1. 研究目的与意义（文献综述）

nowadays, with the development of the automobile industry, the concept of the car has gone far beyond its original meaning media of transportation. while developing the performance of automobiles, people also aim more at improving the smoothness, handling stability and comfort of driving.^[1,2] an automobile suspension, which is a connecting member between the vehicle wheel,vehicle body, and frame, is responsible for transmitting forces and forces acting between the wheel and the frame, and cushioning the impact transmitted from the uneven surface to the frame or the body.meanwhile it can attenuate the vibration caused by forces, to ensure that the car can drive smoothly.^[3]

suspension can be divided into three main suspension kinds, independent suspension, non-independent suspension and semi-independent suspension.^[4] compared to the other two types of suspensions, the independent suspension is lighter, also it can reduce the impact on the car body and improve the ground adhesion of the wheels; the soft spring with small rigidity can be used to improve the comfort of the car; the position of the engine can be lowered. when the vehicle is lowered, the car's center of gravity is also reduced, which increases the driving stability of the car; the left and right wheels run independently and are independent of each other, which can reduce the body's tilt and vibration. independent suspension can be divided into horizontal arm type, vertical arm type, multi-link type, candle type and macpherson type suspension. compared to other main forms of rear suspension of automobiles, the main advantages of double wishbone suspension are: large lateral rigidity, excellent anti-rolling performance, good grip performance, clear road feelings.its strength is far better than double-link structure and is superior to the torsion beam in terms of comfort and maneuverability, slightly inferior to multi-links, and has obvious advantages over the integral bridge type of pure suv. at this stage, the double wishbone suspension system has been widely used in various suv such as the honda crv, audi q7 and so on. in this paper, by taking the rear suspension of havel h6 as an example,i try to study the double wishbone suspension .i try to design the basic geometry model of it by using cad/cae^[5]. also the paper aims at optimizing this model to improve the performance of the suspension system, reducing design costs. by the basic functions of adams,the position parameters such as toe-in and toe-out,camber,caster of the rear suspension system is simulated and optimized^[6,7]. the purpose of this paper is to use modern software for analysis and design to simplify the design and development structure of the double-wishbone rear suspension, improve the performance of the suspension system, and obtain innovative and optimized products.^[8]

the research of the suspension system design has gone far since its born.with the high requirement of the vehicles people have tried many ways to develop the optimized suspension system^[9].the researcher have been used adams^[10]and the simulink and simmechanic function of the matlab to model a car suspension and then by dynamic analyze to optimize the geometry parameters of the vehicles^[11].stefano uberti,marco gadola etc have focused on the layout and kinematic analysis phases of the design process.^[12]samant saurabh y, santosh kumar etc the cad models of the components in the suspension system used solidworks and the finite element analysis of the components is done using ansys workbench to perform both kinematic and dynamic analysis of the designed suspension system.^[13] kang d. o, heo s. j, kim m. s etc have presented the robust design optimization process of suspension system for improving vehicle dynamic performance by target cascading method.^[14]hazem ali attia uses the laws of particle dynamics to derive the equations of motion of the system of particles which results in a 31×31 constant sparse symmetric mass matrix with the presence of large number of geometric and kinematic constraints.^[15]

2. 研究的基本内容与方案

(1)collecting paper and researches of the rear suspension,especially double wishbone suspension in china and aboard,analyze the advantages and disadvantages of this kind of suspension.

(2)studying the basic structure and principle of the rear suspension. determine the main parameters, original size of the double wishbone suspension with the help of the design manual and the size of the havel h6 car.

(3)using software such as cad to model and do the kinematics simulation analysis to get the stress and the force

3. 研究计划与安排

1-2. (7th semester, 19th to 20th weeks) determine the topic of design plan, descriptions of the graduation design selection (parameters), the campus information collection.

3. (8th semester 1st week) design, document retrieval, complete the opening report.

(2nd-3rd weeks) practice outside, the data collection outside, finish internship report.

4. 参考文献（12篇以上）

[1]x. x. guo,y. d. deng,m. h. huang. vehicle design [m].china communications press.(2013): 143-147.

[2]y. tian.double wishbone independent suspension optimization design and vehicle ride comfort[d].northeastern university.2009,06.

[3]z. s. yu. vehicle theory[m].china machine press.(2009): 162-176.