1. 研究目的与意义（文献综述）

with the increasing popularity of school buses, the safety of schoolbuses is attracting more and more attention. as an important part of schoolbuses, the steering system of school buses is the key assembly for the activesafety of school buses, it plays an important role in ensuring the safety ofvehicles, protecting the safety of drivers and students, and improving theworking conditions of drivers. a suitable steering system can perfectly solvethe contradiction between light handling and sensitive steering. how to designthe steering system of the school bus so that the school bus has goodmaneuverability and safety has always been an important research topic forautomobile manufacturers and research institutions.

automobile steering system has experienced five basic developmentstages: pure mechanical steering system, mechanical hydraulic power steeringsystem, electronic hydraulic power steering system, electric power steeringsystem and wire-controlled power steering system. the steering wheel control ofpure mechanical steering system is relatively heavy, the driver's burden isheavier, currently in the edge of elimination. mechanical hydraulic powersteering system can greatly reduce the steering torque, but the hydraulic pumphas been working, a waste of resources. and low speed steering power is notenough, power characteristics cannot be changed, and the hydraulic power systemis easy to damage. electro-hydraulic power steering system reduces energyconsumption, and the size of steering power can also be adjusted according tothe rotation angle, speed and other parameters, which has become the choice ofmany household models. the electric power steering system uses the electricmotor as the power source, according to the speed and steering parameters andother factors, by the electronic control unit to complete the power control. itcan give consideration to the light steering at low speed and the stableoperation at high speed. it has good return-to-normal performance, simpleadjustment, flexible assembly and energy-saving advantages. wire-controlledpower steering system is a new generation of automotive electronic steeringsystem, which eliminates the mechanical connection between the steering wheeland directive wheel. it can improve the passive safety of automobile, bebeneficial to automobile design and manufacture, and greatly improve the ridecomfort of automobile. but it's still in the research phase.

the pure mechanical steering system is simple in structure andreliable in operation. at present, it is used in some micro cars andagricultural vehicles with large steering force and low requirements forsteering performance. hydraulic power steering system technology is mature, canprovide large steering power, widely used in heavy vehicles; electric powersteering system is favored for its unique advantages. it represents thedevelopment direction of power steering technology in the future. thewire-controlled steering system will become the development direction of thepower steering system because it is beneficial to improve the passive safety,design and manufacture, ride comfort and handling stability of the automobile.

2. 研究的基本内容与方案

1. basic contents

3. 研究计划与安排

(1) collected data, conducted research andwrote the opening report

week1

(2) prepared the opening report and practiced the construction ofsteering system week 2 -week 3

4. 参考文献（12篇以上）

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