For the characteristics of complex adjustment and control of the dot-matrix LED high beam lighting field, this paper analyzed the lighting requirements and luminous characteristics of the dot-matrix LED high beam, and then the mapping relationship between the dot-matrix LED high beam and the vehicle front lighting light field was established based on the geometric relationship, and a complete test system was built and tested. The test results show that the proposed method has accurate control effect, good real-time performance, high reliability and easy implementation.

At present, the starting evaluation method of Dual Clutch Transmission (DCT) vehicles is mainly based on the driver’s subjective evaluation. Too much subjectivity leads to inaccurate evaluation. In view of the above problems, a DCT vehicle starting quality evaluation system was established based on the grey relational analysis method and the fuzzy comprehensive evaluation method. In this study, power, comfort and economy were considered, and starting quality evaluation indicators including starting response delay time, starting acceleration time, starting acceleration peak, engine speed fluctuation and shock were selected as evaluation index. The coefficient of variation method calculated the objective weight of the starting quality evaluation indicators, and based on the grey relational analysis method, the order of the correlation degree between each index and the starting quality was clarified, which verified the accuracy and reliability of the weight calculation results. Finally, based on the fuzzy comprehensive evaluation, the starting quality evaluation model of DCT vehicles was established and objectively scored, which made the starting quality evaluation of DCT vehicles more objective and true.

In order to verify the performance of vehicle under the functional interaction between Integrated Boosting System (IBS) and Electronic Stability Control (ESC), troubleshoot and locate the faults when IBS and ESC are interacted, this paper proposes a redundant brake electrical system multiple mechatronics Hardware In the Loop (m-HIL) testing platform scheme based on m-HIL technology, which could test function and performance of brake electrical system under functional interaction between IBS and ESC. According to the combined testing method, regenerative braking condition testing under IBS and ESC redundant controllers was accomplished. In addition, the parameter space corresponding to brake boosting failure under regenerative braking condition was abstracted, the typical test cases of braking boost failure under regenerative braking condition between IBS and ESC were formed.

Based on a 2.0 L naturally aspirated Atkinson gasoline engine with a Low Pressure Exhaust Gas Recirculation (LP-EGR) system, the effects of different EGR and EGR coupling Variable Valve Timing (VVT) on combustion characteristics and performance were studied. The results show that the LP-EGR can effectively suppress knocking and reduce pumping loss, improve fuel thermal efficiency of Atkinson gasoline engine and reduce NO_x emission. For the Best Thermal Efficiency (BTE) point of the engine, the effective fuel thermal efficiency can be improved by 7.4% due to 27% of EGR rate. At the medium load point, the combustion stability can gradually deteriorate with the increase of the EGR rate, and the effective fuel thermal efficiency increases first and then decreases. At the external characteristic point, EGR can lead to a decrease in charging efficiency and power. In addition, the study shows that VVT and EGR have a coupling effect on fuel consumption of Atkinson gasoline engine.

In order to study the noise source characteristics of integrated electric drive assembly, this paper proposed a joint algorithm of RVMD-RobustICA-ST combined with coherence analysis method. Firstly, the spatial dimension of the noise was estimated by Rule of Dominant Eigenvalues(RDE) based on Singular Value Decomposition(SVD), and the variational modal decomposition was subjected to targeted conditional constraints, and then Robust Independent Component Analysis(RobustICA) combined with variational modal decomposition to extract signal features. Secondly, S Transform and Fast Fourier Transform were used to identify the time-frequency characteristics of each component signal. Finally, on the basis of analyzing the waveform error of the component signal using the quadratic residual method, a linear system was established with the vibration signal, noise signal, and time-frequency overlapping component signal of the electric drive assembly as variables for coherence analysis. The results show that the meshing vibration noise of the second gear pair of the reducer has the greatest contribution to the noise of the electric drive assembly under steady state conditions, and the noise energy of the time-frequency overlapping component signal is mainly provided by the meshing vibration of the first gear pair of the reducer.

In order to solve the shortcomings of current longitudinal collision avoidance technologies in specific scenarios such as high relative speed, poor road adhesion conditions and low overlap rate with obstacles, this paper studied the typical test scenarios and road tests of vehicle with less longitudinal distance and higher collision avoidance efficiency. Through analysis of the largest dada dataset for driving attention prediction in China, and in combination with the requirements of the EU ECE-R79 automatic steering standards, the typical test scenarios of Automatic Emergency Steering (AES) were obtained. At the same time, the road tests were designed, and a test software & hardware design scheme was proposed, which can monitor the emergency steering tests of different vehicle speeds under typical test scenarios, thereby realizing the effective test evaluation of the AES system.

In order to study the head crash conditions of two-wheeler cyclist in traffic accident, this paper verified the car-to-two-wheeler crash model by accident reconstruction, and analyzed the differences of head impact area, speed and angle on sedan and SUV models, proposed the evaluation suggestions in combination with the existing pedestrian protection evaluation requirements. The results show that the head crash speed of the cyclist is not different from that of pedestrians. For the vehicle with Bonnet Leading Edge (BLE) height bellow 850 mm, it is recommended to expand the Wrap Around Distance (WAD) of head crash area from 2 100 to 2 300 mm, and the collision angle is 45°. For vehicles with BLE height higher than 850 mm, there is no need to expand the area.

In order to accurately reflect the driving motion characteristics of vehicles on the real road, this paper proposes a vehicle driving cycle construction method based on Markov fusion online map information. In this paper, the actual collected vehicle driving data were cleaned and segmented that were clustered and analyzed by Principal Component Analysis (PCA) method and K-Means clustering method, and a typical working condition fragment library based on Markov was established. The road information of the planned path on the online map was integrated in the fragment database, and the road driving condition of the vehicle was constructed. An electric vehicle was taken as the research object for simulation and analysis, the results show that the energy consumption of online map planning driving condition based on Markov fragment library is closer to the actual road condition than that of online map basic planning condition. The error of characteristic parameters is only 4.29%, and the error of energy consumption is only 4.09%.

In order to obtain reliable analytical calculation methods for the steady-state lateral stiffness considering the end constraints of variable diameter springs, the analytical calculation formulas of spring end restraint moment were obtained by using Moore integral according to the mechanical model of variable diameter spring. Based on the restraint moment of variable diameter spring, the analytical calculation formulas of steady-state lateral flexibility and stiffness of variable diameter spring were derived. With a case study, the steady-state lateral stiffness of variable diameter spring was analyzed and simulated, the calculated values are consistent with the simulated values, the relative deviations of flexibility and stiffness are within 0.21%, which means that the analytical formulas are correct. Finally, based on the steady-state lateral stiffness of variable diameter spring, the analytical calculation formula of transverse deflection of variable diameter spring at any position under transverse load was established, the deviation between the calculated value and the simulation value is within 0.21%, indicating that the analytical formula of the relative lateral deflection of the spring is correct.

In order to solve the problem of low accuracy of oil stirring loss calculation caused by turbulence in the complex multi-pair gearing reducer, based on the Moving Particle Semi-implicit (MPS) method of Lagrangian system, and combined with Smagorinsky turbulence model and the calculation method of turbulent shear stress on polyhedral wall, the calculation accuracy of stirring loss was improved, which was verified by simulation and test. Finally, the influence of different oil stirring loss on the efficiency of recirculating conditions was analyzed. Research results show that the method can effectively improve the calculation accuracy from 47% to 91% on average of the oil stirring loss of the reducer, and the improvement effect is especially obvious in high-speed conditions. In the recirculating condition, the oil stirring loss has a significant impact on the reducer efficiency, and reducing the oil stirring loss can effectively improve the reducer efficiency in the recirculating condition.