1. 研究目的与意义（文献综述）

th the development of china's highway transportation industry and the popularization of vehicles, we can now travel quickly and effectively, but the attendant problem is: traffic accidents have increased accordingly, and the size of faulty models vary, in view of this situation, road scavengers came into being. road scavenger means a special car with road rescue operation equipment, referred to as a scavenger, also known as a road rescue vehicle, trailer, towing car. the scavenger is mainly composed of chassis, lifting device, lift traction device, hydraulic system, electronic control system, vehicle body and toolbox, etc. it has many functions, such as lifting, pulling and lifting traction. it is used for the clearance of highways and urban roads. as the car on the road when the fault and accident is inevitable, the main task of the clearance vehicle amount is to drag the faulty car or accident car away from the scene in time to ensure that the road is unobstructed.

china's scavenger car started in the 80 's, is gradually in line with the world. with the development speed of urbanization in the new century, road traffic conditions have been continuously improved, the situation of vehicle accidents on the road is also changing, the demand for scavenger vehicles is also growing, the function of the scavenger is also increasing. the new type of scavenger will replace the old-fashioned scavenger, safe operation, fast is two important indicators of the vehicle, now the scavenger is personalized, humanized, high efficiency of the form of development. the design of this scavenger to improve the intelligence of the scavenger, in the road clearance process, to ensure that the vehicle in the working state of safe, convenient and fast. as a result, road scavengers are known as "messengers that make the earth's veins more open."

scavengers play an increasingly important role in our daily lives, so it is important to understand the differences in technology between our country and foreign countries. china began to introduce and imitate the scavenger in the late 80, starting from the third stage of the development of foreign scavenger vehicles, starting from a higher beginning, and taking a road combining the introduction of technology with independent development. whether it is r amp; amp; d technology or production capacity, china's enterprises can meet the domestic market demand. however, compared with the world's advanced level there is still a certain gap. the main manifestations are as: first,at present, the basic use of cargo vehicles in the two types of chassis retrofit scavenger.then,product development is mainly in the imitation stage.finally,intelligent monitoring.

2. 研究的基本内容与方案

the basic content， objectives and technical solutions or measures of the design

2.1 basic content

1）determination of key performance indicators.

3. 研究计划与安排

4. 参考文献（12篇以上）

1]yu zhisheng. automobile theory [m]. mechanical industry press: beijing, 2009.

[2]ming pingshun. automobile structure [m]. wuhan university of technology press: wuhan, 2016.

[3]guo xuexun. automobile design [m]. people's communications press: beijing, 2013.