CN-122014717-A - Indirect monitoring system and method for piston displacement of hydraulic oil cylinder of coal mine

CN122014717ACN 122014717 ACN122014717 ACN 122014717ACN-122014717-A

Abstract

The invention provides an indirect monitoring system and a monitoring method for piston displacement of a hydraulic cylinder of a coal mine, wherein the monitoring system comprises a fiber grating array, a monitoring module and a monitoring module, wherein the fiber grating array comprises a plurality of first fiber grating sensors, the first fiber grating sensors are arranged on the outer wall of a cylinder barrel of the hydraulic cylinder, the first fiber grating sensors are sequentially distributed at intervals along the axial direction of the hydraulic cylinder, the first fiber grating sensors are used for detecting the circumferential strain of an axial point position corresponding to the cylinder barrel of the hydraulic cylinder, the monitoring module is used for calculating the strain difference value between each adjacent axial point position and determining the maximum difference value in the plurality of difference values, and a section between the adjacent axial point positions corresponding to the maximum difference value is used as a strain step section. In the indirect monitoring system and the monitoring method for the piston displacement of the hydraulic oil cylinder of the coal mine, a non-invasive installation and detection mode is adopted, so that the operation and maintenance cost and the downtime are greatly reduced, and the underground comprehensive mining efficiency is improved.

Inventors

DU SHANGYU
LIU YANJUN
WANG HAI
SHI HONGYU
PANG XIAOLIANG
LI SHIWEI
XU YAJUN

Assignees

中煤科工开采研究院有限公司
陕煤集团神木张家峁矿业有限公司

Dates

Publication Date: 20260512
Application Date: 20260211

Claims (10)

1. An indirect monitoring system for the displacement of a piston of a hydraulic cylinder of a coal mine, which is characterized by comprising: A fiber grating array, the fiber grating array comprising: the hydraulic cylinder comprises a cylinder barrel, a plurality of first fiber grating sensors, a plurality of second fiber grating sensors, a plurality of third fiber grating sensors, a plurality of fourth fiber grating sensors, a plurality of fifth fiber grating sensors, a plurality of sixth fiber grating sensors and a plurality of sixth fiber grating sensors, wherein the first fiber grating sensors are arranged on the outer wall of the cylinder barrel of the hydraulic cylinder, the plurality of first fiber grating sensors are sequentially distributed at intervals along the axial direction of the hydraulic cylinder, and the first fiber grating sensors are used for detecting the circumferential strain of the corresponding axial point positions of the cylinder barrel; The monitoring module is used for collecting annular strain amounts of all axial points of the cylinder barrel of the hydraulic cylinder through the plurality of first fiber grating sensors, calculating strain amount difference values between all adjacent axial points and determining a maximum difference value among the plurality of difference values, taking a section between the adjacent axial points corresponding to the maximum difference value as a strain step section, determining a maximum point of change rate of the annular strain amounts in the strain step section, and determining an axial position of the hydraulic cylinder corresponding to the maximum point of change rate as a piston position of the hydraulic cylinder.
2. The indirect monitoring system of coal mine hydraulic ram piston displacement of claim 1, wherein the fiber bragg grating array further comprises: The second fiber bragg grating sensor is arranged on a cylinder seat of the hydraulic cylinder; The signal input end of the monitoring module is connected with the signal output end of the second fiber bragg grating sensor, and the monitoring module is used for acquiring the temperature compensation strain quantity of the hydraulic cylinder through the second fiber bragg grating sensor and obtaining the actual circumferential strain quantity of each axial point position of the cylinder barrel of the hydraulic cylinder based on the temperature compensation strain quantity.
3. The indirect monitoring system for the displacement of the piston of the hydraulic cylinder of the coal mine according to claim 2, wherein the monitoring module obtains the actual annular strain of each axial point position of the cylinder barrel of the hydraulic cylinder based on the following formula; ; Wherein, the The actual hoop strain amount for the ith axial point, Is the strain sensitivity coefficient of the fiber bragg grating sensor, The real-time wavelength of the first fiber bragg grating sensor at the ith axial point location, The initial wavelength of the first fiber grating sensor being the ith axial point location, For the real-time wavelength of the second fiber grating sensor, For the initial wavelength of the second fiber grating sensor, For the temperature sensitivity coefficient of the first fiber bragg grating sensor, And the temperature sensitivity coefficient of the second fiber bragg grating sensor.
4. The indirect monitoring system of coal mine hydraulic ram piston displacement according to claim 1, wherein the monitoring module is further configured to perform cubic spline interpolation on the data points of the strain step section to fit a local strain curve of the strain step section, and calculate an extreme point of a first derivative of the local strain curve as a maximum rate of change point of the hoop strain in the strain step section.
5. The coal mine hydraulic ram piston displacement indirect monitoring system of claim 1, wherein the monitoring module is located at an uphole monitoring center, and the system further comprises: an explosion-proof junction box and an underground optical cable; The signal output end of the first fiber bragg grating sensor is connected with the signal input end of the explosion-proof junction box, the signal output end of the explosion-proof junction box is connected with the signal input end of the underground optical cable, and the signal input end of the monitoring module is connected with the signal output end of the underground optical cable.
6. The indirect monitoring system of coal mine hydraulic cylinder piston displacement according to claim 1, wherein the monitoring module is a fiber grating demodulator, and the fiber grating demodulator scans the wavelength of each first fiber grating sensor at a preset frequency to obtain the circumferential strain of each axial point of the hydraulic cylinder barrel through a plurality of first fiber grating sensors.
7. An indirect monitoring method for the displacement of a piston of a hydraulic cylinder of a coal mine is characterized by comprising the following steps: A plurality of axial point positions are sequentially arranged on the outer wall of the cylinder barrel of the hydraulic cylinder at intervals along the axial direction of the hydraulic cylinder; collecting the annular strain of each axial point position of the cylinder barrel of the hydraulic cylinder; calculating the strain difference between each adjacent axial point and determining the maximum difference in a plurality of the differences; taking a section between the adjacent axial point positions corresponding to the maximum difference value as a strain step section; and determining the maximum point of the change rate of the circumferential strain in the strain step section, and determining the axial position of the hydraulic cylinder corresponding to the maximum point of the change rate as the piston position of the hydraulic cylinder.
8. The method for indirectly monitoring the piston displacement of a hydraulic ram of a coal mine according to claim 7, further comprising: collecting the temperature compensation strain of the hydraulic cylinder; and obtaining the actual circumferential strain of each axial point position of the hydraulic cylinder barrel based on the temperature compensation strain.
9. The indirect monitoring method for the piston displacement of the hydraulic cylinder of the coal mine according to claim 8, wherein, Respectively arranging a plurality of first fiber bragg grating sensors on a plurality of axial point positions, and collecting the annular strain of each axial point position of the hydraulic cylinder barrel through the plurality of first fiber bragg grating sensors; A second fiber bragg grating sensor is arranged on a cylinder seat of the hydraulic cylinder, and the temperature compensation strain quantity of the hydraulic cylinder is acquired through the second fiber bragg grating sensor; obtaining the actual circumferential strain of each axial point position of the hydraulic cylinder barrel based on the following formula; ; Wherein, the The actual hoop strain amount for the ith axial point, Is the strain sensitivity coefficient of the fiber bragg grating sensor, The real-time wavelength of the first fiber bragg grating sensor at the ith axial point location, The initial wavelength of the first fiber grating sensor being the ith axial point location, For the real-time wavelength of the second fiber grating sensor, For the initial wavelength of the second fiber grating sensor, For the temperature sensitivity coefficient of the first fiber bragg grating sensor, And the temperature sensitivity coefficient of the second fiber bragg grating sensor.
10. The method for indirectly monitoring the piston displacement of a hydraulic ram of a coal mine according to claim 7, further comprising: Performing cubic spline interpolation on the data points of the strain step section to fit a local strain curve of the strain step section; and calculating an extreme point of the first derivative of the local strain curve as a maximum point of the rate of change of the circumferential strain in the strain step section.

Description

Indirect monitoring system and method for piston displacement of hydraulic oil cylinder of coal mine Technical Field The disclosure relates to the technical field of hydraulic cylinder monitoring, in particular to an indirect monitoring system and a monitoring method for piston displacement of a hydraulic cylinder of a coal mine. Background The hydraulic support is key supporting equipment of the comprehensive mechanized coal mining working face of the coal mine, and stroke (displacement) monitoring of hydraulic oil cylinders such as pushing jacks, upright columns and the like is a basis for realizing automatic alignment and intelligent control of the working face. Currently, displacement measurement of underground coal mine hydraulic cylinders mainly adopts built-in magnetostrictive sensors. However, in an actual coal mine production environment, the magnetostrictive sensor is installed inside the oil cylinder, once the sensor electronic element is damaged, the magnetostrictive sensor cannot be independently replaced in a narrow underground space, and the common treatment mode is to detach and transport the whole hydraulic oil cylinder weighing hundreds of kilograms or even several tons to the ground (a lifting well) for replacement or factory returning maintenance, so that huge equipment and logistics cost are increased, a fully mechanized mining working face is stopped for a long time, and the production efficiency is seriously affected. Disclosure of Invention The present disclosure aims to solve, at least to some extent, one of the technical problems in the related art. Therefore, the purpose of the disclosure is to provide an indirect monitoring system and a monitoring method for the piston displacement of the hydraulic oil cylinder of the coal mine. In order to achieve the aim, the first aspect of the disclosure provides an indirect monitoring system for piston displacement of a hydraulic cylinder of a coal mine, which comprises a fiber grating array, a monitoring module and a control module, wherein the fiber grating array comprises a plurality of first fiber grating sensors, the first fiber grating sensors are arranged on the outer wall of a cylinder barrel of the hydraulic cylinder, the first fiber grating sensors are sequentially distributed at intervals along the axial direction of the hydraulic cylinder, the first fiber grating sensors are used for detecting the circumferential strain quantity of an axial point position corresponding to the cylinder barrel of the hydraulic cylinder, the signal input end of the monitoring module is respectively connected with the signal output ends of the first fiber grating sensors, the monitoring module is used for acquiring the circumferential strain quantity of each axial point position of the cylinder barrel of the hydraulic cylinder through the first fiber grating sensors, calculating the strain quantity difference between each adjacent axial point positions, determining the maximum difference in the axial difference, taking the section between the adjacent axial point positions corresponding to the maximum difference as a step strain section, and determining the circumferential strain rate of the hydraulic cylinder in the step section corresponding to the maximum strain rate. Optionally, the fiber grating array further comprises a second fiber grating sensor, wherein the second fiber grating sensor is arranged on a cylinder seat of the hydraulic cylinder, a signal input end of the monitoring module is connected with a signal output end of the second fiber grating sensor, the monitoring module is used for acquiring temperature compensation strain quantity of the hydraulic cylinder through the second fiber grating sensor, and acquiring actual annular strain quantity of each axial point position of the cylinder barrel of the hydraulic cylinder based on the temperature compensation strain quantity. Optionally, the monitoring module obtains the actual circumferential strain of each axial point position of the hydraulic cylinder barrel based on the following formula; Wherein, the method comprises the steps of, The actual hoop strain amount for the ith axial point,Is the strain sensitivity coefficient of the fiber bragg grating sensor,The real-time wavelength of the first fiber bragg grating sensor at the ith axial point location,The initial wavelength of the first fiber grating sensor being the ith axial point location,For the real-time wavelength of the second fiber grating sensor,For the initial wavelength of the second fiber grating sensor,For the temperature sensitivity coefficient of the first fiber bragg grating sensor,And the temperature sensitivity coefficient of the second fiber bragg grating sensor. Optionally, the monitoring module is further configured to perform cubic spline interpolation on the data points of the strain step section to fit a local strain curve of the strain step section, and calculate an extreme point of a first derivative of the