The A/B system upgrading technology is proposed to solve the problem that the System on Chip (SoC) Electronic Control Unit (ECU) cannot roll back the software when the Over-The-Air (OTA) upgrading failed. The technology downloads the program to the backup slot by reading the MISC of ECU slot information, and starts the installation by designing the priority level of the A/B system to select the active partition or rolls back the software in case of upgrading failed. At the same time, the differential graded technology of A/B system is designed. The ECU using this technology can perform software rollback when upgrading fails,and the feasibility, effectiveness and stability of rolling back software technology are verified by building a test environment.

To analyze the performance of the battery direct cooling and heating management system coupled with passenger cabin air conditioning, a power battery thermal management system model is established based on AMESim software. The charging time of typical liquid cooling and direct cooling and heating management systems under high-temperature fast charging conditions is compared. The results show that under the same fast charging MAP, the charging time of the direct cooling system is shortened by 7.6% compared with the liquid cooling system. The passenger cabin air conditioning and battery thermal management system is further coupled, and a thermal management control strategy is designed with the goal of controlling the temperature of the passenger cabin and the maximum temperature of the battery cells. Results show that compared with the uncoupled system, the maximum temperature difference on the top of the battery increases by 2.9 ℃ when using the coupled system, but the charging time is shortened by 4.9%.

For the issue of driving style identification, this paper proposes a method based on subjective and objective fusion. Firstly, the subjective style scale is developed and transformed into subjective factors. Secondly, a data acquisition system is implemented to gather the natural driving data and the basic behavior scenarios of car following and lane changing are mined. Thirdly, the fusion of subjective and objective identification system of driving style is constructed by extracting the key behavioral characteristics and subjective factors. Based on Principal Component Analysis (PCA) and K-means methods, the sample set is processed and the clustering results are verified. Finally, specific characteristics with physical significance are introduced to identify radical, moderate and conservative driving styles. The results reveal a strong correlation between the distribution of subjective style factors and objective behavioral characteristics, and the fusion method can be used to identify driving style effectively.

To tackle the challenge of exhaust gas leak detection, this paper proposes an exhaust gas leakage detection method based on distributed fiber optic vibration sensing technology. Firstly, sensors are mounted on the vehicle’s exhaust pipe to detect variations in both intensity and phase of the optical fiber light signal, which arise from local pressure disturbances associated with exhaust gas leaks. A distributed vibration sensing system that utilizes a dual Mach-Zehnder interferometer setup is applied with a differential cross-correlation algorithm for demodulating vibrations captured at both ends. Secondly, a cross-correlation delay algorithm is used to precisely pinpoint any leakage locations. In simulation test, leak scenarios are emulated using a piezoelectric ceramic device along with a designated fiber length of 2 m, achieving remarkable positioning accuracy of 0.01 m and validating the feasibility of this proposed method.

To address the issue of deterioration of soot caused by EGR technology, a shunt centrifugal oil filter is introduced based on the principle of centrifugal sedimentation, and its structure principle, critical characteristic and influencing factors are systematically reviewed. A magneto-electric test system based on speed characteristics is developed, and the key points of adaptive design of centrifugal oil filter are explored. The soot-removal effects of the centrifugal oil filter are analyzed from the aspects of physical and chemical testing of oil products, plugging life of filter element and driving test. The results show that the soot-filtration effect of centrifugal oil filter is more obvious for EGR models, but slightly redundant for SCR models. The paper analyzes the influence of soot on oil viscosity and the benefit mathematical model of centrifugal rotor filter on fuel consumption builds based on the relationship between oil viscosity on fuel economy.

To improve the static comfort of normal family cars, this paper proposes the seat static comfort simulation analysis method including H-point position prediction and seat cushion pressure distribution uniformity based on SAE J826 tooling finite element model and the 50^th percentile flexible human body FE model provided by CASIMIR software, and the static comfort performance is improved by HyperStudy optimization tool. The simulation results are consistent with the experiments results.

In order to solve the problem of difficulty in Computer Aided Engineering (CAE) evaluation of forming failure of small fillet feature line, for a door outer panel with such feature, AutoForm was used to control the material inflow by adjusting the drawbead, and four kinds of door outer panel models with different forming states are obtained. Meanwhile, the forming condition and practical stamping condition with and without thickness stress are analyzed respectively. The results show that the forming limit of small size fillet feature line is reduced due to the influence of thickness stress, and uneven plastic deformation will occur in further forming, so the traditional formability CAE evaluation method is not suitable for small size fillet feature lines. Finally, a CAE method for evaluating the formability of small fillet feature lines combined with slippage is proposed, that is, when the slippage is less than 5mm and the thickness reduction rate and maximum nonlinear failure value meet the requirements, it can be considered that there is no formability risk of small fillet feature lines.

The rainwater pollution on vehicle side window affects driver’s safety critically, it is necessary to study this kind of water management situations. By improving the key parameters of windshield water bar, and in combination of vehicle climate wind tunnel test results of different windshield water bars of a SUV, this article quantiataively analyzes water pollution area of the front side window and the exterior rear view mirror area by image processing technology, and proposes an evaluation method considering the lateral and rearview field comprehensively. It is found that increasing the height of the windshield water bar and the water storage area can reduce the water flow to the side window and weaken the water pollution of the side window. Finally, a water bar scheme for the front wind window with better visual field and engineering feasibility is obtained.