Wellbore maintenance communication device and method based on electromagnetic coupling principle

Abstract

The invention belongs to the technical field of coal mine shaft maintenance emergency communication, and particularly discloses a shaft maintenance communication device and method based on an electromagnetic coupling principle. The device comprises an elevator controller, a car room main controller, a signal transmission medium and two pairs of electromagnetic coupling coils. The elevator controller is arranged in an elevator cage, and the car room main controller is arranged in a ground winch control room; a pair of electromagnetic coupling coils is respectively arranged at the top of a skip bucket of the elevator and below a guide wheel through a lasso structure and is respectively used for sending and receiving signals. A closed-loop lifting link where a steel wire rope of the elevator is located is used as a signal transmission medium, and bidirectional long-distance transmission of signals is achieved between an elevator controller and a car room main controller based on the electromagnetic coupling communication principle. A maintainer can actively lock the hoister through the hoister controller, accidental starting of the hoister caused by misoperation of a winch control room is avoided, and after locking is released, a winch driver can be informed of starting and stopping the hoister through voice and dotting control signals.

Description

Technical Field

[0001] The invention belongs to the technical field of emergency communication for shaft maintenance in coal mines, and particularly relates to a shaft maintenance communication device and method based on the principle of electromagnetic coupling. Background Art

[0002] The coal mine hoisting system is a key link in the safe production of coal mines, and its operating status is directly related to the safe production and economic benefits of coal mines. Once a failure occurs in the hoisting system, it will lead to production stagnation at best and serious accidents at worst, causing economic losses and even casualties. In traditional shaft maintenance operations, shaft maintenance personnel and the winch control room mainly communicate with each other by using walkie-talkies or wired telephones through the relay communication device at the shaft mouth. This communication method often has problems such as complex wiring, unstable signal transmission, high power consumption, and high failure rate, and is easily affected by the subjective factors of the winch room driver. When a dangerous situation occurs, the winch room driver cannot quickly and accurately obtain the real-time feedback of the underground operation personnel, resulting in delays in emergency decision-making and increasing the accident risk.

[0003] In actual operations, shaft maintenance usually involves dangerous equipment maintenance and debugging, and any poor communication may lead to misoperation of equipment. For example, in the winch room, the driver controls the operation of the hoist relying on the limited information transmitted from underground. Once the communication is not timely or the operation is misjudged, it is extremely easy to cause the wrong start and stop of the skip, which may lead to serious accidents such as personnel falling into the well and equipment damage. Therefore, problems such as traditional communication delay and information misjudgment must be solved. In addition, the mine environment is complex and changeable, with a large depth and many interference factors. Traditional wireless communication methods are difficult to maintain stable signal coverage throughout the shaft. Especially in emergency situations, such as abnormal equipment operation and underground emergencies, the communication system must be able to penetrate thick strata and complex steel structures to ensure that the signal can be accurately transmitted to the winch control room regardless of the position of the hoist underground.

[0004] In view of the high risk during shaft maintenance operations, the communication and emergency stop systems supporting the hoisting system must have high reliability and real-time performance, so as to ensure that the transmitted signal can reach the receiving end within a very short time and execute the emergency stop operation. Summary of the Invention

[0005] The purpose of the invention is to provide a shaft maintenance communication device based on the principle of electromagnetic coupling to realize real-time emergency communication between the winch control room on the ground and shaft maintenance personnel in the coal mine hoisting system, and to ensure a reliable voice and control signal transmission system in a complex mine hoisting environment. Especially in emergency situations, shaft maintenance personnel can quickly and stably issue an emergency stop command to remotely control the hoist to stop urgently and ensure the safety of shaft maintenance operations.

[0006] In order to achieve the above object, the invention adopts the following technical solutions:

[0007] A wellbore maintenance communication device based on the principle of electromagnetic coupling, comprising a hoist controller, a main controller in the winch house, a signal transmission medium, and two pairs of electromagnetic coupling coils;

[0008] The hoist controller is arranged inside the hoist cage, and the main controller in the winch house is arranged inside the winch control room above the well;

[0009] Define the two pairs of electromagnetic coupling coils as the first pair of electromagnetic coupling coils and the second pair of electromagnetic coupling coils. The first pair of electromagnetic coupling coils is connected to the hoist controller, and the second pair of electromagnetic coupling coils is connected to the main controller in the winch house;

[0010] The first pair of electromagnetic coupling coils and the second pair of electromagnetic coupling coils are respectively arranged on the top of the hoist skip and below the guide pulley; each pair of electromagnetic coupling coils includes a transmitting coupling coil and a receiving coupling coil;

[0011] Wherein, the steel wire rope of the hoist sequentially passes through the first pair of electromagnetic coupling coils and the second pair of electromagnetic coupling coils arranged on the top of the hoist skip and below the guide pulley, and the steel wire rope is not in contact with each pair of electromagnetic coupling coils;

[0012] Take the closed-loop hoisting link where the steel wire rope of the hoist is located as the signal transmission medium;

[0013] Between the hoist controller and the main controller in the winch house, through a transmission link composed of two pairs of electromagnetic coupling coils and a signal transmission medium, based on the principle of electromagnetic coupling, realize the bidirectional long-distance transmission of the dot control signal and the voice signal;

[0014] Among them, the dot control signal includes unlocking / locking, starting / stopping, and lifting / lowering control signals.

[0015] Preferably, both the hoist controller and the main controller in the winch house include an electromagnetic coupling communication circuit board, a microphone, a speaker, an operation indicator light, dot control buttons, voice intercom buttons, and signal indicator lights;

[0016] The dot control buttons include unlocking / locking buttons, starting / stopping buttons, and lifting / lowering buttons;

[0017] The electromagnetic coupling communication circuit board includes a microcontroller module, an FSK modulation and demodulation module, a voice signal processing module, an operation and power amplification module, a pre-amplification module at the receiving end, a low-pass filter module, and a transceiver gating module;

[0018] The voice signal processing module includes a voice acquisition module and an audio power amplification module;

[0019] The pre-amplification module at the receiving end includes a receiving filter module and an operational amplifier module;

[0020] The voice acquisition module, FSK modulation module, operation and power amplification module serve as the signal transmission part; the pre-amplification module at the receiving end, low-pass filter module, FSK demodulation module and audio power amplifier module serve as the signal reception part;

[0021] The microcontroller module is connected to the voice signal processing module, FSK modulation and demodulation modules, responsible for encoding and decoding voice and control signals, enabling / disabling relevant control ports, and programming to control the FSK modulation module to output modulation signals of different frequencies;

[0022] The FSK modulation module is used to convert the digital signal encoded and output by the microcontroller module into an analog signal suitable for transmission;

[0023] The voice acquisition module is used to filter and amplify the voice signal collected by the microphone; the audio power amplifier module is used to perform audio power amplification on the analog voice signal restored by the microcontroller module and drive the speaker to play the voice;

[0024] The operation and power amplification module is used to amplify the amplitude and power of the transmitted modulation signal;

[0025] The receiving filter module is used to filter and amplify the received modulation signal at the signal receiving end;

[0026] The FSK demodulation module is used to demodulate the received analog modulation signal and restore the original digital signal;

[0027] The transceiver gating module is used to switch the working state of the controller, so that the controller is default in the signal receiving state.

[0028] In addition, based on the above wellbore maintenance communication device based on the electromagnetic coupling principle, the present invention also proposes a corresponding wellbore maintenance communication sending method based on the electromagnetic coupling principle, and this method adopts the following technical solutions:

[0029] A wellbore maintenance communication sending method based on the electromagnetic coupling principle includes the following steps:

[0030] A1. The microcontroller module inside the hoist controller / car house main controller detects that a key is pressed, controls the transceiver gating module to make the system in the sending state, the microcontroller module triggers the power control module in the multi-voltage power supply device to conduct, controls the voltage conversion module to output multiple working voltages, and makes the controller work normally;

[0031] A2. The microcontroller module converts the collected voice, unlocking / latching, lifting or starting / stopping control instructions into corresponding digital signals, and after processing according to the set data frame format, transmits them to the FSK modulation module through the USART;

[0032] A3. The microcontroller module controls the FSK modulation module to output a corresponding analog modulation signal according to the digital signal;

[0033] A4. The modulation signal is processed by the operation and power amplification module to improve the strength and load - carrying capacity of the output signal;

[0034] A5. The modulation signal is sent to the RCL series resonance circuit after power amplification, so that the current passing through the transmitting coupling coil increases and the energy is effectively utilized to improve the coil coupling efficiency;

[0035] A6. The processed modulation signal is input to the transmitting coupling coil, and data is transmitted using the signal transmission medium;

[0036] A7. When the button is released and the signal sending is completed, the microcontroller module controls the power control module to disconnect, and drives the transceiver gating module to make the hoist controller / main controller in the signal receiving state, and re - enters the low - power standby mode.

[0037] In addition, based on the above - mentioned shaft maintenance communication device based on the electromagnetic coupling principle, the present invention also proposes a corresponding shaft maintenance communication receiving method based on the electromagnetic coupling principle. The method adopts the following technical solutions:

[0038] A shaft maintenance communication receiving method based on the electromagnetic coupling principle includes the following steps:

[0039] B1. The receiving coupling coil restores the original analog modulation signal by analyzing the induced electromotive force;

[0040] B2. The modulation signal is input to the main controller in the car / hoist controller through a four - core shielded communication cable, and is processed by the internal RCL parallel resonance circuit to increase the amplitude of the received signal voltage;

[0041] B3. The modulation signal passes through the pre - amplifier module at the receiving end to filter out the high - frequency noise interference generated in the transmission channel, amplify the signal within the passband, and at the same time drive the power control module to make the system powered on and work normally;

[0042] B4. The amplified signal is input into a low - pass filter to reduce the harmonic distortion and unnecessary high - frequency components in the signal;

[0043] B5. The processed signal is sent to the FSK demodulation module for demodulation to restore the original digital information;

[0044] B6. The microcontroller module receives the demodulation signal output by the FSK demodulation module through the USART, decodes it according to the pre - set data frame format, and executes predefined operations (such as unlocking / locking, lifting, starting / stopping, and audio decoding);

[0045] B7. When the signal reception is completed, the microcontroller module controls the power control module to disconnect, and the hoist controller / master controller in the shaft house returns to the reception state and enters the low-power standby mode.

[0046] The present invention has the following advantages:

[0047] As described above, the present invention relates to a shaft maintenance communication device based on the electromagnetic coupling principle. First, a non-contact signal transmission based on electromagnetic coupling communication technology is adopted between the hoist controller and the master controller in the shaft house. The existing metal structure of the mine hoisting system (such as the closed loop composed of the hoist wire rope, tail rope, and hoist cage, etc.) is used as the signal transmission medium. Without contacting the wire rope or other metal media, the electromagnetic coupling coil realizes the bidirectional coupling transmission of voice and signal for signaling, simplifies the wiring requirements, does not damage the shaft structure, and does not affect the normal operation of the hoisting system. Secondly, this device enables shaft maintenance personnel to actively lock the hoist when working in the shaft, avoiding accidental start-up of the hoist due to misoperation in the winch control room. The lock can also be released through the hoist controller, and real-time voice communication with the winch control room can be carried out through the built-in voice intercom function of the controller, ensuring information synchronization and timely decision-making between both parties. In addition, the portable wearable emergency stop controller enables maintenance personnel to remotely and actively control the hoist to stop urgently in case of emergency, improving the emergency response ability during shaft maintenance operations. The present invention provides an economical, reliable, convenient, and flexible emergency communication method to ensure the safety of shaft maintenance operations. Description of the Drawings

[0048] Figure 1 It is a schematic structural diagram of the shaft maintenance communication device based on the electromagnetic coupling principle in the embodiment of the present invention.

[0049] Figure 2 It is a schematic diagram of the communication data frame format of the shaft maintenance communication device in the embodiment of the present invention;

[0050] Figure 3 It is a schematic diagram of the internal modular structure of the hoist controller / master controller in the shaft house in the embodiment of the present invention;

[0051] Figure 4 It is a schematic diagram of the structure of the electromagnetic coupling coil in the embodiment of the present invention;

[0052] Figure 5 It is the equivalent circuit of the electromagnetic coupling communication device in the embodiment of the present invention;

[0053] Figure 6 It is the software working flow chart of the shaft maintenance communication device in the embodiment of the present invention.

[0054] Among them, 1 - hoist controller; 2 - main controller in the shaft house; 3 - portable wearable emergency stop controller; 4 - multi - voltage power supply device; 5 - transmitting coupling coil; 6 - receiving coupling coil; 7 - steel wire rope; 8 - tail rope; 9 - top of the hoist skip; 10 - guide pulley; 11 - aviation plug; 12 - four - core shielded communication cable; 13 - electromagnetic coupling communication circuit board; 14 - hollow tubular bracket; 15 - hoist cage; 21 - magnetic core; 22 - enameled copper wire; 23 - circular magnetic ring housing; 24 - bolt; 25 - hexagonal metal inner cavity; 26 - connecting column. Specific Embodiment

[0055] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0056] Embodiment 1

[0057] This Embodiment 1 describes a shaft maintenance communication device based on the electromagnetic coupling principle. It works in coordination between the hoist controller 1 and the main controller 2 in the shaft house to achieve efficient voice communication and control instruction interaction, integrating signal acquisition, processing, transmission, and receiving modules to ensure the coordinated operation of each unit. In addition, the present invention also combines Bluetooth serial communication technology to design a set of portable wearable emergency stop controllers 3 to solve problems such as information transfer delay, poor communication, and operation misjudgment in traditional coal mine hoisting systems. In addition, the present invention also designs a set of high - performance integrated circuits as the core of the communication device, using a 32 - bit microcontroller as the control core. Through its built - in peripheral units such as ADC, DAC, DMA, and USART, and in combination with peripheral signal processing modules, it completes the acquisition, conversion, and transmission of voice and signal control signals for marking. Compared with wired communication, the non - contact connection between the electromagnetic coupling coil and the steel wire rope 7 allows the position to be freely selected, avoiding the complex wiring and poor contact problems of traditional communication methods. Compared with underground wireless communication methods, it improves the information transmission rate and stability and reduces system power consumption.

[0058] As Figure 1 shown, the shaft maintenance communication device based on the electromagnetic coupling principle in this embodiment includes a hoist controller 1, a main controller 2 in the shaft house, a portable wearable emergency stop controller 3, a signal transmission medium, and two pairs of electromagnetic coupling coils.

[0059] Among them, the hoist controller 1 and the portable wearable emergency stop controller 3 are both arranged inside the hoist cage 15, and the main controller 2 in the workshop is arranged in the winch control room above the well, which is used to realize real-time information interaction between above and below the well. During the shaft maintenance operation, the maintenance personnel wear the portable wearable emergency stop controller 3 inside the hoist cage, and the hoist controller 1 is directly installed inside the hoist cage 15. The portable wearable emergency stop controller 3 realizes high-speed and low-latency wireless communication with the hoist controller 1 through the Bluetooth serial communication module, which is used for remote emergency stop operation during shaft maintenance.

[0060] The portable wearable emergency stop controller 3 consists of a microcontroller module, a Bluetooth serial communication module, an emergency stop button and a feedback indicator light. All components are integrated in a portable protective cover. The system architecture design focuses on being lightweight, easy to operate, low power consumption and high reliability. The main interface of the portable wearable emergency stop controller 3 includes an emergency stop button and a feedback indicator light, ensuring that the maintenance personnel can quickly and accurately press the stop button for parking operation in case of emergency, and can easily trigger it even under vibration or other external disturbances during the wearing process. The Bluetooth serial communication module can use the ESP32 wireless communication chip, which is responsible for realizing the wireless connection between the portable wearable emergency stop controller 3 and the hoist controller 1. The control commands and status information are exchanged between the two through the Low Energy Bluetooth (BLE) protocol.

[0061] When the maintenance personnel press the emergency stop button in the middle part of the controller, the interruption mechanism of the microcontroller module built in the emergency stop controller 3 is immediately triggered, waking up the emergency stop system in the low-power mode. The microcontroller module transmits the stop instruction to the hoist controller 1 through the GATT Write operation of the ESP32 Bluetooth module. After receiving the stop instruction, the hoist controller 1 transmits the stop instruction to the main controller 2 in the workshop in the winch control room through the electromagnetic coupling communication device, realizing the remote parking operation of the shaft maintenance personnel. At the same time, the hoist controller 1 uses the GATT Notify feedback operation status to the portable wearable emergency stop controller 3 through the ESP32 Bluetooth module. The feedback indicator light on the portable wearable emergency stop controller 3 lights up green to indicate successful operation, or flashes red to indicate a fault, ensuring two-way verification after the stop instruction is successfully transmitted.

[0062] Two pairs of electromagnetic coupling coils are defined as the first pair of electromagnetic coupling coils and the second pair of electromagnetic coupling coils. The first pair of electromagnetic coupling coils is connected to the hoist controller 1, and the second pair of electromagnetic coupling coils is connected to the main controller 2 in the workshop.

[0063] The first pair of electromagnetic coupling coils is arranged on the top of the hoist skip 9, and the second pair of electromagnetic coupling coils is arranged below the guide pulley 10, as Figure 1As shown. Each pair of electromagnetic coupling coils includes a transmitting coupling coil 5 and a receiving coupling coil 6.

[0064] Among them, the steel wire rope 7 of the hoist sequentially passes through the first pair and the second pair of electromagnetic coupling coils arranged below the top 9 of the hoist skip and below the guide pulley 10, and the steel wire rope 7 does not contact each pair of electromagnetic coupling coils.

[0065] Take the closed-loop hoisting link where the steel wire rope 7 of the hoist is located as the signal transmission medium. The closed-loop hoisting link here refers to the closed loop composed of the steel wire rope 7, the tail rope 8 and the hoist cage 15, which is an existing structure, such as Figure 1 As shown.

[0066] Between the hoist controller 1 and the main controller 2 in the shaft house, through the transmission link composed of two pairs of electromagnetic coupling coils and the signal transmission medium, based on the electromagnetic coupling principle, the two-way long-distance transmission of the marking control signal and the voice signal is realized.

[0067] Among them, in this embodiment, the marking control signal includes unlocking / locking, starting / stopping and lifting control signals.

[0068] The present invention relies on the existing mechanical structure of the hoisting system (that is, the closed loop composed of the steel wire rope 7, the tail rope 8 and the hoist cage 15, that is, the closed-loop hoisting link mentioned above) to realize the two-way long-distance transmission of signals.

[0069] In the actual mine hoisting system, the tail ropes 8 at the bottoms of the two hoists are mechanically connected to form a part of the closed loop, and the traction steel wire ropes 7 at the tops are connected to the traction steel wire ropes 7 of another hoist through the shared hoisting system. Therefore, in fact, the hoist cages 15 of the two hoists are respectively connected to the steel wire rope 7 at the top and the tail rope 8 at the bottom to form a complete closed transmission path, and the electromagnetic coupling coils transmit data through this closed loop, such as Figure 1 As shown.

[0070] Although the resistivity of the steel wire rope 7 as the signal transmission medium is relatively high, it can reduce the standing wave effect during signal transmission. In this embodiment, a medium-frequency signal of 180k - 250kHz and a transmission power of 800mW are selected. The steel wire rope 7 can achieve low signal attenuation and high transmission stability within a certain transmission distance.

[0071] Between the hoist controller 1 and the main controller 2 in the shaft house, through the transmission link composed of the first pair and the second pair of electromagnetic coupling coils and the signal transmission medium, the transmission of the marking control signal and the voice signal is realized.

[0072] Specifically, the shaft maintenance personnel can send dotting control signals, such as up and down movement, emergency stop, unlocking and locking, etc., through the corresponding buttons on the hoist controller 1. Through the electromagnetic coupling coil, two-way data transmission is achieved with the help of the signal transmission medium. After receiving the control signal, the main controller 2 in the winch control room activates the operation indicator light to prompt the winch driver to control the hoist to perform the corresponding operation. The maintenance personnel and the winch driver can communicate through the voice intercom buttons on the hoist controller 1 and the main controller 2 in the winch control room. Both the hoist controller 1 and the main controller 2 in the winch control room are connected to the electromagnetic coupling coils (transmitting coupling coil 5 and receiving coupling coil 6) through the aviation plug 11 and the four-core shielded communication cable 12 to ensure the electrical connection stability during the operation of the equipment. Based on the principle of electromagnetic induction, between the hoist controller 1 and the main controller 2 in the winch control room, through the change of the electromagnetic field between the first and second pairs of electromagnetic coupling coils respectively connected to them, non-contact signal transmission is achieved.

[0073] When the transmitting coupling coil 5 at the hoist controller 1 is used as the transmitting end, the receiving coupling coil 6 at the main controller 2 in the winch control room is used as the receiving end, and the hoist controller 1 sends a signal to the main controller 2 in the winch control room. Similarly, when the transmitting coupling coil 5 at the main controller 2 in the winch control room is used as the transmitting end, the receiving coupling coil at the hoist controller 1 is used as the receiving end.

[0074] A compensation capacitor and an equivalent resistor are connected in series at both ends of the transmitting coupling coil 5 to form a series resonance circuit, and a compensation capacitor and an equivalent resistor are connected in parallel at both ends of the receiving coupling coil 6 to form a parallel resonance circuit. By adding compensation capacitors and equivalent resistors, an RCL resonance circuit is formed to optimize the resonance characteristics of the coupling circuit, so that the current passing through the coil increases and the energy is effectively utilized.

[0075] Taking the hoist controller 1 sending a signal as an example, the modulation signal generated by its internal electromagnetic coupling communication circuit board 13 first undergoes power amplification and RCL resonance processing, and then is input to the transmitting coupling coil 5 of the first pair of electromagnetic coupling coils through the four-core shielded communication cable 12. A changing magnetic field is formed inside the toroidal ferrite of the transmitting coupling coil 5. According to Faraday's law of electromagnetic induction, the relationship between the magnetic field change B(t) generated by the transmitting coupling coil 5 and the modulation signal waveform can be expressed as: Among them, μ is the magnetic permeability of the toroidal ferrite, N is the number of turns of the transmitting coupling coil, I(t) is the input signal current, is the current change rate. The magnetic field in the toroidal ferrite changes with the modulation signal waveform, and an axially changing current is excited on the closed loop, thereby transmitting the current signal to the receiving coupling coil 6 of the second pair of electromagnetic coupling coils, forming a corresponding changing induced electromotive force ε(t). The receiving coupling coil 6 restores the original electrical signal by analyzing the change of the induced electromotive force, and inputs the electrical signal to the main controller 2 in the winch control room through the four-core shielded communication cable 12.

[0076] In this embodiment, the hoist controller 1 and the main controller 2 in the winch house follow a point-to-point non-contact half-duplex communication method. Both can send and receive data. Inside the microcontroller module, according to the set data frame format, combined with frame synchronization and error detection mechanisms, it ensures the integrity of data transmission and avoids information loss and garbled characters.

[0077] As Figure 2 shows the communication data frame format. The frame header uses a 4-byte fixed value to identify the start of the data frame and prevent data loss; a 1-byte identifier is used to identify the data frame type, where 0x59 represents the transmission of voice data and 0x43 represents the transmission of control data; the timestamp uses a 4-byte relative timestamp to identify the time tag of each data frame for frame synchronization; the data area contains the data to be transmitted. One frame of voice data contains 160 bytes of data after 8-bit PCM sampling and encoding, and one frame of control data is 8 bytes. The control data is sent repeatedly in a loop to ensure the accurate transmission of the control signal; a 2-byte CRC-16 check code is added after the data area to detect errors during data transmission using cyclic redundancy check and improve the reliability of data transmission; a 4-byte fixed value is added at the end of one frame of data to identify the end of one frame of data and ensure the integrity of data transmission.

[0078] Both the hoist controller 1 and the main controller 2 in the winch house include an electromagnetic coupling communication circuit board 13, a microphone, a speaker, an operation indicator light, a dotting control button (such as unlocking / locking, starting / stopping, lifting), a voice intercom button, and a signal indicator light, and can switch between the sending and receiving states, as Figure 3 shown. The shaft maintenance personnel can actively lock the hoist through the locking button on the hoist controller 1 to avoid accidental start-up of the hoist due to misoperation in the winch control room; after unlocking, the dotting control button (such as unlocking / locking, starting / stopping, lifting) can be used to trigger the microcontroller module to send a control signal to the main controller 2 in the winch house in a specific frame format. After receiving the dotting control signal, the main controller 2 in the winch house activates the corresponding operation indicator light according to the received data frame format to prompt the winch driver to control the hoist and monitor the running state of the hoist in real time.

[0079] Secondly, both the vehicle house master controller 2 and the hoist controller 1 are equipped with a voice intercom function, allowing maintenance personnel to have real-time voice calls with the winch control room. The maintenance personnel can communicate by pressing the voice intercom button on the controller to use the microphone, ensuring information synchronization and timely decision-making between both parties. The signal indicator light is used to display the signal transmission quality of the communication device under the current operating state. The microcontroller module evaluates the signal transmission quality by real-time monitoring of the received signal strength and bit error rate, and provides feedback on the system operating state and communication quality in real-time. When the system is working properly, the signal indicator light is always on, indicating stable signal transmission; when the signal quality is poor, the brightness of the signal indicator light decreases, indicating signal attenuation or interference.

[0080] As Figure 3 shown, the electromagnetic coupling communication circuit board 13 uses a 32-bit microcontroller module as the control core, and is equipped with an FSK modulation and demodulation module, a voice signal processing module, an arithmetic and power amplification module, a pre-amplification module at the receiving end, a low-pass filter module, and a transceiver gating module. Among them, the voice signal processing module includes a voice acquisition module and an audio power amplifier module, and the pre-amplification module at the receiving end includes a receiving filter module and an operational amplifier module; through the collaborative work of each module, long-distance digital signal modulation transmission and weak signal reception and demodulation are realized between the winch control room and the hoist.

[0081] The voice acquisition module, the FSK modulation module, and the arithmetic and power amplification module serve as the signal transmission part; the receiving filter module, the operational amplifier module, the low-pass filter module, the FSK demodulation module, and the audio power amplifier module serve as the signal reception part.

[0082] The microcontroller module is the core of the entire system. It uses a low-power main control chip. After the system is powered on, it first performs initialization configuration of various peripherals, including initializing the system clock, configuring the USART serial port, initializing the ADC (analog-to-digital converter) and DAC (digital-to-analog converter), configuring the DMA (direct memory access), timer, various flag bits, and registers; through its rich peripheral resources, it completes the encoding and decoding of voice and control signals, enables / disables relevant control ports, and programmatically controls the FSK modulation module to output modulation signals of different frequencies, realizing flexible communication modulation and signal processing. In this embodiment, the microcontroller module uses, for example, an STM32G431RBT6 chip based on the ARM Cortex-M4 kernel as the core processing unit.

[0083] The modulation module adopts FSK (Frequency Shift Keying) modulation technology with high spectrum utilization rate and stable signal envelope, converts the digital signal encoded and output by the microcontroller module into an analog signal suitable for transmission by the electromagnetic coupling communication device, selects an intermediate frequency signal in the frequency range of 180k - 250kHz, while effectively avoiding electromagnetic interference in the high-frequency band, has good penetration ability and high data transmission rate, and ensures sufficient bandwidth to support voice signal transmission.

[0084] In this embodiment, the FSK modulation module adopts the DDS chip AD9959 for example. The direct digital frequency synthesis technology (DDS) is used to realize the conversion of digital - analog signals. The microcontroller module configures the internal registers of the modulation module through the SPI interface, and the frequency f of the output signal out is determined by the frequency control word K, the reference clock frequency f ref and the number of bits N of the frequency resolution:

[0085]

[0086] In this embodiment, the AC carrier frequencies of the modulation signals select intermediate frequency signals of 200k and 220kHz. The reference clock frequency f ref is controlled by an external 25MHz crystal oscillator. With 32-bit frequency resolution, the frequency control words K corresponding to the output frequencies of 200k and 220kHz are 3435969 and 4294968 respectively, and the serial port data transmission rate is 70kbps.

[0087] In addition, by optimizing the USART serial port transmission rate and the modulation module configuration, the output modulation signal is made to be consistent with the 70kbps symbol transmission rate of the digital baseband signal, ensuring that the delay time of the FSK signal is much less than the symbol time T b , and the delay time is fixed, avoiding symbol misalignment and phase offset problems during the communication process.

[0088] The voice acquisition module at the sending end is responsible for filtering and gain amplification of the voice signal collected by the microphone and disturbed by electromagnetic and mechanical noises, making the voice signal collected by the hoist controller 1 or the main controller 2 in the switch room clear and distinguishable. An adaptive band-pass filter is used to dynamically adjust the filtering parameters to filter out background noise and unnecessary frequency components, and then through the built-in automatic gain control (AGC) system, the amplification factor is adaptively adjusted according to the intensity of the input signal, effectively avoiding the clipping phenomenon and avoiding distortion caused by excessive amplification of the voice signal. The voice acquisition module can adopt the MAX9814 voice gain chip.

[0089] In the processing of the received voice signal by the audio power amplifier module, it is mainly responsible for amplifying the voice signal restored by the DAC peripheral of the microcontroller module through audio power amplification, amplifying the weak signal and driving the speaker. By simply adjusting the resistance value of the feedback resistor, the gain of the output signal can be flexibly controlled to control the output volume of the speaker. The audio power amplification module can use the PAM8403 chip.

[0090] The operation and power amplification module (including the operational amplifier module and the power amplification module) is used to amplify the amplitude and power of the transmitted modulated signal, improve the signal strength and load-carrying capacity, and overcome the medium loss during the transmission process. For example, the AD8054 is used as the operational amplifier in the operational amplifier module, and the ADA4870 current feedback amplifier is used as the power amplification module.

[0091] The operational amplifier module is used to linearly amplify the input signal, so that the signal has higher driving ability and signal strength before entering the power amplification module and the demodulation module; adopting a differential input structure and a negative feedback regulation mechanism, powered by a ±5V power supply and the high common-mode rejection ratio of the operational amplifier, providing an excellent output dynamic range and overdrive recovery ability. By adjusting the ratio of the input resistor to the feedback resistor, the amplification factor can be flexibly set to match the dynamic range requirements of the subsequent circuit.

[0092] A power amplification module is added between the operational amplifier module and the transceiver gating module to improve the load-carrying capacity of the signal, ensuring that the signal can maintain sufficient strength and clarity during long-distance transmission. A set of broadband amplification circuits is used inside the power amplification module to keep the signal output stable within a wide frequency band range; an efficient radio frequency power amplification chip is selected in combination with the bias circuit and stable power supply set in the module to effectively improve the transmission performance of the signal and enhance the anti-attenuation ability of the signal without introducing additional noise or distortion.

[0093] The receiving filter module is used to filter and amplify the received signal at the signal receiving end, improving the clarity and anti-interference ability of the transmitted signal. In this embodiment, the receiving filter module uses the MAX275 to form an active filter circuit, for example.

[0094] In this embodiment, an active filter circuit is used at the receiving end to design the receiving filter module to extract the transmitted signal buried in the noise. A complete band-pass filter circuit is formed by two independent second-order filters and an RC network. Each filter is composed of an operational amplifier, a capacitor and a resistor element, and has high-pass and low-pass filtering characteristics respectively. By adjusting the feedback resistor outside the filter, the gain and frequency response are optimized.

[0095] In this embodiment, before FSK demodulation, an elliptical fourth-order low-pass filter is added to the output end of the operational amplifier to further suppress high-frequency noise interference outside the bandwidth. Its out-of-band attenuation is calculated by the following formula:

[0096] where A(f) is the out-of-band attenuation at frequency f, f s is the out-of-band cut-off frequency, and n is the order of the elliptical filter. While maintaining the signal transmission bandwidth, the elliptical low-pass filter effectively suppresses interference signals outside the spectrum boundary, reducing harmonic distortion and unnecessary high-frequency components in the signal.

[0097] The FSK demodulation module is used to perform high-precision demodulation on the received analog signal transmitted through the electromagnetic coupling communication device to restore the original digital information. The FSK demodulation module, for example, uses a phase-locked loop (PLL) demodulation chip XR2211 dedicated to data communication, which integrates multiple high-performance functional units, including a preamplifier, a voltage-controlled oscillator (VCO), a loop phase detector (LPD), a quadrature phase detector (QPD), an FSK comparator, and a lock detection comparator. The dynamic range of the input signal is 10 mV to 3 V, and the operating frequency range is 0.01 Hz to 300 kHz. The specific implementation steps are as follows: The input signal is processed by the preamplifier to ensure that the signal has sufficient strength and amplitude; the amplified signal is sent to the phase-locked loop circuit, and the loop phase detector compares the phase difference between the input signal and the reference signal output by the control oscillator; the loop phase detector generates a control voltage according to the phase difference, and this voltage controls the voltage-controlled oscillator to adjust its output frequency to keep it synchronized with the frequency of the input signal, thereby achieving frequency locking; the quadrature phase detector further adjusts the phase of the signal to optimize the accuracy and stability of the demodulation process; the FSK comparator compares the voltage change output by the loop phase detector with the internal reference voltage and converts it into digital information, thereby achieving FSK demodulation.

[0098] The transceiver gating module is used to switch the working state of the controller, so that the controller defaults to the receiving state. In this state, the microcontroller module, the transceiver gating module, and the preamplifier module at the receiving end work normally, and the remaining modules are in the low-power standby mode to reduce the power consumption of the system; when it is detected that a key is pressed, the system is controlled by the microcontroller module to enter the sending state, and each module is powered on again to work. The keys include dot control keys (such as unlocking / locking, lifting, starting / stopping) and voice intercom keys. The transceiver gating module can use a TS12A12511 analog switch chip to implement channel switching and switch the working state of the controller.

[0099] Such as Figure 3As shown, the wellbore maintenance communication device based on the electromagnetic coupling principle further includes a multi-voltage power supply device 4, which includes a voltage conversion module, a power control module, and a parallel protection circuit. Among them, the voltage conversion module, the power control module, and the parallel protection circuit can all adopt existing mature circuits. The multi-voltage power supply device 4 is powered by a 12V intrinsically safe power supply. The voltage conversion module provides power supply voltages of ±5V, 3.3V, and 1.8V for the electromagnetic coupling communication circuit boards 13 inside the hoist controller 1 and the main controller 2 in the control room, meeting the power requirements of different modules; the power control module controls the voltage conversion module to provide voltage for the system, monitors the power status of the system in real time, and reduces power consumption; and the parallel protection circuit realizes functions such as voltage and current limiting protection, input overvoltage and undervoltage detection, reverse connection protection, and transient suppression, ensuring the electrical safety of the equipment in the underground flammable and explosive environment and enabling the electrical equipment to meet the requirements of mine intrinsic safety design. Through the design of two-way parallel protection circuit, the burden and conduction loss of the single-way current are reduced. When one protection circuit fails, the other can still continue to work, enhancing the redundancy and reliability of the system and ensuring the safe and reliable operation of the equipment in the underground flammable and explosive environment.

[0100] The working modes inside the hoist controller 1 and the main controller 2 in the control room include normal and low-power standby modes. After the hoist controller 1 / the main controller 2 in the control room is powered on and the initialization configuration is completed, the controller defaults to the signal receiving state, and continuously monitors the data transmitted from the transmitting coupling coil 5 of the main controller 2 in the control room / the hoist controller 1. In the signal receiving state, except for the microcontroller module, the transceiver gating module, and the pre-amplification module at the receiving end, the remaining modules of the controller are in the low-power standby state, and the power control module in the multi-voltage power supply device 4 disconnects the corresponding power supply to reduce the power consumption of the system.

[0101] As Figure 4 shown, the structures of the transmitting coupling coil 5 and the receiving coupling coil 6 are the same, and both include a circular magnetic ring and a hexagonal metal inner cavity 25 located inside the circular magnetic ring. The hexagonal metal inner cavity 25 is concentric with the circular magnetic ring, and the hexagonal metal inner cavity 25 is connected to the inner side wall of the circular magnetic ring through connecting columns 26 to form an integral whole. The whole composed of the circular magnetic ring, the connecting columns 26, and the hexagonal metal inner cavity 25 is divided into two detachable and symmetrical parts, that is, the circular magnetic ring is divided into two symmetrical parts, and at the same time, the hexagonal metal inner cavity 25 is also divided into two symmetrical parts; at the connection of the detachable parts, the coil is quickly installed and disassembled through bolts 24. The circular magnetic ring includes an insulating circular magnetic ring shell 23, a magnetic core 21, and enameled copper wire 22 located inside the circular magnetic ring shell 23; a high-frequency ferrite is used as the magnetic core 21, and large-diameter enameled copper wire 22 is evenly wound around it to increase the inductance and coupling efficiency of the coil and reduce signal attenuation.

[0102] Inside each circular magnetic ring, a high-frequency ferrite with high magnetic permeability, high saturation magnetic flux density, and high resistivity is used as the magnetic core 21. Its inductance per turn is 285 nH, and its magnetic permeability is 4000 H / m. Enameled copper wire 22 with a wire diameter of 0.27 mm is evenly wound around the magnetic core 21. The number of turns of the coil is 90, the outer diameter is 20 cm, the inner diameter is 15 cm, and the thickness is 3.5 cm. At the same time, to ensure magnetic stability and prevent short circuits and wear caused by the contact between the wire rope 7 and the magnetic core 21 and the enameled copper wire 22, a layer of polyurethane compound (insulating protective layer) is covered on the outer surface of the magnetic core 21 and the enameled copper wire 22 as the outer shell 23 of the circular magnetic ring, ensuring electrical safety in a complex environment. The hexagonal metal inner cavity 25 designed above the electromagnetic coupling coil is divided into two parts and fixed to the semi-circular magnetic ring through the connecting column 26. The electromagnetic coupling coil adopts an integrated opening and closing structure design for quick installation and disassembly. During installation, the integrated structure composed of the magnetic ring and the hexagonal metal inner cavity 25 is separated from the middle bolt 24 connection, allowing the wire rope 7 to pass through the hexagonal metal inner cavity 25 at the center of the circular magnetic ring, and then the hexagonal metal inner cavity 25 is firmly connected to the wire rope 7 or the hollow tubular bracket 14 through the bolt 24, preventing the coil from displacing due to vibration and torsion during lifting, while the circular magnetic ring itself remains suspended and in a non-contact state with the wire rope 7, avoiding the risk of mechanical wear caused by direct contact.

[0103] Specifically, the first pair of electromagnetic coupling coils located at the top 9 of the hoist skip are fixed to the wire rope 7 at the top 9 of the skip through the hexagonal metal inner cavity 25 and move vertically and synchronously with the hoist cage 15. The second pair of electromagnetic coupling coils located below the guide pulley 10 are fixed to the hollow tubular bracket 14 through which the wire rope 7 passes through the hexagonal metal inner cavity 25. The bracket itself remains stationary and is fixed to the shaft steel structure, ensuring that the coil remains fixed during the vertical movement of the hoist and does not move up and down with the wire rope 7. In this embodiment, the outside of the hollow tubular bracket 14 is fixed to the shaft steel structure, for example, by welding, and the wire rope 7 can freely pass through its interior without affecting the normal operation of the hoisting system.

[0104] As Figure 5 shown, the transmitting coupling coil 5 and the receiving coupling coil 6 can be equivalent to two groups of transformers connected by the wire rope 7. The transmitting end is a step-down transformer with a turns ratio of N:1, which converts the high-voltage signal into a lower voltage, realizes effective signal coupling, reduces signal attenuation, and increases the transmission distance; the receiving end is a step-up transformer with a turns ratio of 1:N, which increases the amplitude of the output voltage and compensates for the signal attenuation during transmission. The difference is that in order to achieve the purpose of stepping up and stepping down, the number of turns of the coils on both sides of the transformer is different, while the electromagnetic induction channel can transmit in both directions with the same effect. Therefore, the turns ratio of the coils on both sides of the transmitting coupling coil 5 and the receiving coupling coil 6 in this system is 1:1, and the structures are the same, showing symmetry.

[0105] From the perspective of the circuit, the closed loop composed of the steel wire rope 7, the tail rope 8, and the hoist cage 15 of the hoist can be regarded as a distributed parameter circuit. According to Kirchhoff's law, the transmission line equation is derived. The equivalent circuit of the electromagnetic coupling communication device based on the steel wire rope 7 is as Figure 5 shown. At the signal sending end (such as Figure 5 the left part in i ), the modulated signal is input into the sending coupling coil 5 after power amplification and RCL series resonance processing, and is converted into a waveform signal U 1 that can be used for transmission. This signal serves as the input of a primary transformer, and a changing current I 2 is formed on its input winding. The closed loop composed of the steel wire rope 7, the tail rope 8, and the hoist cage 15 of the hoist serves as the output of the primary transformer, and a changing current I o is formed in this closed loop. This current also serves as the input of a secondary transformer, and a corresponding electromotive force is induced on the output winding of the secondary transformer. By analyzing the change of this induced electromotive force, the waveform signal U

[0106] Among them, L 1 is the self-inductance of the winding of the sending coupling coil 5, L 2 is the inductance of the closed loop, L 3 is the self-inductance of the winding of the receiving coupling coil 6, M 1,2 is the mutual inductance between the sending coupling coil 5 and the closed loop, M 2,3 is the mutual inductance between the closed loop and the receiving coupling coil 6, X 1 , X 2 , X 3 are the equivalent impedances of the sending coupling coil 5, the closed loop, and the receiving coupling coil 6 respectively. C is the distributed capacitance on both sides of the sending coupling coil 5 and the receiving coupling coil 6, and C p is the stray capacitance between the coils.

[0107] According to Kirchhoff's voltage law, the input voltage U i at the sending end is equal to the sum of the voltage drops across each component:

[0108]

[0109] The closed loop is composed of the mutual inductance M 1,2 , the self-inductance L 2 , the equivalent impedance Z 2 , and the mutual inductance M 2,3 . According to KVL, ignoring minor losses (such as eddy current and hysteresis losses), the voltage equation of the closed loop is:

[0110]

[0111] The receiving coupling coil 6 circuit includes the mutual inductance M 2,3 , the self-inductance L of the coil 3 , the equivalent impedance X 3 , the distributed capacitance C, and the output voltage U o , and the voltage equation of the receiving circuit is:

[0112]

[0113] Among them, Z 1 = X 1 + jωL 1 is the total impedance of the transmitting coupling coil 5, is the total impedance of the closed-loop circuit, Z 3 = jωL 3 + X 3 is the total impedance of the receiving coupling coil 6.

[0114] is the coupling coefficient between the primary and secondary coils T 1 and T 2 .

[0115] The input current I 1 of the transmitting coupling coil 5 is:

[0116]

[0117] Substitute I 1 into the intermediate loop equation and after arrangement, we get:

[0118]

[0119] Among them, the intermediate equivalent impedance is defined as Z 2 ′ :

[0120]

[0121] Substitute the expression of I 2 into the receiving circuit voltage equation, and the relationship between U o and U i is:

[0122]

[0123] From the above formula derivation, the amplitude-frequency response H(ω) of the closed-loop electromagnetic coupling channel is:

[0124]

[0125] Through the transmission line equation, the output voltage U o is affected by the total impedances Z 1 of the transmitting coupling coil 5, the closed-loop circuit, and the receiving coupling coil 6, Z2 , Z 3 , coupling coefficient M 1,2 , M 2,3 , the influence of the change of magnetic ring parameters and the carrier frequency ω. In the system design, by adjusting the RCL resonant circuit and optimizing the coupling coefficient, the energy transmission efficiency is improved, the reflection loss is reduced, a larger carrier frequency ω and a higher transmission signal amplitude are selected, the distortion of the transmission signal is reduced, and while ensuring the transmission distance, the transmission rate is increased.

[0126] For the magnetic field generated by the transmitting coupling coil 5, the variation of its magnetic induction intensity B(d) with the communication distance d can be expressed as:

[0127]

[0128] In the formula, μ 0 is the vacuum permeability, n is the number of turns of the coil, I is the coil current, R is the radius of the coil, and d is the distance between the transmitting and receiving coils. The length L s of the steel wire rope 7 in the closed loop determines the effective magnetic resistance R m of the closed loop, thereby affecting the magnetic flux φ between the transmitting and receiving coils:

[0129]

[0130] In the formula: l 1 is the magnetic path length of the transmitting coupling coil 5, μ 1 and μ s are the magnetic permeabilities of the transmitting coupling coil 5 and the steel wire rope 7 respectively, A 1 and A s are the cross-sectional areas of the transmitting coupling coil 5 and the steel wire rope 7 respectively.

[0131] Combining the relationship between the magnetic induction intensity and the magnetic resistance, the effective range of the communication distance d is approximately estimated by the following formula:

[0132]

[0133] It can be seen from the derivation of the above formula that when the length of the steel wire rope 7 increases, the magnetic resistance R m of the magnetic path increases, the magnetic flux φ decreases, and the communication distance d is limited. In this embodiment, by increasing the coil cross-sectional area A 1 , the coil magnetic permeability μ 1 and the number of turns n of the coil to reduce the equivalent magnetic resistance, increase the magnetic flux φ between the transmitting and receiving coupling coils, and increase the communication distance d.

[0134] At a specific carrier frequency f lim there is a matching inductance value L lim, when the coil inductance is less than this critical value, the RCL circuit can reach resonance by adjusting the capacitance, optimizing the coil transmission distance. In this embodiment, a 1nF low-frequency resonant capacitor is selected, which has less loss and stable capacitance, and the coil inductance value L in is:

[0135]

[0136] In this embodiment, a high-frequency ferrite is used as the coil core 21, and its inductance per turn is L T = 285 nH / turn 2 , then the number of turns N of the coil is:

[0137]

[0138] Furthermore, in this embodiment, 200k - 220kHz is selected as the carrier frequency of the modulation signal. Considering the skin effect of the current, the skin depth of the 200kHz carrier signal is:

[0139]

[0140] In the formula, Δ is the skin depth, μ r is the relative permeability of the enameled copper wire 22, μ 0 is the permeability of free space, is the conductivity of the enameled copper wire 22.

[0141] In coil design, to ensure the effective transmission of high-frequency signals, when the wire diameter of the enameled copper wire 22 is twice the skin depth, the current can be evenly transmitted in the wire, improving the signal transmission efficiency and reducing signal attenuation and distortion caused by uneven high-frequency current distribution.

[0142] In this embodiment, the electromagnetic coupling coils 5 and 6 use a high-frequency ferrite with a permeability of 4000 H / m as the core, and are evenly wound with enameled copper wire with a wire diameter of 0.27 mm. The outer diameter of the coil is 20 cm, the inner diameter is 15 cm, and the thickness is 3.5 cm.

[0143] When two semi-circular magnetic rings are used in combination, it is inevitable to generate gaps, thereby changing the magnetic permeability of the magnetic ring and causing the inductance of the magnetic ring to decrease. In this embodiment, the number of turns of the coil is doubled to increase the coil inductance, that is, the number of turns N of the coil is 90 turns.

[0144] In this embodiment, to improve the coupling efficiency of the coil in the 200k - 220kHz carrier frequency range, increase the current passing through the coil and effectively utilize the energy, an RCL circuit is formed by adding a compensation capacitor and an equivalent resistor at the coupling coil to make the circuit close to the resonant state, that is, satisfying:

[0145]

[0146] Where: f Q is the resonant frequency, L is the inductance of the coil, and C is the compensation capacitor.

[0147] Specifically, a compensation capacitor C r and an equivalent resistance R r are connected in series across both ends of the transmitting coupling coil (5) to form a series resonant circuit. At series resonance, the inductive reactance X L = ωL r of the transmitting coupling coil (5) compensates with the capacitive reactance of the compensation capacitor, making the total impedance Z r of the circuit minimum and the transmission current maximum. The expression for the total impedance is:

[0148]

[0149] At the resonant frequency, it satisfies:

[0150]

[0151] At this time, the total impedance of the coil is:

[0152] Z r = R r ;

[0153] When the circuit is in the resonant state, the current i 1 (t) of the transmitting coupling coil (5) can be approximately expressed as:

[0154]

[0155] By connecting a compensation capacitor C s and an equivalent resistance R s in parallel across both ends of the receiving coupling coil (6), a parallel resonant circuit is formed. By adjusting the resonant frequency f Q of the system, it is made to fall within the target frequency range (200k - 220kHz). In the resonant state, the impedance of the circuit is maximized within the frequency range, and the voltage amplitude at the receiving end is increased.

[0156] When the signal received by the receiving coupling coil 6 is filtered and amplified by the pre - stage amplification module, it triggers the power control module to conduct, controlling the voltage conversion module to output multiple working voltages to make the controller work properly. When the micro - controller module inside the hoist controller 1 / the main controller 2 in the shed detects that a key is pressed, the controller switches from the signal receiving state to the signal sending state, and the micro - controller module triggers the power control module to conduct, controlling the voltage conversion module to output multiple working voltages to make the controller work properly.

[0157] The software processing flow of the communication device is as Figure 6As shown in the figure, a 32-bit microcontroller module is used as the control core. After the system is powered on, it first enters the initialization configuration process of hardware peripherals. Configure USART1 as the sending serial port, and its buffer as the sending buffer. Configure USART3 as the receiving serial port, and its buffer as the receiving buffer. Perform an initial handshake with the electromagnetic coupling communication module through the USART interface to ensure the normal operation of the communication link. When the system completes self-check and successful initialization configuration, it defaults to the receiving state, waiting for the electrical signal received by the coupling coil 6. Quickly identify the received data frame format in the microcontroller module. When a control data frame is detected, the microcontroller module performs predefined control operations according to the signal type, enables / disables relevant control ports, activates or extinguishes the corresponding operation indicator lights, and provides real-time feedback and status display. If a voice data frame is detected, it is decoded through the DAC module to restore the voice information. When the microcontroller module detects that the control button is pressed, the system switches to the sending state. The microcontroller module generates corresponding digital coding signals according to the button operation. When the voice button is detected to be pressed, the system enters the voice data acquisition and sending process, reads a frame of voice signal every 20 ms, completes sampling and encoding. Whether it is a voice signal or a control signal, it is finally processed into a digital signal inside the microcontroller module, and is sent through FSK modulation after being processed according to the set data frame format. Combining frame synchronization and error detection mechanisms (CRC check) to ensure the integrity of the transmitted data and avoid information loss and garbled phenomena.

[0158] For the distortion of some audio sampling values caused by error codes, based on the time series characteristics of the data frame, combined with the continuity of the inter-frame data, use the data of adjacent code elements to estimate the value of the error code element, compensate for the signal distortion caused by error codes during the transmission process, and reconstruct the missing data points through the linear interpolation algorithm. That is, for the error code element x i , use the adjacent code elements x i-1 and x i+1 to calculate the interpolation x i :

[0159]

[0160] In the formula: t i , t i-1 , t i+1 are the time stamp sequences of the corresponding code elements in the data area.

[0161] Furthermore, for the encoding process of voice signals, the sampling and encoding of voice signals are completed through the ADC peripheral of the microcontroller module. Use the timer trigger method to trigger the single conversion function of the ADC, and transfer the data to the memory through the DMA mechanism. Only by setting the trigger interval of the timer can the ADC timing sampling conversion function be realized.

[0162] Specifically, this system uses a sampling rate of 8 kHz and a resolution of 8 bits. It reads one frame of voice signal every 20 ms through the timer trigger method. That is, one frame of voice signal needs to be sampled 160 times and contains 1280-bit data in total. The data transmission rate of the electromagnetic coupling communication device is 70 kbps, and it takes 18.3 ms to transmit each frame of signal, which is lower than the set sampling period of 20 ms. The system has enough time for data transmission. At the same time, the DMA half-transfer complete interrupt and transfer complete interrupt mechanisms are set. Whenever half-frame data is collected, DMA will trigger a half-transfer interrupt signal, allowing the microcontroller module to start preliminary processing of the collected data before the data transmission is completed. When DMA completes all data transmission, a transfer complete interrupt is triggered. At this time, the microcontroller module can process the remaining data and prepare for the sampling and transmission of the next frame of data.

[0163] For the decoding and processing of voice signals, the work of restoring digital signals to voice signals is completed through the DAC peripheral of the microcontroller module. By configuring the timer to generate a periodic trigger signal of 8 kHz, the same time reference as the ADC module is maintained. The DAC converts the current digital signal into an analog voltage output when each timer trigger signal arrives. Similarly, DMA is used to transfer data in memory to the peripheral. Through the DMA half-transfer complete and transfer complete interrupt mechanisms, data is automatically transferred, liberating CPU resources and ensuring seamless data transmission.

[0164] Embodiment 2

[0165] This Embodiment 2 describes a wellbore maintenance communication sending method based on the electromagnetic coupling principle. This wellbore maintenance communication sending method based on the electromagnetic coupling principle is implemented based on the device in the above Embodiment 1.

[0166] Specifically, the wellbore maintenance communication sending method based on the electromagnetic coupling principle in this embodiment includes the following steps:

[0167] A1. The microcontroller module inside the hoist controller 1 / the main controller 2 in the shed detects that a key is pressed, controls the transceiver gating module to make the system in the sending state, triggers the power control module in the multi-voltage power supply device 4 to conduct, and controls the voltage conversion module to output multiple working voltages to make the controller work properly;

[0168] A2. The microcontroller module converts the collected voice or control instructions (such as unlocking / locking, lifting, starting / stopping) into corresponding digital signals, and after processing according to the set data frame format, transmits them to the FSK modulation module through USART;

[0169] A3. The microcontroller module controls the FSK modulation module to output a corresponding analog modulation signal according to the digital signal;

[0170] A4. The modulation signal is processed by the operation and power amplification module to increase the intensity of the output signal and the load - carrying capacity.

[0171] A5. The modulation signal is sent to the RCL series resonance circuit after power amplification, increasing the current passing through the transmitting coupling coil and effectively utilizing the energy, and improving the coil coupling efficiency.

[0172] A6. The processed modulation signal is input to the transmitting coupling coil 5 through the four - core shielded communication cable 12, and data transmission is carried out through the closed loop composed of the hoist steel wire rope 7, the tail rope 8 and the hoist cage 15.

[0173] A7. When the button is released and the signal transmission is completed, the micro - controller module controls the power control module to disconnect, and drives the transceiver gating module to make the hoist controller 1 / the main controller 2 in the signal receiving state, and re - enters the low - power standby mode.

[0174] Embodiment 3

[0175] This Embodiment 3 describes a wellbore maintenance communication receiving method based on the electromagnetic coupling principle, and this wellbore maintenance communication receiving method based on the electromagnetic coupling principle is implemented based on the device in the above Embodiment 1.

[0176] Specifically, the wellbore maintenance communication receiving method based on the electromagnetic coupling principle in this embodiment includes the following steps:

[0177] A wellbore maintenance communication receiving method based on the electromagnetic coupling principle includes the following steps:

[0178] B1. The receiving coupling coil 6 restores the original analog modulation signal by analyzing the induced electromotive force.

[0179] B2. The modulation signal is input to the main controller 2 in the control room / the hoist controller 1 through the four - core shielded communication cable 12, and is processed by the internal RCL parallel resonance circuit to increase the amplitude of the received signal voltage.

[0180] B3. The modulation signal filters out the high - frequency noise interference generated in the transmission channel through the receiving - end pre - amplifier module, amplifies the signal within the passband, and at the same time drives the power control module to make the system powered on and work normally.

[0181] B4. The amplified modulation signal is input into the low - pass filter to reduce the harmonic distortion and unnecessary high - frequency components in the signal.

[0182] B5. The processed signal is sent to the FSK demodulation module for demodulation to restore the original digital information.

[0183] B6. The microcontroller module receives the demodulated signal output by the FSK demodulation module through USART, decodes it according to the pre-set data frame format, and performs predefined operations (such as unlocking / locking, lifting, starting / stopping, and audio decoding).

[0184] B7. After the signal reception is completed, the microcontroller module controls the power control module to disconnect, and the car house master controller 2 / hoist controller 1 returns to the receiving state again and enters the low-power standby mode.

[0185] Of course, the above description is only the preferred embodiment of the present invention. The present invention is not limited to listing the above embodiments. It should be noted that all equivalent substitutions and obvious deformation forms made by any person skilled in the art under the teaching of this specification fall within the substantial scope of this specification and should be protected by the present invention.

Claims

1. A wellbore maintenance communication device based on the electromagnetic coupling principle, characterized in that: It includes a hoist controller (1), a garage master controller (2), a signal transmission medium and two pairs of electromagnetic coupling coils; The hoist controller (1) is arranged in the hoist cage, and the engine room master controller (2) is arranged in the winch control room above the well; The two pairs of electromagnetic coupling coils are defined as a first pair and a second pair of electromagnetic coupling coils, the first pair of electromagnetic coupling coils is connected to a hoist controller (1), and the second pair of electromagnetic coupling coils is connected to a garage master controller (2); The first and second pairs of electromagnetic coupling coils are respectively arranged at the top (9) of the elevator bucket and below the guide wheel (10); each pair of electromagnetic coupling coils includes a transmitting coupling coil (5) and a receiving coupling coil (6); The steel wire rope (7) of the hoist passes through the first pair and the second pair of electromagnetic coupling coils arranged at the top of the hoist bucket (9) and below the guide wheel (10) in sequence, and the steel wire rope (7) does not contact each pair of electromagnetic coupling coils; Using the closed-loop lifting link where the steel wire rope (7) of the hoist is located as a signal transmission medium; A transmission link consisting of two pairs of electromagnetic coupling coils and a signal transmission medium is established between the hoist controller (1) and the garage master controller (2), and bidirectional long-distance transmission of the dot control signal and the voice signal is achieved based on the electromagnetic coupling principle. Among them, the dot control signals include unlocking / locking, start / stop and lifting control signals.

2. The wellbore maintenance communication device based on the electromagnetic coupling principle according to claim 1 is characterized in that: The wellbore maintenance communication device also includes a portable wearable emergency stop controller (3); The portable wearable emergency stop controller (3) is located in the elevator cage and can be worn by maintenance personnel, and wirelessly communicates with the elevator controller (1) via a Bluetooth serial communication module, so that the maintenance personnel can remotely control the elevator to stop running.

3. The wellbore maintenance communication device based on the electromagnetic coupling principle according to claim 1 is characterized in that: The signal transmission process between the hoist controller (1) and the garage master controller (2) is as follows: The modulation signal generated by the hoist controller (1) / the garage master controller (2) is input to the transmission coupling coil (5) of the first / second pair of electromagnetic coupling coils, thereby forming a changing magnetic field at the transmission coupling coil (5); The magnetic field changes with the waveform of the modulation signal, and simultaneously excites a correspondingly changing axial current on the signal transmission medium, and the signal transmission medium transmits the current signal to the receiving coupling coil (6) of the second / first pair of electromagnetic coupling coils; An induced electromotive force that changes accordingly is formed at the receiving coupling coil (6), and the receiving coupling coil (6) analyzes the change in the induced electromotive force to restore the original electrical signal, and inputs the electrical signal to the garage master controller (2) / hoist controller (1).

4. The wellbore maintenance communication device based on the electromagnetic coupling principle according to claim 1 is characterized in that: The hoist controller (1) and the garage master controller (2) both include an electromagnetic coupling communication circuit board (13), a microphone, a loudspeaker, an operation indicator light, a dot control button, a voice intercom button and a signal indicator light; The dot control buttons include unlock / lock button, start / stop button, and lift button; The electromagnetic coupling communication circuit board (13) comprises a microcontroller module, an FSK modulation and demodulation module, a voice signal processing module, an operation and power amplification module, a receiving end pre-amplification module, a low-pass filtering module and a transceiver selection module; The voice signal processing module includes a voice acquisition module and an audio power amplifier module; The receiving end pre-amplifier module includes a receiving filter module and an operational amplifier module; The voice acquisition module, FSK modulation module, operation and power amplifier module are used as the signal sending part; the receiving end pre-amplifier module, low-pass filter module, FSK demodulation module and audio power amplifier module are used as the signal receiving part; The microcontroller module is connected to the voice signal processing module and the FSK modulation and demodulation module, and is responsible for encoding and decoding voice and control signals, enabling / disabling related control ports, and programming and controlling the FSK modulation module to output modulation signals of different frequencies; The FSK modulation module is used to convert the digital signal encoded and output by the microcontroller module into an analog signal suitable for transmission; The voice acquisition module is used to filter and gain amplify the voice signal collected by the microphone; the audio power amplifier module is used to perform audio power amplification processing on the analog voice signal restored by the microcontroller module to drive the speaker to play the voice; The operation and power amplification module is used to amplify the amplitude and power of the transmitted modulated signal; The receiving filter module is used to filter and gain amplify the received modulated signal at the signal receiving end; The FSK demodulation module is used to demodulate the received analog modulation signal and restore the original digital signal; The transceiver selection module is used to switch the working state of the controller, including the signal receiving state and the signal sending state.

5. The wellbore maintenance communication device based on the electromagnetic coupling principle according to claim 4 is characterized in that: The shaft maintenance communication device further comprises a multi-voltage power supply device (4), which is powered by a 12V intrinsically safe power supply and comprises a voltage conversion module, a power control module and a parallel protection circuit; The voltage conversion module is used to provide a variety of power supply voltages for the electromagnetic coupling communication circuit board (13) inside the hoist controller (1) and the garage master controller (2); the power supply control module is used to control the voltage conversion module to provide voltage for the system; The parallel protection circuit is used to achieve voltage and current limiting protection, input overvoltage and undervoltage detection, reverse connection protection and transient suppression.

6. The wellbore maintenance communication device based on the electromagnetic coupling principle according to claim 5 is characterized in that: The transceiver gating module enables the hoist controller (1) and the garage master controller (2) to be in a signal receiving state by default; when the hoist controller (1) / garage master controller (2) is in the signal receiving state, the microcontroller module, the transceiver gating module and the receiving end preamplifier module work normally, and the remaining modules of the controller are in a low power consumption standby mode; When the microcontroller module in the hoist controller (1) / garage master controller (2) detects that the dot control button or the voice intercom button is pressed, the controller switches from the signal receiving state to the signal sending state; the microcontroller module triggers the power control module in the multi-voltage power supply device (4) to turn on, and controls the voltage conversion module to output a variety of working voltages, so that all modules in the controller work normally; at the same time, the microcontroller module generates a corresponding digital code signal according to the corresponding key operation, and sends it through FSK modulation after processing according to the set data frame format; When the signal received by the receiving coupling coil (6) is filtered and amplified by the pre-amplifier module, the power control module is triggered to turn on, and the control voltage conversion module outputs a variety of working voltages, so that each module of the controller works normally; at the same time, the microcontroller module identifies the format of the received data frame and performs predefined control operations according to the signal type, wherein the predefined control operations include unlocking / locking, lifting and lowering, starting and stopping, and audio decoding.

7. The wellbore maintenance communication device based on the electromagnetic coupling principle according to claim 5 is characterized in that: The two ends of the transmitting coupling coil (5) are connected in series with a compensation capacitor and an equivalent resistor to form an RCL series resonant circuit; the two ends of the receiving coupling coil (6) are connected in parallel with a compensation capacitor and an equivalent resistor to form an RCL parallel resonant circuit.

8. The wellbore maintenance communication device based on the electromagnetic coupling principle according to claim 1, characterized in that: The transmitting coupling coil (5) and the receiving coupling coil (6) have the same structure and both comprise a circular magnetic ring and a hexagonal metal inner cavity (25) located inside the circular magnetic ring; The hexagonal metal inner cavity (25) and the circular magnetic ring are arranged concentrically, and the hexagonal metal inner cavity (25) and the inner side wall of the circular magnetic ring are connected to form a whole through a connecting column (26); The circular magnetic ring comprises an insulating circular magnetic ring shell (23), a magnetic core (21) located in the circular magnetic ring shell (23), and an enameled copper wire (22), wherein the magnetic core (21) is made of an annular ferrite, and the enameled copper wire (22) is wound on the magnetic core (21); The transmitting coupling coil (5) and the receiving coupling coil (6) located at the top (9) of the elevator bucket are respectively fixed to the traction wire rope at the top of the bucket through the corresponding hexagonal metal inner cavity (25), and move vertically synchronously with the elevator cage; The transmitting coupling coil (5) and the receiving coupling coil (6) located below the guide wheel (10) are respectively fixed to a hollow tubular support (14) through which the steel wire rope passes through corresponding hexagonal metal inner cavities (25); The hollow tubular support (14) itself remains stationary and is fixed by the shaft steel structure, and does not move up and down with the steel wire rope.

9. A method for sending wellbore maintenance communication based on the electromagnetic coupling principle, implemented by the wellbore maintenance communication device based on the electromagnetic coupling principle as claimed in claim 7, characterized in that: The sending method comprises the following steps: A1, the microcontroller module inside the hoist controller (1) / garage master controller (2) detects that a key is pressed, controls the transceiver selection module to put the system in a sending state, and the microcontroller module triggers the power control module in the multi-voltage power supply device (4) to turn on, controls the voltage conversion module to output a variety of working voltages, and enables the controller to work normally; A2, the microcontroller module converts the collected voice, unlocking / locking, lifting or starting and stopping control instructions into corresponding digital signals, and transmits them to the FSK modulation module through USART after processing according to the set data frame format; A3, the microcontroller module controls the FSK modulation module to output the corresponding analog modulation signal according to the digital signal; A4. The modulated signal is processed by the operation and power amplification module to improve the strength and load capacity of the output signal; A5, the modulated signal is sent to the RCL series resonant circuit after power amplification, so that the current passing through the transmitting coupling coil (5) is increased and the energy is effectively utilized to improve the coil coupling efficiency; A6. The modulated signal after processing is input to the transmitting coupling coil (5), and data is transmitted using the signal transmission medium; A7. The button is released, the signal transmission is completed, the microcontroller module controls the power control module to disconnect, drives the transceiver selection module to put the hoist controller (1) / garage master controller (2) in the signal receiving state, and re-enters the low power standby mode.

10. A method for receiving wellbore maintenance communication based on the electromagnetic coupling principle, implemented by the wellbore maintenance communication device based on the electromagnetic coupling principle as claimed in claim 7, characterized in that: The receiving method comprises the following steps: B1, the receiving coupling coil (6) recovers the original analog modulation signal by analyzing the induced electromotive force; B2, the modulated signal is input to the garage master controller (2) / hoist controller (1), and processed by the internal RCL parallel resonant circuit to increase the voltage amplitude of the received signal; B3. The modulated signal is filtered out by the pre-amplifier module at the receiving end to remove the high-frequency noise interference generated in the transmission channel, and the signal within the passband is amplified. At the same time, the power control module is driven to enable the system to power on and work normally. B4. The amplified modulated signal is input into a low-pass filter to reduce harmonic distortion and unnecessary high-frequency components in the signal; B5. The processed signal is sent to the FSK demodulation module for demodulation to restore the original digital information; B6, the microcontroller module receives the demodulated signal output by the FSK demodulation module through USART, decodes it according to the preset data frame format, and performs predefined operations, including unlocking / locking, lifting, starting and stopping, and audio decoding; B7. After the signal is received, the microcontroller module controls the power control module to disconnect, so that the garage master controller (2) / hoist controller (1) is in the receiving state again and enters the low-power standby mode.

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