment of the present invention realizes the real-time collection of the pressure of each air chamber of the airbag of the aerostat. The circuit interface can effectively suppress the induced lightning caused by lightning and the radio frequency interference in a complex electromagnetic environment. At the same time, a self-test circuit is designed to effectively detect the working state of the collection circuit. The circuit effectively improves the reliability and safety of the aerostat pressure regulation system.

[0031] like Figure 2 As shown, the anti-interference aerostat differential pressure sensor acquisition and conditioning circuit of the embodiment of the present invention includes a lightning protection unit, a filtering unit, a self-test unit, an I / V conversion unit, an RF protection unit, and a clamping unit.

[0032] Lightning protection unit: including TVS tube V1 and TVS tube V2. TVS tube V1 and TVS tube V2 are connected in parallel with inductor L1 and inductor L2 respectively. The other end of the TVS tube is connected to the housing shielding ground. According to the five-level induction lightning protection requirements of D0-160G test conditions, the TVS tube selects 5.0SMDJ (5000W) series surface-mount TVS.

[0033] Filter unit: one end of capacitor C1 and capacitor C2 are connected to the two ends of inductor L1 respectively, and the other end is connected to AGND; one end of capacitor C3 and capacitor C4 are connected to the two ends of inductor L2 respectively, and the other end is connected to AGND; the parameters of the filter unit are selected as follows: the capacitor is (G)CT41L-2220-2C1-100V-105K (1uF), the inductor is XECJMLC1250-R47M (0.47uH), and the cut-off frequency is 232KHz.

[0034] Self-test unit: The self-test unit consists of a single-pole double-throw switch K1, a single-pole double-throw switch K2 and a current source circuit, wherein the voltage regulator chip D1 of the current source circuit is AD586, and the resistor R1 is a 500 ohm resistor, then the output test current source is 10mA.

[0035] I / V conversion unit: I / V conversion is completed by resistor R2, and the resistance of resistor R2 is a 250 ohm high-precision resistor.

[0036] RF protection unit: For the radio frequency protection unit, capacitor C5 is implemented as a low inductance, high self-resonant frequency x2y capacitor (capacitance is 10nF).

[0037] Clamping unit: Diodes V3 and V4 are connected to the A+ input terminal of operational amplifier D2, and diodes V5 and V6 are connected to the A- input terminal of operational amplifier D2. The forward clamping voltage is +10V, and the negative clamping voltage is -10V. The clamping diode is 1N4148.

[0038] The specific connection relationship is as follows:

[0039] TVS tube V1 and TVS tube V2 are connected in parallel with inductor L1 and inductor L2 respectively, and the other end of the TVS tube is connected to the housing shielding ground; one end of capacitor C1 and capacitor C2 are connected to the two ends of inductor L1 respectively, and the other end is connected to AGND; one end of capacitor C3 and capacitor C4 are connected to the two ends of L2 respectively, and the other end is connected to AGND; single-pole double-throw switch K1 is connected to the rear end of inductor L1, pin 1 of resistor R1 and pin 1 of resistor R2 respectively; the single-pole double-throw switch K2 is connected to the rear end of inductor L2, pin 2 of resistor R2 and pin 1 of resistor R3 respectively; x2y capacitor C Pin 1 and Pin 2 of 5 are connected to Pin 1 and Pin 2 of resistor R2 respectively, and Pin 3 and Pin 4 of x2y capacitor C5 are connected to system AGND respectively; the negative end of diode V3 and the positive end of diode V4 are connected to Pin 2 of x2y capacitor C5, and are connected to A+ of operational amplifier D2, the positive end of diode V3 is connected to +10V, and the negative end of V4 is connected to -10V; the negative end of diode V5 and the positive end of diode V6 are connected to Pin 1 of x2y capacitor C5, and are connected to A- of operational amplifier D2, the positive end of diode V5 is connected to +10V, and the negative end of V6 is connected to -10V.

[0040] The specific circuit principle is as follows: First, a TVS tube is used to protect the output signal of the aerostat differential pressure sensor from lightning and discharge the lightning interference energy; a filter unit composed of capacitors and inductors is used to purify the sensor output signal and remove the interference on the line; a self-detection circuit is set before the signal enters the acquisition unit. Before the circuit works normally, the K1 / K2 relay is connected to the 2nd and 3rd feet (self-detection state), and the acquisition circuit collects the excitation value output by the excitation source. After the processor judges, if the collection result is consistent with the preset value, it is determined that the circuit can work normally at this time, and the processor sends a control command to switch the K1 / K2 switch to 1 , 2 pins are connected (working state), at this time the self-test unit switches into the normal acquisition state, at this time the output signal will pass through the I / V conversion unit, the current signal output by the sensor is converted into a voltage signal that can be recognized by the subsequent A / D acquisition circuit, the voltage signal is protected by the RF protection unit, RF interference is removed, and the signal quality is improved, the purified voltage signal passes through the clamping power supply, and the input signal is clamped to the normal range that can be collected by the A / D, at this time the high-quality signal processed by the circuit of the present invention can enter the A / D acquisition circuit for signal acquisition, providing a stable and accurate differential pressure signal for the entire airship.

[0041] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. An anti-interference aerostat differential pressure sensor acquisition and conditioning circuit, characterized in that: It includes lightning protection unit, filtering unit, I / V conversion unit, RF protection unit and clamping unit; Among them, the input end of the lightning protection unit is connected to the output end of the differential pressure sensor, which is used to protect the output signal of the differential pressure sensor from lightning interference; the filtering unit is connected in parallel with the lightning protection unit, and the input end of the filtering unit is connected to the output end of the differential pressure sensor, which is used to filter out noise and interference signals in the output signal of the differential pressure sensor; the I / V conversion unit is connected to the output end of the filtering unit, which is used to convert the current signal output by the differential pressure sensor into a voltage signal; the RF protection unit is connected to the output end of the I / V conversion unit, which is used to perform radio frequency protection on the voltage signal; the clamping unit is connected to the output end of the RF protection unit, which is used to clamp the amplitude of the converted voltage signal, and provide a voltage signal that meets the requirements of the operational amplifier for the subsequent circuit, and the output end of the clamping unit is connected to the AD acquisition circuit.

2. The anti-interference aerostat differential pressure sensor acquisition and conditioning circuit according to claim 1 is characterized in that: The circuit further comprises a self-checking unit, which is connected to the output end of the filtering unit through a switch and is used to simulate a sensor current signal according to a control command to provide a reference excitation source for subsequent circuits.

3. The anti-interference aerostat differential pressure sensor acquisition and conditioning circuit according to claim 2 is characterized in that: The circuit also includes a processor, which is connected to the AD acquisition circuit and is used to compare the acquired voltage signal with the reference excitation source to verify the amplitude of the voltage signal.

4. The anti-interference aerostat differential pressure sensor acquisition and conditioning circuit according to claim 2 is characterized in that: The lightning protection unit includes a TVS tube V1 and a TVS tube V2. One end of the TVS tube V1 and one end of the TVS tube V2 are respectively connected in parallel to the output end of the differential pressure sensor, and the other end of the TVS tube V1 and the other end of the TVS tube V2 are both connected to the housing shielding ground.

5. The anti-interference aerostat differential pressure sensor acquisition and conditioning circuit according to claim 4 is characterized in that: The filtering unit includes a filter capacitor C1, a filter capacitor C2 and an inductor L1 connected to the output side of the TVS tube V1, the inductor L1 is connected in series in the circuit, one end of the filter capacitor C1 and one end of the filter capacitor C2 are respectively connected in parallel with the two ends of the inductor L1, and the other end of the filter capacitor C1 and the other end of the filter capacitor C2 are respectively connected to AGND; the filtering unit also includes a filter capacitor C3, a filter capacitor C4 and an inductor L2 connected to the output side of the TVS tube V2, the inductor L2 is connected in series in the circuit, one end of the filter capacitor C3 and one end of the filter capacitor C4 are respectively connected in parallel with the two ends of the inductor L2, and the other end of the filter capacitor C3 and the other end of the filter capacitor C4 are respectively connected to AGND.

6. The anti-interference aerostat differential pressure sensor acquisition and conditioning circuit according to claim 5 is characterized in that: The I / V conversion unit includes a resistor R2; the self-test unit includes a single-pole double-throw switch K1, a single-pole double-throw switch K2, resistors R1 and R3 and a current source circuit, the single-pole double-throw switch K1 is respectively connected to the rear end of the inductor L1, pin 1 of the resistor R1 and pin 1 of the resistor R2; the single-pole double-throw switch K2 is respectively connected to the rear end of the inductor L2, pin 2 of the resistor R2 and pin 1 of the resistor R3; pin 2 of the resistor R1 is connected to the current source circuit, and pin 2 of the resistor R3 is connected to AGND.

7. The anti-interference aerostat differential pressure sensor acquisition and conditioning circuit according to claim 6 is characterized in that: The RF protection unit includes an x2y capacitor C5, wherein pin 1 of the x2y capacitor C5 is connected to pin 1 of the resistor R2, pin 2 of the x2y capacitor C5 is connected to pin 2 of the resistor R2, and pins 3 and 4 of the x2y capacitor C5 are respectively connected to the system AGND.

8. The anti-interference aerostat differential pressure sensor acquisition and conditioning circuit according to claim 7 is characterized in that: The clamping unit includes a diode V3, a diode V4, a diode V5 and a diode V6. The negative end of the diode V3 and the positive end of the diode V4 are connected to pin 2 of the x2y capacitor C5, the positive end of the diode V3 is connected to +10V, and the negative end of the diode V4 is connected to -10V; the negative end of the diode V5 and the positive end of the diode V6 are connected to pin 1 of the x2y capacitor C5, the positive end of the diode V5 is connected to +10V, and the negative end of the diode V6 is connected to -10V.

9. The anti-interference aerostat differential pressure sensor acquisition and conditioning circuit according to claim 8, characterized in that: The circuit also includes an operational amplifier D2, the negative end of the diode V3 and the positive end of the diode V4 are connected to the A+ phase of the operational amplifier D2, the negative end of the diode V5 and the positive end of the diode V6 are connected to the A- phase of the operational amplifier D2, and the output end of the operational amplifier D2 is connected to the AD acquisition circuit.

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