Optimized Design Method Research On Independent Multi-link Suspension Of Sedan

Independent multi-link suspension with its better performance has become the mainstream application form of suspension structure,however research on the positive development and design methods of multi-link suspension failed to cause the attention of chinese scholars.In this paper,the independent multi-link suspension design optimization method were studied from the following three aspects:Firstly,on the theoretical analysis mechanism,took four-link rear suspension structure as example,established a geometric model,completed freedom analysis and derived basic equations of rigid body kinematic.Then according to constraints of the track at each point circle,established a trajectory equations with each ball joint centers coordinate,and furtherly find a method to determine the location of each ball joint centers.with a certain initial conditions,designed hard point arrangement for four-link suspension structure,which meets the requirements of a given design conditions.Derived rigid body kinematic equations and calculation methods derivation of the evaluation of each hard point of spatial position solver during exercise of parallel wheel hop,And preparated the MATLAB code,substituted the design cases.Secondly,on the multi-body dynamics analysis,at first,made a measurement on one car,got the four-link rear suspension parameters and vehicle parameters of it.Then took the vehicle parameters as the benchmark parameters,got other four-link suspension system parameters by calculation,such as suspension subsystem parameters,spring stiffness and shock absorber damping,etc.Then based on the measured parameters and design calculation parameters established two four-link rear suspension system in ADAMS / CAR package.Both systems share a set of vehicle parameters and the elastic element / damping elements and other components.The only difference is that layout parameters of different hard points.Then completed simulation experiments and comparative studies in ADAMS/CAR package to analyzied the K&C characteristics of the two suspension systems.At last,on the optimum design method,firstly got Isight with ADAMS/CAR Integrated Model,which can let the program automatically generates hard spot layout program,automatically simulate,automatically performance evaluation.In the integrated model,the test parameters by DOE study found 12 pairs of high sensitivity performance hard point coordinate directions.Furtherly,took the higher sensitivity of 12 hard point coordinate direction as the design variables for multi-objective optimization,completed the first optimization,but optimization results was not very satisfactory.Followed by expanding the design domain to run the second optimization,eventually achieved better optimization results.