Please select the most similar patent number from A, B, C and D. Which number is?
The present invention relates to a system for dynamically monitoring roadway roof separation based on a fibre grating and a pre-warning method, which belongs to the field of mine safety monitoring. Three parts, i.e., a ground data processing and control sub-system, a downhole data transmission communication sub-system and a downhole sensing data collecting sub-system are comprised: the ground data processing and control sub-system is placed in a ground control centre room, and is composed of a ground upper master monitoring computer, a fibre grating demodulation apparatus and a power supply; the downhole data transmission communication sub-system is composed of a mining transmission fibre and a fibre junction box; and the downhole sensing data collecting sub-system comprises at least one apparatus for monitoring fibre grating roof separation. The real-time online dynamic consecutive measurement of roof separation is realized, a transformation circumstance of a roadway surrounding rock is obtained, and the rationality of a bolting support parameter is verified. Once the pre-warning threshold of separation is exceeded, a pre-warning signal can be sent correctly, so that measures can be taken in time, and roof collapse can be prevented, which is of great importance for the outer roof separation size and the roadway stability in an anchorage zone.
A: Disclosed is a fiber grating intelligent coal-rock identification device for a shearer drum. The fiber grating intelligent coal-rock identification device comprises the shearer drum; a fiber grating acceleration sensor is fixedly provided on the shearer drum, the fiber grating acceleration sensor is electrically connected to a fiber grating demodulator, the fiber grating demodulator is electrically connected to a computer, the computer is electrically connected to a signal receiver, and the signal receiver is connected to an oil pump motor for controlling the drum to move. According to the present invention, vibration signals can be effectively transmitted to a computer data processing system in time, and a curve graph is generated; real-time monitoring is achieved, the precision is high, interference of the severe environment of a coal face is avoided, stable real-time data is provided for a shearer lifting control system, deployment and maintenance are easy, and cost is low.
B: An online temperature monitoring system for a deep well-type grounding electrode, comprising a temperature measuring optical cable (1) that extends underground, a temperature demodulation instrument (2), a communication optical cable (3), an optical fiber grating thermometer (4), a temperature calibration box (5), a temperature calibration optical cable (6), a wireless transmission module (7), a power supply module (8) and a processor (9). An end of the temperature measuring optical cable (1) that extends underground is connected to the optical fiber grating thermometer (4), and the other end of the temperature measuring optical cable (1) extends out of a well opening and is connected to an end of the temperature calibration optical cable (6); the other end of the temperature calibration optical cable (6) is connected to an end of the communication optical cable (3); the temperature calibration optical cable (6) is placed within the temperature calibration box (5); the other end of the communication optical cable (3) accesses the temperature demodulation instrument (2); the wireless transmission module (7) is connected to the temperature demodulation instrument (2); the power supply module (8) supplies power; and the processor (9) is carried on a computer device terminal. Long-term stable real-time online temperature monitoring of a deep well-type grounding electrode may be achieved by means of the described online temperature monitoring system for a deep well-type grounding electrode.
C: An acoustic-emission-based health monitoring system and method. The system comprises: at least one optical fibre grating sensor (1), wherein the optical fibre grating sensor (1) is arranged inside or on a surface of a monitored object (00) and is used to detect an acoustic emission signal generated by the monitored object (00); a light source (2) for providing a light source for the optical fibre grating sensor (1); a demodulation system (3) for obtaining the acoustic emission signal generated by the monitored object (00) according to a central wavelength offset of reflected light of the optical fibre grating sensor (1) and a correlation between the central wavelength offset and the acoustic emission signal; and a control system (4) for comparing the acoustic emission signal with reference data so as to obtain a health degree value of the monitored object (00). Since an optical fibre grating sensor (1) is small in size and light in weight, an optical fibre with the optical fibre grating sensor (1) can be directly arranged inside a transformer, for example, inside a winding, and thus the transmission loss of an acoustic emission signal can be reduced and the sensitivity degree of a monitoring system can be improved.
D: A dynamic state monitor of roof for filling coal mining goaf in a comprehensive and mechanized way is composed of a monitor base, a multiplestage telescopic rod and a floor offer (12). The monitor base is composed of a base cylinder (5), a spring (6), a transmission cable (13), a pattern displacement meter (15) and a guide rod (7). A displacement meter support (9), a protective port (11), a spring seat (8) and range limiting plates (16, 17) are arranged in the base cylinder. The pattern displacement meter (15) contains a chip (14). The base cylinder (5) is fixed on the floor offer (12) with screws. The spring (6) is arranged in the bayonet slot of the spring seat (8), the pattern displacement meter (15) is arranged in the bayonet slot of the displacement meter support (9), the guide rod (7) is directly connected to the pattern displacement meter (15), the guide rod (7)and the pattern displacement meter (15) are sleeved in the spring (6), and the transmission cable (13) is connected with the chip (14). The multiplestage telescopic rod is composed of a first stage rod (4), a second stage rod (20) and a third stage rod (21), wherein the first stage rod is installed in the base cylinder (5)and is in direct contact with the range limiting plates (16, 17) on the guide rod (7). The second stage rod (20) is fixed in the installation groove in the first stage rod (4) with a fastening bolt (19), and the third stage rod (21) and the second stage rod (20) are fixed with a fixing bolt (2). The monitor can directly and accurately monitor the dynamic subsidence amount of the roof, and is ingenious in structure and convenient to use.
Answer: D