| In order to improve the ride comfort of vehicle,people study on the suspension system to improve the dynamic characteristics of the vehicle vibration system,and many achievements have been made in the related field.However,the related researches mostly focus on the small and medium-sized vehicles.Research on the related issues to heavy-duty vehicles also needs continuous deepening and improvement.In this paper,the suspension system of heavy vehicle is taken as the research object.By modeling,simulation and control of suspension system,the response characteristics of vehicle vibration system are improved,the ride comfort and ride comfort of cab are improved,and the road friendliness is evaluated.The main research work of this paper is summarized as follows:Firstly,the random input pavement model and triangle pulse input model are built to generate road roughness incentive in time domain,and the efficiency of the road generated excitation is verified in the frequency domain by comparing with the power spectral density curve of the standard grade pavement.Secondly,based on the analysis of the structure of the heavy truck studied in this paper and the vehicle dynamics theory,the vehicle suspension system is simplified based on different assumptions.The three degrees of freedom model of the front suspension with cab,the balanced suspension model and the eight degree of freedom semi vehicle dynamic model for a three-axle heavy vehicle are established respectively as the foundation of simulation.Thirdly,taking the disturbance of road surface roughness as the input of the suspension system,the simulation is carried out by using Matlab/Simulink.We compare the results of different simplified models,analyze the causes of the difference in response results,which will as a reference for the dynamic analysis of suspension system when selected the model。And we select the models for the research questions in this paper.On this basis,match the suitable air suspension to replace the original steel suspension,and evaluate the indexes related to ride comfort and road friendliness based on the simulation results.Finally,the active control of the cab suspension is carried out.Based on the theory of PID control,the controller is designed to control the cab front and rear suspension systems respectively,and the parameters of the front and rear controllers are adjusted.According to the simulation results,the performance indexes of active and passive cab suspension system are compared,and the improvement of ride comfort of active cab suspension system is analyzed. |
