A multi-channel tunnel ground penetrating radar system and test assembly method

Abstract

The present invention discloses a multi-channel tunnel ground penetrating radar system and test assembly method, the system includes a mainframe box and multiple transceivers; the transceiver includes: a transceiver body, an adjustable structure for transceiver antenna, an antenna slot, a transmitting antenna, and a receiving antenna. The upper horizontal slide is horizontally arranged and located on the inner side wall of the lower layer of the transmitter body and is located at the top. The horizontal slide is a group, located on two side walls opposite to each other on the left and right, and the end extends to the end of the side wall where it is located; the lower horizontal slide is horizontally arranged and located at the bottom of the side wall where the upper horizontal slide is located, and the end extends to the end of the side wall where it is located; the antenna slot is four, all vertically arranged, two by two located between the upper horizontal slide and the lower horizontal slide on the left and right sides, and can slide forward and backward. The transceiver antenna spacing of the ground penetrating radar system is adjustable, and debugging is convenient through the adjustable structure of the transceiver antenna, and the mainframe structure is firm.

Description

Technical Field

[0001] The invention belongs to the technical field of ground penetrating radar, and in particular relates to a multi-channel tunnel ground penetrating radar system and a test assembly method. Background Art

[0002] Ground penetrating radar is a non-destructive detection device that uses high-frequency electromagnetic waves to obtain the distribution law of underground media. It is the mainstream method for detecting defects such as tunnel lining cavities and cracks, and has the advantages of fast speed and high resolution. Traditional multi-channel ground penetrating radar usually consists of four parts: timing control module, signal source, transceiver antenna, and host computer. According to the number of receivers and transmitters, it can be divided into two systems: multiple transmission and multiple reception and one transmission and multiple reception. The former usually has multiple groups of transceiver antennas and pulse sources, and can be configured with multiple frequency bands at the same time to improve the detection accuracy and range of the radar; the latter usually has one transmitting antenna, one pulse source and multiple receiving antennas, and can only be configured with one frequency band to meet a series of more complex detection needs such as three-dimensional imaging.

[0003] The multi-channel ground penetrating radar with a multiple-transmitter and multiple-receiver system is equivalent to multiple single-channel ground penetrating radars working simultaneously and without interfering with each other in terms of working principle and working performance. Therefore, it can significantly improve the detection accuracy and range during tunnel disease detection.

[0004] At present, the structure of the multi-channel ground penetrating radar host with multiple transmitters and receivers on the market is not strong enough, which can easily affect the working stability of the radar system; the external signal interface is easily damaged and the signal quality is easily affected; the transceiver antenna is fixed and cannot be adjusted, which is not conducive to debugging and optimization design; the transceiver shell is angular and has poor waterproofness, and is easily damaged by bumps and water seepage when used in the complex and humid environment of the tunnel. Summary of the invention

[0005] The purpose of the present invention is to provide a multi-channel tunnel ground penetrating radar system and a test assembly method, wherein the distance between the transmitting and receiving antennas is adjustable, the transceiver antenna has an adjustable structure, and debugging is convenient, and the host structure is firm.

[0006] The present invention adopts the following technical scheme: a multi-channel tunnel ground penetrating radar system, the system comprising: a mainframe box and a plurality of transceivers; the multi-channel tunnel ground penetrating radar system is used for non-contact detection of tunnel structural defects;

[0007] Wherein: the mainframe housing is connected to a plurality of transceivers, and is also connected to a Doppler radar and a computer host computer;

[0008] The transceiver comprises: a transceiver body, an adjustable transceiver antenna structure, an antenna slot, a transmitting antenna, and a receiving antenna, wherein:

[0009] The main body of the transceiver is a box with two layers of structure;

[0010] The transceiver antenna adjustable structure is arranged on the side wall in the lower layer of the transceiver body, and includes: an upper horizontal slide groove, a lower horizontal slide groove and an antenna clamping groove;

[0011] The upper horizontal slide groove is horizontally arranged, located on the inner side wall of the lower layer of the transceiver body, and is located at the top. The horizontal slide groove is a group, located on two opposite side walls on the left and right, and the end portion extends to the end portion of the side wall where it is located;

[0012] The lower horizontal chute is horizontally arranged at the bottom of the side wall where the upper horizontal chute is located, and the end thereof extends to the end of the side wall where the lower horizontal chute is located;

[0013] There are four antenna slots, all of which are vertically arranged, located in pairs between the upper horizontal slide slot and the lower horizontal slide slot on the left and right sides, and both can slide forward and backward; the antenna slots are divided into two groups front and back, the upper end of one group of antenna slots supports the mounting of the receiving antenna, and the upper end of the other group of antenna slots supports the mounting of the transmitting antenna.

[0014] Furthermore, the upper and lower layers of the transceiver body are separated by a horizontal partition, and a sampling unit and a pulse source are arranged on the upper layer of the transceiver body and on the partition, the sampling unit is connected to the receiving antenna, and the pulse source is connected to the transmitting antenna.

[0015] Furthermore, inside the transceiver body, the side walls at the lower part of the upper horizontal slide slot, and the lower part of the partition are covered with ferrite horizontal wave absorbing materials.

[0016] Furthermore, the mainframe box is provided with an acquisition card, a power module and a timing control circuit board, and a DB8 aviation socket and a USB aviation socket are provided on one side wall thereof;

[0017] The DB8 aviation socket is used to connect to the Doppler radar, and the USB aviation socket is connected to the computer host computer;

[0018] The power module is connected to the power terminal of the six-core coaxial bundled cable socket, and is also connected to the acquisition card, timing control circuit board and Doppler radar for power supply; the six-core coaxial bundled cable sockets are multiple, arranged on a side wall of the transceiver body, and installed at intervals in the up and down directions.

[0019] Furthermore, the space inside the main body of the transceiver and located at the lower part of the upper horizontal slide groove is filled with pearl cotton sheets for flexibly supporting and fixing the receiving antenna and the transmitting antenna.

[0020] Furthermore, an openable transceiver cover is provided on the upper part of the transceiver body; the lower part of the transceiver cover is integrally provided with a downwardly extending edge around the periphery, the edge is located inside the transceiver body, and its outer side wall is tightly fitted with the inner side wall of the transceiver body; the four corners of the transceiver cover and the transceiver body are all arc-shaped.

[0021] Furthermore, a vertical partition parallel to the antenna surface is provided inside the transceiver body and between the receiving antenna and the transmitting antenna, and ferrite horizontal wave absorbing material is pasted on the front and rear side surfaces of the vertical partition.

[0022] Furthermore, the acquisition card and the power module are each disposed in a metal shell, and a threaded hole is provided on the lower side wall of the metal shell;

[0023] Each of the metal shells is fixed by a metal pressing plate and installed on the bottom of the main chassis. The metal pressing plate is a plate with a connecting hole. The position of the connecting hole is consistent with the position of the threaded hole and is fixed by screws. The end of the metal pressing plate is fixedly connected to the bottom plate of the main chassis.

[0024] Furthermore, both ends of each antenna slot are connected to the upper horizontal slide slot and the lower horizontal slide slot by fastening bolts.

[0025] The present invention also discloses a method for assembling and testing the multi-channel tunnel ground penetrating radar system as follows:

[0026] Step s1. The transceiver performance test and assembly are as follows:

[0027] Step s11. The transceiver performance test: a ferrite horizontal absorbing material is applied inside the transceiver body and on the side wall at the lower part of the upper horizontal chute, the lower part of the transceiver cover, and the front and rear sides of the vertical partition; the antenna slot is always perpendicular to the upper horizontal chute and the lower horizontal chute;

[0028] Use a vector network analyzer to observe the S parameter curve characteristics of the transmitting antenna and the receiving antenna respectively until the transmitting antenna and the receiving antenna both achieve the best 10dB impedance bandwidth in the transceiver body;

[0029] Step s12. The transceiver is assembled as follows: in the transceiver body, the space below the upper horizontal slide is filled with a pearl cotton sheet for supporting and fixing the transmitting antenna and the receiving antenna; the sampling unit is connected to the receiving antenna and the pulse source and the transmitting antenna, and the transceiver cover and the transceiver body are tightly fastened and fitted;

[0030] Step s2. The host box communication test and assembly are as follows:

[0031] Step s21. The host box communication test: Connect the host box to the USB aviation socket to test whether the acquisition card communication function is normal, and execute the next step normally;

[0032] Step s22. Connect the six branches of the six-core coaxial bundled cable to the corresponding ports of the acquisition card, power module and timing control circuit board in the mainframe respectively, so as to realize data interaction with the transceiver and power supply and reception;

[0033] Step s3. Multi-channel whole machine joint debugging test, as follows:

[0034] The Doppler radar input signal is transmitted into the mainframe case through a cable and a DB8 aviation socket and connected to an acquisition card; multiple transceivers are connected to the mainframe case through a six-core coaxial bundled cable, and the radar echo data collected by the acquisition card is connected to a computer host computer through a USB aviation socket. The computer host computer is used to simultaneously display the ground penetrating radar echo waveforms of multiple channels, and observe whether the displayed echo waveform changes in real time when the detected target moves in time sampling and distance sampling modes, respectively, to ensure that the data processing rate meets the real-time display and storage requirements.

[0035] The beneficial effects of the present invention are: 1. The quality detection of the tunnel lining structure is carried out under non-contact conditions, which is not affected by the tunnel lining accessories, and the safety is guaranteed. It is suitable for rapid detection on a mobile carrier. 2. The distance between the transmitting and receiving antennas is adjustable. Through the adjustable structure of the transceiver antenna, the S parameters of the transmitting antenna and the receiving antenna are adjusted conveniently, so that they both obtain a 10dB impedance bandwidth and a large detection depth. 3. One host corresponds to multiple transceivers, and multiple measuring lines can be arranged at the same time to improve the detection radiation range. 4. The coupling degree between the transmitting antenna and the receiving antenna of the transceiver is low, the ability to resist external interference is strong, and the echo signal quality is good. 5. The mainframe box structure is firm and will not affect the working stability of the radar system. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the structure of a multi-channel tunnel defect detection ground penetrating radar system;

[0037] Figure 2 It is a schematic diagram of the internal structure of the host box;

[0038] Figure 3 It is a schematic diagram of the adjustable structure of the antenna inside the main body of the transceiver;

[0039] Figure 4 Schematic diagram of the upper structure inside the main body of the transceiver;

[0040] Figure 5 is a schematic diagram of the external structure of the transceiver housing;

[0041] Figure 6 It is a flow chart of the test and assembly method of the multi-channel tunnel defect detection ground penetrating radar system.

[0042] Wherein: 1. Mainframe, 2. Six-core coaxial bundled cable socket, 3. Transceiver, 4. DB8 aviation socket, 5. USB aviation socket, 6. Computer host, 7. Doppler radar, 101. USB aviation socket mounting hole, 102. DB8 aviation socket mounting hole, 103. Acquisition card, 104. Metal pressing sheet, 105. Power module, 106. Metal shell, 107. Timing control circuit board, 108. Six-core coaxial bundled cable mounting hole, 301. Transceiver cover, 302. Transceiver body, 302a. Fastening bolts, 302b. Antenna slot, 302c. Horizontal slide, 302d. Lower horizontal slide, 302e. Transmitting antenna, 302f. Receiving antenna, 302g. Ferrite horizontal absorbing material. DETAILED DESCRIPTION

[0043] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] The present invention provides a multi-channel tunnel ground penetrating radar system, such as Figure 1 , 2 , 3 and 4, including: a mainframe box 1 and multiple transceivers 3; the multi-channel tunnel ground penetrating radar system is used for non-contact detection of tunnel structural defects, and the distance between the system and the tunnel lining is 0.5-4m, which is not affected by the tunnel lining accessories and has guaranteed safety; it can be installed on a mechanical arm and assumed to be on a mobile device, and the monitoring speed is fast. Among them: the mainframe box 1 is connected to multiple transceivers 3, and is also connected to the Doppler radar 7 and the computer host 6;

[0045] The transceiver 3 includes: a transceiver body 302, an adjustable transceiver antenna structure, an antenna slot 302b, a transmitting antenna 302e, and a receiving antenna 302f, wherein: the transceiver body 302 is a box body with an upper and lower layer structure;

[0046] The transceiver antenna adjustable structure is arranged on the side wall in the lower layer of the transceiver body 302, and includes: an upper horizontal slide groove 302c, a lower horizontal slide groove 302d and an antenna card slot 302b;

[0047] The upper horizontal slide groove 302c is horizontally arranged and located on the lower inner side wall of the transceiver body 302 and at the top. The horizontal slide groove 302c is a group and is located on two opposite side walls on the left and right sides, and the end portion extends to the end portion of the side wall on which it is located;

[0048] The lower horizontal slide groove 302d is horizontally arranged at the bottom of the side wall where the upper horizontal slide groove 302c is located, and the end portion thereof extends to the end portion of the side wall where the lower horizontal slide groove 302d is located;

[0049] There are four antenna slots 302b, all vertically arranged, two by two located between the upper horizontal slots 302c and the lower horizontal slots 302d on the left and right sides, and all can slide forward and backward; the antenna slots 302b are divided into two groups front and back, the upper end of one group of antenna slots 302b carries the receiving antenna 302f, and the upper end of the other group carries the transmitting antenna 302e. The distance between the transmitting antenna 302e and the receiving antenna 302f is adjustable, and the distance is sufficient to obtain the best 10dB impedance bandwidth in the transceiver body 302.

[0050] The transceiver 3 is used for: its bottom is facing the detected part of the tunnel, and the pulse source radiates electromagnetic narrow pulse signals from the transmitting antenna 302e under the action of the trigger signal, and radiates from the bottom to the detected part of the tunnel; the receiving antenna 302f receives the electromagnetic echo signal, and is sampled and restored to a low-frequency radar echo signal by the sampling unit and output to the computer host computer 6.

[0051] like Figure 5 As shown, the upper and lower layers of the transceiver body 302 are separated by a horizontal partition, and a sampling unit and a pulse source are arranged on the upper layer of the transceiver body 302 and on the partition, the sampling unit is connected to the receiving antenna 302f, and the pulse source is connected to the transmitting antenna 302e. An antenna lead connection hole is provided on the horizontal partition, which is detachably fixed to the upper part of the boss provided with the antenna slot 302b inside the transceiver body.

[0052] Inside the transceiver body 302, the side walls at the lower part of the upper horizontal slide groove 302c and the lower part of the partition are covered with ferrite horizontal absorbing materials 302g.

[0053] The host box 1 is provided with an acquisition card 103, a power module 105 and a timing control circuit board 107, and a DB8 aviation socket 4 and a USB aviation socket 5 are provided on one side wall thereof;

[0054] The DB8 aviation socket 4 is used to connect to the Doppler radar 7, and the USB aviation socket 5 is connected to the computer host 6;

[0055] The power module 105 is connected to the power terminal of the six-core coaxial bundled cable socket 2, and is also connected to the acquisition card 103, the timing control circuit board 107 and the Doppler radar 7 for power supply; there are multiple six-core coaxial bundled cable sockets 2, which are arranged on a side wall of the transceiver body 302 and installed at intervals in the up and down directions.

[0056] The space inside the transceiver body 302 and the lower part of the upper horizontal slide groove 302c are filled with pearl cotton sheets for flexibly supporting and fixing the receiving antenna 302f and the transmitting antenna 302e.

[0057] The upper part of the transceiver body 302 is provided with an openable transceiver cover 301; the lower part of the transceiver cover 301 is integrally provided with a downwardly extending edge around the periphery, the edge is located inside the transceiver body 302, and its outer side wall is closely fitted with the inner side wall of the transceiver body 302; on the side walls of the four corners of the transceiver body 302, and located above the upper horizontal slide groove 302c, a transceiver cover fastening seat 302j is provided, and the transceiver cover fastening seat 302j is a strip-shaped protrusion. The four corners of the transceiver cover 301 and the transceiver body 302 are all arc-shaped.

[0058] A vertical partition parallel to the antenna surface is also provided inside the transceiver body 302 and between the receiving antenna 302f and the transmitting antenna 302e. The front and rear sides of the vertical partition are both covered with ferrite horizontal wave absorbing material 302g. The radar signal is radiated only in a specific bottom direction, not in other directions, and the external clutter signal does not come in. The front and rear sides of the vertical partition are both covered with ferrite horizontal wave absorbing material 302g to reduce the coupling between the receiving antenna 302f and the transmitting antenna 302e. The thickness of the ferrite horizontal wave absorbing material 302g is less than 2.5mm.

[0059] The acquisition card 103 and the power module 105 are each disposed in a metal housing 106, and a threaded hole is provided on the lower side wall of the metal housing 106;

[0060] Each metal shell 106 is fixed by a metal pressing plate 104 and installed on the bottom of the main chassis 1. The metal pressing plate 104 is a plate with connecting holes. The positions of the connecting holes are consistent with the positions of the threaded holes and are fixed by screws. The ends of the metal pressing plates 104 are fixedly connected to the bottom plate of the main chassis 1.

[0061] Both ends of each antenna slot 302b are connected to the upper horizontal slide slot 302c and the lower horizontal slide slot 302d through fastening bolts 302a.

[0062] Each metal shell 106 is fixed by a metal pressing sheet 104 and installed on the bottom of the mainframe case 1. The metal pressing sheet 104 is a plate with a connection hole. The position of the connection hole is consistent with the position of the threaded hole, and is fixed by screws, and the end of the metal pressing sheet 104 is fixedly connected to the bottom plate of the mainframe case 1. The metal pressing sheet 104 makes the acquisition card 103 and the power module 105 firmly connected to the metal shell 106, ensuring that the two devices will not work unstably due to external shaking during use. The lower surface of the metal pressing sheet 104 and the upper surface of the metal shell 106 with internal threads are 2mm apart when the flat head bolts are not connected to facilitate fixation.

[0063] The above-mentioned multi-channel tunnel ground penetrating radar system assembly test method is as follows: Figure 6As shown below:

[0064] Step s1. Performance test and assembly of transceiver 3, as follows:

[0065] Step s11 transceiver 3 performance test: in the transceiver body 302, and located on the lower side wall of the upper horizontal chute 302c affixed with ferrite horizontal absorbing material 302g; so that the antenna slot 302b is always perpendicular to the upper horizontal chute 302c and the lower horizontal chute 302d;

[0066] A vector network analyzer is used to observe the S parameter curve characteristics of the transmitting antenna 302e and the receiving antenna 302f respectively until the transmitting antenna 302e and the receiving antenna 302f both achieve the best 10dB impedance bandwidth in the transceiver body 302; the RF signal is led out from the transceiver antenna using a lead, and a 0-3GHz frequency band SMA coaxial cable with an externally loaded ferrite ring is used as the RF signal lead of the transceiver antenna during assembly.

[0067] Step s12 transceiver 3 assembly, as follows: in the transceiver body 302, the space below the upper horizontal chute 302c is filled with pearl cotton sheet material for supporting and fixing the transmitting antenna 302e and the receiving antenna 302f; the transceiver cover 301 and the transceiver body 302 are tightly fitted;

[0068] Step s2. Communication test and assembly of the host box 1, as follows:

[0069] Step s21 host box 1 communication test: the host box 1 and the USB aviation socket 5 connected to the test acquisition card 103 communication function is normal, the normal execution;

[0070] Step s22. The six branches of the six-core coaxial bundled cable are respectively connected to the corresponding ports of the acquisition card 103, the power module 105 and the timing control circuit board 107 in the host box 1 to realize data interaction with the transceiver 3 and power supply and reception;

[0071] Step s3. Multi-channel whole machine joint debugging test, as follows:

[0072] The input signal of Doppler radar 7 is transmitted into the mainframe case 1 through the cable and DB8 aviation socket 4 and connected to the acquisition card 103; multiple transceivers 3 are connected to the mainframe case 1 through a six-core coaxial bundled cable, and the radar echo data collected by the acquisition card 103 is connected to the computer host computer 6 through the USB aviation socket 5. The computer host computer 6 is used to simultaneously display the ground penetrating radar echo waveforms of multiple channels, and observe whether the displayed echo waveform changes in real time when the detection target moves in the time sampling mode and the distance sampling mode respectively, to ensure that the data processing rate meets the real-time display and storage requirements.

[0073] System testing and assembly are carried out step by step in accordance with the laws of electromagnetic physics and the electrical index requirements of the equipment to ensure the normal functions of all parts of the system. At the same time, the adjustable structure of the transceiver antenna and the programming of the debugging steps avoid repeated disassembly and assembly, shortening the testing and debugging time.

Claims

1. A multi-channel tunnel ground penetrating radar system, characterized in that: include: A main housing (1) and a plurality of transceivers (3); the multi-channel tunnel ground penetrating radar system is used for non-contact detection of tunnel structural defects; Wherein: the mainframe housing (1) is connected to a plurality of transceivers (3), and is also connected to a Doppler radar (7) and a computer host computer (6); The transceiver (3) comprises: a transceiver body (302), an adjustable transceiver antenna structure, an antenna slot (302b), a transmitting antenna (302e), and a receiving antenna (302f), wherein: The transceiver body (302) is a box with two layers; The transceiver antenna adjustable structure is arranged on the side wall in the lower layer of the transceiver body (302), and comprises: an upper horizontal slide groove (302c), a lower horizontal slide groove (302d) and an antenna clamping groove (302b); The upper horizontal slide groove (302c) is arranged horizontally, located on the inner side wall of the lower layer of the transceiver body (302), and is located at the top. The horizontal slide groove (302c) is a group, located on two opposite side walls on the left and right, and the end portion extends to the end portion of the side wall on which it is located; The lower horizontal slide groove (302d) is arranged horizontally and is located at the bottom of the side wall where the upper horizontal slide groove (302c) is located, and the end portion extends to the end portion of the side wall where the lower horizontal slide groove (302d) is located; There are four antenna slots (302b), all of which are vertically arranged, located in pairs between the upper horizontal slide slot (302c) and the lower horizontal slide slot (302d) on the left and right sides, and all of which can slide forward and backward; the antenna slots (302b) are divided into two groups front and back, the upper end of one group of antenna slots (302b) supports the mounting of a receiving antenna (302f), and the upper end of the other group of antenna slots supports the mounting of a transmitting antenna (302e).

2. A multi-channel tunnel ground penetrating radar system as claimed in claim 1, characterized in that: The upper and lower layers of the transceiver body (302) are separated by a horizontal partition. A sampling unit and a pulse source are arranged on the upper layer of the transceiver body (302) and on the partition. The sampling unit is connected to the receiving antenna (302f), and the pulse source is connected to the transmitting antenna (302e).

3. A multi-channel tunnel ground penetrating radar system as claimed in claim 2, characterized in that: Inside the transceiver body (302), the side wall located at the lower part of the upper horizontal slide groove (302c) and the lower part of the partition are covered with ferrite horizontal wave absorbing material (302g).

4. A multi-channel tunnel ground penetrating radar system as claimed in claim 3, characterized in that: The host case (1) is provided with an acquisition card (103), a power module (105) and a timing control circuit board (107), and a DB8 aviation socket (4) and a USB aviation socket (5) are provided on one side wall thereof; The DB8 aviation socket (4) is used to connect to the Doppler radar (7), and the USB aviation socket (5) is connected to the computer host (6); The power module (105) is connected to the power terminal of the six-core coaxial bundled cable socket (2), and is also connected to the acquisition card (103), the timing control circuit board (107) and the Doppler radar (7) for power supply; the six-core coaxial bundled cable socket (2) is in plurality, arranged on a side wall of the transceiver body (302), and installed at intervals in the up-down direction.

5. A multi-channel tunnel ground penetrating radar system as claimed in claim 4, characterized in that: The space inside the transceiver body (302) and located below the upper horizontal slide groove (302c) is filled with pearl cotton sheet material for flexibly supporting and fixing the receiving antenna (302f) and the transmitting antenna (302e).

6. A multi-channel tunnel ground penetrating radar system as claimed in claim 5, characterized in that: The upper part of the transceiver body (302) is provided with an openable transceiver cover (301); the lower part of the transceiver cover (301) is integrally provided with a circumferentially extending edge extending downward, the edge is located inside the transceiver body (302), and its outer side wall is tightly fitted with the inner side wall of the transceiver body (302); the four corners of the transceiver cover (301) and the transceiver body (302) are all arc-shaped.

7. A multi-channel tunnel ground penetrating radar system as claimed in claim 6, characterized in that: A vertical partition parallel to the antenna surface is also provided in the transceiver body (302) and between the receiving antenna (302f) and the transmitting antenna (302e), and ferrite horizontal wave absorbing material (302g) is applied to the front and rear sides of the vertical partition.

8. A multi-channel tunnel ground penetrating radar system as claimed in claim 7, characterized in that: The acquisition card (103) and the power module (105) are each arranged in a metal shell (106), and a threaded hole is provided on the lower side wall of the metal shell (106); Each of the metal shells (106) is fixed by a metal pressing sheet (104) and installed on the bottom of the mainframe case (1). The metal pressing sheet (104) is a plate body with a connecting hole formed thereon. The position of the connecting hole is consistent with the position of the threaded hole and is fixed by screws inserted therein. The end of the metal pressing sheet (104) is fixedly connected to the bottom plate of the mainframe case (1).

9. A multi-channel tunnel ground penetrating radar system as claimed in claim 8, characterized in that: Both ends of each antenna slot (302b) are connected to the upper horizontal slide groove (302c) and the lower horizontal slide groove (302d) via fastening bolts (302a).

10. A method for assembling and testing a multi-channel tunnel ground penetrating radar system according to any one of claims 1 to 9, characterized in that: as follows: Step s1. The transceiver (3) is tested and assembled as follows: Step s11. Performance test of the transceiver (3): a ferrite horizontal absorbing material (302g) is applied inside the transceiver body (302) and on the side wall at the lower part of the upper horizontal slide groove (302c), the lower part of the transceiver cover (301), and the front and rear side surfaces of the vertical partition; the antenna slot (302b) is always perpendicular to the upper horizontal slide groove (302c) and the lower horizontal slide groove (302d); Using a vector network analyzer, respectively observing the S parameter curve characteristics of the transmitting antenna (302 e) and the receiving antenna (302 f), until the transmitting antenna (302 e) and the receiving antenna (302 f) both achieve an optimal 10 dB impedance bandwidth in the transceiver body (302); Step s12. The transceiver (3) is assembled as follows: in the transceiver body (302), the space below the upper horizontal slide groove (302c) is filled with pearl cotton sheet material for supporting and fixing the transmitting antenna (302e) and the receiving antenna (302f); the sampling unit is connected to the receiving antenna (302f) and the pulse source is connected to the transmitting antenna (302e), and the transceiver cover (301) and the transceiver body (302) are tightly buckled and fitted; Step s2. The host box (1) is tested and assembled for communication, as follows: Step s21. The host box (1) communication test: connect the host box (1) to the USB aviation socket (5), test whether the communication function of the acquisition card (103) is normal, and execute the next step normally; Step s22. The six branches of the six-core coaxial bundled cable are respectively connected to the corresponding ports of the acquisition card (103), the power module (105) and the timing control circuit board (107) in the host box (1) to realize data interaction with the transceiver (3) and power supply and reception; Step s3. Multi-channel whole machine joint debugging test, as follows: The input signal of the Doppler radar (7) is transmitted into the mainframe housing (1) through a cable and a DB8 aviation socket (4) and connected to the acquisition card 103; a plurality of the transceivers (3) are connected to the mainframe housing (1) through a six-core coaxial bundled cable; the radar echo data collected by the acquisition card (103) is connected to a computer host computer (6) through a USB aviation socket (5); the computer host computer (6) is used to simultaneously display the ground penetrating radar echo waveforms of multiple channels; and when the detected target moves, the displayed echo waveform is observed in time sampling mode and distance sampling mode to see whether it changes in real time, thereby ensuring that the data processing rate meets the real-time display and storage requirements.

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