Simulation And Optimization Of Manipulator For Disassembly And Assembly Of Ballastless Track Fastener

With the development of China’s high-speed railways,the demand for the construction of new lines and the maintenance of existing lines has also continued to increase.It is a key part of the ballastless track fine-tuning operation,but at present the completion of this work is still dominated by manual labor,with high labor intensity and low operation efficiency.Automated fine-tuning is an important way to change the status quo.In order to automate the disassembly and assembly of fastener and improve the efficiency of fine adjustment,it is necessary to design a manipulator for disassembly and assembly of ballastless track fastener,which is of great significance for promoting the development of automatic fine adjustment equipment for ballastless tracks.Firstly,by analyzing the characteristics of four ballastless track fastener systems currently mainly used in China,taking WJ-8 type fastener as the operation object,according to the current manual fine-tuning operation process and the composition characteristics of fastener,a proposed An automatic fine-tuning operation scheme that can realize the overall disassembly and assembly of fastener;according to the actual operation requirements,select the appropriate manipulator structure form,through comparative analysis of different composition schemes of the manipulator,the overall design scheme of the manipulator is determined,and the virtual manipulator is established.The prototype model provides the basis for the automatic fine-tuning of ballastless track.Secondly,the multi-rigid body and rigid-flexible coupled model of the main structure of the manipulator were established by Adams software,and the difference in the dynamic response of the two models during operation was analyzed.The impact was too large;then the S-shaped speed curve drive control method was introduced for optimization,and the maximum offset of the manipulator execution end was reduced from 6.98 mm to 0.39 mm,and the stability of the operation of the manipulator was improved.Subsequently,the finite element model of the manipulator was established by using ANSYS Workbench software,and the static analysis of six typical position conditions of the manipulator was carried out.The results showed that the design requirements of structural strength and stiffness were met.Frequency and mode shape,it is concluded that the overall structure of the manipulator is prone to resonance with external excitations such as motor rotation,and structural optimization is required;The frequency range in which resonance is likely to occur under excitation.Finally,the multi-objective optimization design platform of the manipulator is established by using Isight software combined with SOLIDWORKS and ANSYS Workbench,and the optimal Latin hypercube design method is used for experimental design.The EBF neural network approximates the model,and uses the NSGA-II algorithm to optimize the mass and natural frequency of the manipulator structure.After optimization,the mass of the manipulator is reduced by 15.24%,and the natural frequencies of each order are reduced to outside the excitation frequency.The structural performance of the whole machine has been improved.Through the simulation analysis of the multi-body system dynamics and static and dynamic characteristics of the fastener disassembly manipulator,the defects of the manipulator structure design are obtained and the corresponding optimization and improvement are carried out,which provides theoretical guidance for the manufacture of the actual machine.