Active and passive interference resistant high-precision pipe laying positioning system

Abstract

The invention provides a high-precision pipe laying positioning system resistant to active and passive interference, and relates to the technical field of pipe laying, the high-precision pipe laying positioning system comprises a transmitting probe and a receiver, the transmitting probe is arranged underground, the receiver is arranged on the ground, the transmitting probe comprises a battery, an MCU, a sensor, an electromagnetic wave transmitter 1 and an electromagnetic wave transmitter 2, the receiver comprises a DSP, a display screen, a key, a signal processing unit and an antenna system, and the antenna system is an array three-dimensional antenna capable of adjusting the relative position; the electromagnetic wave emitter 1 and the electromagnetic wave emitter 2 simultaneously send electromagnetic waves; according to the method, the principle that multiple magnetic sources are positioned through an array three-dimensional antenna is utilized, and the position and the advancing direction of a guide drill bit are accurately calculated in the environment with an active interference source and a passive secondary interference source; by utilizing different attenuation of electromagnetic waves with different frequencies in the same medium, the depth distance between the guide drill bit and the ground receiver is accurately calculated through data processing, and the precision is higher.

Description

Technical Field

[0001] The invention relates to the technical field of pipe laying, and in particular to a high-precision pipe laying positioning system that is resistant to active and passive interference. Background Art

[0002] Pipe laying using trenchless horizontal directional traction is a mature technology. The basic process is as follows: the horizontal directional drilling rig uses a drill bit and a drill rod as tools to drill in different strata and depths. The drill bit is guided along the designed trajectory and reaches the designed position exit through the guide system. The pipeline to be laid is pulled back from the side of the drill rod's excavation point along the expanded hole to the side of the drill rod's entry point to complete the pipeline laying. This technology has been widely used in municipal public pipeline construction and has the advantages of no pollution to the environment, high construction efficiency, and low cost. In the process of trenchless traction pipe laying, the construction of the guide hole is very important. It is necessary to drill as much as possible according to the designed trajectory. Otherwise, the pipeline cannot be pulled back and the construction fails. In serious cases, it may hit other existing pipelines and cause significant economic losses. At present, the control of guide hole construction generally includes wireless guidance system and wired guidance system. The wired guidance system is complicated to operate and expensive. It is generally used in construction with great depth and long distance. The wireless guidance is widely used because of its simple and fast construction. Specifically, the sensor at the front end of drilling collects information and transmits it to the ground receiver by wireless means, so as to control the construction method. The basic principle of the wireless guidance system is to place a guide probe in the probe compartment at the drill bit end. The probe has an information collection sensor and a radio electromagnetic wave transmission system. After the ground receiver receives the electromagnetic wave information by the propagation trajectory and amplitude attenuation of the electromagnetic wave, it performs positioning and depth calculation. In this process, if the law of wireless propagation is disturbed or there is an interference source with the same frequency as the signal, it will cause inaccurate positioning and depth calculation. With the increasing complexity of underground pipelines, various interferences are also increasing, which makes the precision control during construction face more and more challenges. Therefore, the present invention proposes a high-precision pipe laying positioning system that is resistant to active and passive interference to solve the problems existing in the prior art. Summary of the invention

[0003] In response to the above problems, the present invention proposes a high-precision pipe-laying positioning system that is resistant to active and passive interference. The high-precision pipe-laying positioning system that is resistant to active and passive interference utilizes the principle of multi-magnetic source positioning of array three-dimensional antennas to accurately calculate the position and forward direction of the guide drill bit in an environment where active interference sources and passive secondary interference sources exist.

[0004] To achieve the purpose of the present invention, the present invention is implemented through the following technical solutions: a high-precision pipe-laying positioning system that resists active and passive interference, including a transmitting probe and a receiver, wherein the transmitting probe is arranged underground, and the receiver is arranged above ground, wherein the transmitting probe includes a battery, an MCU, a sensor, an electromagnetic wave transmitter 1, and an electromagnetic wave transmitter 2, and wherein the receiver includes a DSP, a display screen, a button, a signal processing unit, and an antenna system, wherein the antenna system is an array three-dimensional antenna with adjustable relative position; The electromagnetic wave transmitter 1 and the electromagnetic wave transmitter 2 send electromagnetic waves at the same time, and the carrier information they carry is the same. The frequencies of the electromagnetic wave transmitter 1 and the electromagnetic wave transmitter 2 are selected according to the two frequencies with the least interference under working conditions. The antenna system receives the electromagnetic wave signal emitted by the transmitting probe, and enters the DSP for processing after amplification and filtering by the signal processing unit. The processing result is displayed on the display screen, and the parameters and modes are selected through the buttons on the display screen.

[0005] A further improvement is that the antenna system consists of 5 three-dimensional antenna groups, each three-dimensional antenna group includes 3 antennas, and the 3 antennas in the same group are placed orthogonally to each other in pairs. The first three-dimensional antenna group and the remaining three-dimensional antenna groups are connected by a movable connecting rod, and the DSP adjusts the length of the movable connecting rod through instructions, thereby adjusting the relative positions between multiple three-dimensional antenna groups.

[0006] Further improvements are: when there is no interference, the electromagnetic waves sent by the transmitting probe are consistent with the theoretical waveform, and one group of three-dimensional antenna groups is used for positioning and ranging to achieve the required accuracy. When there are metal pipelines and steel meshes that are secondarily magnetized by electromagnetic waves underground, or power pipelines that themselves generate interfering electromagnetic waves, five groups of three-dimensional antenna groups are used to adjust the relative position for positioning and ranging.

[0007] A further improvement is that the antenna system performs differential operations on magnetic field signals through multiple three-dimensional antenna groups, and uses the measurement values ​​of the first three-dimensional antenna group and the remaining three-dimensional antenna groups to perform differential operations to measure the magnetic field gradient tensor. The magnetic field gradient tensor is shown by the following formula: According to Maxwell's equations for electromagnetic fields, for the passive region in the magnetic field, the following formula holds: The matrix G is a symmetric tensor. In actual working conditions, G is obtained by measuring the magnetic induction intensity B and then using differential calculation.

[0008] A further improvement is to calculate the main invariant of the matrix G using the following formula: And move within the area, based on which a spot diagram of I2 is drawn in the detection plane, with each spot representing a magnetic field source existing below the corresponding position.

[0009] A further improvement is that the intensity of the magnetic source emitted by the transmitting probe is greater than the interfering magnetic field of other secondary magnetic sources or power lines. In this process, the main magnetic source (x0, y0, z0) is found, which is the location of the transmitting probe underground.

[0010] Further improvements are: using magnetic dipoles to calculate the distance, using the signal value to decay according to the cube of the distance, and calibrating the distance value at 3 meters in advance to make an inference, as shown in the following formula: Among them, F3 is the signal value at 3 meters, Fx is the signal value of the current distance, Dx is the calculated distance, and af is the distance value calibrated in advance.

[0011] A further improvement is that when there is a steel mesh or other passive interference, two frequencies are used, and the simultaneous equations are as follows: The ratio of a1 / a2 is calculated by the first and second formulas respectively, and the value of a1 is calculated by the third formula. The value is then substituted into the first formula to calculate the true distance, where the f() function is a database trained in advance.

[0012] The beneficial effects of the present invention are: 1. The present invention utilizes the principle of locating multiple magnetic sources using an array three-dimensional antenna to accurately calculate the position and direction of the guide drill in an environment where active interference sources and passive secondary interference sources exist. The present invention utilizes the different attenuation of electromagnetic waves of different frequencies in the same medium to accurately calculate the depth distance between the guide drill and the ground receiver through data processing with higher accuracy.

[0013] 2. When there are cables or other devices that actively transmit interference signals near the positioning drill bit, the present invention can accurately find the position and direction of the positioning drill bit. When there is passive interference during the propagation process, the position and direction of the drill bit can be accurately found. Under various active, passive and dynamic interference conditions, the depth information of the drill bit from the receiver can be accurately calculated, which has higher construction efficiency and better construction quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is the overall system and environment block diagram of the present invention; Figure 2 This is a functional block diagram of the transmitting probe of the present invention; Figure 3 is a functional block diagram of a receiver of the present invention; Figure 4 is a functional block diagram of the antenna system of the present invention; Figure 5 It is a graphical diagram of the main invariants of the matrix G of the present invention. DETAILED DESCRIPTION

[0015] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with examples. The examples are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention. Embodiment 1

[0016] according to Figure 1 , 2 , 3, 4, and 5, this embodiment proposes a high-precision pipe-laying positioning system that is resistant to active and passive interference, including a transmitting probe and a receiver, wherein the transmitting probe is arranged underground, and the receiver is arranged above ground, and the transmitting probe includes a battery, an MCU, a sensor, an electromagnetic wave transmitter 1, and an electromagnetic wave transmitter 2, and the receiver includes a DSP, a display screen, a button, a signal processing unit, and an antenna system, and the antenna system is an array three-dimensional antenna with adjustable relative position; The electromagnetic wave transmitter 1 and the electromagnetic wave transmitter 2 transmit electromagnetic waves at the same time, and the carrier information they carry is the same. The frequencies of the electromagnetic wave transmitter 1 and the electromagnetic wave transmitter 2 are selected according to the two frequencies with the least interference under the working conditions. The antenna system receives the electromagnetic wave signal emitted by the transmitting probe, and enters the DSP for processing after amplification and filtering by the signal processing unit. The processing result is displayed on the display screen, and the parameters and modes are selected through the buttons on the display screen. The principle of locating multiple magnetic sources using the array three-dimensional antenna is used to accurately calculate the position and forward direction of the guide drill in an environment with active interference sources and passive secondary interference sources; the depth distance between the guide drill and the ground receiver is accurately calculated through data processing by utilizing the different attenuation of electromagnetic waves of different frequencies in the same medium.

[0017] The antenna system consists of five three-dimensional antenna groups, each of which includes three antennas. The three antennas in the same group are placed orthogonally to each other. The first three-dimensional antenna group is connected to the remaining three-dimensional antenna groups through a movable connecting rod. The DSP adjusts the length of the movable connecting rod through instructions, thereby adjusting the relative positions between multiple three-dimensional antenna groups.

[0018] When there are cables or other devices that actively transmit interference signals near the positioning drill bit, the position and direction of the positioning drill bit can be accurately found; When there is passive interference in the propagation process, such as metal pipes, steel mesh and other objects that can be magnetized twice, the drill bit position and forward direction can be accurately found; Under various active, passive and dynamic interference conditions, the depth information of the drill bit from the receiver can be accurately calculated. Embodiment 2

[0019] according to Figure 1 , 2As shown in , 3, 4, and 5, this embodiment proposes a high-precision pipe-laying positioning system that is resistant to active and passive interference, including a transmitting probe and a receiver, and also includes other possible interfering pipelines, such as power pipelines and steel meshes. The transmitting probe is arranged underground, and the receiver is arranged above ground. The transmitting probe includes a battery, an MCU, a sensor, an electromagnetic wave transmitter 1, and an electromagnetic wave transmitter 2. The receiver includes a DSP, a display screen, a button, a signal processing unit, and an antenna system. The antenna system is an array three-dimensional antenna with adjustable relative position; The electromagnetic wave transmitter 1 and the electromagnetic wave transmitter 2 send electromagnetic waves at the same time, and the carrier information they carry is the same. The frequencies of the electromagnetic wave transmitter 1 and the electromagnetic wave transmitter 2 are selected according to the two frequencies with the least interference under the working conditions. The antenna system receives the electromagnetic wave signal emitted by the transmitting probe, and enters the DSP for processing after amplification and filtering by the signal processing unit. The processing result is displayed on the display screen, and the parameters and modes are selected through the buttons on the display screen. The electromagnetic wave transmitter 1 and the electromagnetic wave transmitter 2 send electromagnetic waves at the same time, and the carrier information they carry is the same, but the frequencies of the two are different. This frequency can be selected according to the working conditions. The basis for selection is the two frequencies with the least interference under the working conditions, such as 4k for transmitter 1 and 30k for transmitter 2.

[0020] The antenna system consists of five three-dimensional antenna groups, each of which includes three antennas. The three antennas in the same group are placed orthogonally to each other. The first three-dimensional antenna group is connected to the remaining three-dimensional antenna groups through a movable connecting rod. The DSP adjusts the length of the movable connecting rod through instructions, thereby adjusting the relative positions between multiple three-dimensional antenna groups.

[0021] When there is no interference, the electromagnetic waves sent by the transmitting probe are consistent with the theoretical waveform, and positioning and ranging use one three-dimensional antenna group to achieve the required accuracy. When there are metal pipelines, steel meshes that are magnetized by electromagnetic waves for the second time, or power pipelines that generate interference electromagnetic waves themselves, five three-dimensional antenna groups are used to adjust the relative position for positioning and ranging. When there is no interference, the electromagnetic waves sent by the probe are basically consistent with the theoretical waveform, and positioning and ranging can achieve very high accuracy using one group of antennas. However, when there are metal pipelines, steel meshes that may be magnetized by electromagnetic waves for the second time, or power pipelines that may generate interference electromagnetic waves themselves, the propagation law of electromagnetic waves is destroyed, and using one group of antennas will produce very large errors. Therefore, the present invention uses array antennas for high-precision positioning of interference conditions.

[0022] The antenna system performs differential operation on magnetic field signals through multiple three-dimensional antenna groups, and uses the measurement values ​​of the first three-dimensional antenna group and the remaining three-dimensional antenna groups to perform differential operation to measure the magnetic field gradient tensor. The magnetic field gradient tensor is shown in the following formula: According to Maxwell's equations for electromagnetic fields, for the passive region in the magnetic field, the following formula holds: The matrix G is a symmetric tensor. In actual working conditions, the magnetic induction intensity B is measured and then differential calculation is used to obtain G. The use of multiple antennas allows differential operation of magnetic field signals. The measured values ​​of antenna group 1 and other antenna groups are used to perform differential operations to achieve measurement of the magnetic field tensor.

[0023] To calculate the main invariant of the matrix G, use the following formula: And move in the area, based on which a spot diagram of I2 is drawn in the detection plane, with each spot representing a magnetic field source below the corresponding position. I2 can be drawn in the detection plane as Figure 5 The "spot" diagram shown, each "spot" in the diagram represents the existence of a magnetic field source below the corresponding position.

[0024] The intensity of the magnetic source emitted by the transmitting probe is greater than the interfering magnetic field of other secondary magnetic sources or power lines. In this process, the main magnetic source (x0, y0, z0) is found, which is the location of the transmitting probe underground.

[0025] Use magnetic dipoles to calculate the distance, use the signal value to decay according to the cube of the distance, and calibrate the distance value at 3 meters in advance to make an inference, as shown in the following formula: Among them, F3 is the signal value at 3 meters, Fx is the signal value of the current distance, Dx is the calculated distance, and af is the distance value calibrated in advance.

[0026] When there is a steel mesh or other passive interference, the dielectric constant cannot be equal to that in air. Using two frequencies, the simultaneous equations are as follows: The ratio of a1 / a2 is calculated by the first and second formulas respectively, and the value of a1 is calculated by the third formula. The value is then substituted into the first formula to calculate the true distance, where the f() function is a database trained in advance.

[0027] The high-precision pipe-laying positioning system resistant to active and passive interference utilizes the principle of multi-magnetic source positioning of array three-dimensional antennas to accurately calculate the position and direction of the guide drill bit in an environment where active interference sources and passive secondary interference sources exist; utilizes the different attenuation of electromagnetic waves of different frequencies in the same medium, and through data processing, accurately calculates the depth distance between the guide drill bit and the ground receiver with higher accuracy; and when there are cables or other devices that actively transmit interference signals near the positioning drill bit, the present invention can accurately find the position and direction of the positioning drill bit, and when there is passive interference in the propagation process, the drill bit position and direction can be accurately found, and under various active, passive and dynamic interference conditions, the depth information of the drill bit from the receiver can be accurately calculated, and has higher construction efficiency and better construction quality.

[0028] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A high-precision pipe-laying positioning system that is resistant to active and passive interference, comprising a transmitting probe and a receiver, characterized in that: The transmitting probe is arranged underground, and the receiver is arranged above ground. The transmitting probe includes a battery, an MCU, a sensor, an electromagnetic wave transmitter 1, and an electromagnetic wave transmitter 2. The receiver includes a DSP, a display screen, a button, a signal processing unit, and an antenna system. The antenna system is an array three-dimensional antenna whose relative position can be adjusted. The electromagnetic wave transmitter 1 and the electromagnetic wave transmitter 2 send electromagnetic waves at the same time, and the carrier information they carry is the same. The frequencies of the electromagnetic wave transmitter 1 and the electromagnetic wave transmitter 2 are selected according to the two frequencies with the least interference under working conditions. The antenna system receives the electromagnetic wave signal emitted by the transmitting probe, and enters the DSP for processing after amplification and filtering by the signal processing unit. The processing result is displayed on the display screen, and the parameters and modes are selected through the buttons on the display screen.

2. According to claim 1, a high-precision pipe-laying positioning system that resists active and passive interference is characterized in that: The antenna system consists of five three-dimensional antenna groups, each of which includes three antennas. The three antennas in the same group are placed orthogonally to each other. The first three-dimensional antenna group is connected to the remaining three-dimensional antenna groups through a movable connecting rod. The DSP adjusts the length of the movable connecting rod through instructions, thereby adjusting the relative positions between multiple three-dimensional antenna groups.

3. According to claim 2, a high-precision pipe-laying positioning system that resists active and passive interference is characterized in that: When there is no interference, the electromagnetic waves sent by the transmitting probe are consistent with the theoretical waveform, and one group of three-dimensional antenna groups is used for positioning and ranging to achieve the required accuracy. When there are metal pipelines and steel meshes that are secondarily magnetized by electromagnetic waves underground, or power pipelines that generate interfering electromagnetic waves themselves, five groups of three-dimensional antenna groups are used to adjust the relative position for positioning and ranging.

4. According to claim 3, a high-precision pipe-laying positioning system that resists active and passive interference is characterized in that: The antenna system performs differential operation on magnetic field signals through multiple three-dimensional antenna groups, and uses the measurement values ​​of the first three-dimensional antenna group and the remaining three-dimensional antenna groups to perform differential operation to measure the magnetic field gradient tensor. The magnetic field gradient tensor is shown in the following formula: According to Maxwell's equations for electromagnetic fields, for the passive region in the magnetic field, the following formula holds: The matrix G is a symmetric tensor. In actual working conditions, G is obtained by measuring the magnetic induction intensity B and then using differential calculation.

5. The high-precision pipe-laying positioning system resistant to active and passive interference according to claim 4 is characterized in that: To calculate the main invariant of the matrix G, use the following formula: And move within the area, based on which a spot diagram of I2 is drawn in the detection plane, with each spot representing a magnetic field source existing below the corresponding position.

6. The high-precision pipe-laying positioning system against active and passive interference according to claim 5 is characterized in that: The intensity of the magnetic source emitted by the transmitting probe is greater than the interfering magnetic field of other secondary magnetic sources or power lines. In this process, the main magnetic source (x0, y0, z0) is found, which is the location of the transmitting probe underground.

7. The high-precision pipe-laying positioning system resistant to active and passive interference according to claim 6 is characterized by: Use magnetic dipoles to calculate the distance, use the signal value to decay according to the cube of the distance, and calibrate the distance value at 3 meters in advance to make an inference, as shown in the following formula: Among them, F3 is the signal value at 3 meters, Fx is the signal value of the current distance, Dx is the calculated distance, and af is the distance value calibrated in advance.

8. The high-precision pipe-laying positioning system resistant to active and passive interference according to claim 7 is characterized in that: When there are steel mesh or other passive interferences, two frequencies are used and the system of simultaneous equations is as follows: The ratio of a1 / a2 is calculated by the first and second formulas respectively, and the value of a1 is calculated by the third formula. The value is then substituted into the first formula to calculate the true distance, where the f() function is a database trained in advance.

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