Dynamic Characteristics Analysis Of Series ISD Suspension System Under Different Working Conditions

With the progress of society,the renewal of the automotive field is accelerating,and the comprehensive performance of vehicle driving should meet with higher requirements.Suspension,as a bridge connecting the body and wheel,has been the key research object to improve the handling stability and ride comfort.Because of the high cost and control time delay of the active suspension and the semi-active suspension,the passive suspension is still the mainstream of the market.In order to improve the vibration reduction performance of the passive suspension,"Inerter-Spring-Damper(ISD)" structure is added to the passive suspension.Compared with the semi-active and the active suspension,the passive suspension with this structure is simple and has no energy consumption.Above all,the research of ISD suspension is in line with the development direction of the vehicle suspension in the future.In this paper,the two-stage tandem ISD suspension is taken as the research object.A vehicle model with the two-stage tandem ISD suspension is established,and then the ride comfort and handling stability of vehicles under different operating conditions are analyzed.The main research contents of this paper include:(1)A vehicle model with the two-stage tandem ISD suspension is established.Firstly,the dynamic characteristics of the inertial itself are analyzed,and then the inertial is added to the traditional passive suspension,and thus the ISD suspension is obtained.Secondly,a vehicle model in consideration of the tandem ISD suspension,steering,braking and tire system is established,which is closer to the actual vehicle model.Meanwhile,the sideslip angle and slip rate in the tire model are regarded as time-varying factors,which are studied to make the tire model closer to the actual model.Finally,the interaction between the various systems is analyzed,and the dynamic characteristics of the ISD suspension are prepared from point to surface.(2)The parameters of tandem ISD suspension are optimized based on the particle swarm optimization,and then dynamic characteristics of the tandem ISD suspension under single road excitation are studied.In order to make the ISD suspension have better comprehensive performance and make vehicle parameters match with ISD suspension parameters,there are many new suspension components with inertial container,that is to say,more parameters need to be optimized,so the particle swarm optimization with strong optimization ability and easy realization is used to optimize ISD suspension parameters.Based on the established vehicle model with comprehensive consideration of the ISD suspension,driving and tire system,the ride comfort of the ISD suspension is studied under the input of uneven road excitation(random excitation,impulse excitation,dual-frequency quasi-periodic excitation)and deceleration belt excitation(periodic continuous deceleration belt excitation and non-periodic continuous deceleration belt excitation).The dynamic characteristics of ISD suspension at different speeds are obtained under different working conditions.At the same time,the ISD suspension is compared with the traditional passive suspension to study its performance improvement under more real conditions.(3)The dynamic characteristics of the tandem ISD suspension under coupled road excitation are studied.Based on the established vehicle model with the two-stage series ISD suspension,the dynamic characteristics of the ISD suspension under coupling road excitation are studied,and the dynamic characteristics of the ISD suspension are studied when the vehicle passes through coupling uneven road at different speeds.The optimal vehicle speed under different coupling conditions is obtained,which is then compared with the vehicle speed obtained under above single excitation.At the same time,the ISD suspension is compared with the traditional passive suspension to study the performance improvement of the suspension under more real conditions.(4)The dynamic characteristics of the tandem ISD suspension under steering and braking conditions are studied.Based on the vehicle model established in this paper,the handling stability of the vehicle is analyzed,and then the steering and braking systems are added to the vehicle model to study the performance improvement of the ISD suspension under steering and braking conditions.