[0004] 1) The authorized Chinese invention patent (application number 201510379025.1) reports a device and method for automatic straightening of the body of a scraper conveyor based on an elastic rod and a relative pose measurement device, using an angle sensor to monitor the elastic rod and the target hydraulic pressure The angle of the support is compared with the set threshold (90°), and the propulsion and pulling of the target hydraulic support are controlled according to the comparison result. In addition, the scraper conveying is controlled according to the signal polarity (positive or negative) of the strain sensor The straightening action of the groove in the middle of the machine; however, this automatic straightening device and method is only suitable for the straightening operation of the hydraulic support and the scraper conveyor in the horizontal plane, and cannot be used for the straightness monitoring of the scraper conveyor
[0005] 2) The authorized Chinese invention patent (application number 201310492654.6) reports a system and method for aligning hydraulic supports in coal mine working faces using laser alignment. However, the anti-interference ability of this hydraulic support straightening method is weak, and the long-term cleanliness of the surface of the laser transceiver is very low in the coal mine fully mechanized mining face. Difficult to guarantee, cannot be used for straightness monitoring of scraper conveyor
[0006] 3) Authorized Chinese invention patents (application numbers 201410103888.1 and 201410103904.7 respectively) respectively report a straightness control system and method for working face hydraulic support groups using optical fibers. The optical fiber sensor is installed between two adjacent chutes , when the hydraulic support does not move in place or moves too far, the optical signal in the optical fiber sensor installed at both ends of the chute corresponding to the support will produce a Brillouin frequency offset, and the hydraulic support is calculated according to the Brillouin frequency offset. Position data, using the position data to realize the straightness control of the hydraulic support group on the working face; the straightness control system and method of the hydraulic support group can control the straightness of the hydraulic support group and the scraper conveyor, but it cannot be used for the scraper Monitoring of Conveyor Straightness
[0007] 4) The published Chinese invention patent (application number 201610128789.8) reports a method for measuring the straightness of a scraper conveyor. Taking the chute of the scraper conveyor at the head end as a reference, the chutes of the scraper conveyor are numbered sequentially. The product of the length of the scraper conveyor chute and the number of the target chute is taken as the position of the target chute in the horizontal direction; the distance between the hydraulic support and the coal wall is determined by the ultrasonic sensor, and the advancing distance of the scraper conveyor chute is obtained by the displacement sensor inside the push cylinder , combined with the known length of the hydraulic support base, determine the position of the target chute in the vertical direction; using this method, the spatial distribution information of all chutes of the scraper conveyor can be known, so that the straightness of the scraper conveyor can be monitored; however , a shortcoming of this method is that the straightness requirement of the coal wall is very high. When there is a straightness error in the coal wall, this method will have a large error in the vertical direction when measuring the straightness of the scraper conveyor. Another shortcoming is that the horizontal position of the target chute should be the projection of all chutes between the target chute and the head chute in the horizontal direction. It is necessary to obtain the angles between all chutes and the horizontal direction, and the length of the chute cannot be simply used, otherwise it will lead to scraping. There will be a large error in the horizontal direction when measuring the straightness of the plate conveyor
[0008] 5) A method of monitoring the straightness of the scraper conveyor has also been widely reported. This method is specifically: using the shearer positioning technology to monitor the running track of the shearer, and according to the geometric constraint relationship between the shearer and the scraper conveyor , the trajectory of the scraper conveyor with absolute orientation is inverted from the running trajectory of the coal shearer, and then the straightness monitoring of the scraper conveyor is realized; the disadvantage of this method is that the cost is high, and some core technical problems need further breakthroughs