Research On Control Of Hydro-viscous Clutch And The Jam Breakout Technology Of TBM Cutterhead

The Hard Rock Boring Machine(TBM)is a large-scale equipment of tunnel excavation that completes the formation of the tunnel section at one time through rock crushing,slag transportation,support lining and step-by-step propulsion.It is mainly used in tunnel construction of municipal projects,water conservancy,highway and railway.When TBM excavates in harsh geological environments such as uneven-rock,fault-fracture and unstable-stratum zones,it is extremely easy for the surrounding rock to shrink and deform,or even collapse,causing the TBM cutterhead to be trapped.The manual method of getting the TBM out of jam is time-consuming,labor-intensive and costly.It will also lead to a serious delay in construction period,and accompany with potential safety hazards.It is of great significance for ensuring the efficient excavating of TBM,if the TBM cutterhead driving system can provide a large enough torque to get the TBM out of jam rapidly.In order to increase the output torque of the TBM cutterhead driving system without increasing the installed power,a solution to the jam breakout of TBM cutterhead was designed based on variable-frequency motor,flywheel and hydro-viscous clutch in this issue.It can increase the output torque of the driving system by the storage and release of the flywheel’s energy and get the TBM cutterhead out of jam.As a flexible transmission component,the hydro-viscous clutch can reduce the impact of shocking caused by flywheel.Because of the controllable engagement process,the torque output can be dynamically adjusted in real time by controlling the oil chamber pressure and piston displacement of hydro-viscous clutch,which will lead to the stable and controllable torque of flywheel.However,there is large nonlinearity,uncertainty and timevariability of parameter in hydro-viscous clutch,and its control problems are difficult and critical.Therefore,the control technology of hydro-viscous clutch was studied to improve the control accuracy and stability.Based on this,the hydro-viscous clutch can be regarded as a component with good control performance to study the impact of piston displacement trajectory and flywheel on the jam breakout performance of TBM cutterhead.The main research work of this dissertation is as follows:In the first chapter,the research status and development history of TBM technology at home and abroad and its current deficiencies were introduced.Then the research status of TBM cutterhead driving system and the jam breakout technology of TBM were discussed.The conventional methods of dealing with the jam of TBM in actual engineering were introduced,and the shortcomings of existing cutterhead driving system were analyzed.The solution to getting the TBM out of jam based on variable-frequency motor,inertia flywheel and hydro-viscous clutch was proposed.The related technologies of hydro-viscous clutch in this solution were investigated.Finally,the deficiencies of the existing research were analyzed,and the main research contents and significance of this paper were elaborated.In the second chapter,model of hydro-viscous clutch was built,the forces on the piston of hydro-viscous clutch were analyzed,its dynamic equation was established,and the oil film bearing force was deprived on detail.The hydraulic system of hydro-viscous clutch was designed.The pressure was controlled independently by pump or valve independently at high or low pressure conditions.The pump rotates at a constant speed at high pressure,and the pressure is controlled by an electro-hydraulic proportional relief valve.At the condition of low pressure,the pressure is controlled by a hydraulic pump.The mathematical model of the electro-hydraulic proportional relief valve and hydraulic pump of the key hydraulic components in the hydraulic control system were established,and the flow continuity equation of the hydraulic chamber of the hydro-viscous clutch was listed for the subsequent research of the control technology of hydroviscous clutch and the simulation of the jam breakout of TBM.In the third chapter,due to the serious nonlinearity and parameter uncertainty in the system of hydro-viscous clutch.The sliding mode control of the hydraulic pump at the low-pressure condition and the PID control of the electro-hydraulic proportional relief valve at the highpressure condition were proposed.In addition,the sliding mode control strategy based on RBF(radial basis function)neural network was proposed to improve the control accuracy of piston displacement.The effectiveness of the proposed control strategy was verified compared with conventional PID control in AMESim-MATLAB simulation model.The proposed control strategy can improve the control performance of the hydro-viscous clutch.Due to this,the hydro-viscous clutch can be regarded as a component high-reliability and high-precision to meet the requirement of the jam breakout of TBM.In the fourth chapter,the test bench of the jam breakout of TBM cutterhead was analyzed and summarized,and then the test bench was designed and described in three angles,mechanical structure,hydraulic system and electrical system.The pressure control strategy of the hydraulic system of the hydro-viscous clutch proposed in the third chapter was experimentally verified compared with the conventional PID control.The experimental results show that compared with the conventional PID control algorithm,the smoothed sliding mode control algorithm has a good performance of pressure tracking.It can effectively suppress the chattering of the input signal of the conventional sliding mode control and improve the pressure control accuracy of the hydraulic pump.In the fifth chapter,the simulation model of the jam breakout of TBM cutterhead was set up based on the established dynamic models of vector-controlled variable-frequency motors and load.The physical model of the hydro-viscous clutch and its hydraulic system were built in AMESim,and the variable-frequency motor,load simulation and displacement control modules were established in MATLAB.The co-simulation model of AMESim and MATLAB was established.Finally,based on the control strategy of the hydro-viscous clutch proposed in the third chapter,the effects of piston displacement trajectories such as straight line,concave parabola,convex parabola and sinusoidal curve on the performance of the jam breakout of TBM cutterhead were studied.The effects of flywheel on the torque transmitted by the hydro-viscous clutch were discussed.In order to reduce the impact,the moment of inertia and initial speed of flywheel should be selected as small as possible on the premise of good performance of the jam breakout of TBM.The correctness and effectiveness of the scheme proposed by the research group were verified through simulation,and it has some reference value on the problem of the jam breakout of TBM.In the sixth chapter,the whole work done in this paper was summarized,and the future work prospects were pointed out.