Research On Detection And Control Method Of Straightness Of Hydraulic Support In Fully Mechanized Mining Face

Intelligent mining is not only a new stage of the development of fully mechanized coal mining technology,but also the inevitable requirement of the technological revolution and upgrading development of coal industry.The realization of coordinated automatic action of "three machines" in fully mechanized mining face is an effective way to improve the underground production efficiency and safety of coal mine.The hydraulic support follows the movement of the shearer,automatically moves the scraper conveyor,and maintains the straightness of the scraper conveyor along the working face,which is the most basic and key technology to realize the intelligent working face.At present,multi pump combined long-distance liquid supply of hydraulic support has large pressure fluctuation and impact.It is difficult to realize the accurate position control of scraper conveyor in working face,which seriously affects the straightness control of working face and has become the bottleneck problem of intelligent mining in coal mine.Focusing on the position control of the scraper conveyor in the working face,taking the hydraulic support as the research object,this paper analyzes the factors affecting the straightness of the hydraulic support in the fully mechanized mining face,puts forward the detection and control method of the straightness of the hydraulic support based on double closed-loop and fuzzy PID adaptive,and establishes the experimental platform for the detection and control of the straightness of the hydraulic support.Firstly,the motion characteristics of "three machines" in fully mechanized mining are comprehensively analyzed.A double closed-loop straightness detection method of hydraulic support in fully mechanized mining face based on the inner closed-loop of displacement sensor and the outer closed-loop of laser sensor is proposed in this paper.The flow of emulsion pump station is controlled by the detection value.It provides a theoretical basis for the straightening of hydraulic support in fully mechanized mining face.Secondly,the factors affecting the straightness of the hydraulic support in the liquid supply system of the fully mechanized mining face are analyzed,such as the clearance error of the middle slot pin ear,the fluctuation of the coal seam floor,the movement error of the hydraulic support moving jack and so on.However,the pressure loss of the pipeline system has the most prominent impact on the stability of the action of the hydraulic support and the accuracy of the moving distance of the working face.Therefore,the pressure loss in the liquid supply process of the hydraulic support can not be ignored.We should strive to adopt a liquid supply method with small pressure loss.Then,the pressure loss under different liquid supply modes is simulated and analyzed;The simulation model of hydraulic support straightness based on Double Closed-loop Detection System and fuzzy PID control is established.In the process of straightness detection and control simulation of hydraulic support,the simulation of different liquid supply flow is carried out,and the simulation is carried out for different initial states of underground hydraulic support,and the simulation results are analyzed.Finally,on the basis of theoretical analysis,an experimental platform for straightness detection and control of hydraulic support moving oil cylinder is built,the detection data are displayed and saved by using data acquisition equipment,the data detected by the sensor is converted into electrical signal and compared with the standard value,the comparison results are transmitted to the upper computer,and the liquid supply flow is controlled by frequency conversion control of emulsion pump station,The position and speed of the hydraulic support pushing cylinder are controlled.The experimental results show that the position error of each push cylinder is less than 20 mm,which verifies the accuracy and effectiveness of the straightness control method of hydraulic support based on Double Closed-loop Detection and fuzzy PID control.