CN105807324B - A kind of metallic ore Mined-Out Areas method - Google Patents

Abstract

The present invention is a method for detecting goafs in metal mines, comprising: a. selecting measuring points in the measuring area, encoding 1-n, b. adjusting the parameters of the transmitter, and adjusting the receiver including setting the attenuation range of the received signal; c. .The transmitter sends a bipolar rectangular pulse signal with an amplitude of V to the transmitting coil. After the transformation from the primary field to the secondary field underground, the receiver receives the secondary field signal in the receiving coil and performs data recording and processing. , to complete the measurement of single point single voltage level; d. Change the emission voltage at the position of point 1 to complete the multi-voltage level measurement of point 1, and then repeat the above process for point 2 to complete the multiple Voltage level measurement, complete the multi-voltage level measurement of points 1 to n in sequence. e. Carry out data processing, and obtain the location of the underground mined-out area by finding abnormalities in the same period of data. This method can realize the detection of the maximum depth with the shortest dead time under the premise of ensuring the validity of the data.

Description

A method for detecting gobs in metal mines

technical field

The invention belongs to the field of geophysical prospecting, in particular to a method for detecting goafs in metal mines.

Background technique

Since the middle and late 20th century, my country's infrastructure construction has continued to develop, and the demand and use of metal mineral resources have been in a stage of rapid growth. At present, there are more than 10,000 underground metal mines in my country, which produce more than 2 billion tons of ore every year. However, after the mining and utilization of metal mineral resources, a large number of goafs have been formed due to changes in geological conditions. The existence of a large number of goafs has deteriorated the mining conditions of the mine, and the original mechanical balance of the underground rock mass has been broken. Explosions and other accidents; what is more serious is that the goaf will be filled with gas, groundwater, etc., and there will be huge safety hazards in the construction before the situation is ascertained. Therefore, detecting mined-out areas has always been a difficult problem that must be faced in the field of resource exploration.

At present, there are few detection methods for goafs in metal mines in China, and the traditional transient electromagnetic method is generally used in goafs of coal mines. The transient electromagnetic method is based on the principle of electromagnetic induction. When the transmitting current in the transmitting coil suddenly drops to zero, a primary field will be induced around the coil, and an eddy current will be generated in the underground conductive medium during the propagation of the primary field. During the change process, the spin current will propagate the secondary field to the surface, and the geological anomaly can be judged by receiving and inverting the secondary field. In metal mines, due to the low resistivity of the geological body, several irregular shielding layers will be formed underground, and a large current design must be used to penetrate the signal; at the same time, in order to ensure the detection accuracy of the goaf, a small coil design must be used. The design of small coil and high current will inevitably lead to large inductance of the coil, so that the transmission current cannot be cut off instantaneously, but a period of time is generated. During this period, the weak received signal is mixed with a strong transmitted signal, which cannot be achieved. Analytical inversion, called dead time, is performed. If the dead time is too long, this part of the received signal cannot be effectively used, which leads to the underreporting of the goaf. Therefore, a redesign is required before it can be applied to metal mines.

Contents of the invention

The technical problem to be solved by the present invention is to provide a metal mine goaf detection method, which can realize the detection of the maximum depth with the shortest dead time on the premise of ensuring the validity of the data.

A metal mine goaf detection method is characterized in that it comprises the following steps:

a. Select the measuring point in the survey area, code 1~n, lay the transmitting coil and the receiving coil on the ground centered on the measuring point 1, and lay the two in the way of overlapping loops; connect the transmitting port of the transmitter with the transmitting coil The receiving port of the receiver is connected with the receiving coil, and the synchronous port of the transmitter is connected with the synchronous port of the receiver with a synchronous signal line;

b. Adjusting the parameters of the transmitter includes: adjusting the emission voltage V, different voltages can achieve different emission depths; adjusting the length of the emission time t1 to control the length of the emission waveform; adjusting the length of the delay time t2, which determines the Can the transmitter send a synchronous signal to the receiver at an appropriate time; adjust the acquisition time t4; adjust the receiver including setting the attenuation range of the received signal;

c. The transmitter sends a bipolar rectangular pulse signal with an amplitude of V to the transmitting coil. After the transformation from the primary field to the secondary field underground, the receiver receives the secondary field signal in the receiving coil and performs data recording and Processing, to complete the measurement of single point single voltage level;

d. At the position of point 1, change the emission voltage, repeat the above b-c process, and complete the multi-voltage level measurement of point 1, then repeat the above process for point 2, and complete the multi-voltage level measurement of point 2, Complete the multi-voltage level measurement of points 1 to n in sequence.

e. The collected data, including time and current, are drawn into a function curve, and the data processing includes: ① Intercepting several sets of data at point 1 in different time periods, different voltages are represented by V1, V2...Vn, V1 voltage The level intercepts the time data of T1 period, the V2 voltage level intercepts the T2 period data, and the Vn voltage level intercepts the Tn period data, and normalizes the intercepted data of each period to fit a smooth curve L1; ② Point 2 Repeat the above steps to fit the data into a smooth curve L2. Similarly, complete the fitting of the curves L1~Ln in sequence; ③ invert the curves L1~Ln on the inversion platform, and obtain the underground The location of the goaf.

Further, the transmitters used include:

MCU is the control core;

A band switch group, connected to the MCU for parameter setting;

The energy storage capacitor is connected to the MCU through a DC-DC boost circuit, and then the energy storage capacitor is charged to the set voltage value through the DC-DC boost circuit;

The voltage acquisition circuit is connected between the MCU and the energy storage capacitor, collects the voltage value of the energy storage capacitor and transmits it to the MCU;

The IGBT bridge circuit is connected to the energy storage capacitor, and is turned on and off under the control of the MCU through the IGBT drive circuit to make the energy storage capacitor emit alternating bipolar rectangular pulses to the transmitting coil.

Further, the receivers used include:

The attenuation circuit is connected with the receiving coil, and adjusts the signal received by the receiving coil according to the attenuation factor;

Band switch, connected with the attenuation circuit to set the attenuation range of the received signal;

The PC is connected to the attenuation circuit through the AD acquisition circuit and the conditioning circuit in turn. After the signal is adjusted by the conditioning circuit, it is transferred to the PC through the conversion of the AD acquisition circuit. After the PC is connected to the transmitter, it receives the synchronization signal sent by the transmitter. , and process the data.

Further, in step a), the survey points are selected in the survey area by grid division and other methods.

Further, the band switch group sets the corresponding parameters for the current measurement to the MCU, including the emission voltage V, emission time t1, delay time t2 and acquisition time t4.

Further, if the current voltage of the energy storage capacitor is greater than or equal to the voltage set in the MCU, the charging is stopped, and the MCU controls the on-off of the IGBT bridge to realize that the energy storage capacitor emits bipolar rectangular pulses to the transmitting coil.

Further, the timing control flow of the MCU is as follows:

Detect the current energy storage capacitor voltage;

If the voltage of the energy storage capacitor is lower than the set value, a charging signal is sent to the DC-DC boost power supply;

If the voltage of the energy storage capacitor is greater than or equal to the set value, stop charging and control the IGBT bridge to emit forward current pulses, stop emitting after a duration of t1, and then send a synchronization signal to the receiver after waiting for a time t2, and the duration of the synchronization signal is fixed at t3 value, and detect the current energy storage capacitor voltage after waiting time t4;

If it is less than the set value, a charging signal is sent to the DC-DC boost circuit;

If it is greater than or equal to the set value, the charging will be stopped, and the charging time t5 is not fixed;

Control the IGBT bridge to emit reverse current pulses;

Repeat the above process until the measurement ends.

The present invention is achieved like this,

Compared with the prior art, the present invention has the beneficial effect that: the method of the present invention is based on the principle of electromagnetic induction, multiple measurements are carried out by emitting pulses of different voltage levels, and the collected data is intercepted and normalized. Afterwards, the inversion analysis is carried out. This method can realize the detection of the maximum depth with the shortest dead time under the premise of ensuring the validity of the data.

By controlling the charge and discharge of the energy storage capacitor, the transmission of high-power signals under field conditions is realized; setting various measurement parameters through the band switch group makes the operation simple and improves the reliability of the instrument under field conditions; this method can be used in field conditions It realizes high-power transmission with small coil, large detection depth, high precision and strong reliability. The method can realize the effective detection of the metal mine goaf, and then provide guarantee for the safe production of the mining area.

Description of drawings

FIG. 1 is a block diagram of a module structure of a device provided by an embodiment of the present invention;

FIG. 2 is a schematic diagram of an MCU working sequence provided by an embodiment of the present invention;

Fig. 3 is a schematic flow diagram of a multi-point measurement provided by an embodiment of the present invention;

Fig. 4 is a schematic diagram of data interception and splicing provided by an embodiment of the present invention.

detailed description

In order to make the object, technical solution and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the examples. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

As shown in FIG. 1 , the present invention is implemented in the following way: a metal mine goaf detection method, the detection device adopted includes a transmitter 10 , a receiver 17 , a transmitting coil 6 and a receiving coil 7 . The transmitter 10 includes a band switch group 1, an MCU2, a DC-DC boost circuit 3, an energy storage capacitor 4, an IGBT bridge circuit 5, an IGBT drive circuit 9, and a voltage acquisition circuit 8; the band switch group 1 is connected to the MCU2 for parameter setting , the MCU2 is connected to the IGBT drive circuit 9, the IGBT drive circuit 9 is connected to the IGBT bridge 5 to control its on-off, the MCU2 is connected to the DC-DC boost circuit 3, and the DC-DC boost circuit 3 is connected to the energy storage capacitor 4 for its For charging, the energy storage capacitor 4 is connected to the MCU 2 through the voltage acquisition circuit 8 , and at the same time, the energy storage capacitor 4 is connected to the IGBT bridge 5 , and the output terminal of the IGBT bridge 5 is connected to the transmitting coil 6 .

Receiver 17 comprises attenuation circuit 12, conditioning circuit 13, AD acquisition circuit 14, panel PC machine 16 and band switch 11; The circuit 12 is connected with the band switch 11, receives its attenuation multiple instruction, the output end of the conditioning circuit 13 is connected with the AD acquisition circuit 14, and the output end of the AD acquisition circuit 14 is connected to the panel PC 16 through the serial port 15 for data processing, and the panel PC 16 is connected with the MCU2 of the transmitter 10 to receive the synchronization signal it sends.

The specific working process includes the following steps:

1) adjust the band switch group 1 of the transmitter 10 to set the corresponding parameters of this measurement to the MCU2, including the emission voltage V, the emission time t1, the delay time t2 and the collection time t4, etc.; adjust the band switch 11 on the receiver 17 To set the attenuation range of the received signal;

2) The MCU2 controls the DC-DC step-up circuit 3 to charge the energy storage capacitor 4, while the voltage acquisition circuit 8 continuously detects the voltage V1 of the energy storage capacitor 4 and feeds it back to the MCU2. If the current voltage is less than the voltage set in 1), that is: V1<V, continue charging;

3) If the current voltage is greater than or equal to the voltage set in 1), that is: V1≥V, then stop charging, and at the same time, MCU2 controls the on-off of the IGBT bridge 5 by controlling the IGBT drive circuit 9, and the IGBT bridge 5 acts as a switch The type device is located between the energy storage capacitor 4 and the transmitting coil 6, and the MCU2 controls the on-off of the IGBT bridge 5 so that the energy storage capacitor 4 transmits an alternating bipolar rectangular pulse to the transmitting coil 6 with an amplitude of V, and the transmitting coil 6. Transmit a primary field underground. The primary field passes through the geological body in the detection area, and a current will be generated. When the current changes again, a secondary field will be generated. At this time, the MCU2 sends a synchronization signal to the receiver 17;

4) The secondary field signal is captured by the receiving coil 7 and delivered to the receiver 17, where it will undergo a series of processing, including passing through the signal attenuation circuit 12, the conditioning circuit 13, and the AD acquisition circuit according to the setting in step 1). 14. Finally, the data is transmitted to the tablet PC 16 through the serial port 15, and the tablet PC 16 starts to record the data transmitted from the serial port 15 after receiving the synchronization signal sent by the MCU2 in step 3), so far the single voltage of a single measurement point is completed grade measurement;

As shown in Figure 2, MCU2 is the core of this device, which precisely controls the cooperative work of each module. The timing control process of MUC2 is as follows: detect the current capacitor voltage V1, if V1<V, send a charging signal to the DC-DC boost circuit 3, If V1≥V, then stop charging and control the IGBT bridge 5 to transmit forward current pulses, stop transmitting after a duration of t1, and send a synchronization signal to the tablet PC16 of the receiver 17 after waiting for a time t2, and stop transmitting after a duration of t3. After waiting time t4, detect the current capacitor voltage V1, if V1<V, start to send a charging signal to the DC-DC boost circuit 3, until it detects that V1≥V, then stop charging and control the IGBT bridge 5 to emit reverse current Pulse, repeat the above process until the end of the detection.

The metal mine goaf detection method is carried out by the above-mentioned device, including the following sequence and steps:

a. Measuring points are selected in the surveying area by means of grid division and other methods, and the codes are 1~n. The transmitter coil 6 and the receiver coil 7 are laid on the ground with the No. 1 measuring point as the center, and the two are laid in the way of overlapping loops. The transmitting port of the transmitter 10 is connected with the transmitting coil 6, the receiving port of the receiver 17 is connected with the receiving coil 7, and the synchronous port of the transmitter 10 is connected with the synchronous port of the receiver with a synchronous signal line.

b. Adjust the band switch group 1 on the transmitter 10 to appropriate positions: (1) adjust the emission voltage V, different voltages can reach different emission depths; (2) adjust the length of the emission time t1 to control The length of the transmitted waveform (3) Adjust the length of the delay time t2, this parameter determines whether the MCU2 can send a synchronization signal to the tablet PC16 at an appropriate time; (4) Adjust the acquisition time t4, different depths need corresponding acquisition time Ensure the accuracy of the data; adjust the band switch 11 on the receiver 17 to set the attenuation range of the received signal, so as to avoid damage to the instrument due to excessive signal amplitude.

c. Turn on the power and the instrument starts to work. According to the specific working process described above, the transmitter sends a bipolar rectangular pulse signal with an amplitude of V to the transmitting coil, and after the transformation from the primary field to the secondary field in the ground, the secondary field in the receiving coil is received by the receiver. Field signal and data recording and processing, so far the single-point single-voltage level measurement is completed, and the instrument is turned off. No instrument operation is required during this time.

d. As shown in Figure 3, at the position of point 1, change the emission voltage and other parameters of the band switch group, repeat the above process, and complete the multi-voltage level measurement of point 1. Then put the instrument and coil on point 2 and repeat the above process to complete the multi-voltage level measurement at point 2. Similarly, a total of multi-voltage level measurements of points 1 to n are completed.

e. As shown in Figure 4, the collected data is presented in the form of a function curve, tn represents the dead time at the Vn voltage level, Tn represents the sampling time at the Vn voltage level, the higher the voltage level, the longer the dead time tn . After each set of data is obtained, the data processing platform of the tablet PC performs data processing: ① Intercept several sets of data at point 1 in different time periods, intercept the data of the T1 segment at the V1 voltage level, and intercept the T2 segment data at the V2 voltage level... Vn The voltage level intercepts the Tn segment data. Then the intercepted data of each segment is normalized and fitted into a smooth curve L1. ②Repeat the above steps for the data of point 2 to fit a smooth curve L2. Similarly, complete the fitting of curves L1~Ln in sequence. ③Invert the curves L1~Ln on the inversion platform, and obtain the location of the underground mined-out area by finding the abnormality of the data in the same period.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (7)

1. A metal ore goaf detection method, is characterized in that, comprises the steps: a. Select the measuring point in the survey area, code 1~n, lay the transmitting coil and the receiving coil on the ground centered on the measuring point 1, and lay the two in the way of overlapping loops; connect the transmitting port of the transmitter with the transmitting coil The receiving port of the receiver is connected with the receiving coil, and the synchronous port of the transmitter is connected with the synchronous port of the receiver with a synchronous signal line; b. Adjusting the parameters of the transmitter includes: adjusting the emission voltage V, V=V1, V2...Vn, different voltages can achieve different emission depths; adjusting the length of the emission time t1 to control the length of the emission waveform; adjusting the delay The length of time t2, this parameter determines whether the transmitter can send a synchronization signal to the receiver at an appropriate time; adjust the acquisition time t4; adjust the receiver including setting the attenuation range of the received signal; c. The transmitter sends a bipolar rectangular pulse signal with an amplitude of V to the transmitting coil. After the transformation from the primary field to the secondary field underground, the receiver receives the secondary field signal in the receiving coil and performs data recording and Processing, to complete the measurement of single point single voltage level; d. At the position of point 1, change the emission voltage, repeat the above b-c process, and complete the multi-voltage level measurement of point 1, then repeat the above process for point 2, and complete the multi-voltage level measurement of point 2, Complete the multi-voltage level measurement of points 1 to n in sequence; e. The collected data, including time and current, are drawn into a function curve, and the data processing includes: ① Intercepting several sets of data at point 1 in different time periods, different voltages are represented by V1, V2...Vn, V1 voltage The level intercepts the time data of T1 period, the V2 voltage level intercepts the T2 period data, and the Vn voltage level intercepts the Tn period data, where T1 indicates the sampling time under the V1 voltage level, T2 indicates the sampling time under the V2 voltage level, and Tn indicates Vn For the sampling time under the voltage level, normalize the intercepted data of each segment to fit into a smooth curve L1; ②Repeat the above steps for the data of point 2 to fit into a smooth curve L2, similarly, complete in sequence Fitting of the curves L1~Ln; ③Invert the curves L1~Ln on the inversion platform, and obtain the location of the underground goaf by finding the abnormality of the data in the same period. 2. according to the metal mine goaf detection method described in claim 1, it is characterized in that, the transmitter that adopts comprises: MCU is the control core; A band switch group, connected to the MCU for parameter setting; The energy storage capacitor is connected to the MCU through a DC-DC boost circuit, and then the energy storage capacitor is charged to the set voltage value through the DC-DC boost circuit; The voltage acquisition circuit is connected between the MCU and the energy storage capacitor, collects the voltage value of the energy storage capacitor and transmits it to the MCU; The IGBT bridge circuit is connected to the energy storage capacitor, and is turned on and off under the control of the MCU through the IGBT drive circuit to make the energy storage capacitor emit alternating bipolar rectangular pulses to the transmitting coil. 3. according to the metal mine goaf detection method described in claim 1, it is characterized in that, the receiver that adopts comprises: The attenuation circuit is connected with the receiving coil, and adjusts the signal received by the receiving coil according to the attenuation factor; Band switch, connected with the attenuation circuit to set the attenuation range of the received signal; The PC is connected to the attenuation circuit through the AD acquisition circuit and the conditioning circuit in turn. After the signal is adjusted by the conditioning circuit, it is transferred to the PC through the conversion of the AD acquisition circuit. After the PC is connected to the transmitter, it receives the synchronization signal sent by the transmitter. , and process the data. 4. according to the metal ore goaf detection method claimed in claim 1, it is characterized in that, in the step a), select measuring points in the survey area by methods such as grid division. 5. according to the described metal mine goaf detection method of claim 2, it is characterized in that, the band switch group sets the corresponding parameter of current measurement to MCU, comprises emission voltage V, emission time t1, delay time t2 and acquisition Time t4. 6. according to the metal mine goaf detection method described in claim 2, it is characterized in that, if the current voltage of the energy storage capacitor is greater than or equal to the voltage set in the MCU, then stop charging, while the MCU controls the IGBT bridge circuit The energy storage capacitor is switched off to transmit bipolar rectangular pulses to the transmitting coil. 7. according to the metal ore goaf detection method described in claim 2, it is characterized in that, the sequential control flow process of MCU is as follows: Detect the current energy storage capacitor voltage; If the voltage of the energy storage capacitor is lower than the set value, a charging signal is sent to the DC-DC boost power supply; If the voltage of the energy storage capacitor is greater than or equal to the set value, stop charging and control the IGBT bridge to emit forward current pulses, stop emitting after a duration of t1, and then send a synchronization signal to the receiver after waiting for a time t2, and the duration of the synchronization signal is fixed at t3 value, and detect the current energy storage capacitor voltage after waiting time t4; If it is less than the set value, a charging signal is sent to the DC-DC boost circuit; If it is greater than or equal to the set value, the charging will be stopped, and the charging time t5 is not fixed; Control the IGBT bridge to emit reverse current pulses; Repeat the above process until the measurement ends.