Method and system for measuring resistance value of initiating explosive device of carrier rocket

Abstract

The invention discloses a method and a system for measuring the resistance value of an initiating explosive device of a carrier rocket, and the system for measuring the resistance value of the initiating explosive device of the carrier rocket comprises a central controller, a constant current source detection device, a safety protection device, a measurement control signal output device and a resistance detection result output device. The method has the technical effects of high measurement accuracy and high measurement safety.

Description

Technical Field

[0001] This application relates to the field of aerospace technology, and particularly to a method and system for measuring the resistance value of pyrotechnics for launch vehicles. Background Art

[0002] Pyrotechnics are an important type of component in launch vehicles. Whether they can be detonated accurately and reliably is directly related to the success or failure of the flight test mission of launch vehicles. Therefore, the testing of pyrotechnics is a necessary working step before rocket launch. In the rocket testing process, an important indicator for evaluating the state of pyrotechnics is the resistance value of the pyrotechnic circuit. The resistance value of pyrotechnics is generally small (the standard value is 0.9Ω - 1.2Ω), and the accurate measurement of the resistance value of pyrotechnics is a technical difficulty in the testing work. At the same time, since pyrotechnics contain gunpowder inside and belong to dangerous goods, when their working current exceeds their safety current, there may be a risk of detonation. Therefore, the safety requirements for the resistance value testing link of pyrotechnics are relatively high.

[0003] Currently, the method for measuring the resistance value of launch vehicle pyrotechnics is: constant current source excitation and resistance value detection, that is: applying a constant current below the safety current value to the pyrotechnics, detecting the voltage across the pyrotechnics, and calculating the resistance value of the pyrotechnics according to Ohm's law. This scheme mainly has three components, namely a constant current source excitation circuit, a resistance value detection circuit, and a safety current protection circuit. The constant current source excitation circuit is composed of a voltage stabilizing and constant voltage source and discrete NPN transistor elements; the resistance value detection circuit is composed of a typical differential current detection circuit; most of the safety current protection circuits adopt the method of self - protection of the voltage stabilizing and constant voltage source and current detection control shutdown. However, this scheme has the following deficiencies:

[0004] (1) The current output accuracy of the constant current source excitation circuit composed of a constant voltage source and discrete NPN transistor elements is relatively low. Its typical circuit structure is as Figure 1 shown. The triode Q1 operates in the saturation state. At this time, according to Kirchhoff's current law of the circuit, i3 = i1 + i2; since the potential output by the e - pole of the triode is Vref and is kept constant by the output of the constant voltage source, according to Ohm's law, i3 = Vref / R5. When R5 remains unchanged, i3 is constant. Since the triode Q1 operates in the deep saturation state, by setting the circuit parameters so that the emitter current i3 and collector current i1 of the triode are much larger than the base current i2, it can be approximately considered that i3≈i1; i1 is controlled and kept constant by the feedback of i3. The current i1 flows through the pyrotechnic resistance R3 (R_load), thereby generating a constant current source excitation for the pyrotechnic resistance. This constant current source circuit ignores the influence of the base current i2, the ICBO and IEBO of the triode. The set value of the constant current i3 is relatively large (≥5mA), generally in the range of (10 - 20)mA. This current is provided by the reference source circuit (such as Figure 1The TL431) in it provides an output. A large output current will cause an increase in the power consumption loss of the reference source circuit itself, a relatively large temperature rise of the chip itself, and the relatively large temperature rise affects the working accuracy of the reference source circuit. Generally, the working current of a high-precision reference source is less than 10 mA, and the recommended value for use in the full temperature range is below 5 mA. The relatively large output current (10 - 20) mA of this constant current source circuit is loaded on the resistor R5. According to energy conversion, the heat energy on the resistor R5 causes an increase in the temperature rise of the resistor R5. The temperature drift error causes a change in the resistance value of the resistor R5, thereby causing a change in i3, resulting in a decrease in the output current accuracy of the constant current source. The relatively large i1 (≈i3) is loaded on the pyrotechnic device loop resistor R3 (R_load), making the time to reach thermal equilibrium long, and the thermal drift causes a change in the resistance value of the pyrotechnic device resistor, thereby resulting in low accuracy of the detection resistor R3 (R_load). A relatively large current is loaded on the pyrotechnic device loop resistor R3 (R_load), increasing the safety risk of the detection circuit.

[0005] (2) In terms of the safety current protection circuit, currently, R2 is connected in series in the i1 constant current path for protection. However, due to the relatively large i1 current, to prevent the constant current source path from exceeding the working range, generally, VCC is increased (the set value is generally between 12 V and 28 V), the resistance value of R2 is decreased, and the voltage drop across the R2 resistor is decreased. Generally, the set value is in the tens of ohms. Increasing the VCC voltage and decreasing the resistance value of R2 result in a decrease in the performance of the safety current protection circuit in suppressing the current in the pyrotechnic device loop after a circuit anomaly. In the method of turning off the constant current source by the central processor through connecting R2 in series, since information is collected and judged by the central processor and an instruction is sent to turn off, the reaction time of the entire link is long, and there is a risk of the pyrotechnic device circuit detonating due to passing a large current in a short time. Through Figure 1 As can be seen from the figure, both ends of the pyrotechnic device resistor to be tested are not constrained to the ground (i.e., connected to the ground). Therefore, even if the constant current source is turned off, there is a latent path for the current, resulting in a risk of detonating the pyrotechnic device resistor. Summary of the Invention

[0006] The purpose of this application is to provide a method and system for measuring the resistance value of a pyrotechnic device for a launch vehicle, having the technical effects of high measurement accuracy and high measurement safety.

[0007] To achieve the above object, the present application provides a measurement system for the resistance value of pyrotechnics of a launch vehicle, including: a central controller, a constant current source detection device, a safety protection device, a measurement control signal output device, and a resistance detection result output device; wherein, the central controller is configured to: receive a current detection signal, and output a first resistance value configuration signal and a second resistance value configuration signal according to the current detection signal; when the value of the current constant current io is the standard value, enter the circuit working stage, enable the detection circuit control signal, enable the measurement control signal input signal, and receive the pyrotechnic resistance detection signal; in the circuit working stage, output a cut-off control signal and a peak voltage discharge signal according to the detection situation of the safety protection device, wherein the detection situation includes: normal circuit operation and abnormal circuit operation; the constant current source detection device: is respectively connected to the safety protection device, the measurement control signal output device, and the resistance detection result output device; adjusts the constant current according to the first resistance value configuration signal and the second resistance value configuration signal until the value of the current constant current io detected by the safety protection device is the standard value; detects the pyrotechnic resistance according to the turn-off signal and the measurement control signal; the safety protection device: when initially powered on, detects the constant current power supply in the constant current source detection device, obtains the current constant current io, and sends the value of the current constant current io to the central controller through the current detection signal; when the detection circuit control signal is enabled, participates in the over-current protection self-turn-off control and outputs a turn-off signal; protects the pyrotechnic resistance in the constant current source detection device according to the cut-off control signal, and enables the constant current source detection device to work again according to the peak voltage discharge signal; the measurement control signal output device: when the measurement control signal input signal is enabled, outputs a measurement control signal according to the measurement control signal input signal; the resistance detection result output device: after detecting the pyrotechnic resistance, outputs a pyrotechnic resistance detection signal to the central controller.

[0008] As described above, the constant current source detection circuit of the constant current source detection device at least includes: operational amplifier U1A, operational amplifier U1B, operational amplifier U1C, high-precision digital potentiometer R10, high-precision digital potentiometer R7, resistor R6, resistor R8, resistor R9, resistor R11, resistor R12, resistor R13, resistor R14_A, resistor R14_B, squib resistor R15, temperature compensation resistor R22, triode Q2, triode Q5 and triode Q3; The operational amplifier U1A includes: a first power supply pin, a second power supply pin, a first connection pin, a second connection pin and a third connection pin; The first power supply pin is connected to the power supply voltage VCC, the second power supply pin is connected to the negative voltage power supply VEE, the first connection pin is connected to the reference voltage Vref1, and the second connection pin is respectively connected to one end of the resistor R6 and the high-precision digital potentiometer R7; The third connection pin is respectively connected to the other end of the resistor R6 and the high-precision digital potentiometer R10; One end of the resistor R6 is also connected to the high-precision digital potentiometer R7, and the other end of the resistor R6 is also connected to the high-precision digital potentiometer R10; The high-precision digital potentiometer R7 is also connected to one end of the resistor R8; The high-precision digital potentiometer R10 is also connected to one end of the resistor R11; The high-precision digital potentiometer R7 is adjusted according to the first configuration signal, and the high-precision digital potentiometer R10 is adjusted according to the second configuration signal; The operational amplifier U1B includes: a third power supply pin, a fourth power supply pin, a fourth connection pin, a fifth connection pin and a sixth connection pin; The third power supply pin is connected to the power supply voltage VCC, the fourth power supply pin is connected to the negative voltage power supply VEE, the fourth connection pin is connected to the reference voltage Vref2, and the fifth connection pin is respectively connected to the other end of the resistor R8 and one end of the resistor R9; The sixth connection pin is respectively connected to the other end of the resistor R9 and one end of the resistor R12; One end of the resistor R9 is also connected to the other end of the resistor R8, and the other end of the resistor R9 is also connected to one end of the resistor R12; The operational amplifier U1C includes: a fifth power supply pin, a sixth power supply pin, a seventh connection pin, an eighth connection pin and a ninth connection pin; The fifth power supply pin is connected to the power supply voltage VCC, the sixth power supply pin is connected to the negative voltage power supply VEE; The seventh connection pin is respectively connected to the other end of the resistor R11 and one end of the resistor R13; The eighth connection pin is respectively connected to the other end of the resistor R12 and one end of the resistor R14_B; The ninth connection pin is respectively connected to the other end of the resistor R13 and one end of the resistor R14_A; The resistor R13 is also connected to the other end of the resistor R11 and one end of the resistor R14_A; The other end of the resistor R14_B is respectively connected to the other end of the resistor R14_A and the triode Q2; The other end of the resistor R14_A is also connected to the triode Q2; The triode Q2 is also connected to the triode Q3; The triode Q3 is also connected to one end of the temperature compensation resistor R22, and the other end of the temperature compensation resistor R22 is respectively connected to one end of the squib resistor R15 and the triode Q4;The other end of the triode Q4 is connected to the detonator resistor R15.;

[0009] As described above, the safety protection circuit of the safety protection device at least includes: an instrumentation amplifier U2, a detection circuit control switch SW1, a peak detector U6, a resistor R16, a resistor R19, a comparator U4, a peak voltage discharge switch SW2, and a resistor R18; the instrumentation amplifier U2 includes: a first pin RG-, a first pin RG+, a first output pin VOUT, a first power supply pin V+, a first power supply pin V-, a ground terminal, a first pin +, and a first pin -; the first pin RG- is connected to one end of the resistor R16, and the other end of the resistor R16 is connected to the first pin RG+; the first power supply pin V+ is connected to the power supply voltage VCC, the first power supply pin V- is connected to the negative voltage power supply VEE, and the first output pin VOUT is connected to one end of the detection circuit control switch SW1; the ground terminal is grounded through the wire ground terminal GND; the first pin + is respectively connected to one end of the triode Q3 and the temperature compensation resistor R22, and the first pin - is respectively connected to the other end of the temperature compensation resistor R22, the triode Q4, and one end of the detonator resistor; the first output pin VOUT outputs a current detection signal to the central controller; the peak detector includes: a pin IN, a pin OUT, and a pin XF; the pin IN is connected to the other end of the detection circuit control switch SW1, the pin OUT is connected to one end of the resistor R19, the pin XF is connected to one end of the peak voltage discharge switch SW2, and the other end of the peak voltage discharge switch SW2 is grounded through the wire ground terminal GND; the other end of the resistor R19 is grounded through the wire ground terminal GND; when the detection circuit control switch SW1 is closed, the peak detector receives the cut-off control signal output by the central controller according to the detection situation; when the circuit works abnormally, the peak voltage discharge signal output by the central controller is enabled, and the peak voltage discharge switch SW2 is closed; the comparator U4 includes: a first pin VP, a first pin VN, a first pin V-, a first pin V+, a first pin VO, and a ground terminal; the first pin VP is respectively connected to one end of the resistor R19 and the pin OUT, the first pin VN is connected to the reference voltage Vref3, the first pin V- is connected to the negative voltage power supply VEE, the first pin V+ is respectively connected to the power supply voltage VCC and one end of the resistor R18, the first pin VO is connected to the other end of the resistor R18, and the ground terminal is connected to the negative voltage power supply VEE; the first pin VO outputs a turn-off signal to control the triode Q2 and the triode Q3. When the turn-off signal is VEE, the triode Q2 and the triode Q3 are turned on; when the turn-off signal is VCC, the triode Q2 and the triode Q3 are turned off.

[0010] As described above, the measurement control signal output circuit of the measurement control signal output device includes at least: a comparator U5, a resistor R20, and a resistor R21; the comparator U5 includes: a second pin VP, a second pin VN, a second pin V-, a second pin V+, a second pin VO, and a ground terminal; the second pin VP is connected to one end of the resistor 20, the other end of the resistor 20 is grounded through a wire to the ground terminal GND, the second pin VN is connected to the reference voltage Vref4, the second pin V- is connected to the negative voltage supply VEE, the second pin V+ is respectively connected to the power supply voltage VCC and one end of the resistor R21, the first pin VO is connected to the other end of the resistor R21, and the ground terminal is connected to the negative voltage supply VEE; the measurement control signal input signal of the central controller U7 is input into the comparator U5 through the second pin VP, the comparator U5 outputs a measurement control signal through the second pin VO, and controls the triode Q4 through the measurement control signal. When the measurement control signal is VEE, the triode Q4 is turned on; when the measurement control signal is VCC, the triode Q4 is turned off.

[0011] As described above, the resistance detection result output circuit of the resistance detection result output device includes at least: an instrumentation amplifier U3 and a resistor R17; the instrumentation amplifier U3 includes: a second pin RG-, a second pin RG+, a second power supply pin V+, a second power supply pin V-, a ground terminal, a second pin +, a second pin -, and a second output pin VOUT; the second pin RG- is connected to one end of the resistor 17, the second pin RG+ is connected to the other end of the resistor 17, the second power supply pin V+ is connected to the power supply voltage VCC, the second power supply pin V- is connected to the negative voltage supply VEE, the ground terminal is grounded through a wire to the ground terminal GND, the second pin + is respectively connected to one end of the initiator resistance R15, the other end of the temperature compensation resistor R22, and the triode Q4, the second pin - is respectively connected to the other end of the initiator resistance R15, the triode Q4, and a wire to the ground terminal GND, and the second output pin VOUT outputs an initiator resistance detection signal.

[0012] The present application also provides a method for measuring the resistance value of pyrotechnic devices of a launch vehicle, including the following steps: S210: When initially powered on, the constant current of the constant current source detection device is detected by the safety protection device to obtain the value of the current constant current io, and the value of the current constant current io is sent to the central controller through the current detection signal; S220: The central controller judges the current constant current io through a preset constant current threshold. If the current constant current io is greater than the constant current threshold, a first resistance value configuration signal and a second resistance value configuration signal are sent, and S230 is executed; if the current constant current io is less than or equal to the constant current threshold, the circuit working stage is entered, and S240 is executed; S230: The constant current source detection device adjusts the constant current through the first resistance value configuration signal and the second resistance value configuration signal until the value of the current constant current io detected by the safety protection device is the standard value, and S240 is executed; S240: Enter the circuit working stage, the detection circuit control signal of the central controller is enabled, the safety protection device participates in the overcurrent protection self-shutdown control and outputs a shutdown signal, the measurement control signal input signal of the central controller is enabled, the measurement control signal output device outputs a measurement control signal according to the measurement control signal input signal, the constant current source detection device detects the resistance of the pyrotechnic device according to the shutdown signal and the measurement control signal, and outputs a pyrotechnic resistance detection signal to the central controller through the resistance detection result output device; in the circuit working stage, when the circuit works abnormally, the cut-off control signal output by the central controller is enabled, the peak voltage discharge signal is enabled, the safety protection device protects the pyrotechnic resistance in the constant current source detection device according to the cut-off control signal, and makes the constant current source detection device work again according to the peak voltage discharge signal.

[0013] As described above, wherein the sub-steps for the constant current source detection device to adjust the constant current through the first resistance value configuration signal and the second resistance value configuration signal until the value of the current constant current io detected by the safety protection device is the standard value are as follows: The high-precision digital potentiometer R10 is adjusted through the second configuration signal to meet the differential circuit balance condition; after meeting the differential circuit balance condition, the high-precision digital potentiometer R7 is adjusted according to the first configuration signal until the value of the current constant current io detected by the safety protection device is the standard value.

[0014] As described above, wherein the expression of the differential circuit balance condition is as follows: Wherein, R13 is the resistance value of resistor R13; R10 is the resistance value of the high-precision digital potentiometer R10; R11 is the resistance value of resistor R11; R14_A is the resistance value of resistor R14_A; R14_B is the resistance value of resistor R14_B; R12 is the resistance value of resistor R12.

[0015] As described above, after meeting the differential circuit balance condition, the transfer function expression of the current constant current io output is as follows: io = (1 + 2 * R6 / R7) * (R14 / R12 / R14_A) (Vref2 - Vref1); where, io is the value of the current constant current; R6 is the resistance value of resistor R6; R7 is the resistance value of the high-precision digital potentiometer R7; R14_A is the resistance value of resistor R14_A; R12 is the resistance value of resistor R12; let R14 = R14_A + R14_B, R14_B is the resistance value of resistor R14_B, R6 = R9, R9 is the resistance value of resistor R9; Vref1 is the value of reference voltage Vref1; Vref2 is the value of reference voltage Vref2.

[0016] As described above, during the circuit operation stage, the central controller continuously detects the current detection signal output by the safety protection device, and adjusts the resistance values of the high-precision digital potentiometer R10 and the high-precision digital potentiometer R7 in real time according to the current detection signal through the first resistance value configuration signal and the second circuit configuration signal, dynamically compensating the constant current source current in real time, so that the value of the current constant current io during the circuit operation stage is the standard value.

[0017] The beneficial effects achieved by this application are as follows:

[0018] (1) After detecting the constant current source current in a closed loop, this application uses a peak detector to latch the abnormal current peak voltage, realizing the function of automatically turning off the constant current source in case of overcurrent, ensuring the safety of the initiator test.

[0019] (2) After detecting the constant current source current in a closed loop, this application dynamically adjusts the compensation resistor and adjusts the constant current output in real time, forming a closed-loop feedback system for constant current source compensation, improving the accuracy of the constant current source output.

[0020] (3) This application adopts a constant current source detection circuit in the form of an instrumentation amplifier, effectively improving the common-mode rejection ratio of the circuit. For the parameter drift of individual components in the circuit, compensation is performed through the differential circuit structure, improving the accuracy of the circuit.

[0021] (4) This application designs a bypass protection for the initiator resistance, which can protect the safety of the initiator resistance during the power-on process. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings described below are only some embodiments recorded in the present application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0023] Figure 1Block diagram of the power supply topology for an existing single - power - management chip;

[0024] Figure 2 Schematic diagram of an embodiment of the constant - current source detection circuit of the present application;

[0025] Figure 3 Schematic diagram of an embodiment of the safety protection circuit of the present application;

[0026] Figure 4 Schematic diagram of an embodiment of the measurement control signal output circuit of the present application;

[0027] Figure 5 Schematic diagram of an embodiment of the resistor detection result output circuit of the present application;

[0028] Figure 6 Schematic diagram of an embodiment of the central controller. Detailed implementation manners

[0029] Next, in combination with the accompanying drawings in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of the present invention.

[0030] As Figures 2 - 6 shown, the present application provides a measurement system for the resistance value of pyrotechnic devices of a launch vehicle, including: a central controller, a constant - current source detection device, a safety protection device, a measurement control signal output device, and a resistor detection result output device.

[0031] Among them, the central controller is used to: receive the current detection signal, and output a first resistance - value configuration signal and a second resistance - value configuration signal according to the current detection signal; when the value of the current constant - current io is the standard value, enter the circuit working stage, enable the detection circuit control signal, enable the measurement control signal input signal, and receive the pyrotechnic resistor detection signal; in the circuit working stage, output a cut - off control signal and a peak - voltage discharge signal according to the detection situation of the safety protection device, where the detection situation includes: normal circuit operation and abnormal circuit operation.

[0032] The constant - current source detection device: is respectively connected to the safety protection device, the measurement control signal output device, and the resistor detection result output device; adjusts the constant - current according to the first resistance - value configuration signal and the second resistance - value configuration signal until the value of the current constant - current io detected by the safety protection device is the standard value;

[0033] Detect the pyrotechnic device resistor according to the turn - off signal and the measurement control signal.

[0034] Safety protection device: When initially powered on, it detects the constant current power supply in the constant current source detection device, obtains the current constant current io, and sends the value of the current constant current io to the central controller through the current detection signal; when the detection circuit control signal is enabled, it participates in the overcurrent protection self-turn-off control and outputs a turn-off signal; it protects the initiator resistance in the constant current source detection device according to the cut-off control signal, and makes the constant current source detection device work again according to the peak voltage discharge signal.

[0035] Measurement control signal output device: When the measurement control signal input signal is enabled, it outputs a measurement control signal according to the measurement control signal input signal.

[0036] Resistance detection result output device: After detecting the initiator resistance, it outputs an initiator resistance detection signal to the central controller.

[0037] Further, as Figure 2 shown, the constant current source detection circuit of the constant current source detection device at least includes: operational amplifier U1A, operational amplifier U1B, operational amplifier U1C, high-precision digital potentiometer R10, high-precision digital potentiometer R7, resistor R6, resistor R8, resistor R9, resistor R11, resistor R12, resistor R13, resistor R14_A, resistor R14_B, initiator resistance R15, temperature compensation resistor R22, triode Q2, triode Q5 and triode Q3.

[0038] The operational amplifier U1A includes: a first power supply pin, a second power supply pin, a first connection pin, a second connection pin and a third connection pin; the first power supply pin is connected to the power supply voltage VCC, the second power supply pin is connected to the negative voltage power supply VEE, the first connection pin is connected to the reference voltage Vref1, and the second connection pin is respectively connected to one end of the resistor R6 and the high-precision digital potentiometer R7; the third connection pin is respectively connected to the other end of the resistor R6 and the high-precision digital potentiometer R10. One end of the resistor R6 is also connected to the high-precision digital potentiometer R7, and the other end of the resistor R6 is also connected to the high-precision digital potentiometer R10. The high-precision digital potentiometer R7 is also connected to one end of the resistor R8; the high-precision digital potentiometer R10 is also connected to one end of the resistor R11. The high-precision digital potentiometer R7 is adjusted according to the first configuration signal, and the high-precision digital potentiometer R10 is adjusted according to the second configuration signal.

[0039] The operational amplifier U1B includes: a third power supply pin, a fourth power supply pin, a fourth connection pin, a fifth connection pin, and a sixth connection pin; the third power supply pin is connected to the power supply voltage VCC, the fourth power supply pin is connected to the negative voltage power supply VEE, the fourth connection pin is connected to the reference voltage Vref2, the fifth connection pin is respectively connected to the other end of the resistor R8 and one end of the resistor R9; the sixth connection pin is respectively connected to the other end of the resistor R9 and one end of the resistor R12. One end of the resistor R9 is also connected to the other end of the resistor R8, and the other end of the resistor R9 is also connected to one end of the resistor R12.

[0040] The operational amplifier U1C includes: a fifth power supply pin, a sixth power supply pin, a seventh connection pin, an eighth connection pin, and a ninth connection pin; the fifth power supply pin is connected to the power supply voltage VCC, the sixth power supply pin is connected to the negative voltage power supply VEE. The seventh connection pin is respectively connected to the other end of the resistor R11 and one end of the resistor R13; the eighth connection pin is respectively connected to the other end of the resistor R12 and one end of the resistor R14_B; the ninth connection pin is respectively connected to the other end of the resistor R13 and one end of the resistor R14_A; the resistor R13 is also connected to the other end of the resistor R11 and one end of the resistor R14_A; the other end of the resistor R14_B is respectively connected to the other end of the resistor R14_A and the triode Q2; the other end of the resistor R14_A is also connected to the triode Q2; the triode Q2 is also connected to the triode Q3; the triode Q3 is also connected to one end of the temperature compensation resistor R22, and the other end of the temperature compensation resistor R22 is respectively connected to one end of the initiator resistor R15 and the triode Q4; the triode Q4 is connected to the other end of the initiator resistor R15.

[0041] Further, as Figure 3 shown, the safety protection circuit of the safety protection device at least includes: an instrumentation amplifier U2, a detection circuit control switch SW1, a peak detector U6, a resistor R16, a resistor R19, a comparator U4, a peak voltage discharge switch SW2, and a resistor R18.

[0042] The instrumentation amplifier U2 includes: the first pin RG-, the first pin RG+, the first output pin VOUT, the first power supply pin V+, the first power supply pin V-, the ground terminal, the first pin +, and the first pin -; the first pin RG- is connected to one end of the resistor R16, and the other end of the resistor R16 is connected to the first pin RG+; the first power supply pin V+ is connected to the power supply voltage VCC, the first power supply pin V- is connected to the negative voltage power supply VEE, and the first output pin VOUT is connected to one end of the detection circuit control switch SW1; the ground terminal is grounded through the wire ground terminal GND; the first pin + is respectively connected to one ends of the triode Q3 and the temperature compensation resistor R22, and the first pin - is respectively connected to the other end of the temperature compensation resistor R22, the triode Q4, and one end of the initiator resistor; the first output pin VOUT outputs a current detection signal to the central controller.

[0043] The peak detector includes: the pin IN, the pin OUT, and the pin XF; the pin IN is connected to the other end of the detection circuit control switch SW1, the pin OUT is connected to one end of the resistor R19, the pin XF is connected to one end of the peak voltage discharge switch SW2, and the other end of the peak voltage discharge switch SW2 is grounded through the wire ground terminal GND; the other end of the resistor R19 is grounded through the wire ground terminal GND; when the detection circuit control switch SW1 is closed, the peak detector receives the cut-off control signal output by the central controller according to the detection situation; when the circuit works abnormally, the peak voltage discharge signal output by the central controller is enabled, and the peak voltage discharge switch SW2 is closed.

[0044] The comparator U4 includes: the first pin VP, the first pin VN, the first pin V-, the first pin V+, the first pin VO, and the ground terminal; the first pin VP is respectively connected to one end of the resistor R19 and the pin OUT, the first pin VN is connected to the reference voltage Vref3, the first pin V- is connected to the negative voltage power supply VEE, the first pin V+ is respectively connected to the power supply voltage VCC and one end of the resistor R18, the first pin VO is connected to the other end of the resistor R18, and the ground terminal is connected to the negative voltage power supply VEE; the first pin VO outputs a turn-off signal to control the triode Q2 and the triode Q3. When the turn-off signal is VEE, the triode Q2 and the triode Q3 are turned on; when the turn-off signal is VCC, the triode Q2 and the triode Q3 are turned off.

[0045] Further, as Figure 4 shown, the measurement control signal output circuit of the measurement control signal output device includes at least: the comparator U5, the resistor R20, and the resistor R21.

[0046] Comparator U5 includes: the second pin VP, the second pin VN, the second pin V-, the second pin V+, the second pin VO, and the ground terminal. The second pin VP is connected to one end of resistor 20, and the other end of resistor 20 is grounded through a wire to the ground terminal GND. The second pin VN is connected to the reference voltage Vref4. The second pin V- is connected to the negative voltage supply VEE. The second pin V+ is respectively connected to the power supply voltage VCC and one end of resistor R21. The first pin VO is connected to the other end of resistor R21. The ground terminal is connected to the negative voltage supply VEE. The measurement control signal input signal of the central controller U7 is input to comparator U5 through the second pin VP. Comparator U5 outputs the measurement control signal through the second pin VO, and controls the triode Q4 through the measurement control signal. When the measurement control signal is VEE, the triode Q4 conducts; when the measurement control signal is VCC, the triode Q4 turns off.

[0047] Further, as Figure 5 shown, the resistance detection result output circuit of the resistance detection result output device of the present application at least includes: an instrumentation amplifier U3 and a resistor R17. The instrumentation amplifier U3 includes: the second pin RG-, the second pin RG+, the second power supply pin V+, the second power supply pin V-, the ground terminal, the second pin +, the second pin -, and the second output pin VOUT; the second pin RG- is connected to one end of resistor 17, the second pin RG+ is connected to the other end of resistor 17, the second power supply pin V+ is connected to the power supply voltage VCC, the second power supply pin V- is connected to the negative voltage supply VEE, the ground terminal is grounded through a wire to the ground terminal GND, the second pin + is respectively connected to one end of the initiator resistor R15, the other end of the temperature compensation resistor R22, and the triode Q4, the second pin - is respectively connected to the other end of the initiator resistor R15, the triode Q4, and a wire to the ground terminal GND, and the second output pin VOUT outputs the initiator resistance detection signal.

[0048] The present application also provides a method for measuring the resistance value of the initiator of a launch vehicle, including the following steps:

[0049] S210: When initially powered on, detect the constant current of the constant current source detection device through the safety protection device, obtain the value of the current constant current io, and send the value of the current constant current io to the central controller through the current detection signal.

[0050] Specifically, when initially powered on, the detection circuit control signal of the central controller is in a disabled state. At this time, the detection circuit control switch SW1 is disconnected, and the safety protection circuit of the safety protection device does not form a feedback loop. The cut-off control signal and the measurement control signal input signal are both in a disabled state. The first pin VP of the comparator U4 is grounded, the voltage at the first pin VN is equal to the reference voltage Vref3, the voltage at the first pin VP is less than the voltage at the first pin VN, and the turn-off signal output by the safety protection device is VEE. Similarly, the measurement control signal output by the comparator U5 is VEE, and the turn-off signal is the control signal for the triode Q2 and the triode Q3. When the turn-off signal is VEE, the triode Q2 and the triode Q3 are turned on, and the measurement control signal is the control signal for the triode Q4. When the turn-off signal is VEE, the triode Q4 is turned on, but at this time the triode Q4 is turned on and grounded, and the initiator resistance R15 is bypassed; the constant current source detection circuit of the constant current source detection device works, outputs a constant current, and the safety protection device detects this constant current to obtain the value of the current constant current io, and sends the value of the current constant current io to the central controller through the current detection signal. By detecting the voltage across the temperature compensation resistor R22 (RG_W1), the value of the current constant current io can be calculated according to Ohm's law.

[0051] Among them, as an embodiment, the temperature compensation resistor R22 is a precision resistor.

[0052] S220: The central controller judges the current constant current io through a preset constant current threshold. If the current constant current io is greater than the constant current threshold, it sends the first resistance value configuration signal and the second resistance value configuration signal, and executes S230; if the current constant current io is less than or equal to the constant current threshold, it enters the circuit working stage and executes S240.

[0053] Specifically, the constant current threshold is preset, and the specific value of the constant current threshold depends on the actual situation. In the test, the smaller the preset constant current threshold, the safer it is. For example: 1 mA, or less than 1 mA.

[0054] S230: The constant current source detection device adjusts the constant current through the first resistance value configuration signal (resistance value configuration signal 1) and the second resistance value configuration signal (resistance value configuration signal 2) until the value of the current constant current io detected by the safety protection device is the standard value, and then executes S240.

[0055] Furthermore, the sub-steps for the constant current source detection device to adjust the constant current through the first resistance value configuration signal (resistance value configuration signal 1) and the second resistance value configuration signal (resistance value configuration signal 2) until the value of the current constant current io detected by the safety protection device is the standard value are as follows:

[0056] S2301: Adjust the high-precision digital potentiometer R10 through the second configuration signal to meet the differential circuit balance condition.

[0057] Furthermore, the expression of the differential circuit balance condition is as follows:

[0058]

[0059] Among them, R13 is the resistance value of resistor R13; R10 is the resistance value of the high-precision digital potentiometer R10; R11 is the resistance value of resistor R11; R14_A is the resistance value of resistor R14_A; R14_B is the resistance value of resistor R14_B; R12 is the resistance value of resistor R12.

[0060] Specifically, when the differential circuit balance condition is met, the output resistance Ro of the constant current source = ∞; in this application, by adjusting the resistance value of the high-precision digital potentiometer R10, the proportional relationship in the actual circuit of the constant current source detection device is made close to the differential circuit balance condition.

[0061] S2302: After meeting the differential circuit balance condition, adjust the high-precision digital potentiometer R7 according to the first configuration signal until the value of the current constant current io detected by the safety protection device reaches the standard value.

[0062] Furthermore, after meeting the differential circuit balance condition, the transfer function expression of the output of the current constant current io is as follows:

[0063] io = (1 + 2 * R6 / R7) * (R14 / R12 / R14_A) (Vref2 - Vref1);

[0064] Among them, io is the value of the current constant current; R6 is the resistance value of resistor R6; R7 is the resistance value of the high-precision digital potentiometer R7; R14_A is the resistance value of resistor R14_A; R12 is the resistance value of resistor R12; let R14 = R14_A + R14_B, R14_B is the resistance value of resistor R14_B, R6 = R9, R9 is the resistance value of resistor R9; Vref1 is the value of the reference voltage Vref1; Vref2 is the value of the reference voltage Vref2.

[0065] Specifically, according to the transfer function output by the current constant current io, by adjusting the resistance value of the high-precision digital potentiometer R7 (RG), the output of the constant current source io can be adjusted. Using the difference between the reference voltage (reference source) Vref2 and the reference voltage (reference source) Vref1 to provide a voltage reference can effectively cancel the static error of the reference source. The operational amplifiers U1A and U1B that provide the main gain in the circuit also adopt the differential amplification form, which can effectively cancel the static error of the reference source. The reference source of this circuit form has high working precision and can achieve a small current constant current source at the 1 mA level.

[0066] S240: Enter the circuit working stage. The detection circuit control signal of the central controller is enabled. The safety protection device participates in the overcurrent protection self-shutdown control and outputs a shutdown signal. The measurement control signal input signal of the central controller is enabled. The measurement control signal output device outputs a measurement control signal according to the measurement control signal input signal. The constant current source detection device detects the initiator resistance according to the shutdown signal and the measurement control signal, and outputs an initiator resistance detection signal to the central controller through the resistance detection result output device;

[0067] In the circuit working stage, when the circuit works abnormally, the cut-off control signal output by the central controller is enabled, and the peak voltage discharge signal is enabled. The safety protection device protects the initiator resistance in the constant current source detection device according to the cut-off control signal, and makes the constant current source detection device work again according to the peak voltage discharge signal.

[0068] Specifically, in the circuit working stage, after the constant current source is compensated and adjusted, the value of the current constant current io output by the constant current source detection device is the standard value. At this time, the central controller first enables the detection circuit control signal, closes the detection circuit control switch SW1, accesses the current detection signal, and forms a closed-loop circuit of the safety protection circuit to participate in the overcurrent protection self-shutdown control. The central controller enables the measurement control signal input signal. The measurement control signal input signal is greater than the reference voltage Vref4, and the value of the measurement control signal is VCC at this time. The triode Q4 is turned off, and the initiator resistance R15 is connected to the constant current source loop of the constant current source detection circuit for loop resistance testing. The voltage across the precise detection temperature compensation resistor R22 (RG_W1) is detected through the resistance detection result output circuit, and the initiator loop resistance value can be obtained according to Ohm's law. The initiator loop resistance value is sent to the central controller through the initiator resistance detection signal.

[0069] During the circuit operation stage, when the circuit malfunctions, the current output in the constant current source detection circuit exceeds the set rated current imax (where the rated current imax is set within the peak detector U6), causing the voltage signal output by the current detection signal to increase. When the voltage signal forms a peak voltage VJ greater than the reference voltage Vref3 (where the reference voltage is a preset voltage safety threshold) after passing through the peak detector U6, the turn-off signal value of the comparator U4 is VCC. When the turn-off signal is VCC, the triodes Q2 and Q3 turn off, thus opening the constant current source path (i.e., the constant current source detection circuit is open). The peak detector U6 has a latch function for the detected peak voltage VJ, that is, even if the front-end input signal disappears or decreases, the peak detector U6 can still maintain the output peak voltage, ensuring that the turn-off circuit remains self-latched in the off state when the constant current source is turned off, only protecting the safety of the initiator test. The central controller enables the peak voltage discharge signal, closes the peak voltage discharge switch SW2, the peak detector U6 discharges the charge, the peak voltage returns to zero, and when the peak voltage VJ is less than the reference voltage Vref3, the turn-off signal value of the comparator U4 is VEE, causing the triodes Q2 and Q3 to conduct, and the constant current source resumes operation.

[0070] Furthermore, during the circuit operation stage, the central controller continuously detects the current detection signal output by the safety protection device and adjusts the resistance values of the high-precision digital potentiometer R10 and the high-precision digital potentiometer R7 in real time through the first resistance value configuration signal and the second circuit configuration signal according to the current detection signal, dynamically compensating the constant current source current in real time, so that the value of the current constant current io during the circuit operation stage is the standard value.

[0071] The beneficial effects achieved by this application are as follows:

[0072] (1) After the constant current source current is detected in a closed loop, this application uses the peak detector to latch the abnormal current peak voltage, realizing the function of automatically turning off the constant current source overcurrent and ensuring the safety of the initiator test.

[0073] (2) After the constant current source current is detected in a closed loop, this application dynamically adjusts and compensates the resistance, adjusts the constant current output in real time, forms a closed-loop feedback system for constant current source compensation, and improves the accuracy of the constant current source output.

[0074] (3) This application uses a constant current source detection circuit in the form of an instrumentation amplifier, effectively improving the common-mode rejection ratio of the circuit. For the parameter drift of individual components in the circuit, compensation is carried out through the differential circuit structure, improving the accuracy of the circuit.

[0075] (4) This application designs a bypass protection for the initiator resistance, which can protect the safety of the initiator resistance during the power-on process.

[0076] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concept. Therefore, the scope of protection of the present application is intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application. Obviously, those skilled in the art can make various changes and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of protection of the present application and the scope of equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A measurement system for the resistance value of pyrotechnic devices of a launch vehicle, characterized in that, Including: A central controller, a constant current source detection device, a safety protection device, a measurement control signal output device, and a resistance detection result output device; Among them, the central controller is used to: receive a current detection signal, and output a first resistance value configuration signal and a second resistance value configuration signal according to the current detection signal; when the value of the current constant current io is the standard value, enter the circuit working stage, enable the detection circuit control signal, enable the measurement control signal input signal, and receive the primer resistance detection signal; in the circuit working stage, output a cut-off control signal and a peak voltage discharge signal according to the detection situation of the safety protection device, where the detection situation includes: normal circuit operation and abnormal circuit operation; The constant current source detection device: is respectively connected to the safety protection device, the measurement control signal output device, and the resistance detection result output device; adjusts the constant current through the first resistance value configuration signal and the second resistance value configuration signal until the value of the current constant current io detected by the safety protection device is the standard value; detects the primer resistance according to the turn-off signal and the measurement control signal; The safety protection device: when initially powered on, detects the constant current power supply in the constant current source detection device, obtains the current constant current io, and sends the value of the current constant current io to the central controller through the current detection signal; when the detection circuit control signal is enabled, participates in the overcurrent protection self-turn-off control and outputs a turn-off signal; protects the primer resistance in the constant current source detection device according to the cut-off control signal, and enables the constant current source detection device to work again according to the peak voltage discharge signal; The measurement control signal output device: when the measurement control signal input signal is enabled, outputs a measurement control signal according to the measurement control signal input signal; The resistance detection result output device: after detecting the primer resistance, outputs a primer resistance detection signal to the central controller.

2. The measurement system for the resistance value of pyrotechnic devices of a launch vehicle according to claim 1, characterized in that, The constant current source detection circuit of the constant current source detection device at least includes: operational amplifier U1A, operational amplifier U1B, operational amplifier U1C, high-precision digital potentiometer R10, high-precision digital potentiometer R7, resistor R6, resistor R8, resistor R9, resistor R11, resistor R12, resistor R13, resistor R14_A, resistor R14_B, primer resistance R15, temperature compensation resistor R22, triode Q2, triode Q5, and triode Q3; The operational amplifier U1A includes: a first power supply pin, a second power supply pin, a first connection pin, a second connection pin, and a third connection pin; the first power supply pin is connected to the power supply voltage VCC, the second power supply pin is connected to the negative voltage power supply VEE, the first connection pin is connected to the reference voltage Vref1, the second connection pin is respectively connected to one end of the resistor R6 and the high-precision digital potentiometer R7; the third connection pin is respectively connected to the other end of the resistor R6 and the high-precision digital potentiometer R10; One end of the resistor R6 is also connected to the high-precision digital potentiometer R7, and the other end of the resistor R6 is also connected to the high-precision digital potentiometer R10; The high-precision digital potentiometer R7 is also connected to one end of the resistor R8; the high-precision digital potentiometer R10 is also connected to one end of the resistor R11; the high-precision digital potentiometer R7 is adjusted according to the first configuration signal, and the high-precision digital potentiometer R10 is adjusted according to the second configuration signal; The operational amplifier U1B includes: a third power supply pin, a fourth power supply pin, a fourth connection pin, a fifth connection pin, and a sixth connection pin; the third power supply pin is connected to the power supply voltage VCC, the fourth power supply pin is connected to the negative voltage power supply VEE, the fourth connection pin is connected to the reference voltage Vref2, the fifth connection pin is respectively connected to the other end of the resistor R8 and one end of the resistor R9; the sixth connection pin is respectively connected to the other end of the resistor R9 and one end of the resistor R12; One end of the resistor R9 is also connected to the other end of the resistor R8, and the other end of the resistor R9 is also connected to one end of the resistor R12; The operational amplifier U1C includes: a fifth power supply pin, a sixth power supply pin, a seventh connection pin, an eighth connection pin, and a ninth connection pin; the fifth power supply pin is connected to the power supply voltage VCC, and the sixth power supply pin is connected to the negative voltage power supply VEE; The seventh connection pin is respectively connected to the other end of the resistor R11 and one end of the resistor R13; The eighth connection pin is respectively connected to the other end of the resistor R12 and one end of the resistor R14_B; The ninth connection pin is respectively connected to the other end of the resistor R13 and one end of the resistor R14_A; The resistor R13 is also connected to the other end of the resistor R11 and one end of the resistor R14_A; The other end of the resistor R14_B is respectively connected to the other end of the resistor R14_A and the triode Q2; The other end of the resistor R14_A is also connected to the triode Q2; The triode Q2 is also connected to the triode Q3; The triode Q3 is also connected to one end of the temperature compensation resistor R22, and the other end of the temperature compensation resistor R22 is respectively connected to one end of the initiator resistor R15 and the triode Q4; The triode Q4 is connected to the other end of the initiator resistor R15.

3. The measurement system for the resistance value of pyrotechnic devices of a launch vehicle according to claim 2, wherein The safety protection circuit of the safety protection device at least includes: an instrumentation amplifier U2, a detection circuit control switch SW1, a peak detector U6, a resistor R16, a resistor R19, a comparator U4, a peak voltage discharge switch SW2, and a resistor R18; The instrumentation amplifier U2 includes: the first pin RG-, the first pin RG+, the first output pin VOUT, the first power supply pin V+, the first power supply pin V-, the ground terminal, the first pin +, and the first pin -; the first pin RG- is connected to one end of the resistor R16, and the other end of the resistor R16 is connected to the first pin RG+; the first power supply pin V+ is connected to the power supply voltage VCC, the first power supply pin V- is connected to the negative voltage power supply VEE, and the first output pin VOUT is connected to one end of the detection circuit control switch SW1; the ground terminal is grounded through the wire ground terminal GND; the first pin + is respectively connected to one ends of the triode Q3 and the temperature compensation resistor R22, and the first pin - is respectively connected to the other end of the temperature compensation resistor R22, the triode Q4, and one end of the initiator resistor; the first output pin VOUT outputs a current detection signal to the central controller; The peak detector includes: the pin IN, the pin OUT, and the pin XF; the pin IN is connected to the other end of the detection circuit control switch SW1, the pin OUT is connected to one end of the resistor R19, the pin XF is connected to one end of the peak voltage discharge switch SW2, and the other end of the peak voltage discharge switch SW2 is grounded through the wire ground terminal GND; the other end of the resistor R19 is grounded through the wire ground terminal GND; After the detection circuit control switch SW1 is closed, the peak detector receives the cut-off control signal output by the central controller according to the detection situation; when the circuit works abnormally, the peak voltage discharge signal output by the central controller is enabled, and the peak voltage discharge switch SW2 is closed; The comparator U4 includes: the first pin VP, the first pin VN, the first pin V-, the first pin V+, the first pin VO, and the ground terminal; The first pin VP is respectively connected to one end of the resistor R19 and the pin OUT, the first pin VN is connected to the reference voltage Vref3, the first pin V- is connected to the negative voltage power supply VEE, the first pin V+ is respectively connected to the power supply voltage VCC and one end of the resistor R18, the first pin VO is connected to the other end of the resistor R18, and the ground terminal is connected to the negative voltage power supply VEE; The first pin VO outputs a turn-off signal to control the triode Q2 and the triode Q3. When the turn-off signal is VEE, the triode Q2 and the triode Q3 are turned on; when the turn-off signal is VCC, the triode Q2 and the triode Q3 are turned off.

4. The measurement system for the resistance value of pyrotechnic devices of a launch vehicle according to claim 3, wherein, The measurement control signal output circuit of the measurement control signal output device includes at least: the comparator U5, the resistor R20, and the resistor R21; The comparator U5 includes: the second pin VP, the second pin VN, the second pin V-, the second pin V+, the second pin VO, and the ground terminal; The second pin VP is connected to one end of the resistor 20, the other end of the resistor 20 is grounded through the wire ground terminal GND, the second pin VN is connected to the reference voltage Vref4, the second pin V- is connected to the negative voltage power supply VEE, the second pin V+ is respectively connected to the power supply voltage VCC and one end of the resistor R21, the first pin VO is connected to the other end of the resistor R21, and the ground terminal is connected to the negative voltage power supply VEE; The input signal of the measurement control signal of the central controller U7 is input into the comparator U5 through the second pin VP. The comparator U5 outputs the measurement control signal through the second pin VO, and controls the triode Q4 through the measurement control signal. When the measurement control signal is VEE, the triode Q4 is turned on; when the measurement control signal is VCC, the triode Q4 is turned off.

5. The measurement system for the resistance value of the pyrotechnic device of the launch vehicle according to claim 4, wherein The resistance detection result output circuit of the resistance detection result output device at least includes: an instrumentation amplifier U3 and a resistor R17; The instrumentation amplifier U3 includes: a second pin RG-, a second pin RG+, a second power supply pin V+, a second power supply pin V-, a ground terminal, a second pin +, a second pin - and a second output pin VOUT; The second pin RG- is connected to one end of the resistor 17, the second pin RG+ is connected to the other end of the resistor 17, the second power supply pin V+ is connected to the power supply voltage VCC, the second power supply pin V- is connected to the negative voltage power supply VEE, the ground terminal is grounded through the wire ground terminal GND, the second pin + is respectively connected to one end of the initiator resistor R15, the other end of the temperature compensation resistor R22 and the triode Q4, the second pin - is respectively connected to the other end of the initiator resistor R15, the triode Q4 and the wire ground terminal GND, and the second output pin VOUT outputs the initiator resistance detection signal.

6. A method for measuring the resistance value of pyrotechnic devices of a launch vehicle, characterized in that, Including the following steps: S210: When initially powered on, the constant current of the constant current source detection device is detected by the safety protection device to obtain the value of the current constant current io, and the value of the current constant current io is sent to the central controller through the current detection signal; S220: The central controller judges the current constant current io through the preset constant current threshold. If the current constant current io is greater than the constant current threshold, the first resistance value configuration signal and the second resistance value configuration signal are sent, and S230 is executed; if the current constant current io is less than or equal to the constant current threshold, it enters the circuit working stage and S240 is executed; S230: The constant current source detection device adjusts the constant current through the first resistance value configuration signal and the second resistance value configuration signal until the value of the current constant current io detected by the safety protection device is the standard value, and S240 is executed; S240: Enter the circuit working stage, the detection circuit control signal of the central controller is enabled, the safety protection device participates in the overcurrent protection self-shutdown control and outputs a shutdown signal, the input signal of the measurement control signal of the central controller is enabled, the measurement control signal output device outputs the measurement control signal according to the input signal of the measurement control signal, the constant current source detection device detects the initiator resistor according to the shutdown signal and the measurement control signal, and outputs the initiator resistance detection signal to the central controller through the resistance detection result output device; In the circuit working stage, when the circuit works abnormally, the cut-off control signal output by the central controller is enabled, the peak voltage discharge signal is enabled, the safety protection device protects the initiator resistor in the constant current source detection device according to the cut-off control signal, and makes the constant current source detection device work again according to the peak voltage discharge signal.

7. The measuring method for the resistance value of the pyrotechnic device of a launch vehicle according to claim 6, wherein The sub-steps for the constant current source detection device to adjust the constant current through the first resistance value configuration signal and the second resistance value configuration signal until the value of the current io detected by the safety protection device is the standard value are as follows: Adjust the high-precision digital potentiometer R10 through the second configuration signal to meet the differential circuit balance condition; After meeting the differential circuit balance condition, adjust the high-precision digital potentiometer R7 according to the first configuration signal until the value of the current io detected by the safety protection device is the standard value.

8. The measuring method for the resistance value of the pyrotechnic device of the launch vehicle according to claim 7, wherein The expression for the differential circuit balance condition is as follows: Where, R13 is the resistance value of resistor R13; R10 is the resistance value of the high-precision digital potentiometer R10; R11 is the resistance value of resistor R11; R14_A is the resistance value of resistor R14_A; R14_B is the resistance value of resistor R14_B; R12 is the resistance value of resistor R12.

9. The measuring method for the resistance value of the pyrotechnic device of the launch vehicle according to claim 8, characterized in that After meeting the differential circuit balance condition, the transfer function expression of the output of the current io is as follows: io = (1 + 2 * R6 / R7) * (R14 / R12 / R14_A) * (Vref2 - Vref1); Where, io is the value of the current io; R6 is the resistance value of resistor R6; R7 is the resistance value of the high-precision digital potentiometer R7; R14_A is the resistance value of resistor R14_A; R12 is the resistance value of resistor R12; assume R14 = R14_A + R14_B, R14_B is the resistance value of resistor R14_B, R6 = R9, R9 is the resistance value of resistor R9; Vref1 is the value of the reference voltage Vref1; Vref2 is the value of the reference voltage Vref2.

10. The method for measuring the resistance value of pyrotechnic devices of a launch vehicle according to claim 9, wherein, During the circuit operation stage, the central controller continuously detects the current detection signal output by the safety protection device, and adjusts the resistance values of the high-precision digital potentiometer R10 and the high-precision digital potentiometer R7 in real time through the first resistance value configuration signal and the second circuit configuration signal according to the current detection signal, and dynamically compensates the constant current source current in real time, so that the value of the current io in the circuit operation stage is the standard value.

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