International Journal of Vehicle Systems Modelling and Testing (5 papers in press)

Regular Issues

• Designing and optimising seat's new suspension using TPS-NSS to enhance driver's comfort  
  by Li Zhang, Vanliem Nguyen, Hui Zan 
  Abstract: Based on the isolation efficiency of negative-stiffness-structures (NSS) in vertical direction and three parallel suspensions (TPS) in the pitch and roll directions, a seat's new suspension combined with TPS and NSS (TPS-NSS) has been proposed for enhancing ride quality in three directions of driver. In order to further enhance TPS-NSS performance, Genetic-algorithm is also applied for optimising its design parameters. Root Mean Square acceleration of driver seat in vertical, pitch, and roll directions are used to assess the TPS-NSS’s isolation efficiency. The results indicate that all Root-Mean-Square seat accelerations with TPS-NSS are strongly improved by 29.08%, 85.75%, and 91.25% compared to the NSS. Therefore, based on the good isolation and simple structure of TPS-NSS, this new isolation model should be equipped in the seat suspension for enhancing driver's ride quality in vehicles.
  Keywords: seat's new suspension; TPS-NSS; driver's comfort; vehicle vibration model.
  DOI: 10.1504/IJVSMT.2024.10062757
   
  
• A study of boundary conditions for pedestrian thorax impact test  
  by Yongcheng Long, Yu Liu, Yu Xiao, Zhisheng Ruan, Zhi XIAO, Guanjun Zhang, Huang Jing 
  Abstract: Thorax injury is one of the main injuries during pedestrian impact accidents, and it is very important to evaluate the vehicle performance for pedestrian thorax injury protection, which is required to determine the boundary conditions for thorax impactor tests. A series of virtual numerical cases were carried out to simulate the impact accidents between sedan, SUV and pedestrians based on the statistical characteristics of VRU traffic accident data in China, then the kinematic process were analyzed during the vehicle-pedestrian impacts, and thorax impact parameters such as the wrap-around distance (WAD), the impact angle, the impact speed, and the angle of thorax impact velocity were extracted in each case, finally the statistical characteristics of these impact parameters were obtained for thorax impactor tests. These results can provide the effective reference data to set the test areas and the loading conditions for pedestrian thorax impactor tests.
  Keywords: pedestrian impact; thorax; boundary condition; simulation.
  DOI: 10.1504/IJVSMT.2024.10063656
   
  
• Control system for electric vehicles energy use in urban routes  
  by Carlos Armenta-Déu, Alejandro Alonso 
  Abstract: One of the most relevant issues of the electric vehicle industry is the driving range. Driver attitude and driving conditions may lower the theoretical autonomy set up by car manufacturers. The result is the complaining action of unsatisfied car owners because of a reduction in the driving range. In this paper, we develop a method to maximize electric vehicle driving range by controlling driving conditions and drivers' attitudes. The methodology predicts the maximum autonomy with high accuracy based on the energy consumption of the electric vehicle. The predicting method uses a computational simulation process based on the driver's selection of specific parameters to calculate the energy consumption. The control system blocks the starting up of the electric vehicle if the selected driving conditions for the chosen urban route are non-compatible with the energy state of charge of the battery. The control system also avoids any change in driving conditions during the running that is non-compatible with the battery state of charge. As a result sudden stop due to battery exhaustion is prevented, warrantying the fulfilment of the selected route.
  Keywords: electric vehicle; driving range; control system; driving conditions simulation; software design.
  DOI: 10.1504/IJVSMT.2024.10063843
   
  
• A strategy for vehicle air resistance and rolling resistance calculation based on the hierarchical estimation method  
  by Jun Luo, JiaXi Guan, XingLin Zhou, Pan Zhu 
  Abstract: To accurately calculate the air resistance and rolling resistance of the moving vehicle, we propose an adaptive hierarchical estimation method. Firstly, real-time road slope is obtained by correcting the accelerometer with angular velocity short-time integration. Then, a sliding mode observer (SMO) is employed to estimate the vehicle’s longitudinal driving force and tire lateral force. The obtained road slope and tire forces from the sliding mode observer are used as inputs with proportional parameters to an adaptive extended Kalman filter (AEKF), enabling the separate estimation of tire rolling resistance coefficient and air resistance coefficient. Further, the rolling resistance for different tires is calculated by applying vertical loads. In the hierarchical algorithm, a new sliding mode observer, adaptive extended Kalman filter, and fast slope fusion algorithm are introduced, enhancing the precision and robustness of the algorithm. Finally, the effectiveness of the algorithm is validated through simulation tests and real vehicle experiments.
  Keywords: Vehicle dynamics; rolling resistance; air resistance; parameter estimation; extended Kalman filter.
  
  
• Thermal Optimization Study on Electrical Machine Controller for an Electric Vehicle  
  by Yang Ping, Ahmad Zhafran Ahmad Mazlan 
  Abstract: In this study, IGBT module of a pure electric vehicle motor is investigated through thermal simulation and analysis, experimental verification, and structural optimization. Based on the temperature rise test, and the comparison of temperature rise and heat dissipation curve using FEA, it is found that the result can accurately simulates the heat dissipation of the IGBT module, with the temperature error within 2 ? and the natural heat dissipation errors less than 3 ? during forced heat dissipation. This data supports the optimization of the controller radiator heatsink. Finally, the ANSYS optimization module was employed to parametrically optimize dimensions and positional parameters such as length, width, and spacing of the heat sink fins, as well as fan-to-heatsink distance. The ideal parameter solution was produced using multi-objective optimization algorithms and iterative methods, resulting in minimizing mass and lowest temperature while meeting the heat dissipation requirements.
  Keywords: Pure electric vehicles; Motor controller; IGBT; Heatsink optimization; Simulation study.