Research On Nonlinear Characteristic Response And Vibration Control Of Vibratory Roller

With the continuous increase of traffic volume,vehicle weight and load,higher requirements are put forward for the compaction quality of the current highway subgrade.As the compaction machinery of highway subgrade,vibratory roller plays a decisive role in the compaction quality of subgrade and pavement.It is of great significance to study the dynamic response of the vibrating wheel in the compaction process to improve the compaction effect of the roadbed.In this thesis,the dynamic response of vibrating wheel in the whole compaction condition is studied,which provides a theoretical basis for vibrating compaction.Secondly,the dynamic response of vibratory compaction in the middle stage is analyzed,and the system dynamics coupling model of vibratory drum-soil is established.Through simulation analysis,the motion state of the vibrating wheel in the middle stage of compaction is a single-period motion state.Considering that the middle stage of vibration compaction is the most stable motion state in the compaction process.On this basis,the influence of road roughness on vibration compaction is considered.Then,the dynamic response of the later stage of vibratory compaction is analyzed,and the system dynamics coupling model of vibratory drum-soil is established.By studying the time domain diagram,frequency domain diagram,phase diagram and Poincare section diagram of the response of the vibrating wheel,it is obtained that the vibration state of the vibrating wheel gradually changes from single-cycle motion to multi-cycle motion in the later stage of compaction,and finally evolves into irregular chaotic motion.With the increase of soil stiffness,multiple harmonics gradually appear in the spectrum,indicating that the vibration wheel has jump vibration.Therefore,considering the influence of system parameters on vibration compaction from the perspective of suppressing jump vibration,on the basis of ensuring that the other parameters remain unchanged,the jump vibration phenomenon can be avoided and the soil compaction can be improved by changing the excitation frequency or excitation force of the vibration wheel.Finally,considering that the jump phenomenon affect the ride comfort of the operator of the vibratory roller,the vibration control performance of the primary vibration reduction system between the vibration drum and the frame of the vibratory roller is studied.Aiming at the first-level vibration reduction system,a fuzzy PID control is established to optimize the vibration reduction system of the vibratory roller.Although the acceleration amplitude of the rack in the later stage of compaction is improved and the jump vibration of the vibration wheel is suppressed in the later stage,the stability of the vibration drum is not well improved.Therefore,considering that the sliding mode control can eliminate the influence of chattering through the saturation function,the sliding mode control is selected to optimize the vibration reduction system of the vibratory roller.The vibration reduction effect under sliding mode control is obviously better than that under no control and fuzzy PID,and the vibration of the vibrating roller is obviously improved.