Implementation method for measuring ignition resistance of industrial electronic detonator

Abstract

The invention provides an implementation method for measuring the ignition resistance of an industrial electronic detonator, which belongs to the technical field of resistance measurement, and comprises the following steps: the measurement of the ignition resistance of the industrial electronic detonator is realized based on a detection circuit, the detection circuit comprises an MCU microcontroller U1, a single-pole double-throw physical relay U2, a relay change-over switch triode Q1, a divider resistor R1 and a divider resistor R2 of the measurement circuit, and a dual-path integrated operational amplifier. The test state of the ignition resistor is switched based on a single-pole double-throw physical relay U2 and a relay change-over switch triode Q1; a millivolt-level weak signal is output to a measuring circuit based on the MCU microcontroller U1, and specific voltage values of a point A and a point B corresponding to the divider resistor R1 and the divider resistor R2 in different test states are controlled; the specific voltage values of the point A and the point B are amplified by the same multiple based on the integrated operational amplifier of the two paths, so that the current value flowing through the measuring circuit is calculated, the ignition resistance value is calculated, and the measuring precision is effectively guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of resistance measurement, and in particular to a method for measuring the ignition resistance of an industrial electronic detonator. Background Art

[0002] With rapid economic development, my country's infrastructure construction is also advancing rapidly. Digital electronic detonators are now widely used for blasting operations in engineering fields such as tunnel excavation, dangerous building reconstruction, and geological exploration. With their excellent cost-effectiveness and safety, digital electronic detonators have gradually replaced traditional electric detonators and noning cords. In industrial electronic detonators, the ignition resistor is a critical electronic component. Its main function is to discharge the energy storage capacitor to generate an electric spark, thereby detonating the ignition charge in the detonator's head. Ignition resistors come in a wide variety of types and shapes. Based on their resistance characteristics, they can be defined as small resistors ranging from 2Ω to 10Ω. These resistors can only pass an operating current of no more than 3mA, otherwise they risk burning out.

[0003] First, based on the characteristics of the ignition resistor mentioned above, how to measure tiny resistance values ​​within 10Ω has always been a technical challenge in the civil explosives industry. Second, electronic detonators are civilian pyrotechnic products, and to ensure measurement safety, there are strict requirements for measuring current. Third, the ignition resistor is closely related to the corresponding powder head and its corresponding charge. For reliable detonation, it is necessary to ensure that the resistance measurement error does not exceed 5%.

[0004] Therefore, the present invention proposes a method for measuring the ignition resistance of industrial electronic detonators. Summary of the Invention

[0005] The present invention provides a method for measuring the ignition resistance of industrial electronic detonators, so as to solve the above-mentioned technical problems.

[0006] The present invention provides a method for measuring the ignition resistance of an industrial electronic detonator, comprising: The measurement of the ignition resistance of industrial electronic detonators is realized based on a detection circuit, wherein the detection circuit includes: an MCU microcontroller U1, a single-pole double-throw physical relay U2, a relay switching transistor Q1, a voltage divider resistor R1 and a voltage divider resistor R2 of the measurement circuit, and a dual-channel integrated operational amplifier; Based on the single-pole double-throw physical relay U2 and the relay switching transistor Q1 switching the test state of the ignition resistor; The MCU microcontroller U1 outputs a weak signal at the millivolt level to the measurement circuit, controlling the specific voltage values ​​corresponding to points A and B based on the voltage divider resistors R1 and R2 under different test conditions; Based on the dual-channel integrated operational amplifier, the specific voltage values ​​of point A and point B are amplified by the same multiple, and then the current value flowing through the measurement circuit is calculated, and the ignition resistance value is calculated.

[0007] Preferably, the dual-channel integrated operational amplifier includes: an integrated operational amplifier U3 and an integrated operational amplifier U4; The connection method of the detection circuit is specifically as follows: Pin 1 of the MCU microcontroller U1 is connected to one end of the voltage divider resistor R1, Pin 2 of the MCU microcontroller U1 is connected to the input end of the integrated operational amplifier U3, and the output end of the integrated operational amplifier U3 is connected to one end of the voltage divider resistor R1; Pin 3 of the MCU microcontroller U1 is connected to the input end of the integrated operational amplifier U4, and the output end of the integrated operational amplifier U4 is connected to the other end of the voltage divider resistor R1; Pin 4 of the MCU microcontroller U1 is connected to the base of the relay switching transistor Q1, and the collector of the relay switching transistor Q1 is connected to pin 8 of the single-pole double-throw physical relay U2; Pin 1 of the single-pole double-throw physical relay U2 is connected to the power supply VCC, pin 3 of the single-pole double-throw physical relay U2 is connected to the other end of the voltage-dividing resistor R1, pin 6 of the single-pole double-throw physical relay U2 is connected to one end of the voltage-dividing resistor R2, pin 4 of the single-pole double-throw physical relay U2 is connected to the VB end of the ignition resistor RX, and pin 5 of the single-pole double-throw physical relay U2 is connected to the VX end of the ignition resistor RX; pin 2 of the single-pole double-throw physical relay U2 is short-circuited to pin 7; The third terminals of the integrated operational amplifier U3 and the integrated operational amplifier U4 are grounded respectively, and the emitter of the relay switch transistor Q1 and the other terminal of the voltage divider resistor R2 are grounded respectively.

[0008] Preferably, the test state of the ignition resistor includes: a bypass ignition resistor state and a connected ignition resistor state.

[0009] Preferably, when the test state is the bypass ignition resistor state, the connection mode of the corresponding bypass ignition resistor state equivalent circuit is specifically as follows: Pin 1 of the MCU microcontroller U1 is connected to one end of the voltage-dividing resistor R1, pin 2 of the MCU microcontroller U1 is connected to the input end of the integrated operational amplifier U3, the output end of the integrated operational amplifier U3 is connected to one end of the voltage-dividing resistor R1, pin 3 of the MCU microcontroller U1 is connected to the input end of the integrated operational amplifier U4, the output end of the integrated operational amplifier U4 is connected to the other end of the voltage-dividing resistor R1, the other end of the voltage-dividing resistor R1 is connected to one end of the measurement path line resistance Rd, and the other end of the measurement path line resistance Rd is connected to one end of the voltage-dividing resistor R2; The third terminals of the integrated operational amplifier U3 and the integrated operational amplifier U4 are grounded respectively, and the other terminal of the voltage divider resistor R2 is grounded.

[0010] Preferably, when the test state is the ignition resistor state, the connection mode of the corresponding ignition resistor state equivalent circuit is specifically as follows: Pin 1 of the MCU microcontroller U1 is connected to one end of the voltage-dividing resistor R1, pin 2 of the MCU microcontroller U1 is connected to the input end of the integrated operational amplifier U3, the output end of the integrated operational amplifier U3 is connected to one end of the voltage-dividing resistor R1, pin 3 of the MCU microcontroller U1 is connected to the input end of the integrated operational amplifier U4, the output end of the integrated operational amplifier U4 is connected to the other end of the voltage-dividing resistor R1, the other end of the voltage-dividing resistor R1 is connected to one end of the measurement path line resistance Rd, the other end of the measurement path line resistance Rd is connected to one end of the ignition resistor RX, and the other end of the ignition resistor RX is connected to one end of the voltage-dividing resistor R2; The third terminals of the integrated operational amplifier U3 and the integrated operational amplifier U4 are grounded respectively, and the other terminal of the voltage divider resistor R2 is grounded.

[0011] Preferably, the measurement path resistance Rd is calculated based on the bypass ignition resistor state equivalent circuit: ; Among them, Vadc1 and Vadc2 are respectively the measurement values ​​of MCU_ADC1 and MCU_ADC2 based on the low voltage output of the MCU microcontroller U1, and R1 and R2 are the resistance values ​​of the voltage divider resistor R1 and the voltage divider resistor R2.

[0012] Preferably, the value of the ignition resistor Rx is calculated based on the access ignition resistor state equivalent circuit: ; Among them, Vadc3 and Vadc4 are respectively the measurement values ​​of MCU_ADC3 and MCU_ADC4 based on the high voltage output of the MCU microcontroller U1.

[0013] Preferably, the MCU microcontroller U1 reads the voltage value of the ADC twice after outputting a low voltage, and reads the voltage value of the ADC twice after outputting a high voltage.

[0014] Compared with the prior art, the present invention has the following advantages: 1) The introduction of a physical relay effectively offsets the influence of line resistance on the measurement results through two measurement processes in different states, greatly improving measurement accuracy. 2) The introduction of dual integrated operational amplifiers ensures that the ADC voltage value read by the MCU is sufficiently accurate, thus ensuring measurement accuracy; 3) Two current-limiting and voltage-dividing resistors are introduced to make the measured current through the ignition resistor much smaller than the standard value, thus ensuring the safety of the measurement; 4) The ignition resistance value can be calculated by reading the ADC voltage value only four times, making the measurement software implementation simpler. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 A detection circuit diagram of a method for measuring the ignition resistance of an industrial electronic detonator according to an embodiment of the present invention; Figure 2 : is an equivalent circuit diagram of the bypass ignition resistor state in an embodiment of the present invention; Figure 3 This is an equivalent circuit diagram of the connected ignition resistor state in an embodiment of the present invention. DETAILED DESCRIPTION

[0016] The preferred embodiments of the present invention will be described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0017] The present invention provides a method for measuring the ignition resistance of an industrial electronic detonator, comprising: The measurement of the ignition resistance of industrial electronic detonators is realized based on a detection circuit, wherein the detection circuit includes: an MCU microcontroller U1, a single-pole double-throw physical relay U2, a relay switching transistor Q1, a voltage divider resistor R1 and a voltage divider resistor R2 of the measurement circuit, and a dual-channel integrated operational amplifier; Based on the single-pole double-throw physical relay U2 and the relay switching transistor Q1 switching the test state of the ignition resistor; The MCU microcontroller U1 outputs a weak signal at the millivolt level to the measurement circuit, controlling the specific voltage values ​​corresponding to points A and B based on the voltage divider resistors R1 and R2 under different test conditions; Based on the dual-channel integrated operational amplifier, the specific voltage values ​​of point A and point B are amplified by the same multiple, and then the current value flowing through the measurement circuit is calculated, and the ignition resistance value is calculated.

[0018] Preferably, the dual-channel integrated operational amplifier includes: an integrated operational amplifier U3 and an integrated operational amplifier U4; like Figure 1As shown, the connection method of the detection circuit is specifically as follows: pin 1 of the MCU microcontroller U1 is connected to one end of the voltage divider resistor R1, pin 2 of the MCU microcontroller U1 is connected to the input end of the integrated operational amplifier U3, and the output end of the integrated operational amplifier U3 is connected to one end of the voltage divider resistor R1; pin 3 of the MCU microcontroller U1 is connected to the input end of the integrated operational amplifier U4, and the output end of the integrated operational amplifier U4 is connected to the other end of the voltage divider resistor R1; Pin 4 of the MCU microcontroller U1 is connected to the base of the relay switching transistor Q1, and the collector of the relay switching transistor Q1 is connected to pin 8 of the single-pole double-throw physical relay U2; Pin 1 of the single-pole double-throw physical relay U2 is connected to the power supply VCC, pin 3 of the single-pole double-throw physical relay U2 is connected to the other end of the voltage-dividing resistor R1, pin 6 of the single-pole double-throw physical relay U2 is connected to one end of the voltage-dividing resistor R2, pin 4 of the single-pole double-throw physical relay U2 is connected to the VB end of the ignition resistor RX, and pin 5 of the single-pole double-throw physical relay U2 is connected to the VX end of the ignition resistor RX; pin 2 of the single-pole double-throw physical relay U2 is short-circuited to pin 7; The third terminals of the integrated operational amplifier U3 and the integrated operational amplifier U4 are grounded respectively, and the emitter of the relay switch transistor Q1 and the other terminal of the voltage divider resistor R2 are grounded respectively.

[0019] Preferably, the test state of the ignition resistor includes: a bypass ignition resistor state and a connected ignition resistor state.

[0020] Preferably, when the test state is the bypass ignition resistor state, the connection mode of the corresponding bypass ignition resistor state equivalent circuit is specifically as follows: like Figure 2 As shown, pin 1 of the MCU microcontroller U1 is connected to one end of the voltage-dividing resistor R1, pin 2 of the MCU microcontroller U1 is connected to the input end of the integrated operational amplifier U3, the output end of the integrated operational amplifier U3 is connected to one end of the voltage-dividing resistor R1, pin 3 of the MCU microcontroller U1 is connected to the input end of the integrated operational amplifier U4, the output end of the integrated operational amplifier U4 is connected to the other end of the voltage-dividing resistor R1, the other end of the voltage-dividing resistor R1 is connected to one end of the measurement path line resistance Rd, and the other end of the measurement path line resistance Rd is connected to one end of the voltage-dividing resistor R2; The third terminals of the integrated operational amplifier U3 and the integrated operational amplifier U4 are grounded respectively, and the other terminal of the voltage divider resistor R2 is grounded.

[0021] Preferably, when the test state is the ignition resistor state, the connection mode of the corresponding ignition resistor state equivalent circuit is specifically as follows: In this embodiment, the ignition resistor of a target industrial electronic detonator refers to the key resistor element used to generate the electric spark that detonates the charge. Its resistance is typically small and directly impacts the reliability and safety of the detonator's initiation, ensuring proper ignition during blasting operations. For example, in tunnel blasting, the accuracy of the ignition resistor's value can determine whether a blind shot or explosion refusal occurs.

[0022] like Figure 3 As shown, pin 1 of the MCU microcontroller U1 is connected to one end of the voltage-dividing resistor R1, pin 2 of the MCU microcontroller U1 is connected to the input end of the integrated operational amplifier U3, the output end of the integrated operational amplifier U3 is connected to one end of the voltage-dividing resistor R1, pin 3 of the MCU microcontroller U1 is connected to the input end of the integrated operational amplifier U4, the output end of the integrated operational amplifier U4 is connected to the other end of the voltage-dividing resistor R1, the other end of the voltage-dividing resistor R1 is connected to one end of the measurement path line resistance Rd, the other end of the measurement path line resistance Rd is connected to one end of the ignition resistor RX, and the other end of the ignition resistor RX is connected to one end of the voltage-dividing resistor R2; the third ends of the integrated operational amplifier U3 and the integrated operational amplifier U4 are grounded respectively, and the other end of the voltage-dividing resistor R2 is grounded.

[0023] Preferably, the measurement path resistance Rd is calculated based on the bypass ignition resistor state equivalent circuit: ; Among them, Vadc1 and Vadc2 are respectively the measurement values ​​of MCU_ADC1 and MCU_ADC2 based on the low voltage output of the MCU microcontroller U1, and R1 and R2 are the resistance values ​​of the voltage divider resistor R1 and the voltage divider resistor R2.

[0024] Preferably, the value of the ignition resistor Rx is calculated based on the access ignition resistor state equivalent circuit: ; Among them, Vadc3 and Vadc4 are respectively the measurement values ​​of MCU_ADC3 and MCU_ADC4 based on the high voltage output of the MCU microcontroller U1.

[0025] Preferably, the MCU microcontroller U1 reads the voltage value of the ADC twice after outputting a low voltage, and reads the voltage value of the ADC twice after outputting a high voltage.

[0026] In this embodiment, the MCU microcontroller U1 can be a general-purpose MCU or any main control chip. Its main functions are: first, outputting a controllable millivolt-level measurement voltage signal (MCU_DAC) to the measurement circuit, and also controlling other voltage-divider circuits to output a tiny measurement voltage; second, outputting high and low levels (MCU_GPIO) to control the relay switching switch, so that the relay switches to different measurement states; third, receiving the measurement signal output by the integrated operational amplifier (MCU_ADC1, MCU_ADC2); fourth, using the measurement data to calculate the specific value of the ignition resistor.

[0027] Single-pole, double-throw (SPDT) relay U2 and relay-switching transistor Q1 are used to switch between two different test states: "ignition resistor bypassed" and "ignition resistor engaged." Pin 1 of the relay is connected to the VCC power supply, pin 8 is connected to the collector of the switching transistor, pins 2 and 7 are short-circuited, pins 3 and 6 are connected to the measurement path, and pins 4 and 5 are connected to the electronic detonator's ignition resistor Rx. When the MCU outputs a low level, transistor Q1 is turned off, pins 3 and 2 of the relay are connected, and pins 6 and 7 are connected. The measurement circuit is short-circuited through pins 3, 2, 7, and 6 of the relay, placing the test circuit in the "ignition resistor bypassed" state. When the MCU outputs a high level, transistor Q1 is turned on, pins 3 and 4 of the relay are connected, and pins 6 and 5 are connected, connecting the ignition resistor Rx to the measurement circuit and placing the test circuit in the "ignition resistor engaged" state.

[0028] The voltage divider resistors (R1, R2) of the measuring circuit: their main functions are, first, to provide voltage divider for the entire measuring circuit and measure the Figure 1 The specific voltage values ​​at points A and B are used to calculate the current flowing through the measurement circuit and finally the ignition resistor value. Second, the entire measurement circuit is current-limited to ensure that the measurement current through the ignition resistor does not exceed the standard 3mA.

[0029] Integrated operational amplifiers (U3, U4): Their main function is to amplify the voltage values ​​at points A and B by the same multiple, making the voltage values ​​obtained by the MCU (MCU_ADC1, MCU_ADC2) more accurate.

[0030] Figure 2 Where "I1" is the measured current, "Vadc1" and "Vadc2" are the voltage readings of the MCU, "Ua" is the voltage at point A, "Ub" is the voltage at point B, and "Rd" is the measured resistance. "R1" and "R2" are known precision resistors.

[0031] The purpose of this measurement is to obtain the measured path resistance "Rd", and the steps to obtain it are as follows: Step 1: MCU outputs low level, and the relay is in the "bypass ignition resistor test state"; Step 2: MCU reads the measured values ​​of MCU_ADC1 and MCU_ADC2. Assuming the integrated amplifier amplification factor is β, then: Ua=Vadc1 / β, Ub=Vadc2 / β; --- Equation ① Step 3: Calculate the current "I1" in the measurement path according to Ohm's law: I1=(Ua-Ub) / R1=(Vadc1-Vadc2) / R1*β; -----Equation ② Step 4: Calculate the resistance value "Rd + R2". According to Ohm's law: Rd + R2 = Ub / I1, substitute into equations 1 and 2 to obtain the formula for calculating Rd: ; Figure 3 Here, "I2" is the measured current, "Vadc3" and "Vadc4" are the voltage readings from the MCU, "Ua" is the voltage at point A, "Ub" is the voltage at point B, and "Rd" is the measured resistance. "R1" and "R2" are known precision resistors, and "Rx" is the ignition resistance to be measured.

[0032] The purpose of this measurement is to obtain the ignition resistance value "Rx" to be measured. The acquisition steps are as follows: Step 1: MCU outputs a high level, switching the relay to the "ignition resistance test state"; Step 2: MCU reads the measured values ​​of MCU_ADC3 and MCU_ADC4. Assuming the integrated amplifier amplification factor is β, then: Ua=Vadc3 / β, Ub=Vadc4 / β; --- Equation ① Step 3: Calculate the current "I2" in the measurement path according to Ohm's law: I2=(Ua-Ub) / R1=(Vadc3-Vadc4) / R1*β;-----Equation ② Step 4: Calculate the resistance value "Rd + Rx + R2". According to Ohm's law: Rd + Rx + R2 = Ub / I2, substitute equation 1 and equation 2 to obtain the calculation formula for Rx:

[0033] Step 5: Combining Formula 1 and Formula 2, the final calculation formula for the ignition resistance value can be obtained: (R1 is a known resistance): .

[0034] The beneficial effects of the above technical solution are: 1) the introduction of a physical relay effectively offsets the influence of line resistance in the measurement path on the measurement result through two measurement processes in different states, greatly improving the measurement accuracy; 2) The introduction of dual integrated operational amplifiers ensures that the ADC voltage value read by the MCU is sufficiently accurate, thus ensuring measurement accuracy; 3) Two current-limiting and voltage-dividing resistors are introduced to make the measured current through the ignition resistor much smaller than the standard value, thus ensuring the safety of the measurement; 4) The ignition resistance value can be calculated by reading the ADC voltage value only four times, making the measurement software implementation simpler.

[0035] By switching between "bypassing the ignition resistor" and "connecting the ignition resistor," the MCU, relays, and operational amplifiers are used to calculate Rd (the measured line resistance) and Rx (the ignition resistor), addressing line resistance interference and measurement safety issues. However, this solution doesn't consider the impact of environmental factors (such as temperature, humidity, and air pressure) on resistance measurement. Environmental fluctuations can cause deviations in the actual value of Rd, affecting the accuracy of Rx calculations. Therefore, a dynamic environmental parameter correction mechanism is added. Sensors collect environmental data, combined with historical trend analysis, to perform real-time corrections to Rd. This ultimately improves Rx measurement accuracy, forming a closed-loop "hardware measurement + environmental correction" solution. Specifically, this solution includes: Based on multiple pre-installed sensors, multiple resistance measurement environmental parameters of the target industrial electronic detonator are collected to correct Rd, as follows: Environmental parameters are collected using multiple pre-installed sensors to obtain multiple initial resistance measurement environmental parameters of the target industrial electronic detonator; Determine the trend of environmental parameter changes for each sensor based on the historical resistance measurement of the environmental parameter for each sensor; Determining a degree of match between the initial resistance measurement environmental parameter and the corresponding environmental parameter change trend based on the environmental parameter change trend of each sensor, the initial resistance measurement environmental parameter corresponding to each sensor, and the acquisition time of each environmental parameter; If the matching degree exceeds the preset value, the initial resistance measurement environment parameters are determined as the resistance measurement environment parameters; If the matching degree does not exceed the preset value, the virtual environment parameters of the corresponding sensor are determined based on the trend of the environmental parameter change, and the resistance measurement environment parameters of the corresponding sensor are determined based on the virtual environment parameters and the initial resistance measurement environment parameters; determining a weight of each resistance measurement environmental parameter based on the degree of influence of each resistance measurement environmental parameter on the measurement of the ignition resistance of the target industrial electronic detonator; Constructing a measurement value correction matrix based on the weight of each resistance measurement environment parameter and each resistance measurement environment parameter; The adjustment matrix is ​​determined based on the circuit characteristics of the detection circuit. At the same time, the measurement characteristic vector of Rd is extracted through circuit detection. ; Correct Rd according to the adjustment matrix and the measurement value correction matrix to obtain the correction value;

[0036] in, is the correction value, is the feature scaling factor, To adjust the matrix, is the measurement correction matrix, Environmental inhibitory factors, is the smoothing constant, Frobenius norm of the measurement correction matrix.

[0037] In this embodiment, multiple sensors are deployed in environmental monitoring equipment near the industrial electronic detonator measurement area, covering key factors affecting resistance, such as temperature, humidity, and air pressure (because resistance increases with temperature, humidity may cause surface leakage, and air pressure affects the dielectric constant of air). The initial resistance measurement environmental parameters are the current environmental data collected by the sensors in real time and serve as the "original input" for correction. For example, the sensor selection includes: PT100 thermistor (accuracy of ±0.1°C, converted to a digital signal via ADC) for temperature, SHT35 digital sensor (accuracy of ±2%RH, I2C communication) for humidity, and BMP388 (accuracy of ±0.1kPa, sampling frequency of 1Hz) for air pressure. Specifically, three sensors are evenly arranged around the detonator test bench, with a spacing of ≤50cm to avoid local environmental deviations.

[0038] For data acquisition, an MCU (such as STM32F4) reads sensor data every 5 seconds and records the initial parameters such as [T=25.3℃, H=58%RH, P=101.2kPa].

[0039] Historical resistance measurement environmental parameters are long-term accumulated historical data from a single sensor (such as temperature records at 09:00 daily for the past year). They are used to explore patterns in environmental changes. Trends in environmental parameters are categorized into three types: Periodic trends (such as the daily temperature cycle of 2:00 PM and 6:00 AM): Use Fourier transform to extract the period or use moving average fitting (window = period length, such as 24 hours).

[0040] Linear trend (such as temperature rising by 0.5℃ each year): use linear regression (y=k*t+b, t is time, k is slope).

[0041] Nonlinear trends (such as seasonal fluctuations in humidity): Fit using LSTM neural networks or ARIMA models.

[0042] In this embodiment, the degree of matching is achieved based on |initial value - trend prediction value| / trend prediction value, which measures the degree of fit between real-time data and historical patterns (the greater the deviation, the higher the probability of sensor abnormality). The preset value is the maximum allowable deviation (e.g., 5%, determined by a reasonable range of fluctuations in the experimental test environment).

[0043] Trend prediction predicts that the temperature at the current time (such as 2025 / 07 / 22 14:30) will be 25.0°C. For example, if the initial value is 25.8°C, the matching degree is |25.8-25.0| / 25.0=3.2%<5% (does not exceed the preset value and requires further processing).

[0044] The preset value calibration is to simulate environmental fluctuations in a constant temperature box and measure the maximum matching degree when the Rx error is ≤3%, which is set to 5%.

[0045] The virtual environment parameters are the “theoretical values” predicted by the trend model (environmental values ​​when there are no sensor errors).

[0046] The resistance measurement environment parameters are the effective parameters (the fusion results of the initial values ​​or virtual values) ultimately used for correction.

[0047] For example: Virtual parameter generation: The trend model predicts the temperature to be 25.0℃ (virtual value).

[0048] Threshold judgment: Set the temperature threshold to 1°C (through experiments, when the temperature deviation is >1°C, the Rx error exceeds 5%).

[0049] Fusion logic: Initial temperature 25.8°C vs. virtual temperature 25.0°C, difference 0.8°C < 1°C → average temperature 25.4°C.

[0050] If the initial temperature is 23.0℃ (difference 2.0℃>1℃) → directly use the virtual value 25.0℃.

[0051] Threshold calibration: Test the rate of change of Rx with temperature in a high and low temperature chamber (for example, Rx changes by 0.5Ω for every 1°C change in temperature), and infer the allowable temperature deviation.

[0052] The measurement impact is the degree to which environmental parameters affect the Rx measurement (quantified through experiments, such as the effect of temperature on resistance is much greater than that of humidity).

[0053] Weight is the priority assigned to a modification based on its impact (the greater the impact, the higher the weight).

[0054] Temperature influence: In a constant temperature chamber, keep the humidity and air pressure constant and measure the change of Rx with temperature (e.g., when T changes from 20 to 30°C, Rx changes from 10 to 10.5Ω, with a change rate of 0.05Ω / °C).

[0055] Humidity influence: In a humidity chamber, keep the temperature and air pressure constant and measure the change of Rx with humidity (e.g., when H changes from 50 to 60% RH, Rx changes from 10 to 10.1Ω, with a change rate of 0.01Ω / %RH).

[0056] Weight calculation: total influence 0.05+0.01+0.001=0.061 (the influence of air pressure can be ignored, set as 0.001), so the weight of temperature is 0.82 (0.05 / 0.061), humidity 0.16 (0.01 / 0.061), and air pressure 0.02 (normalized).

[0057] In this embodiment, the measurement value correction matrix is ​​a matrix constructed by the weights and values ​​of the environmental parameters, and is used to systematically correct the measurement values. for: ; in, is the environmental parameter weight vector, is the adjusted resistance measurement environment parameter vector, is the n-dimensional identity matrix, is the environmental coupling gain coefficient.

[0058] In this embodiment, the adjustment matrix is ​​defined based on the characteristics of the measurement system, where the characteristics of the measurement system include, for example, signal amplification factor.

[0059] In this embodiment, The physical meaning of is to quantify the influence of environmental parameters on Rd and the coupling effect between parameters (such as temperature and humidity interaction); The physical meaning of quantization is the distortion of the measured signal caused by the non-ideal characteristics of the circuit (such as gain drift leading to voltage amplification error).

[0060] The circuit characteristics are the hardware characteristics of the detection circuit (such as operational amplifier gain and relay switching time, which affect the signal acquisition accuracy), and the adjustment matrix quantifies the impact of the circuit characteristics on the measurement (for example, if the gain is 100, the matrix contains 100 elements).

[0061] The measurement characteristic vector is the signal characteristic during Rd measurement (such as voltage fluctuation standard deviation and current stability, reflecting the measurement quality). Circuit characteristic measurement: operational amplifier U2 gain G=100 (multimeter measures input-output voltage ratio), relay K1 switching time t=10ms (oscilloscope measures level jump).

[0062] Adjust the matrix A=diag([100,1 / 10,...]) (the gain amplifies the signal, and the switching time affects the measurement timing).

[0063] Feature vector extraction: collect 100 Rd voltage values ​​and calculate the standard deviation (reflects fluctuations), current stability = ±0.05mA, forming a vector .

[0064] The feature scaling factor is used to limit the correction amplitude (for example, setting it to 0.1 can avoid over-correction in extreme environments).

[0065] The environmental suppression factor weakens strong environmental interference and is generally 0.05.

[0066] The smoothing constant is to prevent the denominator from being zero (such as , to ensure stable operation).

[0067] In this embodiment, The function limits the correction amplitude through saturation characteristics to avoid excessive correction in extreme environments (for example, high temperature causes the theoretical correction value to far exceed the actual value, and tanh will compress its influence). The exp function: reflects the global attenuation of environmental interference. When the norm of the environmental correction matrix is ​​large (interference is strong), the exp term approaches 0, and the correction is mainly dominated by the local nonlinear characteristics of tanh; when the interference is weak, the exp term approaches 1, and the two work together to correct.

[0068] That is: if the environmental interference is strong ( large), the exp term approaches 0, and the correction is mainly dominated by the tanh term; If the environmental interference is weak ( small), the exp term approaches 1, and the two are corrected together.

[0069] The beneficial effects of the above scheme are as follows: The environmental parameter change trend is determined through the historical data of each sensor. Combined with the environmental parameter change trend, it is determined whether the initial resistance measurement environmental parameters conform to the change trend. If they do, the initial resistance measurement environmental parameters are used as the resistance measurement environmental parameters. If they do not, a virtual value is determined based on the change trend, and the two are combined to obtain the resistance measurement environmental parameters. This can prevent the impact of sensor problems on the resistance measurement environmental parameters. The weight of each resistance measurement environmental parameter is determined by the degree of influence of the resistance measurement environmental parameters on the ignition resistance of the target industrial electronic detonator. Combining the weight of each resistance measurement environmental parameter with each resistance measurement environmental parameter, a measurement value correction matrix is ​​constructed. Combined with the measurement characteristics, an adjustment matrix is ​​determined to correct Rd. This improves the measurement reliability of the ignition resistance of industrial electronic detonators from the two dimensions of "hardware measurement accuracy assurance" and "software environmental interference elimination," meeting the strict resistance accuracy requirements (error ≤ 5%) for blasting operations.

[0070] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A method for measuring the ignition resistance of industrial electronic detonators, characterized in that: include: The measurement of the ignition resistance of industrial electronic detonators is realized based on a detection circuit, wherein the detection circuit includes: an MCU microcontroller U1, a single-pole double-throw physical relay U2, a relay switching transistor Q1, a voltage divider resistor R1 and a voltage divider resistor R2 of the measurement circuit, and a dual-channel integrated operational amplifier; Based on the single-pole double-throw physical relay U2 and the relay switching transistor Q1 switching the test state of the ignition resistor; The MCU microcontroller U1 outputs a weak signal at the millivolt level to the measurement circuit, controlling the specific voltage values ​​corresponding to points A and B based on the voltage divider resistors R1 and R2 under different test conditions; Based on the dual-channel integrated operational amplifier, the specific voltage values ​​of point A and point B are amplified by the same multiple, and then the current value flowing through the measurement circuit is calculated, and the ignition resistance value is calculated.

2. The method for measuring the ignition resistance of industrial electronic detonators according to claim 1, characterized in that: The dual-channel integrated operational amplifier includes: an integrated operational amplifier U3 and an integrated operational amplifier U4; The connection method of the detection circuit is specifically as follows: Pin 1 of the MCU microcontroller U1 is connected to one end of the voltage divider resistor R1, Pin 2 of the MCU microcontroller U1 is connected to the input end of the integrated operational amplifier U3, and the output end of the integrated operational amplifier U3 is connected to one end of the voltage divider resistor R1; Pin 3 of the MCU microcontroller U1 is connected to the input end of the integrated operational amplifier U4, and the output end of the integrated operational amplifier U4 is connected to the other end of the voltage divider resistor R1; Pin 4 of the MCU microcontroller U1 is connected to the base of the relay switching transistor Q1, and the collector of the relay switching transistor Q1 is connected to pin 8 of the single-pole double-throw physical relay U2; Pin 1 of the single-pole double-throw physical relay U2 is connected to the power supply VCC, pin 3 of the single-pole double-throw physical relay U2 is connected to the other end of the voltage-dividing resistor R1, pin 6 of the single-pole double-throw physical relay U2 is connected to one end of the voltage-dividing resistor R2, pin 4 of the single-pole double-throw physical relay U2 is connected to the VB end of the ignition resistor RX, and pin 5 of the single-pole double-throw physical relay U2 is connected to the VX end of the ignition resistor RX; pin 2 of the single-pole double-throw physical relay U2 is short-circuited to pin 7; The third terminals of the integrated operational amplifier U3 and the integrated operational amplifier U4 are grounded respectively, and the emitter of the relay switch transistor Q1 and the other terminal of the voltage divider resistor R2 are grounded respectively.

3. The method for measuring the ignition resistance of industrial electronic detonators according to claim 2, characterized in that: The test state of the ignition resistor includes: a bypass ignition resistor state and a connected ignition resistor state.

4. The method for measuring the ignition resistance of industrial electronic detonators according to claim 3, characterized in that: When the test state is the bypass ignition resistor state, the corresponding bypass ignition resistor state equivalent circuit connection method is as follows: Pin 1 of the MCU microcontroller U1 is connected to one end of the voltage-dividing resistor R1, pin 2 of the MCU microcontroller U1 is connected to the input end of the integrated operational amplifier U3, the output end of the integrated operational amplifier U3 is connected to one end of the voltage-dividing resistor R1, pin 3 of the MCU microcontroller U1 is connected to the input end of the integrated operational amplifier U4, the output end of the integrated operational amplifier U4 is connected to the other end of the voltage-dividing resistor R1, the other end of the voltage-dividing resistor R1 is connected to one end of the measurement path line resistance Rd, and the other end of the measurement path line resistance Rd is connected to one end of the voltage-dividing resistor R2; The third terminals of the integrated operational amplifier U3 and the integrated operational amplifier U4 are grounded respectively, and the other terminal of the voltage divider resistor R2 is grounded.

5. The method for measuring the ignition resistance of industrial electronic detonators according to claim 3, characterized in that: When the test state is the ignition resistor state, the corresponding connection mode of the ignition resistor state equivalent circuit is as follows: Pin 1 of the MCU microcontroller U1 is connected to one end of the voltage-dividing resistor R1, pin 2 of the MCU microcontroller U1 is connected to the input end of the integrated operational amplifier U3, the output end of the integrated operational amplifier U3 is connected to one end of the voltage-dividing resistor R1, pin 3 of the MCU microcontroller U1 is connected to the input end of the integrated operational amplifier U4, the output end of the integrated operational amplifier U4 is connected to the other end of the voltage-dividing resistor R1, the other end of the voltage-dividing resistor R1 is connected to one end of the measurement path line resistance Rd, the other end of the measurement path line resistance Rd is connected to one end of the ignition resistor RX, and the other end of the ignition resistor RX is connected to one end of the voltage-dividing resistor R2; The third terminals of the integrated operational amplifier U3 and the integrated operational amplifier U4 are grounded respectively, and the other terminal of the voltage divider resistor R2 is grounded.

6. The method for measuring the ignition resistance of industrial electronic detonators according to claim 4, characterized in that: The measurement path resistance Rd is calculated based on the bypass ignition resistor state equivalent circuit: ； Among them, Vadc1 and Vadc2 are respectively the measurement values ​​of MCU_ADC1 and MCU_ADC2 based on the low voltage output of the MCU microcontroller U1, and R1 and R2 are the resistance values ​​of the voltage divider resistor R1 and the voltage divider resistor R2.

7. The method for measuring the ignition resistance of industrial electronic detonators according to claim 6, characterized in that: The value of the ignition resistor Rx is calculated based on the equivalent circuit of the access ignition resistor state: ； Among them, Vadc3 and Vadc4 are respectively the measurement values ​​of MCU_ADC3 and MCU_ADC4 based on the high voltage output of the MCU microcontroller U1.

8. The method for measuring the ignition resistance of industrial electronic detonators according to claim 1, characterized in that: The MCU microcontroller U1 reads the voltage value of the ADC twice after outputting a low voltage, and reads the voltage value of the ADC twice after outputting a high voltage.

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