Study On Stability Optimization Of Rotary Drilling Rig Walking System

Rotary drilling rig is widely used in railway,bridge and urban and rural infrastructure because of its convenience and high efficiency.As one of the most important systems,the running system directly affects the stability and safety of the rig running.Walking is divided into three stages: starting,driving and braking.Because of its high center of gravity,large inertia,variable walking conditions and other characteristics,in the driving stage,the time variability of the left and right track load,as well as in the rapid starting and braking stage,the system inherent parameters setting or matching improper will aggravate the fuselage shaking,affecting the walking stability.In view of the above problems,this paper mainly carries out the following research:(1)Research on the influencing factors of the stability of the rig walking system.By modeling and analyzing the dynamic mechanism and hydraulic system of the drilling rig,the internal and external factors affecting the stability of the walking system are obtained.Internal factors include system flow gain,motor displacement,total volume of motor two cavities and rubber tube cavity,effective bulk elastic modulus of oil;External factors:external load variation.(2)Research on anti-jamming control of rig running stage.The key factor affecting the walking stability at this stage is the disturbance caused by time-varying load.Through the mathematical modeling of time-varying load,the establishment of state space equation of walking system,the design of load disturbance observer and acceleration control system,the anti-interference control strategy of feedforward compensation of spool displacement is proposed.Based on the simulation verification,the time-varying load tracking error is only 0.3%,the peak value of acceleration is weakened by 61.5%,and the acceleration convergence rate is increased by 63%,which greatly improves the stability and safety during running.(3)Sensitivity analysis of the internal parameters of the walking system in the fast start and braking stage of the rig.At this stage,the key factors affecting walking stability are internal factors.Based on the AMESim simulation platform,the detailed modeling of the main pump,main valve,load and other components is reproduced.Through the sensitivity analysis of the internal parameter changes of the simulation model,the stability optimization scheme of the walking system in the starting and braking stages is proposed,which lays a foundation for the subsequent experimental verification of the whole machine.(4)Machine experiment verification of walking starting and braking stability.Relying on a domestic model to carry out the whole machine experiment,by reducing the flow gain of the system,the maximum shaking amount of the mast is reduced by 32.5% in the walking start stage and 26.7% in the braking stage.By increasing the total volume of the motor hose chamber,the maximum swaying amount of the mast is reduced by 24.4%in the starting stage and 21.6% in the braking stage.Verify the effectiveness of the optimization scheme to improve the stability and safety of starting and braking.