Underground signal wireless transmission equipment

Abstract

The invention relates to the technical field of coal mine gas prevention and control of drilling while drilling signals, in particular to underground signal wireless transmission equipment which comprises a drill rod assembly and a signal transmission system installed in the drill rod assembly. The drill rod assembly comprises a plurality of common drill rods and relay drill rods which are in threaded connection to form a drill rod component; a first female head of a common drill rod of the drill rod assembly is in threaded connection with the front end part of the adapter; a bayonet at the outer end of a rotating shaft on the inner side of the tail end of the adapter is clamped with a connecting end of the water pipe, and when the drill rod component rotates, the water pipe does not rotate together with the drill rod component; an adapter, a relay drill rod and a common drill rod are combined and transformed to form a drill rod assembly with a wireless signal transmission function; and a signal transmission system is mounted in the drill rod assembly, so that the drilling track during drilling of a drill bit can be transmitted to an upper computer on the ground from the underground in real time by utilizing data information acquired by a sensor.

Description

Technical Field

[0001] The invention relates to the technical field of drilling-while-drilling signals for gas prevention and control in coal mines, and in particular to underground signal wireless transmission equipment. Background Art

[0002] When drilling in a coal mine, the drill bit must transmit the collected data signal to the well during the implementation of drilling. The modulation methods commonly used in the traditional communication industry are: phase shift keying (PSK), frequency shift keying (FSK) and amplitude shift keying (ASK). Specifically for the signal transmission used for the well and underground of the present invention, the above three methods have their own scope of application and characteristics. Of course, there are some improved and special modulation methods such as minimum frequency shift keying (MSK) and orthogonal frequency division multiplexing (OFDM). The premise of proper modulation is that the characteristics of the signal and the channel must match, so before selecting the modulation method, the characteristics of the underground radio electromagnetic wave communication channel must be analyzed. Since there is no universal law and random changes between different formation parameters in the well, and the electromagnetic wave is severely attenuated during transmission in the formation, the amplitude of the transmitted signal changes irregularly and the fluctuation is relatively sensitive. Based on this formation channel characteristic, it can be determined that ASK modulation is not suitable for underground transmission systems. Therefore, it is very necessary to develop a transmission system for underground and underground signals of coal mine gas prevention and control drilling. Summary of the invention

[0003] The purpose of the present invention is to provide an underground signal wireless transmission device in view of the defects and shortcomings of the prior art.

[0004] An underground signal wireless transmission device according to the present invention comprises a drill rod assembly and a signal transmission system installed in the drill rod assembly;

[0005] The drill rod assembly comprises a plurality of common drill rods and relay drill rods connected by threads to form a drill rod component; the first female head of the common drill rod of the drill rod assembly is threadedly connected to the front end of the adapter; the bayonet at the outer end of the rotating shaft inside the rear end of the adapter is clamped with the connecting end of the water pipe, and when the drill rod component rotates, the water pipe does not rotate with the drill rod component;

[0006] The signal transmission system includes a signal acquisition module, which sends the collected signal to the upper computer on the well through the signal wireless transmission module to form a signal transmission system;

[0007] The signal acquisition module includes a first single-chip microcomputer, which receives signal data from a track sensor and a vibration sensor. The track sensor and the vibration sensor are installed on a signal conditioning circuit board in the inner cavity of a common drill pipe. A storage module is installed on the signal conditioning circuit board to store the detected signal data.

[0008] The signal wireless transmission module includes a signal demodulation module for receiving a signal sent from the first single-chip microcomputer, modulating the received signal data, and then relaying and amplifying it to the relay module through an electromagnetic channel, and then filtering and demodulating it again, and then sending the amplified signal data to the second single-chip microcomputer; the second single-chip microcomputer then sends the signal data to the host computer through the WIFI module through the switch in the base station, forming information data processing.

[0009] Furthermore, a first annular groove is provided on the inner wall of the front end portion of the adapter, and the shape of the first annular groove matches the electromagnetic coil; the inside of the rotating shaft of the adapter is a cavity; a horizontal base is provided at the bottom of the middle cylinder of the adapter; and a square signal module groove is provided on the front of the top surface of the middle cylinder of the adapter.

[0010] Furthermore, one end of the relay rod body of the relay drill rod is a second female head, and the other end of the relay drill rod is a second male head; a drawer-type groove is provided on the relay rod body of the relay drill rod; the inner ends of the second female head and the second male head of the relay drill rod are respectively provided with second electromagnetic coil grooves for installing electromagnetic coils.

[0011] Furthermore, the ordinary drill rod includes a drill rod body, the end of the drill rod body away from the first female head is a first male head, and a first center axis hole is arranged in the drill rod body; the inner wall of the first female head of the ordinary drill rod is provided with a coil base for placing the electromagnetic wire; the inner wall of the first male head of the ordinary drill rod is provided with a third electromagnetic coil groove for storing the electromagnetic coil.

[0012] Furthermore, a first circuit board for integrating reception and WIFI functions is installed in the square signal module slot of the adapter, and a signal demodulation module and a signal forwarding module are integrated on the first circuit board; a relay circuit board is installed in the drawer-type slot of the relay drill rod, and a relay module is integrated on the relay circuit board.

[0013] The beneficial effects of the present invention are as follows: an underground signal wireless transmission device described in the present invention combines and transforms an adapter, a relay drill rod and an ordinary drill rod to form a drill rod assembly with wireless signal transmission; and installs a signal transmission system in the drill rod assembly, which can realize the drilling trajectory when the drill bit is drilling a hole, and use sensors to send the collected data information in real time from the well to the upper computer above the well. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application, but do not constitute an improper limitation of the present invention. In the drawings:

[0015] Figure 1 It is a schematic diagram of the structure of the adapter in the present invention;

[0016] Figure 2 It is a structural schematic diagram of the relay drill pipe modification in the present invention;

[0017] Figure 3 It is a structural schematic diagram of the ordinary drill pipe modification in the present invention;

[0018] Figure 4 It is a topological schematic diagram of the present invention;

[0019] Figure 5 It is a topological schematic diagram of the above-hole and downhole signal collection and transmission to the host computer in the present invention;

[0020] Figure 6 It is a comparison diagram of the bit error rate characteristics of the three traditional modulation methods in the present invention.

[0021] Description of reference numerals:

[0022] Adapter-1; relay drill pipe-2; ordinary drill pipe-3. DETAILED DESCRIPTION

[0023] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, wherein the illustrative embodiments and descriptions are only used to explain the present invention but are not intended to limit the present invention.

[0024] An underground signal wireless transmission device described in this specific embodiment includes a drill rod assembly and a signal transmission system installed in the drill rod assembly;

[0025] like Figure 1-Figure 3 As shown, the drill rod assembly includes a plurality of ordinary drill rods 3 and relay drill rods 2 that are threadedly connected to form a drill rod component; the first female head 33 of the ordinary drill rod 3 of the drill rod assembly is threadedly connected to the front end 13 of the adapter 1; the bayonet 18 at the outer end of the rotating shaft 17 inside the rear end 19 of the adapter 1 is clamped with the connecting end of the water pipe, and when the drill rod component rotates, the water pipe does not rotate with the drill rod component.

[0026] like Figure 1 As shown, the inner wall of the front end portion 13 of the adapter 1 is provided with a first annular groove 14, and the shape of the first annular groove 14 matches the electromagnetic coil; the rotating shaft 17 of the adapter 1 has a cavity 15; the bottom of the middle cylinder 11 of the adapter 1 is provided with a horizontal base 16; the front of the top surface of the middle cylinder 11 of the adapter 1 is provided with a square signal module slot 12.

[0027] like Figure 2As shown, one end of the relay rod body 22 of the relay drill rod 2 is a second female head 25, and the other end of the relay drill rod 2 is a second male head 23; a drawer-type groove 21 is provided on the relay rod body 22 of the relay drill rod 2; the inner ends of the second female head 25 and the second male head 23 of the relay drill rod 2 are respectively provided with second electromagnetic coil grooves 24 for installing electromagnetic coils; an electromagnetic channel is formed between the electromagnetic coils in the second electromagnetic coil grooves 24 in the second female head 25 and the second male head 23 in this design.

[0028] like Figure 3 As shown, the ordinary drill rod 3 includes a drill rod body 31, and the end of the drill rod body 31 away from the first female head 33 is a first male head 33, and a first central axis hole 34 is arranged in the drill rod body 31; the inner wall of the first female head 33 of the ordinary drill rod 3 is provided with a coil base 35 for placing electromagnetic wire; the inner wall of the first male head 33 of the ordinary drill rod 3 is provided with a third electromagnetic coil groove 36 for storing the electromagnetic coil; an electromagnetic channel is formed between the electromagnetic coil in the third electromagnetic coil groove 36 and the electromagnetic coil in the coil base 35 in the present design.

[0029] A first circuit board for integrating reception and WIFI functions is installed in the square signal module slot 12 of the adapter 1, and a signal demodulation module 51 and a signal forwarding module 52 are integrated on the first circuit board; a relay circuit board is installed in the drawer-type slot 21 of the relay drill rod 2, and a relay module is integrated on the relay circuit board.

[0030] like Figure 4 - Figure 5 As shown, the signal transmission system includes a signal acquisition module, which sends the collected signals to the upper computer on the well through the signal wireless transmission module to form a signal transmission system.

[0031] The signal acquisition module includes a first single-chip microcomputer, which receives signal data from a track sensor and a vibration sensor. The track sensor and the vibration sensor are installed on a signal conditioning circuit board in the inner cavity of the ordinary drill rod 3. A storage module is installed on the signal conditioning circuit board to store the detected signal data.

[0032] The signal wireless transmission module includes a signal demodulation module for receiving a signal sent from the first single-chip microcomputer, modulating the received signal data, and then relaying and amplifying it to the relay module through an electromagnetic channel, and then filtering and demodulating it again, and then sending the amplified signal data to the second single-chip microcomputer; the second single-chip microcomputer then sends the signal data to the host computer through the WIFI module through the switch in the base station, forming information data processing.

[0033] The working principle of the present invention is specifically described as follows:

[0034] The main technical requirements of this design are: (1) the use of electromagnetic induction coils to achieve wireless real-time data transmission; (2) the data transmission baud rate ≥ 4800; (3) the number of drill rods with wireless data transmission function ≥ 50; (4) the tail end of the borehole drill rod has WIFI transmission capability, and the data can be transmitted through the industrial ring network.

[0035] The drill rod assembly in this design is described as follows:

[0036] (1) Adapter: Located at the tail of the drill pipe, it is used to connect the water injection pipe and the drill pipe. According to the needs of the drilling transmission system, the signal demodulation module and the signal forwarding module are integrated in the adapter connected to the drill pipe, which is used to demodulate the uploaded signal in real time and forward the data to the downhole base station through the wireless WIFI module. In order to obtain an adapter that meets the requirements, the adapter is redesigned. On the premise of meeting the mechanical strength, an annular groove is designed at the front end of the adapter, and the size is designed according to the electromagnetic coil. Slots are made on the surface of the adapter and designed within the range allowed by the mechanical strength. The internal circuit board is used to integrate the receiving and WIFI functions, and a power supply circuit with appropriate capacity is selected for packaging in accordance with safety regulations. The tail end of the adapter is a bayonet structure, which is connected to the water pipe by a snap-on method. The internal integrated shaft structure means that the tail water pipe does not rotate with the drill pipe during operation.

[0037] (2) Relay drill pipe: Magnetic loss occurs during the transmission of electromagnetic signals through the channel, causing the attenuation of electromagnetic signals. The relay drill pipe is used to store the relay module, which is used to amplify the attenuated electromagnetic signal. There is a drawer-type groove on the surface of the relay drill pipe, which is used to install the relay compartment with integrated relay circuit. Both ends of the drill pipe are processed according to the Φ73 drill pipe standard, and electromagnetic coil grooves are designed at both ends to store electromagnetic coils. The relay drill pipe uses steel with a strength not less than R780, can withstand a torque of not less than 10,000 N·m, and has the strength suitable for ground drilling. It has good mechanical properties, high safety performance, and is not easy to be damaged.

[0038] (3) Ordinary drill rod: It is used as a medium for electromagnetic signal transmission during the transmission process and is used to transmit carrier signals in real time. The ordinary drill rod in this design needs to be modified. The male head of the ordinary drill rod needs to be slotted to store the electromagnetic coil, and the female head side of the ordinary drill rod needs to be designed with a coil base to place the electromagnetic wire. The coils at both ends are connected together using a high-speed cable in the middle of the inner cavity of the ordinary drill rod, and the high-speed cable is embedded in the drill rod to achieve a fixing and integration effect, preventing the wire from being exposed and affecting its life.

[0039] The signal transmission system in this design is described in detail as follows:

[0040] In view of the three modulation modes commonly used in the traditional communication industry described in the background technology: phase shift keying (PSK), frequency shift keying (FSK) and amplitude shift keying (ASK), to determine the anti-noise performance of the modulated signal in the communication system, it is necessary to study its bit error rate characteristics (such as Figure 6 The figure shows a comparison of the bit error rate characteristics of the three modulation methods).

[0041] Compared with the other two modulations, under the same signal-to-noise ratio, BPSK shows a lower bit error rate, and MSK is in the middle. After analysis, MSK modulation can be preferred, but the required carrier frequency bandwidth is too small, and high-precision bit synchronization and carrier synchronization are required during demodulation, which increases the difficulty of demodulation and requires more logical resources. By making appropriate changes and slightly increasing the bandwidth required for modulation, the difficulty of demodulation can be reduced. The specific implementation scheme is to use 2FSK modulation. Compared with MSK, its modulation coefficient is increased to h = 1, thereby increasing the carrier frequency bandwidth, while maintaining the characteristics of MSK, that is, the waveform phase after baseband signal 0 code and 1 code modulation is continuous and orthogonal. With orthogonality, the anti-noise performance of the 2FSK signal transmission process is increased, so this special 2FSK modulation is selected for the uplink signal of this subject. 2FSK uses sine waves of different frequencies to represent digital signals "0" and "1". The frequency of the carrier changes between the two frequency points F1 and F2 with the binary baseband signal. Its expression is as follows:

[0042]

[0043] like Figure 4 As shown, the whole system of the present invention is based on two single-chip microcomputers, XR2206 and XR2211 as modulation and demodulation chips, MAX275 as a bandpass filter chip, and the amplifier circuit adopts a basic common emitter amplifier circuit. Temperature, pressure and other information are transmitted upward from the underground, so only the module of single-phase signal transmission is analyzed in the following analysis. Of course, in actual drilling operations, some wells are as deep as a kilometer, and multi-stage drill pipe cascade is required, so the signal needs to be demodulated, amplified and modulated after every 3 to 5 stages of drill pipe. In fact, a relay module is needed, which completes the functions of demodulation, amplification and re-modulation.

[0044] Based on the XR2206 signal modulation chip, when performing FSK frequency modulation, pin 1 should be grounded, and the FSK modulation signal should be input at pin 9 to control the current switch, and the timing resistor at pin 7 or 8 should be selected to connect to the voltage-controlled oscillator to change the oscillation frequency. When the input of pin 9 is low level, the timing resistor at pin 8 is connected to the voltage-controlled oscillator, and the potentiometer is adjusted to generate frequency f1. When the input of pin 9 is high level 1, the timing resistor at pin 7 is connected to the voltage-controlled oscillator, and the potentiometer is adjusted to generate frequency f2, thereby realizing frequency shift keying and completing FSK modulation. The oscillation waveform generated by the VCO is passed through the sine wave adjuster to obtain a FSK frequency modulation wave with very little distortion, which is output from pin 2. When the input of pin 9 is 0, pin 2 outputs a stable sine wave signal with a frequency of f1. The timing capacitor of the VCO should be a capacitor with good temperature stability, preferably a mica capacitor or a polypropylene capacitor. The potentiometer between pins 13 and 14 is used to adjust the distortion of the sine wave, and the potentiometer between pins 15 and 16 is used to adjust the symmetry of the sine wave. Both can minimize the distortion of the sine wave. Pin 3 is the output end of the multiplier and sine wave adjuster, connected to a load resistor to adjust the output amplitude.

[0045] Design FSK demodulation circuit for XR2211 chip. After the signal is input from pin 2, it is amplified by the amplifier and divided into two signals. Then, after phase detection and decoding by the phase detector, the signal is extracted and demodulated. MAX275 is an active filter with small size, low price, stable performance, no need to provide a clock circuit, and reduce the noise after filtering. In view of the low power consumption, high precision, wide operating frequency band and high common mode rejection ratio of INA118, it is suitable for amplifying small signals.

[0046] The relay module is used to amplify the attenuated harmonic signal to ensure that the electromagnetic signal can continue to occur in the electromagnetic transmission channel to ensure longer distance signal transmission. The signal amplification circuit uses OPA189 to perform op amps on the input signal. It has ultra-high precision, ultra-low offset voltage, low noise and powerful MUX-friendly design, which is very suitable for high-precision instruments, signal measurement and active filtering applications. The MAX-friendly input framework can simulate the generation of surge current when a large input differential voltage is applied, thereby improving the settling time performance in multi-channel systems. However, since the sine wave with positive and negative AC signals is amplified, the OPA189 needs to be powered simultaneously with positive and negative power, and the power supply voltage is +5V respectively. Therefore, LM2663 is selected as the voltage conversion chip, which is cheap, has simple peripheral circuits, and is suitable for small-volume circuit board production.

[0047] In the present invention, KT105A-F3 mine intrinsically safe wireless base station adopts the WIFI wireless working principle, acts as a terminal device in the communication system to transfer signals between the system, uses an external antenna and its corresponding component circuit to connect the wireless signal to the system and transmits it through a network cable or optical fiber to realize the wireless communication function. The mine intrinsically safe wireless base station needs to be powered by an external mine flameproof and intrinsically safe uninterruptible power supply. The mine flameproof and intrinsically safe uninterruptible power supply can adopt KDW660 / 12B1 or KDW660 / 12B2 mine flameproof and intrinsically safe DC regulated power supply or KDW127 / 12B mine flameproof and intrinsically safe DC regulated power supply, and adopts local power supply.

[0048] The WIFI module model USR-C215 is used. The hardware of USR-C215 integrates MAC, baseband chip, and RF transceiver unit. The built-in low-power operation mechanism can effectively realize the low-power operation of the module. It supports WI-FI protocol and TCP / IP protocol. Users only need simple configuration to realize the networking function of UART devices. The module is small in size and easy to integrate on the hardware single-board circuit. And the module can choose the application of built-in or external antenna, which is convenient for multiple choices. Through this module, physical devices can be directly connected to the WIFI network, thereby realizing the control and management of the Internet of Things.

[0049] The above description is only a preferred embodiment of the present invention, so all equivalent changes or modifications made according to the features and principles described in the scope of the patent application of the present invention are included in the scope of the patent application of the present invention.

Claims

1. An underground signal wireless transmission device, characterized in that: It includes a drill rod assembly and a signal transmission system installed in the drill rod assembly; The drill rod assembly comprises a plurality of common drill rods and relay drill rods connected by threads to form a drill rod component; the first female head of the common drill rod of the drill rod assembly is threadedly connected to the front end of the adapter; the bayonet at the outer end of the rotating shaft inside the rear end of the adapter is clamped with the connecting end of the water pipe, and when the drill rod component rotates, the water pipe does not rotate with the drill rod component; The signal transmission system includes a signal acquisition module, which sends the collected signal to the upper computer on the well through the signal wireless transmission module to form a signal transmission system; The signal acquisition module includes a first single-chip microcomputer, which receives signal data from a track sensor and a vibration sensor. The track sensor and the vibration sensor are installed on a signal conditioning circuit board in the inner cavity of a common drill pipe. A storage module is installed on the signal conditioning circuit board to store the detected signal data; the signal wireless transmission module includes a signal demodulation module for receiving a signal sent by the first single-chip microcomputer, modulating the received signal data, and then relaying and amplifying the signal data to a relay module through an electromagnetic channel, filtering the signal data, and then demodulating the signal data, and then sending the amplified signal data to a second single-chip microcomputer; The second single chip computer then sends the signal data to the host computer through the WIFI module via the switch in the base station to form information data processing.

2. The underground signal wireless transmission device according to claim 1, characterized in that: A first annular groove is provided on the inner wall of the front end portion of the adapter, and the shape of the first annular groove matches the electromagnetic coil; a cavity is provided inside the rotating shaft of the adapter; a horizontal base is provided at the bottom of the middle cylinder of the adapter; a square signal module groove is provided on the front of the top surface of the middle cylinder of the adapter.

3. The underground signal wireless transmission device according to claim 1, characterized in that: One end of the relay rod body of the relay drill rod is a second female head, and the other end of the relay drill rod is a second male head; a drawer-type groove is arranged on the relay rod body of the relay drill rod; the inner ends of the second female head and the second male head of the relay drill rod are respectively provided with second electromagnetic coil grooves for installing electromagnetic coils.

4. The underground signal wireless transmission device according to claim 1, characterized in that: The common drill rod comprises a drill rod body, the end of the drill rod body away from the first female head is a first male head, and a first central axis hole is arranged in the drill rod body; a coil base for placing electromagnetic wire is arranged on the inner wall of the first female head of the common drill rod; and a third electromagnetic coil groove for storing electromagnetic coil is arranged on the inner wall of the first male head of the common drill rod.

5. The underground signal wireless transmission device according to claim 2, characterized in that: A first circuit board for integrating reception and WIFI functions is installed in the square signal module slot of the adapter, and a signal demodulation module and a signal forwarding module are integrated on the first circuit board; a relay circuit board is installed in the drawer-type slot of the relay drill rod, and a relay module is integrated on the relay circuit board.

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