This paper systematically sorts out the generation methods of simulation test scenarios for autonomous vehicle, summarizes the latest research progress in the fields of autonomous vehicle simulation test scenario definition, scenario deconstruction, scenario generation based on data driven, and scenario generation based on mechanism modeling, and summarizes the relevant evaluation and application of test scenarios. Finally, the paper proposes that future research should focus on integrating the characteristics of Chinese driving scenarios, deepening the research on edge scenario generation strategies, and accelerating the construction of the standard system of scenario construction.

This paper takes the autonomous driving scenario library as the research object,and by analyzing shortcomings of autonomous driving scenario library and industry demand, and formes a set of operation guidelines for autonomous driving scenarios construction based on real world traffic data. Firstly, the elements and formats of autonomous driving scenarios have been illustrated and standardized. Secondly, scenario datasets are generated by a three-step procedure, including scenario mining, automated annotating and data compliance desensitization. Finally, a set of safe, compliant, high-quality, and high-value city level challenging autonomous driving scenarios was ultimately formed by risk assessment of real collection scenarios and standardized processing of abnormal events.

To test the steering function of autonomous vehicles, a vehicle in the loop virtual simulation testing system design is designed. A rotating plate driven by a linear motor is added to the front axle drum group on the traditional drum/brake testing platform to achieve a maximum 10° steering function during vehicle driving. Combined with software simulation technology, dynamic braking force testing is carried out for the speed reduction of autonomous vehicles from 80 km/h to 20 km/h during steering operation, as well as braking friction force testing during the speed reduction to 0 km/h. The test results are analyzed and verified. The analysis results indicate that the testing system can achieve the expected braking ability of autonomous vehicles within a steering angle range of ±10°, and control the testing braking force accuracy within the range of ±5 N, whitch further verifies the effectiveness of the testing system.

In order to investigate the effects of Ionic Liquid (IL) additives on the tribological properties of the key pairs of internal combustion engine, nitriding cylinder liner and molybdenum spray piston ring under high-reinforcement conditions, the lubricating oil with 2% ionic liquid mass fraction is used to lubricate the pairs. By analyzing the surface morphology, composition and tribological chemical reaction products of the worn pairs, the paper investigates wear behavior and relates mechanism of pair under ionic liquid lubrication, and evaluates its influence on friction, wear and wear characteristics of pairs. The experimental results show that the ionic liquid additive can improve the tribological properties of nitriding cylinder liner and molybdenum injection piston ring pair. The ionic liquid has the best tribological properties at 180 ℃, which is related to the tribological chemical reaction of ionic liquid on the surface of cylinder liner and its products.

In order to analyze the dynamic characteristics of electric vehicle body, a modal test is used to identify the modal parameters of an electric vehicle Body-In-White (BIW), and the test results are compared with traditional modal test results through the acceleration sensor. The results show that the maximum error of natural frequency of BIW obtained through 3D laser vibrometry is less than 1.3% and have a high consistency with the vibration mode obtained from the traditional modal test, which verifies the feasibility and accuracy of this test method.

In order to find the cause of sunroof water leakage, this paper systematically studies three types of sunroof water leakage modes based on the bottom-mounted sunroof structure, including water leakage between the body and the roof seal strip, water leakage between the roof seal strip and the sunroof glass, water leakage over the guiding gutter. The result show that the sunroof water leakage are related to factors like the sunroof seal strip, the sunroof guiding gutter, the sunroof drain pipe, the body and the assembly. The sunroof water leakage can be effectively solved by improving the form of the roof seal strip, compression load performance, coordination with environmental components and joint quality, improving the layout, structure and water conductivity of the guiding gutter, improving the form, layout and displacement of the drainage pipe, improving the flanging size and surface quality of the body, optimizing the assembly environment, techniques and tooling positioning.

To address the issue of water leakage of automobile sunroofs, theoretical and experimental research on the inlet and drainage characteristics of automobile sunroofs are carried out. By simplifying the automobile sunroof drainage assembly system, the physical model of the sunroof drainage pipeline is constructed, and the pipeline design are modeled and derived, and the theoretical calculation formula of the maximum drainage capacity of the pipeline is obtained. A sunroof test bench is built to measure the influence of various parameters and pipeline parts on the drainage capacity of the drainage pipeline based on the theoretical analysis results, and the theoretical and test results are compared. The water inlet characteristics of the sunroof are experimentally studied, and the distribution characteristics of the water inlet and drainage of the sunroof under different vehicle conditions were analyzed. It is found that the water flow from the drainage pipe is distributed differently with the tilt angle of the vehicle, and the water drainage of the front side of the horizontal vehicle is higher than that of the rear. It is suggested that the slope of the vehicle should be considered in pipeline design to increase the design margin of the front water pipe.