RU2776511C1 - Apparatus for underground wireless emergency engineering communication - Google Patents

Abstract

FIELD: wireless communication.

SUBSTANCE: invention relates to wireless communication systems installed and intended for operation in underground mine workings, including emergency alarms. Apparatus comprises a transmitting set installed on the surface of the ground, consisting of, series-connected, a reference generator, a frequency divider, a power amplifier, and antenna systems with deep earth rods, and an operating mode control panel connected with the output of the reference generator via a code sequence generator, the outputs of the control panel are connected to the second inputs of the frequency divider and the power amplifier, and a reception set located in the underground workings, containing an antenna connected to the input of the selective amplifier, the output whereof is connected with the inputs of two parallel-connected frequency mixers, and the second input of the first mixer is connected directly with the heterodyne output. The second input of the second frequency mixer is connected with the heterodyne via a phase shifter, the outputs of each frequency mixer are connected via the series-connected low-pass filter and threshold element to the input of the phase detector, the output whereof is connected with the input of the command decoder, connected to a loudspeaker via a speech converter and further via a low-frequency amplifier. The antennas of the transmitting set are therein supplemented with vertical beams, located in boreholes, and the deep earth rods have more than one point of connection with the ground, wherein each of said points has a lead from the borehole onto the surface. The distance between the boreholes is from 300 to 600 m, the vertical beams are buried into the boreholes to a depth of 30 to 1,000 m, and the reception set additionally comprises a low-frequency antenna and is additionally equipped with an RFID tag.

EFFECT: increase in the reliability of wireless emergency engineering communication, increase in the efficiency of electromagnetic wave transmission, including that in underground workings.

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Description

The claimed invention relates to wireless communication systems installed and intended for operation in underground mine workings, including alarms.

A device for wireless emergency signaling and communication with underground workings is known (RF patent 2131515, published 06/10/1999), containing a transmitting set installed on the earth's surface, consisting of a series-connected reference oscillator, a frequency divider, a power amplifier and antenna systems with ground electrodes, and operating modes control panel connected to the reference oscillator output through a code sequencer, the control panel outputs are connected to the second inputs of the frequency divider and power amplifier, and a receiving set located in underground workings, containing an antenna connected to the selective amplifier input, the output of which is connected to the inputs two frequency mixers connected in parallel, the second input of the first mixer is connected directly to the output of the local oscillator, and the second input of the second frequency mixer is connected to the local oscillator through a phase shifter, the outputs of each frequency mixer are connected in series through The low-pass filter and the threshold element are connected to the input of the phase detector, the output of which is connected to the input of the command decoder. The device is equipped with a speech converter connected in series, a low-frequency amplifier and a loudspeaker, and the input of the speech converter is connected to the output of the command decoder.

A disadvantage of the known device is the low reliability of communication with underground workings, due to signal attenuation due to signal shielding by rocks.

The closest known is a device for wireless underground alarm and control of the volume fraction of methane in the atmosphere of mine workings (RF patent 32196, published on September 10, 2003), containing a transmitting set installed on the day surface of the mine, consisting of a unit for generating and supplying an emergency call signal , a transmitter and a transmitting antenna connected to it with ground electrodes at its ends and receiving sets located in underground workings, each of which consists of a receiving antenna connected through an amplifier to a signal processing unit, which includes a selective amplifier, a decoder, a speech converter, a low-frequency amplifier and loudspeaker. Each receiving device is supplemented with a portable mine methane detector containing a methane sensor connected to an alarm unit and a methane concentration meter.

However, a disadvantage of the known method is also the low reliability of communication with underground workings, due to signal attenuation due to signal shielding by rocks.

The purpose of the claimed invention is to eliminate the identified drawback, to achieve the following technical result: improving the reliability of wireless emergency communication, improving the transmission efficiency of electromagnetic waves, including in underground workings.

This goal is achieved as follows: an underground wireless emergency technological communication device containing a transmitting set installed on the earth's surface, consisting of a series-connected reference oscillator, a frequency divider, a power amplifier and antenna systems with deep ground electrodes, and an operating mode control panel connected to the output reference oscillator through a code sequence generator, the outputs of the control panel are connected to the second inputs of the frequency divider and power amplifier, and the receiving set located in the underground workings, containing the antenna connected to the input of the selective amplifier, the output of which is connected to the inputs of two frequency mixers connected in parallel, the second input of the first mixer is connected directly to the output of the local oscillator, and the second input of the second frequency mixer is connected to the local oscillator through a phase shifter, the outputs of each frequency mixer through a series-connected low-pass filter and the threshold element is connected to the input of the phase detector, the output of which is connected to the input of the command decoder, which, through a speech converter and then through a low-frequency amplifier, is connected to a loudspeaker, characterized in that the antennas of the transmitting set are supplemented with vertical beams located in bore holes, and deep ground electrodes have more than one point of connection with the ground, with each point having an outlet to the surface from a bore hole.

The underground wireless emergency technological communication device, in particular, can be characterized by the fact that the distance between the well holes is from 300 to 600 m.

An underground wireless emergency technological communication device, in particular, can be characterized by the fact that vertical beams are buried in wells to a depth of 30 to 1000 m.

The device for underground wireless emergency communication, in particular, may be characterized by the fact that the receiving set additionally contains a low-frequency antenna.

The device for underground wireless emergency technological communication, in particular, may be characterized by the fact that the receiving set is additionally equipped with an RFID tag.

On FIG. 1 is a block diagram of a transmitting terrestrial set, FIG. 2 shows a block diagram of a receiving underground set, an underground wireless emergency technological communication device, where the numbers indicate the following:

1. Reference generator;

2. Frequency divider;

3. Power amplifier;

4. Ground transmitting antenna;

5. Ground electrode;

6. Control panel;

7. Shaper code sequence;

8. Underground receiving antenna;

9. Selective amplifier;

10. Mixer 1;

11. Mixer 2;

12. Local oscillator;

13. Phase shifter;

14. Filter 1;

15. Filter 2;

16. Threshold element 1;

17. Threshold element 2;

18. Phase detector;

19. Command decoder;

20. Speech converter;

21. Amplifier;

22. Loudspeaker;

23. Telecontrol;

24. Mining radio beacon;

25. Mine direction finder;

26. RFID reader.

The presented device for underground wireless emergency technological communication is arranged as follows

The transmission set consists of a reference oscillator (1), a divider with a variable division factor (2), a power amplifier (3), an antenna (4) and ground electrodes (5), and a control panel (6) connected in series, the first output of which is connected to divider (2), and the second with a power amplifier. In this case, the output of the reference oscillator is connected to the input of the control panel through the shaper of the code sequence (7).

The receiving set contains an antenna (8) connected to the input of a selective amplifier (9), the output of which is connected to the input of two frequency mixers (10), (11) connected in parallel. The second input of the first mixer (10) is directly connected to the output of the local oscillator (12), and the second input of the second mixer (11) is connected to the local oscillator (12) through a phase shifter (13). In this case, the outputs of both mixers through low-pass filters (14), (15) and then sequentially through threshold elements (16), (17) are connected to two inputs of the phase detector (18). The output of the phase detector is connected to the input of the command decoder (19), which, in turn, through the speech converter (20) and then through the low-frequency amplifier (21) is connected to the loudspeaker (22). Additionally, the device is equipped with a remote control (23), a miner's radio beacon (24), a mobile search mine direction finder (25), an RFID reader (26), but is not limited to these units, but may contain others similar to them.

The presented device for underground wireless emergency technological communication operates as follows

When typing the required sequence of buttons on the control panel (6) (the keyboard is not shown in Fig.), the shaper (7) generates the corresponding code sequence from the signal coming from the reference oscillator (1). At the end of the set, the signal from the shaper (7) is fed to the input of the control panel (6) and then to the control input of the divider (2). At the same time, a signal from the reference oscillator (1) is sent to its other input. In the divider (2), depending on the code sequence coming from the shaper (7) through the control panel (6), a frequency-shift keyed signal is generated. Further, the signal is amplified by a power amplifier (3), and by antennas (4), through ground electrodes (5), it is radiated into the mountain range.

Electromagnetic signals propagating through the mountain range are received by the receiving set, in particular by its antenna (8), are converted into electric ones, amplified by a broadband selective amplifier (9) and then fed to the first inputs of the mixers (10), (11), to the second inputs of which signals are fed from the local oscillator (12) directly to the mixer (10) and, through the digital phase shifter (13), to the mixer (11). At the outputs of the mixers (10), (11), harmonic oscillations of the difference frequency appear, and these signals are shifted relative to each other by 90°.

Both received signals pass through low-pass filters (14), (15) and are fed to threshold elements (16), (17). Further, through the phase detector (18), where a digital signal corresponding to the transmitted information is generated, the signal is transmitted to the decoder (19), where the corresponding transmitted alarm, call or necessary technological signals are generated. After the decoder (19), the signals are sent to the converter (20), then, after passing through the low-frequency amplifier (21), they are reproduced by the loudspeaker (22); an additional miner's radio beacon (24), a mobile search mine direction finder (25) and a stationary RFID reader (26) make it possible to observe and search for people caught in an accident at a depth of up to 2 km, through a mountain range, regardless of the conductivity of the rocks. The RFID reader module may provide an additional channel to improve the reliability of the wireless communication establishment. Also, the receiving set may additionally have a low-frequency wavelength range antenna. The low frequency range provides the best signal transmission, since high frequency radio waves are easily absorbed by the rock, not providing the proper level of communication. The device for underground wireless emergency technological communication, in particular, may be characterized by the fact that the receiving set is additionally equipped with an RFID tag.

The reliability and efficiency of the transmission of electromagnetic waves in a wireless communication system largely depends on the transmitting antenna. The main criterion that determines the efficiency of a transmitting antenna is, ultimately, the field strength level of the useful signal generated by the antenna at a given receiving point for a given transmitter power. With an increase in the communication range deep into the earth up to 2 km, the transmission frequency shifts to the range of ultra-low and audio frequencies.

To transmit signals from the day surface to underground workings, surface antenna devices in the form of a grounded horizontal dipole have found wide application in practice. The resistance of the ground electrodes of the electric dipole shunts the input capacitance of the antenna and its input impedance becomes mainly active, which has a positive effect on increasing the efficiency of the radiator.

The calculated range of the wireless communication, which provides the transmission of signals from the day surface to the mine workings, is determined by two parameters, namely: the maximum depth of the workings and the maximum radius or area of the mine field. Therefore, when choosing antenna devices for mine communication systems, preference should be given to antenna devices that, at a given range in depth, provide a communication range in the radial direction.

Ensuring the communication range along the depth and strike of the mine using electric dipoles grounded on the surface can only be achieved by increasing the linear dimensions of horizontal electric dipoles and the power of the emitter, and in the presence of highly conductive upper layers of rocks that shield working underground workings, signal transmission to the specified points can be practically impossible.

The field strength level of the useful signal, excited by a horizontal dipole grounded on the earth's surface, penetrates deep into the rock up to 1000 m. If there are highly conductive rocks in the upper layers of the earth, the depth of penetration of the electromagnetic field due to absorption decreases several times.

To solve the problem of increasing the efficiency of transmission of electromagnetic waves and increasing the reliability of communication with mine workings, the antenna is made in the form of vertical beams, which are installed in specially drilled wells. With the surface-borehole design of antennas grounded at the bottom of the well, the antenna is a closed frame, where the source of electromagnetic field excitation is an electrical conductor and highly conductive rock layers that lie at a certain depth underground. Vertical beams can be buried in wells to a depth of 1000 m, which ensures a high level of electromagnetic field strength at depth and, accordingly, communication stability in mine workings. In addition, many spurious signals propagating in the near-ground layer and interfering with the transmission and reception of any terrestrial radio waves are cut off. The interference arising from the noisiness of the radio ether, which creates background radio emission, affects the transmitter signal transmitted in depth. As a result, noise immunity decreases. Since the main background radiation propagates near the earth's surface, then with the depth of the antennas, from 30 meters, it becomes possible to cut off parasitic radiation.

In the horizontal plane, the distance between boreholes can be from 300 to 600 m, which also makes it possible to maintain the electromagnetic field strength of a given level in the area occupied by the mine to ensure communication stability.

Deep ground electrode systems can have several (from two or more) points of connection with the ground, each point has its own output to the surface to adjust the transmitter with the antenna to the maximum strength of the electromagnetic field.

Thus, when using an antenna with vertical beams and deep ground electrodes located in wells, the problem of electromagnetic field propagation to depths of up to 2000 m is solved when using a transmitter with a lower radiation power, as a result of which the claimed technical result is achieved - increasing the reliability of wireless emergency technological communication, increasing the efficiency of transmission of electromagnetic waves, including in underground workings.

Industrial applicability.

The inventive device for wireless emergency communication is widely used in the construction of underground communication networks. It is produced mainly at scientific and technical enterprises of the radio-electronic industry.

Claims (1)

An underground wireless emergency technological communication device, containing a transmitting set installed on the earth's surface, consisting of a reference oscillator connected in series, a frequency divider, a power amplifier and antenna systems with deep ground electrodes and an operating mode control panel connected to the output of the reference oscillator through a code sequence generator, the outputs of the control panel are connected to the second inputs of the frequency divider and the power amplifier, and the receiving set located in the underground workings contains an antenna connected to the input of the selective amplifier, the output of which is connected to the inputs of two frequency mixers connected in parallel, the second input of the first mixer is directly connected to the output of the local oscillator , and the second input of the second frequency mixer is connected to the local oscillator through a phase shifter, the outputs of each frequency mixer through a series-connected low-pass filter and a threshold element are connected to the input of the phase d a detector, the output of which is connected to the input of the command decoder, which is connected to a loudspeaker through a speech converter and then through a low-frequency amplifier, characterized in that the antennas of the transmitting set are supplemented with vertical beams located in boreholes, and deep ground electrodes have more than one connection point with the ground, at the same time, each point has an output to the surface from the borehole, where the distance between the boreholes is from 300 to 600 m, the vertical beams are buried in the wells to a depth of 30 to 1000 m, and the receiving set additionally contains a low-frequency range antenna and is additionally equipped with an RFID tag .

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