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Inspired by the cross-section of a beetle’s elytron, hyperbolic lattice with double-layered feature has received increasing attention in recent years. This paper aims to investigate the compression behavior and energy absorption performance of a truss-based hyperbolic structure. The quasi-static compression simulation for the hyperbolic structure has been performed and validated with a compression test. Through compression simulation and test, the hyperbolic structure proved to show obvious twisting effect. To explore the influences of the geometric parameters in the mechanical properties of hyperbolic structure, this paper has designed 13 cells with varied rotation angle, height, and rod diameter, and investigated the mechanical properties of these configurations.

The origami structures have received increasing attention in recent years due to the high stiffness ratio and lightweight feature. This paper has proposed an origami-based honeycomb structure and investigated the mechanical properties of the structure. The compression response and energy absorption of the structure under quasi-static loading have been investigated experimentally and numerically. The numerical results closely matched the experimental results in terms of the compression force curve and deformation patterns. The effects of different structural parameters on the mechanical response and energy absorption characteristics were analyzed with the validated model. Finally, the comparative results show that the origami-inspired honeycomb structure, which is characterized by rotational folding mode under axial compression, has better performance in terms of mechanical response and energy absorption.

Due to the high center of gravity of medium-duty vehicles, rollover accidents can easily occur during high-speed cornering and lane changes. In order to prevent the deformation of the body structure, which would restrict the survival space and cause compression injuries to occupants, it is necessary to investigate methods for mitigating these incidents. This paper establishes a numerical model of right-side rollover for a commercial medium-duty vehicle in accordance with ECE R66 regulations, and the accuracy of the model is verified by experiment. According to the results, the material and size parameters of the key components of the right side pillar are selected as design variables. The response result matrix was constructed using the orthogonal design method for total mass, energy absorption, maximum collision acceleration, and minimum distance from the survival space.

Distributed drive electric vehicles (DDEVs), characterized by independently controllable torque at each wheel, redundant actuators, and highly integrated drive systems, are considered as the optimal platform for achieving intelligent driving with high safety and efficiency. This paper focuses on the trajectory tracking and lateral stability coordination control problems in high-speed emergency collision avoidance and autonomous lane change scenarios for DDEVs. A trajectory tracking control algorithm is proposed based on model predictive control (MPC) and coordinated optimization of distributed drive torques. The method adopts a hierarchical control architecture. Firstly, the upper-level trajectory planning layer calculates the lane change trajectory data. Based on the trajectory planning results, the middle-level controller designs a time-varying linear model predictive control method to solve the desired front wheel steering angle and additional yaw moment.

Vehicle failure prediction technology is an important part of PHM (Prognostic and Health Management) technology, which is of great significance to the safety of vehicles and to improve driving safety. Based on the vehicle operating data collected by the on-board terminal (T-box) of the telematics system, the research on the state of vehicle failure is conducted. First, this paper conducts statistical analysis on vehicle historical fault data. Preprocessing procedures such as cleaning, integration, and protocol are performed to group the data set. Then, three indexes including recency (R) frequency (F), and days (D) are selected to construct a vehicle security status subdivision system, and K -Means algorithm is utilized to divide different vehicle categories from the perspective of vehicle value. Labeled information of vehicles in different security status are further established.

In order to meet the needs of modern warfare, the research on electromagnetic shielding technology of military vehicle-mounted shelters and improving the electromagnetic shielding performance of shelters will play an increasingly important role in the protection of advanced electronic equipment. At the same time, it is also the core of the development of military vehicle-mounted shelters. In this paper, by selecting and comparing different materials, using multi-layer composite materials to design the military vehicle-mounted shelter. The shelter body comprises a front wallboard, a rear wallboard, a left wallboard, a right wallboard, an upper wallboard and a lower wallboard.

In this paper, for the front wall of a certain automobile, the defects of drawing splits, excessive thinning and excessive springback in the sheet metal forming process are analyzed and predicted. The stamping process has been simulated. The influence of different technical parameters (blank holder force, stamping speed, die gap and friction coefficient) on the forming results was further investigated using the center composite experiment. Through preliminary finite element simulation, the main drawing defects and trimming springback were analyzed. The second-order response surface model was established to perform the multi-objective optimization design of the stamping process with a NGSA-II genetic algorithm. Based on the relevant simulation data, multiple springback compensations are performed on the die surface to reduce the final springback of the part to meet the requirements.

Thin-walled tubes have been mostly used in passive vehicle safety systems due to high crash energy absorption. The structures with negative Poisson’s ratio (NPR) property will contract to increase its stiffness. In this paper, a double-arrowed NPR structure is designed as a new energy-absorption filler for thin-walled tubes to apply as a novel crash energy absorber. Different beam thicknesses, angles and half cellular width are taken into account in the double-arrowed NPR filling tubes (DAFT) designing and the crashworthiness of the structures are analyzed by using validated nonlinear finite element method. The crashworthiness performances of DAFT are also compared with the singular NPR and hollow tube with the same outer dimension to show the efficiency of DAFT.

Lane keeping assist (LKA) is an autonomous driving technique that enables vehicles to travel along a desired line of lanes by adjusting the front steering angle. Reinforcement learning (RL) is one kind of machine learning. Agents or machines are not told how to act but instead learn from interaction with the environment. It also frees us from coding complex policies manually. But it has not yet been successfully applied to autonomous driving. Two control strategies using different deep reinforcement learning (DRL) algorithms have been proposed and used in the lane keeping assist scenario in this paper. Deep Q-network (DQN) algorithm with discrete action space and deep deterministic policy gradient (DDPG) algorithm with continuous action space have been implemented, respectively. Based on MATLAB/Simulink, deep neural networks representing the control policy are designed. The environment as well as the vehicle dynamics are also modelled in Simulink.

The safety and comfort of the truck cab, as driver’s location, are significant to the driver, and the white body of the truck cab is an important part of the truck, whose modal and stiffness are directly impact its safety and comfort. Moreover, its modal and stiffness are the key factors that affect the performance of the car, which are also the important indicators that evaluate the ability of preventing fatigue failure and resisting deformation. In order to study whether the modal and stiffness of a truck cab can meet the working requirements, the white body of a truck cab was taken as the research object, and the finite element method (FEM) was chosen to study the modal and stiffness in this paper. The finite element model of the white body of this truck cab was established. The natural frequency and vibration model of white body were obtained by modal analysis. And the lowest frequency of the white body was 22.8Hz, obtained by modal analysis.

As a global optimization method, dynamic programming (DP) can be employed to seek the optimal velocity with minimum energy consumption for EV on given driving cycles. Due to its terrible computational burden, conventional DP is not suitable for real-time implementation especially with higher dimensions. In this paper, we propose an iterative dynamic programming (IDP) approach to reduce computing time firstly. The IDP can obtain the optimal control laws alike the conventional DP by converging the optimal control strategy iteratively and save considerable computing time. Second, the developed IDP and model predictive control (MPC) are combined to establish a real-time cruising controller called IDP-MPC for an EV with terrain preview. In the predictive controller, we use the IDP to solve a constrained finite horizon nonlinear optimization problem.

In order to reflect the actual power consumption of logistics electric vehicles in a city, sample real vehicle road data. After preprocessing, the short-stroke analysis method is used to divide it into working blocks of no less than 20 seconds. Based on principal component analysis, three of the 12 characteristic parameters were selected as the most expressive. K-means clustering algorithm is adopted to obtain the proportions of various short strokes, according to the proportion, select the short stroke with small deviation degree to combine, and construct the driving cycle, it has the characteristics of low average speed, high idle speed ratio and short driving distance. AVL-cruise software builds the vehicle model and runs the driving cycle of urban logistic EV. Compared with WLTC, the difference in power consumption is 34.3%, which is closer to the actual power consumption, the areas with the highest motor speed utilization are concentrated only in the idle area.

Gearbox fault diagnosis is one of the core research areas in the field of rotating machinery condition monitoring. The signal processing-based bearing fault diagnosis in the gearbox is considered as challenging as the vibration signals collected from acceleration transducers are, in general, a mixture of signals originating from an unknown number of sources, i.e. an underdetermined blind source separation (UBSS) problem. In this study, an effective UBSS-based algorithm solution, that combines empirical mode decomposition (EMD) and kernel independent component analysis (KICA) method, is proposed to address the technical challenge. Firstly, the nonlinear mixture signals are decomposed into a set of intrinsic mode function components (IMFs) by the EMD method, which can be combined with the original observed signals to reconstruct new observed signals. Thus, the original problem can be effectively transformed into over-determined BSS problem.

Auxetic structures/materials with the negative Poisson’s ratio (NPR) properties can contract when compressed and expand when stretched, different from the conventional structures/materials. Due to the unique properties, it can have higher stiffness and better impact resistance with lightweight. Therefore, the auxetic structures/materials have been applied in various engineering field, such as automobile crash box, suspension mount etc. For auxetic structures/materials with negative Poisson’s ratio, there are four typical configurations (re-entrant hexagonal, double-V, tetra star-shaped and tetra-chiral). However, comparisons on the dynamic behaviors and crashworthiness between the four auxetic structures have not been studied. In this paper, the finite element models were developed for four typical auxetic structures. The deformation modes and energy absorption properties of four different auxetic structures were explored under different impact velocities.

This paper presents a novel torque distribution strategy (TDS) and a modified regenerative braking strategy (MRBS) for distributed-drive electric vehicle (DDEV) considering energy saving and brake stability. The presented TDS minimizes the energy consumption from battery in driving process. In order to overcome the shortcomings by using polynomial approximation for motor efficiency and the local minima problem, an exhaustive search method (ESM) is proposed to obtain the optimal front-rear torque distribution ratio. First, the power summation of four in-wheel motors is selected as the cost function of the optimization problem. Second, the ESM is designed to obtain the optimal torque distribution ratio according to current torque demand and motor speed based on motor efficiency map. Maximum motor torque and tire-road conditions are taken as constraints. Third, a MRBS is proposed to improve energy recovery performance by take ECE R13 and motor efficiency into account.

This paper describes an integrated approach to the analysis of brake squeal with newly lattice brake disc design. The procedure adopted to define the lattice properties by considering the periodicity cell of lattice plates, present equations of motion and modes response of a periodic lattice disc in principal coordinates on the rotating disc which excited by distributed axial load. The non-linear contact problem is carried out based on a typical passenger car brake for vanned and lattice brake disc types as it undergoes a partial simulation of the SAE J2521 drag braking noise test. The experimental modal analysis (EMA) with impact hammer test is used to obtain the brake rotor modal properties and validated finite element Free- Free State and stability analysis. The fugitive nature of brake squeal is analyzed through the complex eigenvalue extraction technique to define dynamic instability.

In this advanced technological era, lightweight design for fuel efficiency and environmental friendliness is essential for both conventional and hybrid electric vehicles (HEVs), without sacrificing the durability which is an important design factor for vehicle safety. To achieve these objectives, reduction of the structural mass of the full vehicle plays a vital role. The scope of this paper is to describe design methodologies for the vehicle differential case applied to achieve light weight and to ensure product life. The focus of this paper includes two tasks. The topology optimization and fatigue analysis of a vehicle differential case are conducted. Finite element analysis (FEA) is used to simulate the stress with constraint. After that, optimization parameters (design variables, responses, objective functions and constraints) of a vehicle differential case are selected for lightweight design by solid isotropic microstructures with penalization (SIMP) method.

Engine start-stop system is one of the main mechanisms for fuel saving in hybrid electric vehicles (HEVs). During those transient events, especially during engine starts, the engine torque pulsations can be an NVH issue if there is direct mechanical coupling between the engine and the driveline. In addition, engine starts may also result in the interruption of driving torque. The fast torque response of the electric machines provides a possible solution to mitigate the output torque fluctuation. But the effect is limited by the capability of these two electric machines due to the three missions they must satisfy simultaneously, i.e., starting the engine, compensating the torque pulsations and providing the demanded driving torque. To thoroughly understand this problem and propose possible solutions, in this study, we developed an input-split HEV powertrain model with a grounding clutch.

The design of aluminum foam reinforced thin-walled tubes has garnered much interest recently due to the high energy absorption capacity of these tubes. As a new kind of engineering composite material, aluminum foam can hugely increase the crashworthiness capacity without sacrificing too much weight. In this paper, axisymmetric thin-walled hollow tubes with four different kinds of cross-sections (circular, square, hexagonal and octagonal) are studied to assess their performance for crashworthiness problems. It is found that the tube with square cross-section has the best crashworthiness performance under axial impact. To seek optimal designs of square aluminum foam reinforced thin-walled tubes, a surrogate modeling technique coupled with a multi-criteria particle swarm optimization algorithm has been developed, to maximize specific energy absorption (SEA) and minimize peak crash force (PCF).

In most cases, researches on the ride performance of air suspension system are based on simplified mathematical models which could be too theoretical or not be able to consider the coupling relationship between the various components so that they behave far away from the actual vehicle system. This paper represents the study on the ride performance of an air suspension vehicle based on the accurate complex whole vehicle model which was established though ADAMS and Matlab. The applying of flexible components helped to improve the model accuracy. The stretching and compression test results of the air spring were used to establish the interconnected four-gasbag air suspension system. The vehicle ride performance was studied through the co-simulation between ADAMS and Matlab. The accuracy of the results were verified by the vehicle test results, which demonstrated the reliability of the whole model.