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.

For the influence of electromagnetic coupling vibration caused by random road excitation and unbalanced electromagnetic excitation of in-wheel motor on electric vehicle driven by in-wheel motor, this paper proposed a vibration suppression method based on Active Disturbance Rejection Control(ADRC). Firstly, the mathematical model of a quarter of the vehicle vibration system was established. Secondly, a controller based on ADRC was designed. The road random excitation and the electromagnetic excitation generated by the motor itself were regarded as the total disturbance for unified observation compensation control. Finally, the proposed control strategy was verified by MATLAB/Simulink. The results show that ADRC can suppress the electromagnetic coupling vibration caused by road roughness and eccentric electromagnetic force.

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.

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 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.

To address the problems of small dataset and low efficiency of artificial diagnosis method in the research process of passenger vehicle abnormal noise recognition, this paper proposed an efficient intelligent recognition technique, which applied data expansion method with high recognition accuracy and adopted the parallel working mechanism of Convolutional Neural Network (CNN) and Transformer encoder stack to obtain the classification model. It is found that the data expansion method can effectively improve the classification performance when the extracted Mel Frequency Cepstral Coefficients (MFCCs) features of the augmented data are used as the input to the parallel network, and the proposed model can achieve classification accuracy up to 98.31% on the testing dataset.

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.

For the transient current overloading when the permanent magnet fan for heat pump is powered down and resumed, this paper proposes a sensorless coasting startup strategy based on current resonant tracking control. Utilizing the current suppression control method and the quasi-resonant tracking method, a two-stage starting process was designed including the current-loop suppression tracking and the speed-loop synchronous recovery for motor free coasting condition, to quickly resume the current-speed closed-loop vector control and make the start smooth. The simulation and the testing results showed that in the medium and high-speed coasting, the proposed starting strategy can effectively reduce the steady-state error of the current and improve its dynamic response, and improve the estimation accuracy of the sensorless algorithm for the current tracking process, so as to enhance the smoothness and reliability of the coasting starting process.

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.

To solve the problem that the traditional shift schedule of two-speed transmissions for battery electric vehicles cannot obtain the optimal shift performance under different conditions, this paper proposes a knowledge-based method for shift decision-making. Firstly, the dynamic model of battery electric vehicles was established, the optimal shift data was obtained by dynamic programming. The two-parameter shift schedule was extracted based on support vector machine. Secondly, the data of manual shift was collected to build an exclusive database. The intelligent shift decision model was built based on the long short-term memory network, and the shift decision model was updated online by over-the-air technology. Finally the proposed shift decision method was verified by simulation. The results show that long short-term memory network model has high shift decision accuracy, the proposed knowledge-based shift decision method has better shifting performance than traditional two-parameter shift schedule.