Research On Semi-Active Control Of Suspended PRT Based On Magnetorheological Dampers

In the 14 th Five-Year Plan to build a modern comprehensive transportation system,the future urban transportation will be a safe,convenient,efficient and green transportation system.The sustainable development of urban rail transit is the main task of urban rail development,and exploring new urban rail transit system and reducing construction investment is the important goal to achieve sustainable development,and the suspended personal rapid transit system(suspended PRT for short)is an effective way to solve the above problems.It is necessary to propose a semi-active suspension system to solve the problem of operational stability problems such as transverse sway during the operation of suspended PRT vehicles in curved sections,which causes panic among passengers.In this thesis,a semi-active suspension system scheme based on magnetorheological dampers(MRD for short)is proposed,and the dynamic performance of the vehicle with semi-active suspension system is analyzed by theoretical analysis,experimental testing of the mechanical properties of the dampers and the study of the semi-active control method,using a joint simulation method of UM and MATLAB/Simulink.The main research work of this thesis is as follows:(1)The simulation model of magnetorheological damper is established.Firstly,the structural principle,parametric and nonparametric mechanical models of magnetorheological dampers are analyzed,and the Bouc-Wen mechanical model is determined as the equivalent model of magnetorheological dampers;secondly,the mechanical characteristics of magnetorheological dampers are experimentally studied,and the Bouc-Wen mechanical model is parametrically identified by the nonlinear least squares method;then,according to the results of the parametric identification,Simulink is used to establish the forward simulation model of magnetorheological dampers.The forward simulation model of the magnetorheological damper is established based on the results of the parameter identification,and the simulation results are compared with the experimental data to verify the equivalence of the forward simulation model of MRD.Finally,a BP neural network algorithm is used to build the inverse simulation model of MRD.(2)Establishment of the suspended PRT vehicle dynamics model.Firstly,the structure of the suspended PRT vehicle with semi-active suspension system is analyzed,including vehicle structure,travel and guidance system,track beam structure,travel mechanism and system forces;then the vehicle topology is analyzed,the vehicle topology relationship configuration is established,the differential equations of vehicle motion are derived,and the suspended PRT vehicle dynamics model is established;finally,based on the vehicle topology configuration and modeling parameters,the vehicle dynamics simulation model is established by applying UM dynamics software.(3)Research on the control strategy of semi-active suspension system.Firstly,the control process of semi-active suspension system and the implementation of semi-active control are analyzed;then three semi-active control strategies for suspended PRT vehicles are proposed and Simulink is used to design semi-active controllers for each of the three control strategies;finally,a joint simulation model of UM and Simulink is established and the control effects of lateral and vertical acceleration of the vehicle are compared and analyzed to determine the optimal control strategy for the semi-active suspension system of the vehicle.(4)The comparison of the dynamics performance of the vehicles with two suspension systems is carried out.Firstly,the evaluation indexes applicable to the dynamics performance of the suspended PRT vehicles are discussed;then,based on the joint simulation of UM and MATLAB,the simulation results of the dynamics performance of the passive suspension system vehicles and the semi-active suspension system vehicles are compared and analyzed in combination with the vehicle dynamics performance evaluation indexes,further verify the effectiveness of the semi-active control strategy of the suspended PRT vehicles.In this thesis,a semi-active suspension system based on magnetorheological dampers is proposed through research,which has important reference and application value for optimizing the suspension system of a new type of suspended PRT vehicle.