Demodulation mechanism and method with wireless detonator through-the-earth communication

Abstract

The invention belongs to the technical field of blasting electronics. A demodulation mechanism with a wireless detonator through-the-earth communication function comprises an antenna module used for receiving signals; the amplifier is connected with the antenna module and is used for performing multiple amplification on the signal received by the antenna module; the AGC control circuit is connected with the amplifier and used for controlling the amplification factor of the amplifier; the multi-channel crystal oscillator array circuit is connected with the amplifier and is used for receiving the signals after multiple amplification, performing frequency selection and sending out frequency signals; the follower is connected with the multi-channel crystal oscillator array circuit and is used for receiving the frequency signal and transmitting the frequency signal to the peak detector and the plurality of detonator MCUs respectively; the peak detector is connected with the AGC control circuit and used for sending a feedback signal to the AGC control circuit so that the AGC control circuit can adjust the amplification factor according to the feedback signal, and the feedback signal represents that the signal amplitude is in one of an over-low state, a normal state and an over-saturated state.

Description

Technical Field

[0001] This application belongs to the field of explosive electronics technology, and in particular relates to a demodulation mechanism and method with wireless detonator through-ground communication. Background Technology

[0002] In the field of blasting engineering, electronic detonators have gradually replaced traditional pyrotechnics. Early wired electronic detonators transmitted power and signals via physical wires, relying on embedded microcontrollers for high-precision timing control and multi-factor authentication. With technological advancements, wireless electronic detonators emerged, using radio frequency communication to replace wire connections. They achieve group control of detonators through star or self-organizing network topologies, and in surface environments, utilize specific industrial frequency bands and precise clock synchronization protocols to ensure communication reliability. Regarding signal demodulation, current mainstream solutions mostly employ fixed-gain amplifiers to amplify the signal.

[0003] The shortcomings of existing technology are: Large-scale blasting projects require laying several kilometers of cables, which increases construction time and costs. Furthermore, the cables are prone to breakage and the joints are susceptible to corrosion, resulting in a high rate of duds. Laying cables in complex terrains such as steep slopes and gullies is difficult and has poor terrain adaptability.

[0004] Challenges of underground applications of wireless electronic detonators: When used underground, signal transmission through rock and soil layers faces extreme channel characteristics. Rock layers strongly absorb electromagnetic waves, causing the signal to attenuate exponentially, with even more severe attenuation in metal ore bodies. Reflection from tunnel walls creates multipath effects, resulting in severe signal distortion. The large differences in distance between the detonator and the controller at the blasting site lead to extremely wide fluctuations in the received signal strength, making it difficult for traditional circuits to simultaneously address the issues of strong signal saturation and weak signal submersion.

[0005] Inadequate response to electromagnetic interference: High-power power systems in mines generate low-frequency, high-amplitude power frequency interference, and the operation of rock drilling equipment induces broadband vibration interference. Existing demodulation solutions have weak anti-interference capabilities and cannot effectively cope with complex electromagnetic environments. Summary of the Invention

[0006] Therefore, it is necessary to provide a demodulation mechanism and method with wireless detonator ground-penetrating communication to address the above-mentioned technical problems.

[0007] Firstly, this application provides a demodulation mechanism with wireless detonator ground-penetrating communication, the demodulation mechanism comprising: Antenna module, used to receive signals; An amplifier, connected to the antenna module, is used to amplify the signal received by the antenna module by a factor. The AGC control circuit is connected to the amplifier and is used to control the amplification factor of the amplifier. A multi-channel crystal oscillator array circuit, connected to the amplifier, is used to receive the amplified signal, perform frequency selection, and emit a frequency signal. A follower, connected to the multi-channel crystal oscillator array circuit, is used to receive the frequency signal and transmit it to the peak detector and multiple detonator MCUs respectively; The peak detector is connected to the AGC control circuit and is used to send a feedback signal to the AGC control circuit so that the AGC control circuit can adjust the amplification factor according to the feedback signal. The feedback signal indicates that the signal amplitude is in one of the following states: too low, normal, or oversaturated.

[0008] In one implementable manner, the AGC control circuit is configured as follows: The signal amplitude is divided into multiple intervals, each corresponding to a different gain adjustment rate, forming a segmented adjustment mechanism.

[0009] In one implementable manner, the multi-channel crystal array circuit is configured as follows: The signal-to-noise ratio (SNR) of the output signal of each crystal channel in the multi-channel crystal array circuit is monitored in real time, and the crystal channel with the highest SNR is selected as the current working channel.

[0010] In one feasible embodiment, in the multi-channel crystal array circuit, a fine-tuning capacitor is connected in parallel across the two ends of each crystal.

[0011] In one implementable manner, the multi-channel crystal array circuit includes Crystal oscillators of different frequencies, and analog switches, the analog switches and Crystal oscillators of different frequencies are connected respectively. A series of crystal oscillators of different frequencies are connected in parallel, covering the communication frequency band from 1kHz to 300kHz; each crystal oscillator serves as a crystal oscillator channel, and the center frequency of each crystal oscillator channel is such that the frequency interval Δf < the channel coherence bandwidth; the analog switch is used to switch the current crystal oscillator channel to the corresponding frequency crystal oscillator channel according to the frequency matched by the transmitter.

[0012] In one implementable embodiment, a comparator is further included, which is connected to the follower, the detonator MCU, and the peak detector, respectively, for comparing and processing the signal output by the follower with a reference signal provided by the peak detector, and sending the processed signal to the detonator MCU.

[0013] In one feasible embodiment, the antenna module includes an antenna and a resonant capacitor connected in parallel with the antenna to form a resonant circuit, which is connected to the amplifier for transmitting a filtered signal to the amplifier.

[0014] In one feasible embodiment, a low-noise preamplifier circuit is further included, which is connected to both the amplifier and the resonant circuit, for amplifying the weak signal sent to the amplifier.

[0015] In one feasible embodiment, a signal detection circuit and a battery are also included, the battery being connected to and powered by the antenna module, the amplifier, the AGC control circuit, the multi-channel crystal array circuit, the follower, and the peak detector; the signal detection circuit, connected to the battery, is used to detect signals emitted by the transmitter and captured by the antenna module.

[0016] Secondly, this application provides a demodulation method with wireless detonator through-ground communication, applied to the aforementioned demodulation mechanism with wireless detonator through-ground communication, the method comprising: The antenna module receives wireless signals transmitted through ground and, with the combined effect of the resonant capacitor, enhances the reception of signals at a preset frequency and transmits the signals to the amplifier. Under the control of the AGC control circuit, the amplifier amplifies the received signal by a factor to form an amplified signal; The amplified signal is input to the multi-channel crystal oscillator array circuit. The analog switch switches to the corresponding crystal oscillator channel according to the preset frequency matched with the transmitter, performs frequency selection processing on the signal, and transmits the frequency-selected output signal to the follower. The follower isolates the amplified signal and outputs it to the non-inverting inputs of the peak detector and the comparator, respectively. The peak detector detects the amplitude of the follower's output signal. If it determines that the signal amplitude is too low, it feeds a signal to the AGC control circuit, which then controls the amplifier to increase its amplification factor. If the signal amplitude is oversaturated, it feeds a signal to the AGC control circuit, which then controls the amplifier to decrease its amplification factor. If the signal amplitude is within the normal range, the amplifier's amplification factor remains unchanged. Simultaneously, the peak detector inputs a reference signal to the inverting input of the comparator, where the reference signal represents a DC voltage proportional to the signal amplitude. The comparator compares and processes the signal at the non-inverting input and the reference signal at the inverting input, and outputs the processed signal to the detonator MCU. The detonator MCU analyzes the received signals and, based on the analysis results, controls the detonator execution interface to complete the corresponding actions.

[0017] Beneficial Effects: A demodulation mechanism for wireless detonator through-ground communication effectively overcomes the core channel challenges in through-ground communication by introducing a multi-channel crystal oscillator array circuit and an adaptive control circuit (AGC) working in tandem. The multi-channel crystal oscillator array circuit utilizes multiple high-Q crystal oscillators connected in parallel to cover the communication frequency band. Its narrowband frequency selection characteristics can accurately filter out persistent strong noise such as mine power frequency interference and vibration interference from rock drilling equipment, significantly improving anti-interference capabilities. Simultaneously, the AGC control circuit dynamically adjusts the amplifier gain based on feedback from the peak detector, enabling the circuit to automatically adapt to drastic fluctuations in signal strength caused by differences in blasting distance and rock layer attenuation, solving the problems of strong signal saturation and weak signal overwhelmance, and ensuring that the signal is always within a resolvable and reasonable range. Ultimately, this significantly improves the communication reliability and stability of wireless detonators in complex underground environments, thereby effectively reducing the dud rate and ensuring the safety and efficiency of blasting projects. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a block diagram of a demodulation method for wireless detonator ground communication, which includes a demodulation mechanism for wireless detonator ground communication in one embodiment. Figure 2 This is a block diagram of a multi-channel crystal oscillator array circuit with a demodulation mechanism for wireless detonator ground-penetrating communication in one embodiment. Figure 3 This is an adaptive gain control circuit diagram for wireless detonator through-ground communication, which includes a demodulation mechanism for wireless detonator through-ground communication in one embodiment. Figure 4 This is a flowchart of a demodulation method with wireless detonator ground-penetrating communication in one embodiment.

[0020] Figure label: 1. AGC control circuit; 2. Peak detector; 3. Amplifier; 4. Comparator; 5. Detonator MCU; 6. Follower; 7. Multi-channel crystal oscillator array circuit; 8. Resonant capacitor; 9. Antenna; 10. Input signal; 11. Crystal oscillator 1; 12. Crystal oscillator 2; 13. Crystal oscillator n; 14. Analog switch; 15. Output signal. Detailed Implementation

[0021] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all couplings of one or more of the associated listed items.

[0023] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another.

[0024] The following explanations of some terms used in this application are provided to aid in understanding the application: AGC is an abbreviation for Automatic Gain Control. It is a circuit or algorithm that can automatically adjust the gain (amplification factor) of an amplifier (or system) in real time according to the strength of the input signal, so that the amplitude of the output signal is kept within a relatively stable and ideal range.

[0025] MCU is an abbreviation for Microcontroller Unit. A microcontroller, commonly known as a "single-chip computer", is a microcomputer system that integrates a central processing unit (CPU), memory (RAM, ROM), timer / counter, and various input / output interfaces (I / O) on a single chip.

[0026] The common-emitter amplifier circuit is one of the most basic and commonly used amplifier circuit configurations constructed using bipolar junction transistors (BJTs). Its core feature is that the emitter of the transistor serves as the common reference terminal (i.e., "ground" or common terminal) for both the input and output signals, hence the name "common-emitter" or simply "common-emitter".

[0027] like Figures 1 to 3 In one aspect, this application provides a demodulation mechanism with wireless detonator ground communication, including an antenna module, an amplifier 3, an AGC control circuit 1, a multi-channel crystal oscillator array circuit 7, a follower 6, a peak detector 2, and multiple detonator MCUs 5.

[0028] The antenna module is used to receive signals. The antenna module may include an antenna 9 and a resonant capacitor 8. The resonant capacitor 8 is connected in parallel with the antenna 9 to form a resonant circuit. The resonant circuit is connected to an amplifier 3 to send filtered signals to the amplifier 3.

[0029] Specifically, antenna 9 acts as an electromagnetic wave converter, and its core function is to couple the time-varying electromagnetic field propagating in the ground and convert it into an alternating voltage signal (i.e., an electrical signal) of the corresponding frequency. Considering the characteristics of low-frequency (1kHz-300kHz) communication through the ground, antenna 9 typically adopts a design such as a ferrite rod antenna or a large-size loop antenna to optimize the reception efficiency of low-frequency magnetic fields.

[0030] The resonant circuit formed by the resonant capacitor 8 and the receiving antenna 9 connected in parallel has the core function of frequency selectivity and signal enhancement. The specific process is as follows: Formation of resonant point: This parallel LC circuit has an inherent resonant frequency. Its calculation formula is Where L is the equivalent inductance of antenna 9 and C is the capacitance of parallel resonant capacitor 8.

[0031] By designing and matching the parameters of L and C, the resonant frequency of the circuit can be determined. Adjust it to the communication frequency band used by the wireless detonator system (e.g., a specific center frequency such as 50kHz).

[0032] When electromagnetic signals of various frequencies in the air and on the ground are received by antenna 9, only those with frequencies equal to or close to the circuit's resonant frequency will receive the signal. Only signals of a specific frequency can resonate within the circuit. At the resonant point, the circuit's impedance to that frequency signal reaches its maximum, thus maximizing the establishment of the signal voltage at both ends of the circuit. For frequencies deviating from this range... Interference signals (such as power frequency interference in mines and electromagnetic noise from other equipment) are effectively attenuated or short-circuited due to the very low impedance of the circuit. This achieves preliminary filtering and purification of the target communication signal. Next, the relatively "clean" target frequency signal, after being filtered and enhanced by the resonant circuit, is directly fed to the input of amplifier 3.

[0033] The resonant circuit of the antenna module performs a first-stage coarse frequency selection, which is then combined with the subsequent multi-channel crystal oscillator array circuit 7 for a second-stage fine frequency selection. This two-stage frequency selection architecture greatly enhances the system's anti-interference capability, ensuring reliable extraction of effective signals even in complex mining electromagnetic environments. Furthermore, ground-penetrating signals attenuate significantly, reaching antenna 9 at very weak levels. The signal amplification effect of the resonant circuit ensures that these weak signals are fed into amplifier 3 with the highest possible voltage amplitude, creating favorable conditions for subsequent low-noise amplification and adaptive gain adjustment.

[0034] Amplifier 3 is connected to the antenna module and is used to amplify the signal received by the antenna module.

[0035] Furthermore, a low-noise preamplifier circuit can be installed before amplifier 3. The low-noise preamplifier circuit is connected to amplifier 3 and resonant circuit respectively, and is used to amplify the weak signal sent to amplifier 3.

[0036] It should be noted that amplifier 3 is the core execution unit for signal amplification and has an adjustable amplification factor. The input terminal of amplifier 3 is directly or indirectly connected to the output terminal of the antenna module (i.e., the parallel resonant circuit of antenna 9) to receive the signal after preliminary filtering by the resonant circuit.

[0037] It should also be noted that, in order to optimize the reception of weak signals, a low-noise preamplifier circuit is added before amplifier 3 at the very beginning of the signal path, based on the above scheme. After long-distance attenuation through the ground, the signal reaching antenna 9 may be very weak, comparable to the noise level of the circuit itself. If directly fed into the main amplifier 3, the signal may be submerged in noise. The low-noise preamplifier circuit is inserted between the antenna module and amplifier 3. Its input is connected to the output of the resonant circuit of antenna 9 to perform initial amplification of the captured raw signal; its output is then connected to the input of amplifier 3.

[0038] Low-noise preamplifier circuits use low-noise components (such as the low-noise transistor 2N5088) and circuit structures (such as common-emitter amplifier circuits), resulting in low electronic noise (measured by the noise figure, which can be less than 2dB). In other words, low-noise preamplifier circuits introduce very little additional noise while amplifying the signal.

[0039] The function of a low-noise preamplifier circuit is to amplify the weak effective signal by a fixed gain (e.g., 20dB) at the beginning of the signal chain, before circuit noise becomes predominant. This increases the signal amplitude to a level far exceeding the noise levels of subsequent circuits.

[0040] The signal, after initial enhancement by the low-noise preamplifier circuit, is then fed into amplifier 3 for gain adjustment. This two-stage architecture of "low-noise fixed-gain preamplifier + adaptive variable-gain main amplifier" ensures that even weak effective signals can be amplified in the initial stage, avoiding being drowned out by noise in subsequent circuits, thereby significantly improving the signal-to-noise ratio and sensitivity when receiving signals at long distances or in environments with strong attenuation.

[0041] AGC control circuit 1 is connected to amplifier 3 and is used to control the amplification factor of amplifier 3.

[0042] Specifically, the AGC control circuit 1 is configured to divide the signal amplitude into multiple intervals, each interval corresponding to a different gain adjustment rate, forming a segmented adjustment mechanism.

[0043] It should be noted that the task of AGC control circuit 1 is to dynamically manage the amplification factor of amplifier 3 in order to deal with the problem of drastic and rapid fluctuations in signal strength in transparent ground communication, and to ensure that the signal amplitude delivered to the subsequent processing circuit is always stable within the optimal range.

[0044] AGC control circuit 1 constitutes a complete closed-loop automatic control system, and its working process is as follows: Peak detector 2 continuously monitors the amplitude (voltage value) of the final output signal after amplification and frequency selection. Peak detector 2 compares the monitored signal amplitude with an internally preset threshold to determine the current signal state (e.g., too low, normal, or oversaturated), and feeds this determination back to AGC control circuit 1 in real time as an electrical signal. AGC control circuit 1 generates a corresponding control signal (usually voltage or current) based on the received feedback signal, immediately adjusting the amplification factor (gain) of main amplifier 3. Specifically, if the signal is too low, amplifier 3 is instructed to increase its gain. If the signal is oversaturated, amplifier 3 is instructed to decrease its gain. If the signal is normal, the current gain remains unchanged. Through this continuous "monitoring-judgment-adjustment" closed loop, the system achieves automatic stabilization of the signal amplitude.

[0045] Furthermore, in order to overcome the potential overshoot or slow adjustment problems of the simple AGC control circuit 1, this application utilizes a segmented adjustment mechanism to divide the signal amplitude into multiple different intervals and adopt a differentiated adjustment strategy in each interval.

[0046] For example, the specific adjustment logic is as follows: The first interval is the low signal strength region (fast tracking). When peak detector 2 detects that the signal amplitude is below the lower threshold (e.g., 0.5V), it indicates that the signal is very weak and at risk of being overwhelmed by noise. AGC control circuit 1 activates high-speed gain boost mode, which rapidly increases the amplification factor of amplifier 3 at a relatively fast rate (e.g., 5dB gain per second). The purpose is to amplify the weak signal to a identifiable level as quickly as possible, reducing the probability of signal loss.

[0047] Second interval: Normal signal state region (fine-tuning), where the signal amplitude is within the ideal normal range (e.g., between 0.5V and 2V). AGC control circuit 1 switches to low-speed gain adjustment mode. The gain adjustment rate becomes very slow (e.g., 1dB per second), or not adjusted at all. This avoids frequent and large-scale gain adjustments when the signal is good, thus preventing the introduction of unnecessary adjustment noise, maintaining high output stability, and providing a smooth signal for subsequent comparator 4 decision.

[0048] The third zone: signal oversaturation state zone (rapid protection). When the signal amplitude exceeds the upper limit threshold (e.g., 2V), amplifier 3 faces the risk of saturation distortion. AGC control circuit 1 activates gain reduction mode, rapidly reducing the gain rate of amplifier 3 (e.g., reducing by 8dB per second). This quickly pulls the signal back to the normal range, preventing information loss or misjudgment due to signal clipping (saturation distortion) and protecting amplifier 3 from overload.

[0049] The AGC control circuit 1 achieves intelligent and differentiated response to signal strength through a segmented adjustment mechanism, ensuring both the sensitivity to quickly capture weak signals and the stability and security under strong signals.

[0050] The multi-channel crystal oscillator array circuit 7 is connected to the amplifier 3 to receive the amplified signal, perform frequency selection, and emit a frequency signal.

[0051] Specifically, the multi-channel crystal oscillator array circuit 7 is configured to: monitor the signal-to-noise ratio of the output signal of each crystal oscillator channel in the multi-channel crystal oscillator array circuit 7 in real time, and select the crystal oscillator channel with the highest signal-to-noise ratio as the current working channel.

[0052] It should be noted that the multi-channel crystal oscillator array circuit 7 includes Crystal oscillators of different frequencies, and analog switch 14, analog switch 14 and Crystal oscillators of different frequencies are connected respectively. Several crystal oscillators of different frequencies are connected in parallel, covering the communication frequency band from 1kHz to 300kHz. Each crystal oscillator acts as an independent crystal channel, and the center frequency of each crystal channel is its nominal frequency. The frequency interval Δf is less than the channel coherence bandwidth. In other words, at any given moment in communication, the main energy of the signal is concentrated within a very narrow frequency range, which falls within the effective bandwidth of a particular crystal channel. The purpose of this design is to ensure that the signal can be completely captured by a single channel, without signal loss or attenuation due to frequency deviations between two channels. For example, the frequency interval is Δf = 200Hz.

[0053] Analog switch 14 is used to switch the current crystal oscillator channel to the corresponding frequency channel based on the transmitter's matched frequency. The input of analog switch 14 receives the amplified signal from amplifier 3, and its multiple outputs are connected to each crystal oscillator. The function of analog switch 14 is to connect the input signal to a specific crystal oscillator channel according to control commands. These control commands can be implemented by real-time monitoring of the signal-to-noise ratio (SNR) of the output signals from each crystal oscillator channel and selecting the channel with the highest SNR as the current operating channel.

[0054] To achieve real-time monitoring of the signal-to-noise ratio (SNR) of the output signals from each crystal oscillator channel, a signal quality detection module can be constructed. This module monitors the SNR of the output signals from each crystal oscillator channel in real time. The signal quality detection module can be implemented using a single integrated circuit, and it monitors all crystal oscillator channels (…). The core metric for output signal quality is the signal-to-noise ratio (SNR). Continuously comparing the SNR of all channels follows a simple decision rule: always select the channel with the highest current SNR. Once the signal quality detection module determines that another channel (e.g., f5) has a better SNR than the currently used channel (e.g., f2), it immediately generates a new control command and sends it to analog switch 14.

[0055] The above method achieves frequency self-adaptation. By continuously tuning and automatically finding the optimal working channel, it greatly improves anti-interference capability and communication reliability in complex and ever-changing underground environments.

[0056] Follower 6 is connected to multi-channel crystal array circuit 7 to receive frequency signals and transmit them to peak detector 2 and multiple detonator MCUs 5 respectively.

[0057] Specifically, it also includes a comparator 4, which is connected to the follower 6, the detonator MCU 5 and the peak detector 2 respectively. The comparator 4 is used to compare and process the signal output by the follower 6 with the reference signal provided by the peak detector 2, and send the processed signal to the detonator MCU 5.

[0058] It should be noted that follower 6 and comparator 4 are jointly responsible for reliably converting the frequency-selected analog signal into a digital logic signal for the detonator MCU 5 to analyze.

[0059] The multi-channel crystal oscillator array circuit 7 has a weak driving capability for its output signal, and its operating state is easily affected by the load of subsequent circuits. The core function of the follower 6 (usually composed of operational amplifier 3 forming a voltage follower 6) is isolation.

[0060] Follower 6, utilizing its high input impedance and low output impedance, is inserted between the multi-channel crystal array circuit 7 and subsequent circuitry. The high input impedance ensures that it draws almost no current from the multi-channel crystal array circuit 7, avoiding frequency selectivity variations due to load effects; the low output impedance, on the other hand, allows it to drive multiple subsequent loads.

[0061] After receiving the frequency signal from the multi-channel crystal array circuit 7, follower 6 outputs it unchanged (voltage amplitude remains the same) but with enhanced driving capability, and simultaneously distributes it to two independent subsequent modules: Path 1: Sent to peak detector 2. Used to detect signal amplitude, provide feedback to AGC control circuit 1, and generate a reference signal.

[0062] Path 2: The signal is sent to the non-inverting input ("+") of comparator 4. This is the signal processing path.

[0063] The task of comparator 4 is to convert the analog sine wave (or similar waveform) signal sent by follower 6, whose amplitude may still fluctuate, into a digital square wave signal with only two states: high level and low level.

[0064] Comparator 4 has two inputs: Non-inverting input ("+"): Receives the output signal from follower 6.

[0065] Inverting input ("-"): Receives a reference signal from peak detector 2. This reference signal is not a fixed voltage, but a dynamic threshold generated according to a certain proportion (e.g., 50% to 70%) following the current signal amplitude.

[0066] Comparator 4 continuously compares the voltages at its two input terminals: When the signal voltage is higher than the reference voltage, comparator 4 outputs a high level (e.g., 3.3V).

[0067] When the signal voltage is lower than the reference voltage, comparator 4 outputs a low level (0V).

[0068] Through the above method, the follower 6 ensures signal distribution and the stability of the preceding circuitry; the comparator 4, using the dynamic reference voltage provided by the peak detector 2, reliably converts the analog signal into a digital signal. Working together, they form a crucial bridge for the conversion from analog frequency selection to digital resolution.

[0069] Peak detector 2 is connected to AGC control circuit 1 and is used to send feedback signals to AGC control circuit 1 so that AGC control circuit 1 can adjust the amplification factor according to the feedback signals.

[0070] Among them, the feedback signal represents one of the following states: the signal amplitude is too low, the normal state, or the oversaturated state.

[0071] Specifically, the peak detector 2 continuously monitors the output signal from the follower 6 and quickly tracks the peak voltage (or envelope voltage) of that signal. This reflects the true strength of the signal after amplification and frequency selection. The internal circuit compares the detected real-time amplitude with a preset voltage threshold to determine which of the three states the current signal is in: Low voltage condition: When the peak voltage of the signal is lower than a preset lower threshold (e.g., 0.5V), the signal is determined to be too weak.

[0072] Oversaturation state: When the peak voltage of the signal is higher than a preset upper limit threshold (e.g., 2.0V), it is determined that the signal is too strong, causing clipping distortion in amplifier 3 or subsequent circuits.

[0073] Normal state: When the peak voltage of the signal is between the lower threshold and the upper threshold, the signal strength is considered appropriate.

[0074] Peak detector 2 does not directly transmit a voltage measurement value. Instead, based on the aforementioned state judgment, it generates a feedback signal that the AGC control circuit 1 can directly recognize. This signal can be a specific voltage level representing different states, or it can be a set of digital status codes. Next, the AGC control circuit 1 controls the gain of amplifier 3 based on the received feedback signal.

[0075] For example, upon receiving "too low" feedback, the AGC circuit interprets this as its primary task being to "capture the signal." It will adjust the gain of amplifier 3 to increase the signal amplitude quickly.

[0076] Upon receiving feedback of "oversaturation," the AGC circuit interprets this as its primary task being "preventing distortion." It will quickly adjust the amplification factor to reduce the gain, causing the signal amplitude to rapidly return to the normal range.

[0077] Upon receiving "normal status" feedback, the AGC circuit understands that the current gain setting is appropriate. It will maintain the current amplification factor to preserve the system's stability.

[0078] Peak detector 2 abstracts the continuous signal amplitude into three distinct discrete states (too low, normal, and oversaturated) by comparing thresholds. AGC control circuit 1 then executes simple and explicit actions to increase, maintain, or decrease the gain based on these three state commands. This closed-loop feedback mechanism ensures that the system can dynamically stabilize the signal amplitude within its optimal operating range.

[0079] In one embodiment, to further improve frequency selection accuracy, a fine-tuning capacitor is connected in parallel across the two ends of each crystal oscillator in the multi-channel crystal oscillator array circuit 7.

[0080] Specifically, the actual oscillation frequency of a crystal oscillator is affected by the load capacitance across its terminals. Connecting a trimmer capacitor in parallel is equivalent to increasing the load capacitance of the crystal oscillator. By adjusting the value of this trimmer capacitor (e.g., choosing between 10pF and 30pF), the center frequency of the crystal oscillator can be calibrated very precisely, with a compensation range typically within ±50Hz. The trimmer capacitor compensates for minor frequency deviations caused by manufacturing tolerances in the crystal oscillator itself, ensuring that the center frequency of each channel is accurately accurate. Furthermore, the trimmer capacitor can also compensate for frequency drift caused by temperature and humidity changes or component aging, enabling the circuit to maintain frequency stability over long-term use and in various environments.

[0081] In one embodiment, a demodulation mechanism with wireless detonator through-ground communication further includes a signal detection circuit and a battery. The battery is connected to and powered by the antenna module, amplifier 3, AGC control circuit 1, multi-channel crystal oscillator array circuit 7, follower 6 and peak detector 2. The signal detection circuit, connected to the battery, is used to detect the signal emitted by the transmitter and captured by the antenna module.

[0082] Specifically, the battery, as the total energy source for the entire demodulation mechanism, supplies power to all components that require power through power supply lines.

[0083] The signal detection circuit is directly powered by the battery to maintain continuous operation, and is always in an active state, continuously monitoring the output of the antenna module. Internally, the signal detection circuit includes a threshold comparison mechanism. The total energy (or envelope) of the received signal is compared to a preset reference level. This reference level is set slightly higher than the circuit's inherent background noise level, but lower than the expected level of a valid communication signal. Once the signal energy exceeds the preset threshold, it is determined that "a valid signal may be arriving," and a simple wake-up trigger signal is immediately output (usually a level transition, such as from low to high). The wake-up trigger signal is sent to the power management module, which controls the power network to quickly provide full power to other circuit units in sleep or low-power states (such as amplifier 3, multi-channel crystal oscillator array circuit 7, etc.), enabling the system to instantly switch from standby to full-function operation. Example 1

[0084] This application provides a demodulation mechanism for wireless detonator through-ground communication, comprising an adaptive AGC control circuit 1 and a multi-channel crystal oscillator array circuit 7, and in conjunction with an amplifier 3, a peak detector 2, a follower 6, a comparator 4, a detonator MCU 5, a resonant capacitor 8 connected in parallel with an antenna 9, and other components, to achieve signal demodulation for wireless detonator through-ground communication.

[0085] 1. Overall Architecture: After receiving the signal, the antenna 9 of the wireless detonator transmits the signal to the amplifier 3 for amplification. The amplification factor of the amplifier 3 is adjusted by the adaptive AGC control circuit 1. The amplified signal is connected to the follower 6 after frequency selection by the multi-channel crystal oscillator array circuit 7. The output signal of the follower 6 is transmitted to the peak detector 2 on one hand, and after being processed by the comparator 4 on the other hand, it is input to the detonator MCU 5, and finally the detonator executes the interface response.

[0086] 2. Adaptive AGC control circuit 1: This circuit automatically adjusts the amplification factor of amplifier 3 based on the strength of the output signal from antenna 9, ensuring the signal remains within a reasonable voltage range for successful detonator analysis. Its operation relies on the feedback signal from peak detector 2. Peak detector 2 determines whether the signal amplitude is too low, normal, or oversaturated based on the amplitude of the output signal from follower 6, and feeds the result back to AGC control circuit 1. AGC control circuit 1 then adjusts the amplification factor of amplifier 3 in real time accordingly.

[0087] 3. Multi-channel crystal oscillator array circuit 7: includes multiple crystal oscillators of different frequencies ( The circuit employs n parallel crystal oscillators, covering the communication frequency band from 1kHz to 300kHz. Each channel has an independently set center frequency, with a frequency interval Δf < channel coherence bandwidth (e.g., Δf = 200Hz). The circuit consists of input signals, multiple crystal oscillators, analog switch 14, and output signals. Analog switch 14 switches to the corresponding crystal oscillator channel based on the current frequency matched with the transmitter, realizing the gating function and outputting the frequency-selected signal.

[0088] 4. Functions of other components: Follower 6: Isolates the output signal of the multi-channel crystal oscillator array circuit 7 from the input signal of the non-inverting input terminal of the comparator 4 to avoid mutual interference.

[0089] Peak detector 2: Simultaneously provides a reference signal for comparator 4, which is connected to the inverting input of comparator 4 and used by comparator 4 to process the signal.

[0090] Antenna 9 is connected in parallel with resonant capacitor 8: This forms a resonant circuit with receiving antenna 9, enhancing antenna 9's ability to receive signals of a specific frequency.

[0091] Comparator 4: Compares and processes the signal output by follower 6 with the reference signal provided by peak detector 2, and outputs the processed signal to detonator MCU 5.

[0092] Detonator MCU 5: Receives the signal output from comparator 4, analyzes it, and then controls the detonator to perform interface actions.

[0093] like Figure 3 As shown, Figure 3The functions of each component are as follows: AGC control circuit 1: Adaptive control circuit, used to adjust the amplification factor of amplifier 3.

[0094] Peak detector 2: detects the amplitude of the output signal of follower 6 and feeds back the detection result to AGC control circuit 1 and comparator 4.

[0095] Amplifier 3: Amplifies the signal output from receiving antenna 9, and the amplification factor is controlled by AGC control circuit 1.

[0096] Comparator 4: Receives the signal output from follower 6 and the reference signal provided by peak detector 2, performs comparison processing, and outputs the result to detonator MCU 5.

[0097] Detonator MCU 5: Analyzes the signal output from comparator 4 and controls the detonator to perform interface actions.

[0098] Follower 6: Isolates the output signal of the multi-channel crystal oscillator array circuit 7 from the non-inverting input signal of the comparator 4.

[0099] Multi-channel crystal array circuit 7: performs frequency selection processing on the signal output by amplifier 3.

[0100] Resonant capacitor 8: forms a resonant circuit with receiving antenna 9 to enhance signal reception.

[0101] Receiving antenna 9: Receives wireless signals transmitted through the ground. Example 2

[0102] Based on Example 1, further improvements were made to demodulation performance: 1. Optimized Adaptive AGC Control Circuit 1: A segmented adjustment mechanism is adopted, dividing the signal amplitude into multiple intervals, each corresponding to a different gain adjustment rate. When the signal amplitude is too low, the gain of amplifier 3 is rapidly increased; when the signal approaches the normal range, the adjustment rate is slowed down; when the signal is oversaturated, the gain is rapidly reduced to avoid prolonged signal distortion. Simultaneously, upper and lower limit protections for gain adjustment are added to prevent amplifier 3 from entering extreme operating states and extend the device's lifespan.

[0103] 2. Improvements to the multi-channel crystal oscillator array circuit 7: An adaptive frequency switching algorithm is introduced. The analog switch 14 no longer switches solely based on a preset frequency matched to the transmitter, but dynamically selects the optimal crystal oscillator channel based on the strength and quality of the received signal. By monitoring the signal-to-noise ratio (SNR) of the output signal of each crystal oscillator channel in real time, the channel with the highest SNR is selected as the current operating channel, improving anti-interference capability and signal reception quality. Furthermore, a fine-tuning capacitor is connected in parallel across the crystal oscillator to make minor adjustments to the crystal oscillator's center frequency, compensating for frequency shifts caused by environmental factors such as temperature and humidity.

[0104] 3. Low-noise amplification optimization: A low-noise preamplifier circuit is added to the front end of amplifier 3. A common-emitter amplifier circuit is constructed using low-noise transistors to reduce the noise interference of the circuit itself, improve the amplification capability of small signals, and enable weak signals to be effectively amplified in the initial stage, avoiding being drowned out by noise in subsequent circuits.

[0105] 4. Improved Power Management: A low-power power management module is adopted to dynamically control the power supply of various parts of the circuit. When the circuit is in standby mode, the power supply voltage of non-critical modules is reduced or some circuits are shut down; when a signal is received, full power supply is quickly restored, reducing overall power consumption, extending battery life, and better meeting the battery power supply requirements of wireless detonators.

[0106] Specifically as follows: 1. Adaptive AGC control circuit 1 uses segmented adjustment: The signal amplitude is divided into three ranges: below 0.5V (too low), 0.5V-2V (normal), and above 2V (oversaturation). When the peak detector 2 detects a signal amplitude below 0.5V, the AGC control circuit 1 controls amplifier 3 to increase its gain at a rate of 5dB per second; when the signal amplitude is within the 0.5V-2V range, the gain adjustment rate decreases to 1dB per second; when the signal amplitude is above 2V, the gain decreases at a rate of 8dB per second. Simultaneously, the upper limit of amplifier 3's gain is set to 60dB, and the lower limit to 10dB.

[0107] like Figure 2 As shown, Figure 2 In the diagram, input signal 10 comes from the amplified signal output by amplifier 3. Crystal oscillators 1 and 11, 2 and 12... 13 are crystal oscillators of different frequencies, with frequencies of... It covers the 1kHz–300kHz communication frequency band, with a frequency interval Δf = 200Hz. Analog switch 14: switches to the corresponding crystal oscillator channel according to the frequency matched with the transmitter. Output signal 15: the frequency-selected signal is transmitted to follower 6.

[0108] exist Figure 2 In section 2, the multi-channel crystal oscillator array circuit 7 features adaptive frequency switching: Analog switch 14 is connected to a signal quality detection module, which monitors the signal-to-noise ratio (SNR) of the output signal 15 of each crystal oscillator channel in real time. For example, when the SNR of channel 11 of crystal oscillator 1 is 20dB and the SNR of channel 12 of crystal oscillator 2 is 25dB, analog switch 14, under the control of the signal quality detection module, switches to channel 2 of crystal oscillator 2. A 10pF-30pF trimmer capacitor is connected in parallel across each crystal oscillator; by adjusting the capacitance of the trimmer capacitor, the crystal oscillator frequency can be adjusted by ±50Hz.

[0109] 3. Low-noise preamplifier circuit: A common-emitter amplifier circuit composed of a low-noise crystal 2N5088 is added to the front end of amplifier 3. The noise figure of this circuit is less than 2dB and the gain is 20dB. The weak signal output from the receiving antenna 9 is first amplified with low noise and then transmitted to amplifier 3 for further amplification.

[0110] 4. Power Management: The power management chip LP5907 is used. When the circuit does not receive a valid signal within a second, it automatically reduces the power supply voltage of amplifier 3 and multi-channel crystal oscillator array circuit 7 from 3.3V to 1.8V; when a valid signal is received, the power supply is restored to 3.3V within 0.1 seconds.

[0111] like Figure 4 As shown, in a second aspect, this application provides a demodulation method with wireless detonator through-ground communication, applied to the aforementioned demodulation mechanism with wireless detonator through-ground communication, the method comprising: S100, the antenna module receives wireless signals transmitted through ground, and under the joint action of the resonant capacitor, enhances the reception of signals at a preset frequency and transmits the signals to the amplifier. S200, under the control of the AGC control circuit, amplifies the received signal by a factor to form an amplified signal; S300 amplifies the signal input to the multi-channel crystal oscillator array circuit. The analog switch switches to the corresponding crystal oscillator channel according to the preset frequency matched with the transmitter, performs frequency selection processing on the signal, and transmits the frequency-selected output signal to the follower. S400, the follower isolates the amplified signal and outputs it to the non-inverting inputs of the peak detector and comparator respectively; S500: The peak detector detects the amplitude of the follower's output signal. If it determines that the signal amplitude is too low, it feeds a signal to the AGC control circuit, which then controls the amplifier to increase its amplification factor. If the signal amplitude is oversaturated, it feeds a signal to the AGC control circuit, which then controls the amplifier to decrease its amplification factor. If the signal amplitude is within the normal range, the amplifier's amplification factor remains unchanged. Simultaneously, the peak detector inputs a reference signal to the inverting input of the comparator, where the reference signal represents a DC voltage proportional to the signal amplitude. The S600 comparator compares and processes the signal at the non-inverting input and the reference signal at the inverting input, and outputs the processed signal to the detonator MCU. The S700 detonator MCU analyzes the received signals and, based on the analysis results, controls the detonator execution interface to complete the corresponding actions.

[0112] It should be noted that a detailed description of each step in a demodulation method with wireless detonator ground-penetrating communication can be found in the description of a demodulation mechanism with wireless detonator ground-penetrating communication, and will not be repeated here. Example 3

[0113] A demodulation method with wireless detonator ground-penetrating communication may include the following steps: (1) The receiving antenna receives wireless signals transmitted through the ground. Under the action of the parallel resonant capacitor of the antenna, the reception of specific frequency signals is enhanced and the signal is transmitted to the amplifier.

[0114] (2) The amplifier amplifies the received signal under the control of the AGC control circuit. In the initial state, the amplifier uses a medium amplification factor.

[0115] (3) The amplified signal is input to the multi-channel crystal oscillator array circuit. The analog switch switches to the corresponding crystal oscillator channel according to the preset frequency matched with the transmitter, performs frequency selection processing on the signal, and transmits the frequency-selected output signal to the follower.

[0116] (4) The follower isolates the signal and outputs it, which is transmitted to the peak detector on one hand and to the non-inverting input of the comparator on the other.

[0117] (5) The peak detector detects the amplitude of the follower's output signal. If it determines that the signal amplitude is too low, it feeds a signal back to the AGC control circuit, which then controls the amplifier to increase its amplification factor. If the signal amplitude is oversaturated, it feeds a signal back to the AGC control circuit, which then controls the amplifier to decrease its amplification factor. If the signal amplitude is normal, the amplifier's amplification factor remains unchanged. At the same time, the peak detector inputs a reference signal to the inverting input of the comparator.

[0118] (6) The comparator compares and processes the signal at the non-inverting input terminal and the reference signal at the inverting input terminal, and outputs the processed signal to the detonator MCU.

[0119] (7) The detonator MCU analyzes the received signal and controls the detonator execution interface to complete the corresponding action based on the analysis result. Example 4

[0120] Example 2 is an adjustment based on Example 1, specifically including the following: Before step S100, the power management module dynamically adjusts the power supply voltage of each part of the circuit according to the signal reception status.

[0121] In step S100, the signal received by the antenna is first amplified by a low-noise preamplifier circuit before being transmitted to the amplifier.

[0122] In step S300, the signal quality detection module in the multi-channel crystal oscillator array circuit is also included to monitor the signal-to-noise ratio of each crystal oscillator channel in real time and control the analog switch to switch to the optimal channel; if a crystal oscillator frequency offset is detected, compensation is made by adjusting the fine-tuning capacitor.

[0123] In step S500, the AGC control circuit adjusts the gain of the amplifier according to a segmented adjustment mechanism, and is limited by upper and lower limits of the gain.

[0124] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0125] The various embodiments in this disclosure are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0126] The scope of protection of this disclosure is not limited to the embodiments described above. Obviously, those skilled in the art can make various modifications and variations to this disclosure without departing from its scope and spirit. If such modifications and variations fall within the scope of the claims of this disclosure and their equivalents, then the intent of this disclosure also includes such modifications and variations.

Claims

1. A demodulation mechanism for wireless detonator ground-penetrating communication, characterized in that, The demodulation mechanism comprises: An antenna module for receiving signals; An amplifier connected to the antenna module for multiple amplification of the signals received by the antenna module; An AGC control circuit connected to the amplifier for controlling the amplification multiple of the amplifier; A multi-channel crystal oscillator array circuit connected to the amplifier for receiving the multiple-amplified signals and performing frequency selection and sending frequency signals; A follower connected to the multi-channel crystal oscillator array circuit for receiving the frequency signals and transmitting them to a peak detector and a plurality of detonator MCUs, respectively; The peak detector is connected to the AGC control circuit for sending a feedback signal to the AGC control circuit, so that the AGC control circuit adjusts the amplification multiple according to the feedback signal, wherein the feedback signal represents that the signal amplitude is in one of an excessively low state, a normal state and an excessively saturated state.

2. The demodulation mechanism with wireless detonator ground-penetrating communication according to claim 1, characterized in that, The AGC control circuit is configured to: Divide the signal amplitude into a plurality of intervals, each interval corresponding to a different gain adjustment rate, forming a segmented adjustment mechanism.

3. The demodulation mechanism with wireless detonator ground-penetrating communication according to claim 1, characterized in that, The multi-channel crystal oscillator array circuit is configured to: Real-time monitor the signal-to-noise ratio of the output signals of each crystal oscillator channel in the multi-channel crystal oscillator array circuit, and select the crystal oscillator channel with the highest signal-to-noise ratio as the current working channel.

4. The demodulation mechanism with wireless detonator ground-penetrating communication according to claim 3, characterized in that, Each crystal oscillator in the multi-channel crystal oscillator array circuit has a trimming capacitor connected in parallel across the two ends of the crystal oscillator.

5. The demodulation mechanism with wireless detonator ground-penetrating communication according to claim 1, characterized in that, The multi-channel crystal oscillator array circuit includes Crystal oscillators of different frequencies, and analog switches, the analog switches and Each crystal oscillator of a different frequency is connected separately. A series of crystal oscillators of different frequencies are connected in parallel, covering the communication frequency band from 1kHz to 300kHz; each crystal oscillator serves as a crystal oscillator channel, and the center frequency of each crystal oscillator channel is such that the frequency interval Δf is less than the channel coherence bandwidth; the analog switch is used to switch the current crystal oscillator channel to the corresponding frequency crystal oscillator channel according to the frequency matched by the transmitter.

6. The demodulation mechanism for wireless communication of the wireless detonator according to claim 1, wherein, Further comprising a comparator connected to the follower, the detonator MCU and the peak detector, respectively, for comparing the signal output by the follower with the reference signal provided by the peak detector, and sending the processed signal to the detonator MCU.

7. The demodulation mechanism with wireless detonator ground-penetrating communication according to claim 1, characterized in that, The antenna module comprises an antenna and a resonance capacitor connected in parallel with the antenna to form a resonance circuit, and the resonance circuit is connected to the amplifier for sending filtered signals to the amplifier.

8. The demodulation mechanism with wireless detonator ground-penetrating communication according to claim 7, characterized in that, Further comprising a low-noise preamplifier circuit connected to the amplifier and the resonance circuit for amplifying the weak signals sent to the amplifier.

9. The demodulation mechanism with wireless detonator ground-penetrating communication according to claim 7, characterized in that, Further comprising a signal detection circuit and a battery connected to and powering the antenna module, the amplifier, the AGC control circuit, the multi-channel crystal oscillator array circuit, the follower and the peak detector; The signal detection circuit is connected to the battery for detecting the signals emitted by the transmitter and captured by the antenna module.

10. A demodulation method for wireless detonator through-the-earth communication, applied to the demodulation mechanism for wireless detonator through-the-earth communication according to any one of claims 1-9, the method comprising: The antenna module receives wireless signals transmitted through the earth and enhances the reception of signals of a preset frequency under the joint action of the resonance capacitor, and transmits the signals to the amplifier; The amplifier multiple-amplifies the received signals under the control of the AGC control circuit to form amplified signals; The amplified signals are input to the multi-channel crystal oscillator array circuit, the analog switch is switched to the corresponding crystal oscillator channel according to the preset frequency matched with the transmitter, the signals are processed by frequency selection, and the output signals after frequency selection are transmitted to the follower; The follower separates the amplified signal and outputs to the peak detector and the same direction input of the comparator respectively; The peak detector detects the amplitude of the signal output by the follower, and if the signal amplitude is in an excessively low state, feeds back a signal to the AGC control circuit, and the AGC control circuit controls the amplifier to increase the amplification multiple; if the signal amplitude is in an excessively saturated state, feeds back a signal to the AGC control circuit, and the AGC control circuit controls the amplifier to decrease the amplification multiple; if the signal amplitude is in a normal state, the amplification multiple of the amplifier is not changed, and at the same time, the peak detector inputs a reference signal to the reverse input of the comparator, wherein the reference signal represents a direct current voltage proportional to the signal amplitude; The comparator compares the signal at the same direction input with the reference signal at the reverse input, and outputs the processed signal to the detonator MCU; The detonator MCU analyzes the received signal, and according to the analysis result, controls the detonator execution interface to complete corresponding actions.

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