International Journal of Vehicle Design (24 papers in press)

Regular Issues

• This is a test paper, pleaseignore it
  by ReviewerV ReviewerC 
  Abstract: This is a test submission. Please ignore it
  Keywords: test test test test test test test test test test test test test test test test.
  
  
• Research on active suspension control based on safety constraint reinforcement learning  
  by Lin-feng Zhao, Xiao Feng, Wen-bin Shao, Zhen Mei, Jin-fang Hu 
  Abstract: To tackle the shortcomings of conventional active suspension control algorithms, which struggle to achieve a harmonious balance between ride comfort and handling stability, as well as obvious lack of practical safety considerations for suspension systems in ordinary reinforcement learning algorithms, a Deep Deterministic Policy Gradient(DDPG) Reinforcement Learning(RL) algorithm is proposed, which utilize suspension system safety boundary constraints as its foundation, and integrates the suspension dynamic deflection's limit stroke, as well as safety range of tire dynamic deformation into the reinforcement learning algorithm, and obtains the ideal active suspension control strategy through offline training. Based on MATLAB/Simulink, simulation comparison and HIL(Hardware In the Loop) verification were conducted with Linear Quadratic Regulator (LQR) and ordinary DDPG algorithm under convex road conditions. The results clearly indicates a distinction from the LQR algorithm, in contrast to which the sprung acceleration's rms(root mean square) value using algorithm proposed in this paper is reduced by 6.41%?
  Keywords: active suspension; reinforcement learning; safe boundaries; ride comfort; convex road surface.
  DOI: 10.1504/IJVD.2024.10066193
   
  
• Complete coverage path planning algorithm for multiple agricultural robots  
  by Changjie Liu, Haobo Zhang, Yangjie Ji 
  Abstract: Multi-robot complete coverage path planning (MCCPP) is an important direction in developing intelligent agricultural robots. Firstly, to address the problem that the existing region decomposition algorithm has too many subregions and contains concave subregions, this paper adopts the improved Maklink line to convexly decompose the workspace to obtain the minimum number of convex subregions. Secondly, the current MCCPP algorithm suffers from duplicate coverage of connection paths, uneven task allocation, and failure to consider the robot's extra energy consumption. This paper adopts the Dijkstra algorithm to plan the shortest non-duplicated connected paths between any subregions; improves the existing objective function by combining with the actual; and retains the high-quality gene fragments for chromosome crossover according to the breakpoints. Finally, the improved Non-dominated Sorting Genetic Algorithm (NSGA-II) is simulated in real planting areas, and the total connected paths and planting area balance were optimized compared to the traditional NSGA-II.
  Keywords: precision agriculture; multi-robots; complete coverage path planning; NSGA-II; non-dominated sorting genetic algorithm.
  DOI: 10.1504/IJVD.2024.10067304
   
  
• Feedforward fuzzy LQR path tracking controller based on predictive model and vehicle road position  
  by Xinfeng Zhang, Zhiyuan Li, Huan Liu, Xiaorui Li, Juan Zhao 
  Abstract: This study endeavors to enhance the path tracking precision, maneuver stability, and ride comfort of intelligent vehicles in diverse scenarios. To achieve this, we propose a predictive modeling based fuzzy Linear Quadratic Regulator (LQR) for path tracking control, taking into account the vehicle's relative position with respect to the road To mimic human driver behavior, we introduce a predictive model that allows the vehicle to anticipate the path, thus mitigating control system delay. Addressing the issue of inadequate adaptability associated with fixed weight controllers, we introduce a fuzzy adjustment strategy for weight coefficients that takes into account changes in vehicle speed, path tracking lateral error, and path curvature. Compared to the LQR , SMC and MPC controller, under three distinct operational scenarios, the specific enhancements in path tracking accuracy manifest as follows: an increase of 67%, 87%, and 60%; 62%, 86%, and 73%; 52%, 84%, and 73%, respectively.
  Keywords: intelligent vehicle; path tracking; prediction model; lateral control; fuzzy LQR.
  DOI: 10.1504/IJVD.2024.10068413
   
  
• Vehicle lane change driving intent recognition based on Bayes-XGBoost  
  by Qinghui Zhou, Sun Shunjie 
  Abstract: It is a critical technology to accurately identify the vehicle’s lane-changing intention for traffic safety in intelligent vehicles. A new method for recognizing lane change driving intent based on the Bayesian Extreme Gradient Boosting (Bayes-XGBoost) algorithm was proposed. This method constructed an XGBoost model for lane change driving intent recognition and used a Bayesian algorithm to optimise the hyperparameters of the XGBoost model. To verify the performance of the model, experiments were carried out using the Next Generation Simulation (NGSIM) traffic dataset. Compared to conventional models including XGBoost, LSTM, and SVM, the proposed method demonstrated superior effectiveness in identifying lane-change driving intent, This proves that the proposed method can identify intentions more accurately. Thus, this method has the potential to offer a more effective and significant approach in traffic safety paradigms.
  Keywords: intelligent vehicles; vehicle lane change; XGBoost; Bayesian optimisation; lane change intent recognition.
  DOI: 10.1504/IJVD.2024.10068468
   
  
• Multi-mode servo braking control and experimentation of integrated electro-hydraulic braking system  
  by Houhua Jing, Liwen Dong, Qinggan Lin, Haifeng Liu 
  Abstract: As the critical problem of electric servo braking control, the relationship between hydraulic pressure, motor position and motor current is systematically analyzed. A large hysteresis exists in the pressure-position relationship. Then a multi-mode servo braking control law is proposed on the basis of experimental tests. Firstly, the influence of nonlinear friction is overcome by dither compensation to improve the smoothness of position and pressure. Secondly, the pressure-current cascade control is applied, and the feedforward is obtained based on the experimental data, which effectively avoids the nonlinear and uncertain influence of pressure-position relationship. Thirdly, position-current cascade control is applied to realize the accurate return of the motor in the release process, and overcome the influence of pressure-position large hysteresis and dead zone. Finally, the control method is comprehensively verified and analyzed based on the experimental bench. The practicability of the method is verified.
  Keywords: integrated electro-hydraulic braking; servo braking control; multi-mode control; pressure control; position control.
  DOI: 10.1504/IJVD.2024.10068496
   
  
• Slope estimation of distributed electric drive mining dump truck based on multi-sensor integration  
  by Yilin Wang, Weiwei Yang, Nong Zhang 
  Abstract: The efficient, energy-saving, and unmanned operation of mines is an effective way to achieve safe production and improve efficiency. The current road slope estimation method has the shortcomings of involving more parameters and needing more accuracy. This paper proposes a road slope estimation method that integrates the slope estimation methods based on the vehicle longitudinal dynamics model, based on acceleration sensors, and based on inclination sensors with the help of the Kalman filtering algorithm based on covariance-weighted integration. Combines with the slope characteristics of the open pit mine and obtains the estimation value with an accuracy of less than 8.4% compared to the actual road slope variation. The effectiveness and real-time performance of the multi-sensor integration method for the slope estimation of the distributed electric drive mining dump truck are verified, and the solution idea for the state parameter estimation related to the vehicle control strategy research is provided.
  Keywords: distributed electric drive mining dump truck; state parameter estimation; slope estimation; multi-sensor integration; Kalman filter algorithm.
  DOI: 10.1504/IJVD.2024.10068735
   
  
• Integrated ASMO-DCKF state observer for distributed drive vehicles  
  by Peng Ji, Fengrui Han, Yifan Zhao 
  Abstract: Addressing the issue of inadequate information correction capabilities between the vehicle tire force observer and state estimator, this study introduces an estimation algorithm that combines an adaptive synovial tire force observer with a double-cubature Kalman filtering state estimator (ASMO-DCKF). Firstly, a seven-degree-of-freedom vehicle model is established, and a synovium observer is used to estimate tire forces. A saturation function is utilized as a substitute for singular values to address system oscillation issues. Then, double-cubature Kalman filter state estimators are used: one for vehicle state estimation and the other for road adhesion coefficient estimation, these two estimators mutually correct each other to enhance accuracy in estimating vehicle and road conditions. The Speedgoat-CarSim hardware-in-the-loop simulation platform is established for examining the proposed algorithm under typical operating conditions and comparing it with EKF algorithm, the results demonstrate a notable enhancement in robustness and accuracy of the proposed algorithm proposed over the EKF algorithm.
  Keywords: tire force observation; vehicle state estimation; adaptive synovial observer; double-cubature Kalman filter; road adhesion coefficient.
  
  
• Exploring creep mechanisms in externally pressurised orthotropic cylinders with variable density  
  by Priya Gulial, Pankaj Thakur 
  Abstract: This research article presents a comprehensive analysis of steady-state creep behavior and strain in an orthotropic rotating cylinder subjected to external pressure and varying density, employing Norton's law. Extensive numerical computations have been performed for a wide range of steels and steel alloys commonly used in cylinder manufacturing, considering five distinct types of anisotropy. The study meticulously investigates the significant effects of anisotropy and the exponent 'n' in the creep law. A key finding indicates that the effective stress values for anisotropic materials, particularly in Types I and II, show a marked reduction compared to their isotropic counterpart in Type III. Furthermore, the analysis highlights the role of increasing density parameters in amplifying radial, circumferential, axial stresses, and effective stress within the rotating cylinder composed of anisotropic materials.
  Keywords: strain; density; pressure; cylinder; angular speed; anisotropic; isotropic.
  
  
• Study on the transient dynamics of an electric driving system considering the interference fit and thermal expansion effects of tapered roller bearings  
  by Ming Li, Yufa Zhou, Dong Guo, Chuan Fang, Rao Wenyi 
  Abstract: The dynamic characteristics of the electric driving system in pure electric vehicles are explored in this paper, with consideration given to the effects of bearing interference fit and thermal expansion. Various factors such as radial stiffness of the bearings, axial stiffness of the bearings, gear mesh stiffness, and backlash were taken into account. A transient dynamic model suitable for transient conditions of electric driving system was established. The model's accuracy has been verified through bench tests. The effects of bearing interference fit and thermal expansion on the dynamic characteristics of the electric driving system under tip in/out conditions were studied. Research shows that under tip in/out conditions, as the interference amount and temperature of the tapered roller bearing increase, the fluctuation amplitude of the motor rotor speed has a downward trend. The amplitude of vibration acceleration fluctuations in the bearing seats of each shaft has been reduced.
  Keywords: electric driving system; tip in/out; transient dynamics; bearing interference fit; bearing thermal expansion.
  DOI: 10.1504/IJVD.2025.10069795
   
  
• Modelling of integrated bio-dynamic human model with full car using bond graph for IRC:99-1988 bump  
  by Lalit Batra, Sanjay Kumar, Saurabh Kumar Agrawal 
  Abstract: One of the most intriguing topics for researchers in the area of vehicle dynamics is the use of vehicle vibration to analyse dynamic behaviour. The primary goal of this research is to examine the dynamic behaviour of a road vehicle under various road conditions. In this study, an integrated computer model is developed through the bond graph methodology to analyse the dynamic behaviour of a large road vehicle. The initial stage is to create the 3D models of each vehicle base, suspension unit, tyre, seat, and joint as bond graph elements with power ports for physical connections. This work demonstrates the dynamic behaviour of the 4 DOF lumped human biomechanical model coupled with an 11 DOF full-car vehicle model using the bond graph simulation technique. Ride comfort conditions as per ISO 2631:1997 standards are used to validate the dynamic response of the bio-dynamic human coupled with a full car.
  Keywords: 15 DOF full car model; bond graph modelling; bio-dynamic human model; dynamic simulation.
  DOI: 10.1504/IJVD.2025.10069953
   
  
• Effect of different winding patterns on parasitic capacitance in common mode chokes  
  by Ziyan Wang, Q.I. LI, Dangfang Wang, Haonan Sun 
  Abstract: New energy vehicle electric propulsion systems employ wide-bandgap devices including SiC and GaN, which can cause more severe EMC and EMI issues. Accurate modelling of the filter components, including common mode chokes, is of great importance. The parasitic capacitance in the common mode choke has a major influence on the high-frequency noise suppression performance, and is determined by several factors, including the material permittivity, the geometric parameters and the winding patterns. However, the effect of different winding patterns on the parasitic capacitance of the common mode choke has not been fully researched. This paper aims to reduce the research deficit by comparing the parasitic capacitance of the two different winding patterns, i e, the conventional sectional winding and the bifilar winding in common mode chokes. Expressions for calculating the parasitic capacitance of the two types of chokes are derived by developing the physics-based models.
  Keywords: electric propulsion systems; common mode chokes; equivalent parasitic capacitance; winding patterns.
  DOI: 10.1504/IJVD.2025.10070047
   
  
• Coordinated longitudinal and vertical control of corner module vehicles based on groundtyre adhesion on rugged slopes  
  by Hongliang Wang, Huadong Tao, Dawei Pi, Weihua Wang, Yijie Chen, Xianhui Wang 
  Abstract: The incongruity between the low coefficient of adhesion and the high wheel load at the potholes of rugged ramps reduces the passability of the corner module vehicle. To address this problem, this paper proposes a collaborative control method of longitudinal and vertical dynamics with the target of optimal utilization of the vehicle's overall attachment ellipse. Firstly, this research analyzes the coupling relationship between wheel load and adhesion, combines it with the dynamic identification of the adhesion coefficient of each wheel, and proposes an active suspension control strategy that realizes the optimal matching of wheel load and adhesion coefficient. Furthermore, this paper proposes a drive torque distribution strategy that integrates dynamics and driving stability in conjunction with ellipse boundary identification. The simulation results show that the proposed strategy can dynamically coordinate vertical load and torque distribution. Furthermore, the maximum climbing speed is increased by 8.1% over the simple control approach.
  Keywords: corner module vehicle; longitudinal and vertical coordination; active suspension control; drive torque distribution.
  DOI: 10.1504/IJVD.2025.10070137
   
  
• Multi-vehicle trajectory planning at unsignalized intersections based on cooperative vehicle-infrastructure system  
  by Yangjie Ji, Ziru Yang, Yanjun Huang, Zhuoping Yu 
  Abstract: Collaboration between infrastructures and connected and autonomous vehicles (CAVs) at unsignalized intersections has emerged as an effective strategy for improving transportation efficiency. To enhance the safety and efficiency of CAVs passing through unsignalized intersections, this paper proposes a cooperative vehicle-infrastructure system (CVIS) based multi-vehicle trajectory planning architecture. The architecture comprises a roadside planner and vehicle planners. The roadside planner formulates the problem of generating multi-vehicle trajectories as an optimization task and addresses it using an improved particle swarm optimization approach along with a space-time voxels strategy to determine the times for vehicles to reach the intersection and the trajectories passing through it. Then, the vehicle planner plans according to the results of the roadside planner. The results show that our approach enables potentially conflicting CAVs to pass through unsignalized intersections without stopping and waiting, ensuring safety while improving traffic efficiency.
  Keywords: cooperative vehicle-infrastructure system; connected and autonomous vehicles; multi-vehicle trajectory planning.
  DOI: 10.1504/IJVD.2025.10070249
   
  
• Vibration characteristics and active control strategy of hybrid vehicle dual-motor electric drive system under transient impact conditions  
  by Shuaishuai Ge, Mengke Li, Shuang Hou, Zhengqiu Xie, Zhigang Zhang, Hang Wu 
  Abstract: For torsional vibration due to transient impact loads such as road surface inequality during the driving process of a Hybrid Electric Vehicles(HEV),an electromechanical coupling dynamics model of the dual-motor electric drive system (DEDS) is established by considering the dynamic characteristics of the drive motors, the nonlinear meshing impact excitation of the gear transmission system, etc. The dynamic response and vibration characteristics of the DEDS are analysed during sudden step changes in load. On this basis, the fuzzy active disturbance rejection current compensation (F-ADRCC) control strategy is proposed, and fuzzy controller is applied to adapt the internal parameters of the F-ADRCC controller, to realise the active suppression of transient inrush vibration. The simulation results show that the vibration energy of the gear transmission system is significantly reduced after adopting the F-ADRCC control strategy. The research results can provide a theoretical reference for DEDS vibration damping of HEVs.
  Keywords: transient impact conditions; vibration characteristics; dual-motor electric drive system; active control strategy; fuzzy controller.
  DOI: 10.1504/IJVD.2024.10070325
   
  
• An adaptive sliding mode control for four-wheel HUB electric vehicle yaw stability control  
  by Yuanjie Ma, Xinglin Zhou, Maoping Ran 
  Abstract: This paper aims to improve the stability of four-wheel electric vehicles driven by hub motors. An adaptive sliding mode control (ASMC) is proposed to estimate the additional yaw moment required for stability control system of passenger vehicles. Then the additional yaw moment is distributed to the wheel hub motor through designed optimal distribution controller. The stability of the controller is verified by Lyapunov method. A hierarchical control structure is applied throughout the system. The upper layer is an ASMC, and the lower layer is an optimal distributor for distributing the additional yaw moment to wheels under constraints. The co-simulation between Matlab/Simulink and CarSim shows that the controller suggested in this work performs better in terms of control than traditional sliding mode control (SMC). Moreover, it demonstrates a noteworthy enhancement impact on vehicle stability and driver comfort.
  Keywords: distributed drive; yaw stability control; driving torque distribution; co-simulation.
  DOI: 10.1504/IJVD.2024.10070365
   
  
• Research on fusion control of driving anti-skid and hill starting for distributed driving vehicles  
  by Hongliang Wang, Zhiwei Liu, Pi Dawei, Xiong Wang, Weihua Wang, Jinxiang Wu, Yongjun Yan 
  Abstract: Improvement of off-road passability and safety of off-road vehicles, a hill starting control method fusing drive anti-slip control technology is proposed. Firstly, the axle load adaptive torque distribution method for torque pre-distribution, and secondly, based on the coupling relationship between the attachment force, driving force and braking force in hill start, the braking retardation method is used to identify the wheel attachment state, The wheel drive torque and braking torque of the slipping wheels are limited by the maximum transferable torque method, and the loss torque of the slipping wheels is distributed to the other wheels according to the slipping state and axle load ratio of each wheel , Subsequently, establish a logic threshold-based distributed drive system and electronic parking system (EPB) cooperative control method to adjust the braking force of the parking brake in real time. Finally, comparative studies and simulations confirm its effectiveness.
  Keywords: distributed driving; hill start; EPB; anti-skid control.
  DOI: 10.1504/IJVD.2025.10070440
   
  
• Analysing the impact of magnetic coupler materials for wireless power transfer in electric vehicles  
  by Ankur Yadav, Tushar Kanti Bera 
  Abstract: This research analyzes the effect of different magnetic materials on the performance of electric vehicle wireless power transfer (WPT) systems. It provides the basics of designing a 3D coil and coupler using Ansys Maxwell 3D design software. The study demonstrates how the selection of magnetic materials affects the performance and overall reliability of theWPTsystem. Ansys Maxwell analyzes different material parameters such as coupling coefficient (k), mutual inductance (M), and self-inductance (L) of the coil and coupler materials, as well as magnetic flux density (B), magnetic field strength (H), energy, and thermal effects for various air gaps (ranging from 40mmto 200mm)between transmission and receiving coils. Matlab is used to verify performance in terms of output voltage, current, power, and power transfer efficiency. Notably, the highest power transfer efficiency was 94.3% with an 80 mm air gap for ferrite, which weighs approximately 30.4 kg and has dimensions of 400 mm x 400 mm x 20 mm.With alloy steel, the weight is 50.67 kg, and the power transfer efficiency is 73.9% with the same 80 mm air gap.
  Keywords: materials; ferrite shielding; permalloy; nickel-iron; alloy steel; WPT; wireless power transfer; Ansys Maxwell; coil geometry; magnetic coupler.
  DOI: 10.1504/IJVD.2025.10070441
   
  
• Throttle valve design and control of a hydraulic hub-motor auxiliary system  
  by Chilin Liu, Yuhai Wang 
  Abstract: To realize the differential control of hydraulic motor in a hydraulic hub-motor auxiliary system (HHMAS), this research aims to change the flow rate of motor inlet based on the active control of throttle valve flow. On the bases of the HHMAS characteristics, the design and detailed modeling of the throttle valve are carried out, and the working mechanism and dynamic characteristics of the throttle valve are systematically revealed, laying the foundation for the active control of the fixed displacement motor oil inlet flow. Furthermore, the flow control method based on proportional-integral-derivative (PID) and feedforward + feedback are developed and the stability of control system is validated. Simulation results show that the feedforward + feedback control method has better robustness and control effect than the PID feedback regulation.
  Keywords: hydraulic hub-motor auxiliary system; throttle valve design; PID control; feedforward + feedback control.
  DOI: 10.1504/IJVD.2024.10070575
   
  
• Analysis and optimisation of a new Septal coil in-wheel switched reluctance motor  
  by Dongyu Yang, Zhenjie Zhang, Yanyan Ding 
  Abstract: To enhance the average torque and torque density of in-wheel switched reluctance motors (IWSRM) for electric vehicles, a novel four-phase 16/18 IWSRM with the segmented coil is proposed. The basic structure and electromagnetic characteristics of the new IWSRM are analyzed. Based on finite element analysis, the magnetic flux linkage, magnetic co-energy, inductance, and torque characteristics are studied and compared with the typical four-phase 16/18 IWSRM and 16/20 IWSRM with traditional winding structure. The results show the new IWSRM has higher average torque under medium/low current conditions. A multi-objective optimization function based on average torque and torque density is established. The stator pole arc and rotor pole arc are selected for optimizing the new IWSRM. The results without and with optimization indicate the average torque and torque density of the motor can respectively be improved by 21.6% and 16.7% under a current of 100 A.
  Keywords: in-wheel switched reluctance motor; Septal coil; finite element analysis; multi-objective optimization.
  DOI: 10.1504/IJVD.2025.10070654
   
  
• Delay-tolerant design of the steer-by-wire system in intelligent vehicles for closed-loop stability and maximal target-tracking performances of path-following  
  by Hangyu Lu, Xiaodong Wu, Sheng Zhao, Zhaoyang Zhang, Liang Yan 
  Abstract: The automation of transportation systems inevitably faces challenges in enhancing passenger vehicle safety. Toward full automation, X-by-wire (XBW) technology plays a crucial role in bridging the gap, with steer-by-wire (SBW) systems serving as a key enabler of both automation and electrification. This paper addresses the issue of time delays in the lower control loop of SBW systems and proposes a delay-tolerant control design to ensure optimal target-tracking performance under varying delay conditions and tire aligning moments. To achieve this, SBW system and control models are established, and a systematic approach for designing a stable SBW controller under time delay is developed. Furthermore, an optimization strategy is formulated to maximize target-tracking performance, leading to a gain-scheduling control scheme. Simulation experiments are conducted to validate the effectiveness of the proposed design. The findings provide theoretical insights into system stability under delay and offer practical guidance for the onboard SBW systems.
  Keywords: time delay; SBW; steer-by-wire; closed-loop control; stability analysis; gain scheduling.
  DOI: 10.1504/IJVD.2024.10070689
   
  
• A game theory-based decision model for lane changing in a mixed traffic environment  
  by Xuelong Zheng, Xuemei Chen, Yunhao Tang, Rui Qu, Yaohan Jia 
  Abstract: Lane changing is a fundamental driving maneuver. Cooperative lane changing is a complex challenge in mixed traffic scenarios involving human-driven and autonomous vehicles (HVs and AVs, respectively). With the aim of enhancing cooperation between AVs and HVs, in this study, first, three interactive behaviors were analyzed: free lane change, cooperative lane change, and competitive lane change. The willingness to change lanes was assessed based on the degree of cooperation and competition among the vehicles involved in the interaction process. Second, game theory was used to establish a game model for achieving cooperative lane changing in mixed traffic. The as-designed model aimed to maximize the aggregate expected utility by incorporating the coefficients of competition and cooperation. These coefficients were adjusted and the associated costs of these strategies were evaluated; then, the Lemke-Howson algorithm was employed to determine the Nash equilibrium of the game model. Finally, lane-changing strategies based on the gap acceptance theory, the single-lane expected lane change decision model, and the multi-vehicle cooperative lane-changing game model were compared via experiments on a simulation platform.
  Keywords: autonomous vehicle; mixed traffic; interaction behaviour; decision-making; game theory; Nash equilibrium.
  DOI: 10.1504/IJVD.2024.10070691
   
  
• Research on modelling and extracting methods for personalised driver longitudinal operation features  
  by Jin Zhilin, Juntao Kong, Chao Yang, Shilong Cao 
  Abstract: The characteristic parameters of driver manipulation are crucial for research into human-machine co-driving control strategies in intelligent vehicles. This paper proposes an experimental data-driven modeling and extraction method for accurately obtaining the longitudinal operation feature parameters of drivers. First, a driver manipulation experimental platform and a fuzzy data collection method are created in order to collect longitudinal manipulation experimental data for aggressive and non-aggressive drivers. The feature model is then built using an experimental data-driven deep neural network training method. Combining the feature model and PD theory, feature parameters are extracted using a hierarchical method. Furthermore, experiments and simulations are carried out for two types of drivers. The results demonstrate that the validation set of the feature model has an RMS error of less than 5%. The extracted feature parameters' values are within the longitudinal operation feature value range and can reflect the personalized driver longitudinal operation characteristics.
  Keywords: personalised driver; longitudinal operation feature model; fuzzy data collection method; deep neural network training method; hierarchical extraction method.
  DOI: 10.1504/IJVD.2025.10070782
   
  
• Leakage and dispersion characteristics of hydrogen from hydrogen storage system of fuel cell truck  
  by Shu Liu, Ren He 
  Abstract: The hydrogen storage system of the fuel cell truck is arranged in a semi-confined cabin. The hydrogen disperses quickly and accumulates during a leak, raising safety concerns. Studies on the hydrogen leakage and diffusion behaviours are important to ensure hydrogen safety. The analyses on the influence of leak rate, leak orifice location, ambient wind velocity and direction on the characteristics of hydrogen dispersion are conducted in this article. The results indicate that the flammable region and hydrogen concentration at detecting points increase with leak rate. The leak path is significantly influenced by the obstacles. An extensive cloud of hydrogen easily accumulates on the top and bottom of the cabin when the leakage orifice faces the wall of the cabin. A more narrow profile of hydrogen cloud distributes and the hydrogen at the top of the cabin disperses effectively driven by the wind.
  Keywords: fuel cell truck; high-pressure hydrogen cylinder; semi-confined enclosure; hydrogen leakage; dispersion; hydrogen safety; numerical simulation.
  DOI: 10.1504/IJVD.2025.10070783