To investigate the impact of different control strategies on the performance of vehicle CO₂ refrigeration systems, this study conducted bench tests to analyze the effects of supply air temperature requirements, indoor air volume, and ambient temperature on the cycle characteristics of a CO₂ refrigeration system with a heat recovery function under constant supply air temperature control. Simultaneously, the optimal discharge pressure fitting correlation based on the demand for supply air temperature was established. Research results indicate that among the operating conditions studied, ambient temperature has the most significant influence on optimal discharge pressure, followed by indoor air volume, while the impact of the supply air temperature is minimal. In addition, the evaporator outlet refrigerant temperature is positively correlated with the EER, with an average increase of approximately 2.6% in EER for every 1℃ rise in outlet temperature.. The correlation formula for optimal discharge pressure, derived from the requirements of supply air temperature, demonstrates a relatively high credibility, offering new insights for the optimization of control strategies.

This study developed and validated a one-dimensional simulation model on the Dymola platform to analyze the performance of a dual-mode evaporative-gas-cooled microchannel heat exchanger under various operating conditions. The effects of various refrigerant and air inlet parameters on the heat transfer and pressure drop characteristics of the microchannel heat exchanger in Heat Pump (HP) mode are analyzed. The simulation results show that in HP mode, a moderate increase in refrigerant inlet pressure and heat exchanger inlet airflow volume can both enhance the heat exchange amount while reducing the pressure drop on the refrigerant side. For each 0.5 MPa increase in refrigerant inlet pressure, the heat exchange amount increases by 2.6%, averaging a 9.5% reduction in the pressure drop on the refrigerant side. Increasing the air inlet volume on the air side and decreasing the air inlet temperature both reduce the pressure drop while increasing the heat transfer, but simultaneously decreasing the outlet air temperature.

Path planning is a critical component in autonomous vehicle research, among which the Artificial Potential Field (APF) method has attracted significant attention due to its simplicity and efficiency. However, it also suffers from issues such as local minima, failure to reach the target and insufficient safety. This paper proposes optimizations to the APF method to address these limitations. Firstly, an elliptical repulsive potential field for obstacles is designed to mitigate collision risks when avoiding irregularly shaped obstacles. Secondly, a road boundary repulsive potential field is introduced to ensure strict adherence to traffic rules during vehicle operation. Thirdly, a velocity repulsive potential field is established to prevent collisions with moving obstacles. Fourthly, virtual target points are designed to help the vehicle escape local minima. Finally, these repulsive fields are integrated into a new unified formulation, facilitating the planning of paths consistent with structured road environments. After path planning, the generated path is smoothed using B-spline curve fitting. Validation results demonstrate that the optimized APF method produces safer, shorter and more realistic paths that bet.

To improve the yaw stability of distributed drive electric vehicles, this paper proposes a yaw stability layered control strategy while considering longitudinal vehicle speed control. For the upper controller, the yaw moment controller is designed based on the sliding mode control principle. Additional yaw moments are obtained by tracking the expected yaw velocity and the sideslip angle respectively, while the total additional yaw moment is obtained by weighted calculation according to vehicle state. The lower controller chooses the tire load rate as the optimization objective function to allocate the torque of each wheel. Finally, a co-simulation model is established by CarSim and Simulink, and two working conditions of double shift line and angular step input are selected for simulation verification. The results demonstrate that the proposed layered control strategy can make the actual yaw velocity and sideslip angle of the vehicle better track the expected value, and effectively enhances vehicle stability.

To enhence the rationality of the vehicle torque control strategy for distributed-drive vehicles, this paper proposes a control strategy based on an optimize torque distribution strategy to reduce the operating conditions of synchronous zero-crossing of the front and rear dual motors, thereby improving issues such as vehicle resonance and impact. In addition, for typical operating conditions such as rapid acceleration with a large throttle depression when the battery has low power, a torque following filtering optimization control method is proposed to improve the problem of slow vehicle acceleration caused by insufficient system capacity. The test results show that the proposed zero-crossing control strategy effectively optimizes the problem of vehicle impact caused by the synchronous zero-crossing of dual motors; the proposed vehicle torque filtering optimization control method increases the vehicle's acceleration at a characteristic point by 0.62 m/s² in a power-feedback state, while ensuring driving comfort.

In order to improve vibration isolation effect of NEV powertrain mounting system, this paper proposes design flow of passenger vehicle powertrain mounting system. Next, for the design objective of a passenger vehicle, a dynamic model of powertrain mounting system is established to analyze its modal frequency and decoupling rate. Then, based on the mounting stiffness, the three-dimensional nonlinear stiffness curve of mounting is designed. Inherent frequency and strength of the mounting bracket 1st order constraint mode are obtained based on the calculation results of the mounting system 28 working conditions. The results indicate that this scheme meets requirement of design objective.

To improve the massage efficacy of electric vehicle massage seats, this paper proposes an evaluation method based on the analysis of time-frequency domain characteristics of surface Electromyography (sEMG) signals. Firstly electromyographic signals are collected from the trapezius, lower trapezius, latissimus dorsi and erector spinae muscles under three distinct states: comfort, fatigue, and massage, then those sEMG signals are preprocessed through filtering and normalization, followed by the extraction of Median Frequency (MDF) and Root Mean Square (RMS) features. Characteristic difference of the sEMG features among the three states (P<0.05) is compared, which confirms validity of the proposed evaluation method. Furthermore, the analysis of muscle relaxation across different muscle groups provides insights into the optimization of the mechanical massage structure.