In order to efficiently realize the measurement of vehicle wheel brows, a non-contact vehicle wheel fender clearance measurement system is designed based on image processing technology, and corresponding measurement software is created with the Graphical User Interface (GUI) of MATLAB. The verification results show that for actual clearance of at least 15 mm, the error of the wheel fender clearance calculated by the system under different shooting distance conditions is controlled within 2%, which exhibiting a high degree of measurement accuracy.

In order to improve the accuracy, stability and flexibility of the vehicle chassis geometric parameter detection system, a vehicle chassis geometric parameter measurement system consisting of LED type 3D surface measurement sensors is designed based on stereo photogrammetry, using a structured LED light source to form a “spatial measurement area” based on the entire wheel side surface and wheel cover edge. By using 3D photography technology to obtain point cloud data under dynamic measurement, and combining with x-line software, a 3D wheel hub model is established to analyze and calculate the front toe camber angle of the chassis, the linearity and repeatability of the measurement system. The results show that linearity error of this measurement system is 1.528', repeatability error of front toe angle and camber angle are ±0.03' and ±0.05' respectively, verifying stability and reliability of the measurement system.

In order to analyze the influence of random and impulse road surface on the smoothness of commercial vehicles, a commercial vehicle is taken as the research object to construct the vehicle dynamics model containing front and rear suspension, tire, body, steering system and human body-seat system by using the ADAMS/Car software. The smoothness analysis of impulse and random input is carried out for the vehicle, and simulation results show that the smoothness of the vehicle increases after increasing the vehicle speed under the excitation of pulse road surface; the effect of smoothness is more significant on Class C road compared with Class B road under the random road surface input condition, which is more effective in the evaluation and improvement of driving comfort of commercial vehicles.

In order to improve the vehicle driving range of a pure electric light commercial vehicle, this paper proposes to reduce the electric power consumption per 100 kilometers by reducing power consumption and increasing coasting energy recovery power. Firstly, for ECO energy-saving mode, the paper proposes the energy-saving control technology based on different vehicle usage scenarios and working conditions, which significantly reduces the energy consumption of the vehicle in the whole scenario. Secondly, in the view of the coasting energy recovery deceleration of commercial vehicles with empty and full load varies greatly, the paper proposes the energy recovery control based on the vehicle mass to achieve the same coasting deceleration under different loads to recover more energy. Then, for the problem that coasting energy recovery is usually designed with low adhesion coefficient road surface, the paper proposes adaptive adjustment of coasting energy recovery based on road adhesion coefficient. Finally, the pure electric light truck is tested on real road. The results show that the ECO mode reduces the electricity consumption per 100 kilometers by 2.9%, and by 2.1% for scenarios of turning on the air conditioning and opening the car door. The energy recovery strategy based on the vehicle’s mass shows a 2.7% reduction in electricity consumption per 100 kilometers.

In order to realize automatic test and effectiveness verification of Automatic Mechanical Transmission (AMT), an automatic testing sequence is constructed based on the Hardware-in-the-Loop (HiL) testing system and automated testing software for the low gear shifting stuck fault of AMT front auxiliary gearbox. The fault diagnosis response is tested, and the test results show that the fault diagnosis response meets expectations, verifying the accuracy of the test sequence and fault diagnosis. Based on the test sequence, the normal gear shifting at high speed, gear shifting without fault and the low gear shifting of the front auxiliary gearbox under fault response are established. Test results show that the Transmission Control Unit (TCU) recognizes and responds in time when the front auxiliary gearbox low gear shift stuck fault occurs. The response is in line with expectations, and it also can keep the vehicle running normally under the fault diagnosis response, which verifies the effectiveness of the fault diagnosis response.

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.