Study On Load Sharing Control Of Main Driving System For Hard Rock Tunnel Boring Machine Under Complex Geology

Hard rock tunnel boring machine is the key equipment in the field of railway,highway,water conservancy project,urban construction and other fields.It has the advantages of fast speed,short construction period,small impact on the ecological environment,and high comprehensive benefits,and has been widely used in the domestic and overseas tunnel construction.Cutterhead driving system is the principal driving system of TBM,a series of driving motors of the cutterhead driving system drives the cutterhead rotates,hobs,scrapers installed on the disk,with the rotating cutterhead disk cutting rock mass.However,facing the cutterhead interface load fluctuation caused by the complex geology environment and multi-field coupling effect,the existing main driving system of the TBM is easy to produce the torque imbalance in the running process,resulting in the non-normal damage of driving shaft and other key components.At the same time,there is a lack of accurate prediction of the penetration rate of the TBM,which is difficult to determine construction plan.In view of the safety,stability and high efficiency requirements in TBM construction,the load sharing control and penetration rate pridiction model of TBM were studied in this paper,the main research contents are as follows:First,we research on the control strategy for the driving motor.According to the principle of coordinate transformation,the mathematical model of the driving motor is established,and the torque and speed control of induction motor is decoupled.Therefore the vector control strategy can be adopted,and the improved particle swarm optimization algorithm is used to set the PID parameters.By using Matlab/Simulink software to build vector control module,we realize the high efficiency control of driving motor.Then,the load sharing control of multi-motor for the main driving system is studied.We analyze the working mechanism,transmission structure and mutual coupling relationship of the main driving system of TBM.We analyze the imbalance of the motor load,from the geological rock distribution and the actual construction data.Aiming at the multi-motor robust torque load sharing control target under complex geology environment,we propose regional coupling based synchronization control,and establish the model;the simulation results display its control effect is superior to the traditional master-slave control.Finally,prediction of hard rock TBM penetration rate is studied.According to the actual surrounding rock geological data,based on random forests prediction algorithm,we established the TBM penetration rate prediction model,the simulation results show that the random forests based prediction model has better predictive accuracy and can sort the features of rock mass properties by the importance.