A real-time optical fiber wear detection system under the shield machine normal pressure cutterhead

Abstract

The present invention discloses a real-time optical fiber wear detection system under the normal pressure cutterhead of a shield machine, which includes a cutter barrel, a sensor detection module, a signal demodulation and transmission unit, and a control unit. The sensor detection modules inside and outside the cutter barrel include a wear detection device, and the wear detection device includes an optical fiber wear detection cutter and an optical fiber wear sensor installed in the optical fiber wear detection cutter. The optical fiber wear sensor includes an outer layer component and a chirped optical fiber grating embedded in the outer layer component. The present invention can detect the wear data of the roller cutter in real time, find that the roller cutter has been worn and worn eccentrically, and improve the construction efficiency.

Description

Technical Field

[0001] The invention belongs to the field of shield machine equipment, and in particular relates to a real-time optical fiber wear detection system under a normal pressure cutterhead of a shield machine. Background Art

[0002] With the advent of the 21st century, my country's urbanization process has accelerated, urban construction has developed rapidly, and the scale of cities has continued to increase. The utilization and development of urban underground space has become a global development trend and a symbol of urban modernization. During construction, shield cutters often suffer from severe wear, breakage, and falling off, which leads to engineering accidents, has a serious impact on the construction period and cost of the entire project, and even threatens human life. Therefore, it is of great significance to study the wear of shield cutters to improve the working efficiency of shield machines. The existing technology for detecting cutter wear can only detect the wear of the cutter through hydraulic detection and cannot detect the value in real time. The resistance detection method is seriously affected by temperature and electromagnetic interference. Summary of the invention

[0003] The purpose of the invention is to provide a real-time optical fiber wear detection system under the normal pressure cutterhead of a shield machine.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a real-time detection system for optical fiber wear under the normal pressure cutterhead of a shield machine, which includes a cutter barrel, a sensor detection module, a signal demodulation and transmission unit, and a control unit. The sensor detection modules inside and outside the cutter barrel, the sensor detection module includes a wear detection device, the wear detection device includes an optical fiber wear detection knife, an optical fiber wear sensor installed in the optical fiber wear detection knife, and the optical fiber wear sensor includes an outer layer component and a chirped optical fiber grating embedded in the outer layer component.

[0005] Optimized, the sensor detection module also includes a protective oil pipe in the knife barrel, a second pair of wires on the knife cover, a wall penetration piece on the outside of the knife cover, a ball valve, and a middle oil pipe connecting the ball valve and the optical fiber distribution box.

[0006] Optimally, the wear detection device also includes a fixing screw, a fixing thread and a connecting external thread.

[0007] Optimally, the knife barrel is provided with a first anti-collision block, a second anti-collision block and a third anti-collision block for protecting the optical fiber wear detection knife, and the outermost end surfaces of the first anti-collision block, the second anti-collision block and the third anti-collision block are flush with the outermost end surface of the optical fiber wear detection knife.

[0008] Furthermore, a through hole is provided on the knife cover, one end of the reducer thread is screwed on the through hole on the knife cover, and a first sealing ring is installed in the groove of the reducer thread to seal the reducer thread and the knife cover; a reducer inner ring is provided inside the reducer inner thread, which divides the thread inside the reducer inner thread into two sections of thread with different inner diameters, and the thread with smaller inner diameter is connected to the other end of the reducer thread, and a second sealing ring is provided inside the reducer inner thread, and the second sealing ring seals the end of the reducer thread screwed into the reducer inner thread; a pressure cover is provided in the reducer inner thread and is located on the side with larger inner diameter, and it includes a left end cover and a right end cover which is coaxially connected to the left end cover and has an outer diameter smaller than the left end cover, the right end cover is passed through the reducer inner ring and pressed against the second sealing ring, the first pair of threads are screwed into the end with larger inner diameter of the reducer inner thread, and a first sealing ring for sealing the reducer inner thread is installed in its groove, and the other end of the first pair of threads is connected to a ball valve.

[0009] Furthermore, the control unit includes a signal converter and a computer, and the signal demodulation and transmission unit also includes an optical fiber demodulation wireless transmitter, an optical fiber distribution box, a wireless receiving module, a central swivel joint, a slip ring inside the central swivel joint, a 24V power supply cable of the wireless receiving module, a connecting cable between the wireless receiving module and the signal converter in the driver's cab, and a connecting cable between the wireless receiving module and the central swivel joint slip ring. After the optical fiber outlet of the optical fiber wear sensor passes through the inside of the normal pressure knife cylinder, it passes through the inside of the reducer wire, puts on a second sealing ring, and then passes through the inside of the reducer inner wire; The paired pressure caps lock and fix the optical fibers, and the optical fiber outlets of the optical fiber wear sensors pass through the inside of one side of the first pair of wire grooves, and are connected to the optical fiber distribution box after passing through the ball valve. The optical fiber distribution box is connected to several optical fiber wear sensors; the ball valve on the normal pressure knife cylinder is connected to the oil pipe and the oil pipe joint on the optical fiber distribution box to protect the optical fiber outlets of the optical fiber wear sensor; the optical fiber distribution box is connected to the optical fiber demodulation wireless transmitter via the MPO optical fiber, and the outside of the MPO optical fiber is protected by the oil pipe to transmit the signal of the optical fiber wear sensor to the optical fiber demodulation wireless transmitter.

[0010] Furthermore, the optical fiber demodulation wireless transmitter is composed of an optical fiber demodulation module, a wireless transmission module and a battery module; the optical fiber demodulation module demodulates the optical fiber wavelength data from the signal collected by the optical fiber wear sensor; the optical fiber demodulation module transmits the demodulated wavelength data to the wireless transmission module, and the wireless transmission module wirelessly transmits the data to the wireless receiving module through data compression.

[0011] Furthermore, the wireless receiving module and the optical fiber demodulation wireless transmitter have both wired and wireless communication modes, and use dual-bus technology for power supply and wired communication. The optical fiber demodulation wireless transmitter and the wireless receiving module have both wired communication interfaces and use a DC 24V power supply system. The negative pole of the DC 24V power supply system is grounded through the shield shell, and the positive pole is connected to the cable.

[0012] Due to the application of the above technical scheme, the present invention has the following advantages compared with the prior art: the present invention can detect the wear data of the hob in real time, find that the hob has been worn and worn unevenly, and improve the construction efficiency; the chirped fiber grating is gradually worn down by wearing, thereby improving the sensing accuracy of the wear sensor, and the scanning interferometer and the second photodetector establish a reference microwave photon link for measuring the phase change disturbance of the radio frequency signal caused by the optical fiber, thereby eliminating the DCF (dispersion compensation) disturbance caused by environmental factors such as temperature fluctuations and mechanical vibrations in the measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a system architecture diagram of the present invention;

[0014] Figure 2 A schematic diagram of a wear detection knife of the present invention;

[0015] Figure 3 It is a schematic diagram of the optical fiber wear sensor of the present invention;

[0016] Figure 4 It is a schematic diagram of the wear detection knife anti-collision block of the present invention;

[0017] Figure 5 It is a schematic diagram of the wall penetration member of the present invention;

[0018] Figure 6 It is a communication transmission flow chart of the present invention;

[0019] Figure 7 Schematic diagram of wavelength analysis of the chirped optical fiber of the present invention. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the embodiments shown in the accompanying drawings.

[0021] like Figure 1 As shown, the optical fiber wear detection system under the normal pressure cutterhead of the shield machine includes sensor detection modules installed inside and outside the cutter barrel, a signal demodulation and transmission system in the normal pressure chamber, and a control system in the driver's cab.

[0022] The sensor detection module inside and outside the knife barrel includes a wear detection device, a protective oil pipe 2 in the knife barrel 3, a second pair of wires 33 on the knife cover 32, a wall penetration piece 4 on the outside of the knife cover 32, a ball valve 5, and a middle oil pipe 6 connecting the ball valve and the optical fiber distribution box 7.

[0023] The signal demodulation and transmission system inside and outside the atmospheric pressure warehouse includes a fiber optic demodulation wireless transmitter 9, a fiber optic distribution box 7, a wireless receiving module 14, a central swivel joint 15, a slip ring 37 inside the central swivel joint, a 24V power supply cable 34 of the wireless receiving module 14, a connecting cable 35 between the wireless receiving module 14 and the signal converter 16 in the driver's cab, and a connecting cable 36 between the wireless receiving module 14 and the central swivel joint slip ring.

[0024] The control system in the operating room includes a signal converter 16 and a computer 17.

[0025] The wear detection device is composed of an optical fiber wear detection knife 1, an optical fiber wear sensor 18, a fixing small screw 19, a fixing thread 21 and a connecting external thread 31; the interior of the head of the optical fiber wear detection knife 1 is a threaded hole for installing the optical fiber wear sensor 18, and the interior behind the threaded hole is a through hole for the optical fiber of the optical fiber wear sensor 18 to output the optical fiber; the optical fiber wear sensor 18 is screwed on the knife head of the optical fiber wear detection knife 1 and is flush with the knife head; two fixing small screws 19 are screwed on the knife head of the optical fiber wear detection knife 1 to fix and lock the optical fiber wear sensor 18 to prevent the optical fiber wear sensor 18 from loosening or even falling off due to vibration.

[0026] The blade diameter part 38 of the optical fiber wear detection knife 1 is welded on the knife barrel 3; the optical fiber wear detection knife 1 is fixed on the knife seat in the normal pressure knife barrel by screwing the fixing nut on the fixing thread 21 at the rear of the optical fiber wear detection knife 1 to prevent the optical fiber wear detection knife 1 from falling off due to excessive impact; the optical fiber wear detection knife 1 can be replaced after being worn to a certain extent.

[0027] The outer component 18 is an ordinary iron cylinder with a threaded exterior. A through hole 40 is drilled at the axis of the outer component 18, and a chirped fiber grating 0 is embedded in the through hole 40 and fixed and packaged with sealant. An optical fiber outlet line 39 is led out from the outside, and the wear of the tool is estimated by detecting the spectral width of the reflected light of the chirped fiber grating 0.

[0028] The principle of chirped fiber grating detection is that the grating period of the chirped fiber grating is not a constant, but varies along the axial direction. Different grating periods correspond to different Bragg reflection wavelengths. Incident light of different wavelengths is reflected at different positions of the chirped fiber grating. In this way, light of different wavelengths will produce the required reflected light spectrum after being reflected by the chirped fiber grating. The wear detection sensor developed using this principle can correspond the demodulated reflected light spectrum width to the length of the chirped fiber grating. As the chirped fiber grating decreases, the width of the reflected light spectrum will also decrease accordingly, so the wear amount can be calculated based on the reflected light spectrum width.

[0029] The optical fiber wear detection knife 1 is protected by three anti-collision blocks on the knife barrel 3, including a first anti-collision block 22, a second anti-collision block 23 and a third anti-collision block 24; the three anti-collision blocks are processed after being welded to the normal pressure knife barrel; the height of the three anti-collision blocks is flush with the height of the optical fiber wear detection knife 1; in order to more accurately detect the wear condition of the optical fiber wear detection knife 1, the heads of the three anti-collision blocks are chamfered; the second anti-collision block 23 mainly protects the optical fiber wear detection knife 1 from the impact of the knife disc turning left, and the first anti-collision blocks 22 and 24 mainly protect the optical fiber wear detection knife 1 from the impact of the knife disc turning right.

[0030] The wear detection device has three sealing measures in total; first, sealant is injected into the through hole 20 in the optical fiber wear detection knife of the optical fiber wear sensor 18 to prevent water from seeping in from the sensor head; second, sealing protection is performed outside the normal pressure knife barrel through the wall penetration piece 4 to prevent water from leaking into the normal pressure bin due to factors such as damage to the protective oil pipe 2 of the optical fiber outlet line 39; third, a ball valve 5 is connected to the other end of the wall penetration piece 4 for protection. If water seeps out, the ball valve 5 is directly closed.

[0031] The protective oil pipe 2 in the knife barrel is connected to the connecting external thread 31 of the optical fiber wear detection knife 1, and the other end is connected to the second pair of threads 33 in the knife cover 32; after the optical fiber wear sensor 18 comes out from the tail of the optical fiber wear detection knife 1, it passes through the protective oil pipe 2 to the outside of the knife barrel 3.

[0032] The wall penetration component 4 includes a first pair of threads 251 , a first sealing ring 26 , a gland 271 , a reducing inner thread 28 , a second sealing ring 29 , and a reducing pair of threads 301 .

[0033] The knife cover 32 is provided with a through hole, one end of the reducer thread 301 is screwed on the through hole on the knife cover 32, and the first sealing ring 26 is installed in the groove of the reducer thread 301 to seal the reducer thread 301 and the knife cover 32; the reducer inner thread 28 is provided with a reducer inner ring, which divides the thread inside the reducer inner thread 28 into two sections of threads with different inner diameters, and the thread with a smaller inner diameter is connected to the other end of the reducer thread 301, and the second sealing ring 29 is provided inside the reducer inner thread 28, and the second sealing ring 29 is used to seal the reducer thread 301. The end of the variable diameter pair of wires 301 inserted into the variable diameter internal wire 28 is sealed; the pressure cap 271 is arranged in the variable diameter internal wire 28 and is located on the side with a larger inner diameter, which includes a left end cap 27 and a right end cap 272 coaxially connected to the left end cap 27 and having an outer diameter smaller than the left end cap 27, and the right end cap 272 is penetrated in the variable diameter inner ring and pressed against the second sealing ring 29; the first pair of wires 251 is tightened in the end with a larger inner diameter of the variable diameter internal wire 28, and the first sealing ring 26 for sealing the variable diameter internal wire 28 is installed in its groove. The right end of the first pair of wires 251 is connected to the variable diameter internal wire 28, and the left end thereof is connected to a ball valve.

[0034] The first pair of wires 251 includes a first body portion 25 that is generally tubular, a first annular boss 252 that is disposed on the circumference of the first body portion 25, the first boss 252 is coaxially disposed with the first body portion 25, and the groove of the first pair of wires 251 is disposed on the end surface of the first boss 252 that faces the reduced diameter inner wire 28. The reduced diameter pair of wires 301 includes a second body portion 302 that is generally stepped tubular, a second annular boss 30 that is disposed on the circumference of the second body portion 302, the second boss 30 is coaxially disposed with the second body portion 302, and the groove of the reduced diameter pair of wires 301 is disposed on the end surface of the second boss 30 that faces the blade cover 32.

[0035] After the optical fiber output line 39 of the optical fiber wear sensor 18 passes through the inside of the knife barrel 3, it passes through the inside of the reducer wire 301 and is covered with the second sealing ring 29; the second sealing ring 29 is used to seal and protect the inside of the oil pipe 2 to prevent water from flowing out of the knife barrel after entering. The optical fiber output line 39 of the optical fiber wear sensor 18 then passes through the inside of the reducer inner wire 28; the optical fiber is locked and fixed by two pressure caps 271, and the optical fiber output line 39 of the optical fiber wear sensor 18 passes through the inside of one side of the groove of the first pair of wires 251, and passes through the ball valve 5 to connect to the optical fiber distribution box 7.

[0036] The inner diameter of the pressure cover 271, the inner diameter of the second sealing ring 29 and the outer diameter of the optical fiber outlet line 39 of the optical fiber wear sensor 18 are consistent.

[0037] The optical fiber distribution box 7 can connect 8 optical fiber wear sensors 18; the ball valve 5 on the knife barrel 3 is connected to the oil pipe joint on the middle oil pipe 6 and the optical fiber distribution box 7 to protect the optical fiber outlet 39 of the optical fiber wear sensor 18; the optical fiber distribution box 7 is connected to the optical fiber demodulation wireless transmitter 9 through the MPO optical fiber, and the outside of the MPO optical fiber is protected by the oil pipe 8 to transmit the signal of the optical fiber wear sensor 18 to the optical fiber demodulation wireless transmitter 9.

[0038] The optical fiber demodulation wireless transmitter 9 is composed of an optical fiber demodulation module 12, a wireless transmission module 11 and a battery module 10; the optical fiber demodulation module 12 demodulates the optical fiber wavelength data from the signal collected by the optical fiber wear sensor 18; the optical fiber demodulation module 12 transmits the demodulated wavelength data to the wireless transmission module 11, and the wireless transmission module 11 wirelessly transmits the data to the wireless receiving module 14 by data compression.

[0039] The data compression method is to compress and transmit the wavelength data of an optical fiber wear sensor 18. By analyzing the data type structure characteristics of the optical fiber wear sensor 18 demodulated by the optical fiber demodulation wireless transmitter 9, it is found that the optical fiber data is a number of peak data, and a large amount of data 0 is used between the peaks to represent the time information; the data volume of an optical fiber wear sensor 18 is about 10,000 bytes. According to the analyzed data type structure characteristics, the shape of the peak, the peak position and other information are described in a data formula language. There is no need to store the information of each point, only the basic parameter information of the wavelength needs to be stored. The wireless transmission data is reduced by about 80%, which reduces the occupancy of a large number of channels and the communication time.

[0040] The wireless receiving module 14 and the optical fiber demodulation wireless transmitter 9 have both wired and wireless communication modes; and the working mode is mutual backup; the power supply mode also adopts a dual redundant mode of external power supply and internal battery power supply; the optical fiber demodulation wireless transmitter 9 adopts a wireless communication mode with a radio wave frequency of 433MHz, and the wireless transmission antenna is built-in; the wired communication mode is a two-wire 485 communication interface MODBUS protocol; and two-bus technology is used for power supply and wired communication.

[0041] The dual-bus technology combines the power supply and signal lines into one, that is, the communication line and the power line are combined into one through the power carrier technology, and the digital signal is amplified and loaded on the power signal for transmission, making the communication networking simple and convenient; the wireless receiving module 14 is connected to the optical fiber demodulation wireless transmitter 9 in the normal pressure warehouse through the cable 36 via the DC 24V power supply slip ring 37 in the central rotary joint 15, and all optical fiber demodulation wireless transmitters 9 are connected in parallel for networking communication and power supply; the communication mode of the main station wireless receiving module 14 and several optical fiber demodulation wireless transmitters 9 from the station is polling mode; the cable in the normal pressure warehouse is protected by the oil pipe 13.

[0042] The dual-bus technology has a dual redundant mode, and the optical fiber demodulation wireless transmitter 9 and the wireless receiving module 14 both have a wired communication interface. In actual technical applications, the power cord adopts a DC 24V power supply system, in which the negative pole adopts the shield shell grounding technology, and the positive pole is connected by a cable; in this way, only one cable is used for connection in actual wiring, which greatly improves the system reliability; in actual applications, in order to improve the reliability of the slip ring 37, two slip rings are used, one as a backup, that is, the wireless receiving module 14 uses the DC 24V power supply slip ring 37 in the center slewing joint 15 and the optical fiber demodulation wireless transmitter 9 in the normal pressure chamber. The cable has two cores, one for use and one for backup, which improves the reliability of wired communication.

[0043] The optical fiber demodulation wireless transmitter 9 and the wireless receiving module 14 have both wired and wireless communication modes; in order to maintain the stability of large data wireless transmission data, the communication process is: the optical fiber demodulation wireless transmitter 9 sends data wirelessly, and the wireless receiving module 14 verifies its data. If the wireless communication mode fails 5 times, the wireless receiving module 14 automatically requests the wired communication mode for data transmission; if the wired communication data transmission fails 5 times, the upper computer interface alarms the communication abnormality and proceeds to the next communication cycle.

[0044] The optical fiber demodulation wireless transmitter 9 has two power supply modes: battery module 10 power supply and external power supply power supply. The battery module 10 is a backup power supply. When the external power supply is interrupted, the battery module 10 can provide power for communication of the optical fiber demodulation wireless transmitter 9. When the external power supply is restored and the power in the battery module 10 is low, the battery module 10 can be charged until it is fully charged and the optical fiber demodulation module 12 and the wireless transmission module 11 can be powered.

[0045] The wireless receiving module 14 is installed inside the normal pressure warehouse, on one side of the central rotary joint; the 24V power supply of the wireless receiving module 14 is directly taken from the control box in the normal pressure warehouse, and the connecting cable 35 between the wireless receiving module 14 and the computer passes through the special threading hole of the normal pressure warehouse and communicates with the computer 17; the MODBUS communication protocol is used for data transmission between the wireless receiving module 14 and the computer 17.

[0046] The wireless receiving module 14 can receive data transmitted by several optical fiber demodulation wireless transmitters 9; the internal circuit design of the wireless receiving module 14, the connecting cables between the wireless receiving module 14 and the computer 17, and the number of signal converters 16 are designed according to the number of optical fiber demodulation wireless transmitters 9.

[0047] The control system in the driver's cab receives the wavelength data from the wireless receiving module 14. The upper computer analyzes the wavelength data through an algorithm and calculates the wear of the tool, which is displayed on the software interface at the same time, making it convenient for construction personnel to decide whether to replace the tool based on the wear.

[0048] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A real-time optical fiber wear detection system under the normal pressure cutterhead of a shield machine, characterized by: It includes a knife barrel, a sensor detection module, a signal demodulation and transmission unit, and a control unit. The sensor detection modules inside and outside the knife barrel, the sensor detection module includes a wear detection device, the wear detection device includes an optical fiber wear detection knife, an optical fiber wear sensor installed in the optical fiber wear detection knife, the optical fiber wear sensor includes an outer layer component, a chirped optical fiber grating embedded in the outer layer component; the sensor detection module also includes a protective oil pipe in the knife barrel, a second pair of wires on the knife cover, a wall-penetrating piece on the outside of the knife cover, a ball valve, and a middle oil pipe connecting the ball valve and the optical fiber distribution box; the wall-penetrating piece includes a first pair of wires, a first sealing ring, a pressure cover, a reducing inner wire, a second sealing ring, and a reducing pair of wires; a through hole is provided on the knife cover, one end of the reducing pair of wires is screwed on the through hole on the knife cover, and the first sealing ring is installed in the groove of the reducing pair of wires, so that the reducing pair of wires The reducing inner thread and the knife cover are sealed; a reducing inner ring is provided inside the reducing inner thread, which divides the thread inside the reducing inner thread into two sections of thread with different inner diameters, and the thread with smaller inner diameter is connected to the other end of the reducing inner thread, and a second sealing ring is provided inside the reducing inner thread, and the second sealing ring seals the end of the reducing inner thread screwed into the reducing inner thread; a pressure cover is provided in the reducing inner thread and is located on the side with larger inner diameter, and comprises a left end cover and a right end cover which is coaxially connected to the left end cover and has an outer diameter smaller than that of the left end cover, the right end cover is passed through the reducing inner ring and pressed against the second sealing ring, the first pair of threads are tightened in the end with larger inner diameter of the reducing inner thread, and a first sealing ring for sealing the reducing inner thread is installed in its groove, and the other end of the first pair of threads is connected to a ball valve; the wear detection device also comprises a fixing screw, a fixing thread and a connecting external thread.

2. The optical fiber wear real-time detection system under the shield machine normal pressure cutterhead according to claim 1 is characterized by: The knife barrel is provided with a first anti-collision block, a second anti-collision block and a third anti-collision block for protecting the optical fiber wear detection knife. The outermost end surfaces of the first anti-collision block, the second anti-collision block and the third anti-collision block are flush with the outermost end surface of the optical fiber wear detection knife.

3. The optical fiber wear real-time detection system under the shield machine normal pressure cutterhead according to claim 1 is characterized by: The control unit includes a signal converter and a computer, and the signal demodulation and transmission unit also includes an optical fiber demodulation wireless transmitter, an optical fiber distribution box, a wireless receiving module, a center rotary joint, a slip ring inside the center rotary joint, a 24V power supply cable of the wireless receiving module, a cable connecting the wireless receiving module and the signal converter in the driver's cab, and a cable connecting the wireless receiving module and the center rotary joint slip ring. After the optical fiber outlet of the optical fiber wear sensor passes through the inside of the normal pressure knife barrel, it passes through the inside of the reducer wire and is covered with a second sealing ring, and then passes through the inside of the reducer inner wire; the paired pressure caps lock and fix the optical fiber, and the optical fiber outlet of the optical fiber wear sensor passes through the inside of one side of the first pair of wire grooves, and is connected to the optical fiber distribution box after passing through the ball valve. The optical fiber distribution box is connected to several optical fiber wear sensors; the ball valve on the normal pressure knife barrel is connected to the oil pipe joint on the optical fiber distribution box through the oil pipe to protect the optical fiber outlet of the optical fiber wear sensor; the optical fiber distribution box is connected to the optical fiber demodulation wireless transmitter through the MPO optical fiber, and the outside of the MPO optical fiber is protected by the oil pipe to transmit the signal of the optical fiber wear sensor to the optical fiber demodulation wireless transmitter.

4. The optical fiber wear real-time detection system under the shield machine normal pressure cutterhead according to claim 3 is characterized by: The optical fiber demodulation wireless transmitter is composed of an optical fiber demodulation module, a wireless transmission module and a battery module; the optical fiber demodulation module demodulates the optical fiber wavelength data from the signal collected by the optical fiber wear sensor; the optical fiber demodulation module transmits the demodulated wavelength data to the wireless transmission module, and the wireless transmission module wirelessly transmits the data to the wireless receiving module by data compression.

5. The optical fiber wear real-time detection system under the shield machine normal pressure cutterhead according to claim 3 is characterized by: The wireless receiving module and the optical fiber demodulation wireless transmitter have both wired and wireless communication modes, and use dual-bus technology for power supply and wired communication. The optical fiber demodulation wireless transmitter and the wireless receiving module have both wired communication interfaces and use a DC 24V power supply system. The negative pole of the DC 24V power supply system is grounded through the shield shell, and the positive pole is connected to the cable.

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