The Regression Analysis Of Linear Handling Performance Indexes And Assembly Parameters For AO Type Passenger Car

Because there are so many vehicle design parameters that influence the dynamic handling behavior of a vehicle, it is difficult to consider all of their complex interactions in an intuitive way so as to make the best design compromises. Associated with the project of National 863 Program, this paper is about the regression analysis of linear handling performance indexes and primary assembly characteristic parameters for AO type passenger car.lt can help engineers to choose the type of assemblies at the early stage of vehicle's development; to predict vehicle's linear handling performance, based on primary assembly parameters; to get targets of assembly with the analytical target cascading's guidance in the forward development process.Also,this method can be used to analysis the relation of other chassis performance indexes and primary assembly characteristic parameters.This paper is divided into six parts:Chapter 1 briefly introduces the current development status of Chinese vehicle industry and its strength and disadvantage.It is the matching design and optimizing of chassis that restrict our research level, by comparing to vehicle's development and tools used abroad.Meanwhile, the main research contents of this paper are also put forward.Chapter 2 introduces the establishment of an AO type vehicle model in veDYNA, and checks for its component characteristic, assembly characteristic, and for its handling performance. The results show that the vehicle model which is established in this paper is basically correct; it can describe the dynamical characteristics in linear area correctly and accurately. The vehicle model can be used for further study.Chapter 3 gives the regression model of vehicle linear handling performance steady-state indexes(understeer Gradient:K.. Roll Gradient:R(?))and primary assembly parameters for AO type passenger car.Fristly, this paper gives the mean value and the±3<σ values for component characteristic parameters,assembly characteristic parameters and vehicle performance indexes from different AO type passenger cars,using'3σprinciple '.Secondly, screens the assembly characteristic parameters, with the sensitivity analysis guidance.Thirdly, establishes the regression model of vehicle linear handling performance steady-state indexes and key assembly characteristic parameters for AO type passenger car.The results of statistical check show that the statistical accuracy is good.Chapter 4 gives the regression model of vehicle linear handling performance transient-state indexes(Natural Frequency:ω,Response Time:Tf,Relative Damping Factor:) and primary assembly characteristic parameters for AO type passenger car.Due to the nonlinear feature of transient-state indexes, this paper gets the expression of vehicle linear handling performance transient-state indexes and effective cornering stiffness(front effective cornering stiffness:C,> rear effective cornering stiffness:C2) firstly,based on the linear bicycle model;then establishes the regression model of C,^ C2 and primary assembly characteristic parameters for AO type passenger car;Lastly, gets these models back into the expressions,we get the regression model of vehicle linear handling performance transient-state indexes and primary assembly characteristic parameters for AO type passenger car. The results of statistical check show that the statistical accuracy is good.Chapter 5 analyses the application of the regression models of linear handling performance indexes and primary assembly characteristic parameters for AO type passenger car.lt is of great importance at the early stage of vehicle forward development, the models can be used to choose the key assembly, to predict vehicle linear handling performance, to set the targets of key assembly characteristic indexes.Chapter 6 is the summary and conclusion; it also puts forward the future research directions.Major innovations are as follows:(1) Analysising vehicle's assembly parameters,at one time, may ignore the impact of some important assembly parameters to vehicle linear handling performance indexes. Parameters of the assembly is divided into several modules in this paper,also, it arranges orthogonal test for every module, and gives the sensitivity of vehicle's assembly parameters and vehicle's linear handling performance indexes at different significance levels.(2) Establishing the regression model of linear handling performance indexes and primary assembly characteristic parameters for AO type passenger car, using DOE.This model is a useful tool to choose primary assemblies, to predict vehicle linear handling performance, to set targets of key assembly characteristic indexes.