Research On The Design Of Vehicle Suspension Based On System Engineering

In the development process of vehicle suspension system,the re-design problems of suspension system caused by an unreasonable designed part occur frequently,which leads to the mismatching of assembled suspension and the vehicle;the vehicle performance field test must be carried out under specific road conditions and climate conditions,which have a long experimental cycle and cost high,and its results will greatly affected by the precision of testing instruments.The vehicle suspension system update quickly,and it should match models multiply;how to design a practical and effective vehicle suspension system rapidly at low cost has become the focus of the study.In order to solve the problems in suspension design,design suspension with high efficiency and low cost,the paper made the following research.(1)The necessity of using system engineering method to develop suspension system was analyzed,and the system engineering method was applied into the development of suspension system.The suspension was planned completely in the view of system,and the development method of vehicle suspension was established based on system engineering.By analyzing the demand of suspension system,the user demand for vehicle systems was translated into design demand of suspension system,subsystem,component according to the decomposition order of “system ? subsystem ? component”.Then the system of the suspension was designed step by step at all levels according to the internal and external limiting factors of the system.And then the verification was done in accordance with the system integration sequence in order of “component?subsystem?vehicle” step by step.Finally the suspension system that meets user demand was finally obtained.(2)According to the system engineering development method,the suspension model was designed based on the requirement analysis and the integral parameters.The suspension helical spring model with self-contact was established based on the finite element method,the accuracy of the model were verified by comparing theoretical analysis results with static analysis;the anti-fatigue property of suspension helical spring was analyzed,the safety factor of the dangerous zone was obtained under the condition of frequency 3Hz working 400 thousand times,which meets the use requirements.(3)The suspension system of single wheel vibration experimental station was established based on virtual simulation technology,and the relationship between the suspension positioning parameters with the wheel jump was obtained.The minimum value of each location parameter was set as the optimization objective,the optimization variables were obtained through the sensitivity analysis of the design variables of the guide mechanism.Using response surface methodology,the relationship between optimization variables and optimization objectives was fitted by selecting quadratic model.Using full factorial design method,iterative optimization was done and the optimal variable value was obtained.Combined with the standard variance tool,the results show that the optimization effect was ideal.(4)Simulation and analysis scheme of vehicle ride performance was proposed based on virtual prototype technology.Virtual prototype model of vehicle was established based on multi body dynamics,and the accuracy of the simulation was verified by combining field test of the triangle convex block with the virtual prototype simulation.The simulation program of vehicle ride performance was carried out according to the national standard,including sine wave excitation scan test and random uneven road simulation,and the corresponding root mean square value of weighted acceleration was obtained and evaluated according to standard.The results showed that the vehicle has good ride comfort performance.(5)Simulation and analysis scheme of vehicle handling and stability performance was proposed based on virtual prototype technology.The construction method of virtual prototype model of automobile was studied,the virtual prototype model was established and its accuracy was checked.Vehicle handling and stability performance was annualized according to the national standard,including pylon Course Slalom Test,steering transient response test,return-ability test,steering efforts test procedure and steady state circular test.Simulation results showed the understeer characteristic of the car.The development method of the suspension system based on system engineering is driven by the customer's demand,depended on industry standard,aided by virtual prototype.Corresponding the gradually decomposition of system,subsystem and component demand with the gradually design,integration and verification of parts,subsystems and systems,step by step,the rapid development process of the vehicle suspension system is finally completed,which can find and solve problems at all levels of the design process,contributing to improving the development efficiency and shorten the development cycle of the suspension system.