Development Of Cutting Section Experimental Platform Of Digital Twin Roadheader Based On Similarity Theory

In the process of coal mine production,the imbalance between mining and excavation consistently restricts the efficient mining of coal and rock.As one of the important comprehensive excavation equipment in coal mining,cantilever tunneling machines have important operational functions such as mining,loading,and transportation,and are widely used in coal mining.When a roadheader is cutting coal and rock in a coal mine,due to the relatively complex conditions of the roadway coal wall and the impact loads with high intensity changes,the equipment is damaged,and its cutting part is damaged and its cutting performance is poor,which seriously affects the tunneling efficiency.Affected by the low visibility caused by high dust at the proximal end of coal mining,the cutting part of the key component of the roadheader has always lacked effective monitoring.Aiming at the difficulty of monitoring the cutting proximal end of a roadheader,this paper carried out research on the development of a digital twin roadheader cutting part experimental platform based on similarity theory.Firstly,based on the similarity theory,a scaled model test rig for the cutting part of the key component of the roadheader was developed,and a simulated coal wall was fabricated according to the ratio of coal rock,sand,cement,and water at 50:20:15:14.After similar simplification and strength verification of mechanical components,mechanical structure optimization is completed to meet industrial site requirements.In order to ensure the long-term stable operation of the hydraulic system,the strength of the cylinder barrel and the cylinder bottom were checked,and the stability of the hydraulic rod was analyzed.It was determined that the cylinder barrel thickness was not less than9.33 mm,and the cylinder bottom thickness was not less than 15.4 mm.Then,the hardware of the electrical control system is selected,the wiring and port allocation of the control system are introduced,the schematic diagram of the electrical control system is given,and the electrical control system is built.Based on the pulse and analog module,the displacement data of the hydraulic cylinder is collected,and the cutting head posture formula of the cutting part of the roadheader is derived.The temperature data is collected using the temperature acquisition module.Based on RS485 communication,the rotational speed control of the frequency converter is realized,and the program design of the automatic cutting system is completed.Finally,the user operation and monitoring interface is created,and the remote control of the cutting part system of the roadheader is completed.Based on similar vibration parameters,the performance evaluation method of roadheader cutting part test bench is proposed,and the similarity between the vibration test bench of roadheader cutting part and the vibration signal of roadheader real machine is verified.According to the actual cutting,it is determined that the cutting section test platform can carry out roadway excavation with a length of 2.4m and a width of 2.0m,and its cutting efficiency is0.2m3/min.The 3D model is established in the virtual simulation layer,the motion control algorithm is established in the data analysis layer,the database is built,the signal mapping relationship is established,and the digital twin system of the cutting part of the cantilever roadheader is constructed.The real-time action of the digital twin system of the cutting part of the roadheader is guaranteed by setting the highly sensitive motion following method.The data interpolation instruction makes the virtual model of the cutting part of the roadheader move more smoothly,and the average time delay of data is controlled within 500 ms.Real-time monitoring of cutting head speed and real-time tracking of cutting head position are completed in digital twin system.In this paper,the similarity theory is applied to build the cutting section experimental platform of a roadheader,and the high fidelity features of digital twin technology are applied to the operation monitoring of the cutting section.This effectively solves the problem of incomplete and unsafe monitoring of the equipment layer,providing technical support for the new model of smart mining in the future.Provide direction for the upgrading and transformation of roadheader,and be able to detect design defects in advance,effectively reducing the occurrence of safety accidents,and improving the efficiency of roadheader work.