RU2022904C1 - Method and system for transmission and reception of information through communication line in mine shaft - Google Patents

Abstract

FIELD: mine communication systems. SUBSTANCE: method involves modulation of carrying signal by information signal, excitation in line of modulated high-frequency signal, its reception, selection and demodulation, creating an additional communication line in shaft, converting analog signal into a binary code pulse, providing it with redundancy, exciting TEN-wave with a frequency f = 20 MHz in communication line modulated by information signal, separating code pulse from demodulated signal, checking it and converting into analog signal. System comprises hoisting metal rope, additional metal conductor running along shaft axis, the metal structures of upper receiving platform of mine head gear being interconnected galvanically. Besides, system has transmitter 1, two clock pulse generators 2,3, code transformation units 4,5, synchropulse shaper 6, synchronizing unit 7, line units 8,9, analog-to-digit converter, modulator, transmitter, transmitting antenna, receiving antenna, receiver, demodulator, operating element. EFFECT: improved functional and operating characteristics. 5 cl, 4 dwg

Description

 The invention relates to a mine hoist and may find application in a similar industrial material handling equipment.

 A known method implemented in a device using a radio frequency transmission method and from a moving vessel in a mine shaft, including modulating the carrier signal with a signal from the sensor, the radiation of the emitted signal, its demodulation and measurement [1]. The disadvantage of this method and device is the instability of the received signal in a mine shaft due to the large linear attenuation, requiring the use of a high power transmitter, poor noise immunity, lack of verification, the reliability of the received signal. These shortcomings do not provide reliability and noise immunity of the transmission-reception of information throughout the entire depth of the barrel and limit the scope of the method and device.

 The aim of the invention is to increase the reliability of the process of transmission-reception of information in a mine shaft.

 This is achieved by the fact that the analog signal from the sensor is converted into a pulse sending of a binary code, provide redundancy, while the high-frequency signal of the transmitter is modulated by the received digital signal and excite the TEM wave in the communication line, and, after reception, selection, amplification and demodulation, the code packet is isolated signal, check and convert to an analog signal.

 The proposed method of transmitting and receiving information from a moving vessel in a mine shaft differs from the prototype in converting an analog signal from a sensor to a pulse sending of a binary code, providing it with redundancy, exciting a TEM wave in a communication line, extracting a code message, checking, correcting and converting it into an analog signal that meets the criteria of the invention of "novelty."

 Signs that distinguish the proposed method from the prototype, in the sources of information in this section of the technology are not found. Thus, the proposed method meets the criteria of the invention "significant differences".

и магнитными

векторами Герца. Напряженность электрического

и магнитного

полей выражается через

и

в общем случае следующим образом:

= grad div

+ k

= -j

rot

= j

rot

[1]
H = grad div

+ k²

, где ε_a′ - абсолютная диэлектрическая проницаемость среды;
μ_a′- абсолютная магнитная проницаемость;
k =

- волновое число.The essence of the method is as follows: to ensure noise immunity, the analog signal is converted into a code-pulse sending of a binary code and provided with redundancy, after demodulation, the code message is extracted, checked (if it is distorted by interference, it is forbidden to use) and converted to an analog signal; to ensure reliability, a high-frequency code-pulse signal of the transmitter is excited, forming a TEM wave. In this wave, the lines of force of the electric and magnetic fields lie completely in a plane perpendicular to the direction of wave propagation, i.e. the electric and magnetic fields do not have a longitudinal component; the field of the two-wire line, in our case, formed by hoisting ropes and barrel reinforcement, has such a structure. It is convenient to describe the electromagnetic field in a system with boundary conditions by electric

and magnetic

Hertz vectors. Electric tension

and magnetic

fields expressed through

and

in the general case as follows:

= grad div

+ k

= -j

rot

= j

rot

[1]
H = grad div

+ k ²

where ε _a ′ is the absolute dielectric constant of the medium;
μ _a ′ is the absolute magnetic permeability;
k =

is the wave number.

и

имеют лишь по одной компоненте, совпадающей с осью, причем эти компоненты имеют вид волны, распространяющиеся вдоль оси Z. Для положительного направления распространения можно записать:

= П^ee

= П^μe

, [2] где

и

- скалярные функции, зависящие только от поперечных координат;
B_Z - постоянная распространения;
Z_o - орт вдоль оси Z.From simple mathematical transformations and introducing the condition of boundedness of the electromagnetic field by the surfaces of the barrel reinforcement, we make sure that the vectors

and

have only one component coinciding with the axis, and these components have the form of waves propagating along the Z axis. For a positive propagation direction, we can write:

= П ^e e e

= П ^μ e

, [2] where

and

- scalar functions depending only on the transverse coordinates;
B _Z is the propagation constant;
Z _o - unit along the Z axis.

k $\genfrac{}{}{0ex}{}{\text{2}}{\text{o}}$ -

П^eμ= 0 [3].Further mathematical transformation leads to the formula:
▽ _┴ П ^eμ +

k $\genfrac{}{}{0ex}{}{\text{2}}{\text{o}}$ -

E ^eμ = 0 [3].

 This shows that the task of determining the magnetic field in the shaft is reduced to solving equation (3) in a flat region, which is a cross section of the shaft.

 The above allows us to conclude that it is possible to use a communication line formed by the trunk reinforcement and lifting ropes. As can be seen from (3), the antenna of the receiver must be located on the reinforcement, and the transmitter on the hoisting rope.

The TEM wave is excited at a frequency of 30 MHz. The choice of this frequency is due to several factors:
low linear attenuation;
sufficiently high efficiency of a small-sized loop antenna, this makes it possible to generate very small powers of the order of 20-30 mW;
TEM waves in this frequency range are formed in real conditions by barrel reinforcement and a lifting rope;
in a closed communication channel that does not have matching devices at its ends, there are "dead" zones associated with the addition of incident and reflected waves. At frequencies of 30 MHz, the quality factor of the system decreases, i.e. the depth of the "dead" zones is reduced to almost zero, which is confirmed by these experiments;
the value of “fading” at 30 MHz is 3–4 dB, which is explained by an increase in the total losses due to absorption and scattering at the ends of the barrel (on the lifting vessel and on the lower platform of the copra), while the amplitude of the reflected signal decreases, which leads to a decrease in “fading” due to the formation of standing waves.

 As studies have shown, from the point of view of factors such as "fading", the possibility of transmitting a wide range of information frequencies and a small amount of industrial interference is optimal in the frequency range near 30 MHz.

 This method, compared with the prototype, provides significantly higher reliability, which can be seen from the experimental diagrams in FIG. 4 changes in signal level during movement of the stand in an experimental sample of a device that implements the claimed method.

 It is known device [1] transmitting and receiving information on a communication line formed by a barrel reinforcement and a lifting rope, limited by metal structures of the copra upper receiving platform and a lifting vessel, comprising a transmitting device mounted in a lifting vessel, including a sensor, an electronic converter, a modulator connected in series , a transmitter, a transmitting antenna with a cable and a receiving device located in the barrel, including a receiving antenna connected in series with each other, receiving nickname, demodulator and actuator. The disadvantage of this device is the instability of the received signal in the mine shaft due to the large linear attenuation, requiring a high power transmitter, poor noise immunity, lack of verification of the reliability of the received signal. These shortcomings do not provide reliability and noise immunity of the transmission-reception of information throughout the entire depth of the barrel and limit the scope of the device.

 The aim of the invention is to increase the reliability of transmission-reception.

 This goal is achieved by the fact that in the transmitter mounted on the lifting vessel, in addition to a sensor, a modulator, a transmitter, a transmitting antenna with a cable, an analog-to-digital converter, a clock pulse generator, a code conversion unit, a clock generator, a linear unit are placed, while the sensor is connected to an analog-to-digital converter, to which a clock generator is connected, and the outputs of the analog-to-digital converter are connected to a code conversion unit and a clock driver, data through a linear node with a modulator and then sequentially with a modulator, cable and transmitting antenna, the receiving device is located in the mine shaft, in addition to the receiving antenna, receiver, demodulator and actuator connected in series, contains a linear node, a synchronization node, a clock generator, a conversion node a code and a digital-to-analog converter, the demodulator output being connected to a linear node, the line node output being connected to a code protection node and a synchronization node, and the clock generator O pulses also connected to the code conversion unit, which output through a digital to analog converter is connected to the actuator.

 The proposed device differs from the prototype by the presence of an analog-to-digital converter, a clock pulse generator, a code conversion unit, a clock generator, a linear transmitting unit, a linear unit, a code conversion unit, a synchronization unit, a clock generator, a digital-to-analog converter in the receiving part, while the transmitting part, the sensor is connected to an analog-to-digital converter, to which a clock pulse generator is connected, and the outputs of the analog-to-digital converter connected to the code conversion node and the clock generator connected via a linear node with a modulator in the receiving part of the device, the output of the demodulator is connected to the linear node, the output of the linear node is connected to the code conversion node, the output of which is connected to the actuator through the digital-to-analog converter, which corresponds to the criteria of the invention of "novelty."

 Signs that distinguish the proposed device for the prototype, the information sources for this section were not found, thus, the proposed device meets the criterion of "significant differences".

 In FIG. 1 shows the location of the device in the shaft; in FIG. 2 is a block diagram of a device; in FIG. 3 - time diagrams of the device in dynamics.

 A lifting vessel 1 with a transmitter 2 located in a shaft 3 and mounted on a lifting cable 4 with a transmitting antenna 5 mounted on it at a distance l = c / 2 f (where c is the speed of light, f is the excitation frequency of the TEM wave) from the vessel 1 and a receiving antenna 6, located at a distance l = c / 2 f (where c is the speed of light, f is the excitation frequency of the TEM wave) from the metal structures 7 of the upper part of the pile, and connected by a cable 8 to the receiver 9. Sensor 10, generator clock pulses 11 connected to an analog-to-digital Converter 12 are electrically connected Through the code conversion node 13 and the clock generator 14 with a linear node 15, which is connected to a modulator 16, which in turn is connected to a transmitter 17 connected to the transmitting antenna 5. The receiving part of the device includes a demodulator 18 connected via a linear node 19 to the node synchronization 20 and to the code conversion unit 21, in turn, the synchronization unit is connected to the clock generator 22, which is connected to the code conversion unit 21, electrically connected to the digital-to-analog converter 23, connected to the actuator 24.

 The proposed device operates as follows. The analog signal from the sensor 10, with a frequency of up to hundreds of hertz and a value of 1.5, enters the analog-to-digital converter 12, executed on the K 155 series microcircuits, and converts it into a parallel 4-bit code of standard amplitude with a frequency of 1000 Hz determined by the clock generator 11 made on the K 155 AG1 chip. Through practice and analysis, the applicants came to the conclusion that for telemetry purposes in a mine environment a 2-pulse code is necessary and sufficient, which allows transmitting numbers to 15, which corresponds to 1111. In order to narrow the passband of the radio frequency transmission and reception channel 13 code conversion unit, made on K-series microcircuits, converts parallel binary code coming from converter 12 to serial. The code conversion node 13 includes the K 155 IP2 chip (an eight-bit circuit for checking the evenness or oddness of the sum of units), which, if the input signal from the analog-to-digital converter 12 is even, adds one, if the signal is odd, zero. Thus, a five-digit code is formed: four digits carry direct information, and the fifth digit is an auxiliary one. The signal from the analog-to-digital Converter 12 is also fed to the clock generator 14, which controls the passage of pulses of a sequential binary code through the supply of clock pulses to the second input of the linear node 15, which is a driver-amplifier implemented on the K 155 chips. Formed at the output of the linear node 15 the code package, consisting of 4 information pulses and a fifth test pulse, enters the pulse modulator 16, assembled according to the classical scheme, which opens or closes flushes the passage of high-frequency oscillations of the transmitter 17 (assembled to the RF transistors). The master oscillator of the transmitter 17 is tuned to a frequency of 30 MHz. In the transmitting antenna 5, code and synchronization pulses are thus formed, filled with high-frequency oscillations of 30 MHz of the transmitter carrier frequency, the output power of which is 30 mW. The transmitting and receiving antennas are identical and represent an open frame autotransformer circuit tuned to a frequency of 30 MHz. The circuit is matched to the transmitter output (receiver input) by selecting turns. The applicants settled on the next option, which showed the best results.

 The frame coil with sides 90x30 mm is wound on a rigid frame and consists of 4 turns of wire PEV-2-1.0 with a winding pitch of 3 mm. The frame with a parallel-tuned capacitor is enclosed in an insulating casing with external dimensions of 140x100x40 mm. The antenna body is attached with non-magnetic metal brackets. It is possible to adjust the antenna with a capacitor through an opening in the housing. High-frequency oscillations modulated by a code transmission and synchronization pulses are received by a receiving frame antenna 6 that responds to the magnetic component of the TEM wave and is fed to the input of the receiver 9, which is a superheterodyne made on an integrated circuit of the K 237 series, which has a sensitivity of 300 μV and a passband 15 kHz. In the receiver 9, the received signal is selected and amplified, which then enters the demodulator 18, where the code-sending pulses and synchronization pulses are extracted, which are generated and amplified in the linear node 19 and fed to the synchronization node 20, where the clock pulses are extracted, which are then transmitted to the generator clock pulses 22, performed on the K 155 AG1 chip, and to the code conversion unit 21. Dedicated by the demodulator 18 and amplified in the linear node 19, the five-bit code sending of the pulses enters the node p code conversion 21, which includes the K 155 IP2 chip, which checks the five-digit parcel, if the sum of the units of the first four parcel pulses is even and the fifth pulse is one, or if the sum of the units of the first four parcel pulses is odd and the fifth pulse is zero, then the information goes to the digital-to-analog converter 23 , which converts the digital signal to analog, from where it enters the actuator 24. In the case of a negative result, the code conversion unit 21 prohibits the use of this information ui. The high speed of information transfer (830 bps) practically does not lead to information loss, because 90 measurements per second occur. The above nodes 19, 20, 21, 22, 23 are implemented on the K 155 series microcircuits.

 To clarify and illustrate the operation of the device in dynamics, time diagrams are given, FIG. 3. In this example, the signal from the sensor 10 had a value of 0.7 V. Timing diagrams are given at the output of these blocks. The analog signal from the sensor 10 has the particular form 25a. Kotelnokov's theorem shows that there is no fundamental difference between the transmissions of a discrete and continuous signal, i.e. the signal can be transmitted in the form of discrete values of the form 25b, therefore, as an example, we trace the transmission of information corresponding to a voltage of 0.7 V, which corresponds to the value of t in the form 25a. The clock generator 11 generates clock pulses with a frequency of 1000 Hz, type 26, which quantize the analog signal from the sensor 10, which can be seen in view 25b. The information corresponding to the value of t in the form 25b (0.7 V), the analog-to-digital Converter 12 is converted into a parallel code of the form 27, which can significantly reduce the processing time of the information. However, only with a sequential code of a number all its bits can be fixed on one element and transmitted over one channel of information, which greatly complicates the device. Therefore, the parallel code by the code converting unit 13 is converted into a serial code of the form 28a, then it is supplied with a service overdischarge in the form 28b, forming a code message. Since the values of the nodal signals by the elements of digital devices are not perceived continuously, but at discrete points in time, the interval between which is called the duty cycle (T cycle), for one duty cycle in digital devices one elementary conversion is received at the input of the code message. Time sampling is carried out by the sync pulse generator 14 generating clock type 29 pulses. Linear node 15 generates a T cycle formed by a code packet of synchronized clock pulses of the form 30. Pulse modulator 16 generates type 31 pulses, which are transmitted by transmitter 17 to form 32, which are emitted by antenna 5, are received by antenna 6 and fed to receiver 9, where they are selected, amplified, and fed to demodulator 18 in the form 33, where code pulses and sync pulses are extracted onization in the form 34. The clock pulses of type 36 from the synchronization node 20 are sent to a clock pulse generator 22, which generates clock pulses of the form 35. The code packet, selected by the demodulator 18, amplified in the linear node 19 of the form 37a, goes to the code conversion node 21, where in the form 37b, and then in the form of 38. A signal of the form 38 is fed to the input of the digital-to-analog converter 23, which converts it into an analog signal of the form 39, which is supplied to the actuator 24.

 The relationship and the need for the above blocks follows from the description of the device that implements the proposed method.

 The transmitting antenna 5 is a small rectangular frame consisting of four turns of wire. The long side of the frame is attached to the rope using brackets, and for maximum electrical coordination, the attachment point is at a distance l = c / 2 f from the vessel, where c is the speed of light and f is the excitation frequency of the TEM wave. The parameters of the frame - its inductance and capacitance are chosen so that they form a circuit tuned to resonance with the oscillations of the transmitter with a frequency of 30 MHz. Thus, the efficiency of a small-sized antenna is significantly increased and, due to its narrow-band, the frequencies of side harmonics are suppressed. The excitation by the frame of electrical vibrations in the line formed by the barrel reinforcement and the lifting rope, limited by the metal structures of the copra upper receiving platform and the lifting vessel, contributes to the formation of the TEM wave characteristic of this case. The receiving antenna 6 is similar to the transmitting one. Since the loop antennas are sensitive to the magnetic component, their use in this case is preferable. A receiving antenna is attached with the long side of the frame along the shaft of the shaft at a distance l = c / 2 f from the metal structures of the upper receiving platform of the copra, where c is the speed of light and f is the excitation frequency of the TEM wave.

Thus, the proposed device allows for the transmission and reception of information by means of a modulated radio signal in a mine shaft, providing high reliability. As you know, reliability is the property of a product to perform specified functions, while maintaining its performance in predetermined limits for the required period of time. Only the use of digital manipulation in comparison with an analog signal can increase the noise immunity by at least an order of magnitude. In our case, the probability of an erroneous reception of one count is ≈ 10 ^-6 , which is confirmed by the experiment.

Claims (4)

 1. A method of transmitting / receiving information in a mine shaft via a communication line containing a lifting metal rope, comprising modulating a carrier signal with an information signal, exciting a modulated high-frequency signal in a communication line, receiving, selecting and demodulating, characterized in that, in order to increase reliability due to the use of a TEM wave as a carrier wave, an additional communication line is created in the trunk, which is a metal rope shorted in the lower and upper parts of the trunk, analogues th information signal is converted into a binary pulse package, provided with redundancy to excite link modulated digital information signal TEM wave frequency f = 30 MHz, is isolated from the demodulated signal sending code, it is checked and converted to an analog signal.  2. The system of transmitting and receiving information in the conditions of a mine shaft via a communication line, which is a lifting metal rope, containing a transmitter mounted in a lifting vessel, including a sensor and a modulator, through a transmitter connected to a transmitter antenna, and a receiver device located in the shaft of the shaft, including a receiving antenna, through a receiver and a demodulator connected to a linear block, and an actuating element, characterized in that, in order to increase reliability by using as a carrier TEM waves, it is equipped with an additional metal conductor installed along the axis of the barrel, the metal structures of the copra upper receiving platform are galvanically connected to each other, the lifting vessel is made of metal, and it is equipped with two clock generators, an analog-to-digital converter, and two conversion nodes code, a second linear block, a clock driver, a synchronization unit and a digital-to-analog converter, the sensor being connected to the first input of analog-to-digital of the first converter, the first output of which is connected through the first node of the code conversion to the first input of the second linear block, the output of which is connected to the input of the modulator, the first clock generator is connected to the second input of the analog-to-digital converter, the second output of which is connected to the second input of the second through the clock generator a linear block, the demodulator output is connected to the input of the first linear block, the output of which is connected to the first inputs of the second code converter and synchronization node, Exit is via a second clock pulse generator is connected to the second input node of the second code conversion, which is output through a digital to analog converter is connected to the actuator element.  3. The system according to claim 2, characterized in that the transmitter is tuned to a frequency f = 30 MHz.  4. The system according to claim 2, characterized in that the receiving and transmitting antennas are made in the form of a rectangular frame, and the transmitting antenna is mounted on a lifting metal rope with the long side along its axis at a distance l = C / 2f (where C is the speed of light, f is the excitation frequency of the TEM wave) from the vessel, and the receiving antenna is mounted on the barrel reinforcement with the long side along the shaft and at a distance l = C / 2f from the metal structures of the copra upper receiving platform.

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