1. 研究目的与意义（文献综述）

1. purpose and significance (including domestic and foreign research status analysis)

suspension is the general term for all power transmission connections between the frame (car body) and the axle (wheel). its function is to transfer vertical reaction force (support force), longitudinal reaction force (driving force and braking force) and lateral reaction force acting on the road surface by the wheel and the moment caused by these reaction forces to the frame (or the carrier body) to ensure the normal driving of the car. nowadays, despite its various structural forms, the suspension of a car is generally composed of three parts: an elastic element, a shock absorber, and a guide mechanism. as far as cars exist in the market, shanghai volkswagen passat, guangzhou automobile honda fit, dongfeng peugeot 307, faw toyota corolla, shanghai general lacrosse, faw-volkswagen magotan mazda 2 and other front suspensions all adopt mcpherson independent suspension. mcpherson suspension has been used as a common suspension.

volkswagen nms (new midsize sedan), meaning the new mid-size sedan, is a new-generation mid-size sedan code developed by volkswagen for the north american and chinese markets. the nms is a branch of the seven-generation model, officially named "new passat" in china. "the passat's front suspension uses the macpherson suspension, which is more common on the market. it is usually composed of two basic parts: the pillar-type shock absorber and the a-shaped support arm, which is priced at 200,000." the front suspension form commonly used for small and medium sized cars. the macpherson suspension is also called a strut link suspension and consists of a sliding column and a yaw. it can be seen as an improved version of the candle suspension. due to the addition of the yaw arms, the stress condition of the sliding columns is improved. the choice of suspension structural form and performance parameters will affect the performance of the vehicle. these are mainly reflected in the vehicle's ride comfort, handling stability, etc., so the choice of suspension structural form and performance parameters is critical for the vehicle. choosing a suitable suspension for the car will simplify the car's other structural design while improving the car's performance. the mcpherson suspension has advantages in this respect. it can increase the inner space of the two front wheels comparatively, and it is convenient for the arrangement of the engine and other parts. it is suitable for front-drive models and can be installed at the front of the car. the engine and gearbox save space, because most small and medium-sized cars are ff type, so mcpherson suspension becomes a common choice. at the same time, macpherson suspension also has its shortcomings; the friction and wear of the sliding column are large. the use of spiral springs does not provide much support for the lateral force, which results in the vehicle not being able to control the roll when cornering. it is also relatively easy to nod. because we want to retain the advantages of the macpherson suspension, we can only optimize the mcpherson suspension on the basis of the original design (specifically where to optimize the design is the main task of this topic) to reduce the impact of its shortcomings on the car's performance. the weight of the entire car body and the impact of the car during its movement are mainly borne by the two components of the a-shaped support arm and the pillar type vibration absorber. the design should focus on the design and optimization of the vibration-reducing support, and add the stabilizer bar to the design. it can also reduce the roll of the vehicle, improve the driving stability of the vehicle and reduce the friction and wear of the sliding column.

1.1 research state in china

with the development of cad design, virtual prototype simulation and advanced control technology, zhu tianjun proposed to use virtual simulation software adams and fuzzy control simulation software matlab/simulink for analysis. he analyzed the change of the suspension parameters during driving. according to adams/insight, the model of the adams/car model was optimized by the guidance mechanism, and the optimal solution of the suspension system was obtained. secondly, the matlab modeling and simulation for the control of the vehicle suspension damping controller is proposed ^[1].

2. 研究的基本内容与方案

2. research basic content and technical solutions

2.1 fundamental contents

1 the structural selection of the front suspension of the passat car (structural analysis and options).

2. design and calculation of the passat front suspension (determination of main macpherson suspension parameters).

oslash; design of coil spring: selection of spring material; force and deformation of spring; calculation of spring geometrical parameters; processing of calculation results, and checking.

3. 研究计划与安排

3. Schedule

4. 参考文献（12篇以上）

4. references

[1] zhu tianjun. dynamic simulation of a mcpherson suspension based on fuzzy logic[j]. jilin university, 2005

[2] shao zhaohui. 3d design and motion analysis of mcpherson suspension[d]. wuhan university of technology, 2011

[3] liao licheng. kinematics simulation and optimization design of macpherson suspension based on multi-body system dynamics [d]. wuhan university of science and technology, 2009