Vehicle Body Research Articles

Performance enhancements of semi-active vehicle air ISD suspension

To explore an innovative approach for enhancing the vibration isolation performance of vehicle air suspension systems, this study introduces the inerter element into the vehicle air suspension and investigates the dynamic behavior of the semi-active vehicle air ISD (inerter-spring-damper) suspension. Initially, a dynamic model of the quarter semi-active vehicle air ISD suspension is established, followed by conducting multi-objective optimization of the core parameters using the genetic algorithm. Subsequently, the dynamic performance of the semi-active vehicle air ISD suspension is thoroughly examined through simulations and analyses in both the time and frequency domains. The results demonstrate notable improvements in various aspects: the root-mean-square (RMS) value of the vehicle body acceleration in the semi-active vehicle air ISD suspension is reduced by 12.8%, the RMS value of the suspension working space is decreased by 37.3%, and the RMS value of the dynamic tire load experiences an 8.9% reduction. The findings of this paper indicate that the proposed semi-active vehicle air ISD suspension outperforms both the passive vehicle air suspension and the semi-active vehicle air suspension without an inerter, significantly enhancing the vehicle’s ride comfort, handling stability, and driving safety.

Dynamic Performance Optimization of Monorail Rapid Transit Formation Vehicles Based on Improved Artificial Potential Field Algorithm

This paper presents a new type of monorail rapid transit vehicle, which can operate in formation. In order to optimize the dynamic performance of the formation vehic-les when passing through the small radius curve, this paper first analyzes the structure of the new monorail rapid transit vehicle, and establishes the vehicle dynamic model and multi-body dynamics simulation model. Then the improved artificial potential field algorithm is used to build the formation vehicle operation controller. Finally, the dynamic performance evaluation index of the new mono-rail rapid transit formation vehicle is formulated, and the formation vehicle passing through the small radius curve scene is simulated. The simulation results show that the controller of the formation vehicle with dynamic optimi-zation control can effectively optimize the load transfer coefficient of running wheels, unbalanced centrifugal acce-leration and roll angle of vehicle body when passing thro-ugh the curve. Through this control method, the dynamic performance of formation vehicles passing through small radius curve lines can be optimized.

Control of the PVTOL with Strong Input Coupling

This paper studies the modeling and control of a Planar Vertical Take-Off and Landing (PVTOL) with steerable thruster. A longitudinal model is obtained using Newton’s second law for the PVTOL which evolves in 3 degrees of freedom and has two control inputs. The aerial vehicle is driven by steerable propulsion controlling its evolution in the vertical plane through the thrust and torque control inputs, which drive the vehicle body and generate a rotation. The obtained model is nonlinear and is significantly different with respect to the well-known PVTOL. For this reason, different control algorithms are presented, and the closed-loop behavior is studied for each of them. The proposed control strategies perform a stationary flight at a desired altitude and control the position of the aerial vehicle. The performance of the proposed control algorithms is tested in numerical simulations.

Можливості підвищення безпеки руху рейкових екіпажів з колесами, що незалежно обертаються

One of the promising ways to achieve high speed and smooth running of rail vehicles during stable movement in straight sections of the track and to improve the characteristics of fitting the vehicles in a curve is the use of independently rotating wheels in their running parts. Such undercarriages are already becoming quite widespread, for example, in urban rail transport vehicles. But independently rotating wheels can rotate in a wheel pair around a common axis with different angular velocities. It follows that during their movement, longitudinal creep forces do not arise, which form the controlling moment and center the wheel pair in the rail track. This can lead to increased angles of attack of the wheels on the rails, increased lateral forces and accelerated wear of the wheels and rails. In turn, this increases the tendency of vehicles with independently rotating wheels to derail by rolling the flange onto the head of the rail. 
 The accumulated global experience of operating similar vehicles confirms this. To overcome the mentioned disadvantages of independently rotating wheels, a number of various technical solutions have been proposed. Some of them relate to ensuring the given elastic-dissipative characteristic of the torsional articulation of the wheels in a wheel pair. A promising direction is the improvement of the characteristics of the connections of wheel pairs with the bogye and bogyes with the vehicle body, the use of mechatronic systems for controlling the position of the wheel pairs in the horizontal plane for their radial installation in curved sections of the track. In this work, attention is paid to the issue of the use in the design of independently rotating wheels of a perspective design scheme that allows independent rotation of the wheel's support surface and its guide surface (flange). The question of the effect of changing the design scheme of the wheel on the safety of movement due to the roll-in of the ridge on the rail head was considered. 
 The influence of a promising design scheme of a wheel in comparison with a traditional design scheme of a wheel on the safety of driving down a rails was investigated. The peculiarities of the distribution of frictional forces in the ridge contact during movement along the rails of the wheels of both design schemes are analyzed. For a wheel of a traditional design scheme, the module and the direction of the friction force vector in the ridge contact are uniquely determined by the geometric characteristics of the contact between the wheel and the rail and the angular speed of the wheel rotation. At the same time, when the wheel of the prospective design scheme moves, the direction and module of the friction force vector of the ridge on the rail also depend on the ratio of the angular velocities of rotation of the supporting surface of the wheel and its guiding surface (flange) around the common axis. The obtained results allow us to draw a conclusion about the expediency of using a promising design scheme in independently rotating wheels to increase the safety of movement of rail vehicles.

Explicit solution to the nonlinear geometry of double wishbone suspension by decoupling steering and wheel jumping DOF

The suspension system is vital to vehicle performance because it undertakes most of the interactions between wheels and the vehicle body. Due to the significant geometric nonlinearity, there is still a gap of suitable suspension models that are both accurate and computationally efficient. To solve the problem, this paper proposes an explicit solution to the nonlinear geometry of double wishbone suspension by decoupling steering and wheel jumping degrees of freedom (DOF). By discarding the small displacement assumption in the derivation process, the new model gets rid of repeated numerical iterations, resulting in substantial enhancement in computational efficiency. Furthermore, it is noticed in the comparative study that the proposed model can achieve the same level of accuracy as Adams. Benefiting from high computational efficiency and accuracy, the decoupling model presented is successfully used in the optimal design of a double wishbone suspension for smaller variation ranges of wheel alignment parameters. It is anticipated that the research will make significant contribution to fast dimension design of suspension geometry and real-time control of active variable geometry suspensions.

Optimal FLC-Sugeno Controller based on PSO for an Active Damping System

In this paper, a method for the design of an optimal Sugeno model (FLC-Sugeno) fuzzy logic controller for the active suspension system of quarter-vehicle models is presented. The parameters of the FLC-Sugeno controller are optimally searched, using the Particle Swarm Optimization (PSO) algorithm. The 16 optimized parameters include 3 parameters for adjusting the domain of the input state variables and control variables at the controller’s output, 4 fuzzy set adjustment numbers of the linguistic variables, and 9 parameters as the fuzzy rule weights of the rule system control. To compare and evaluate the effectiveness of the optimal FLC-Sugeno controller, an optimal PID controller using PSO is also implemented. Simulation results of the active damping system with the controllers when affected by the same type and standard road surface excitation show that the FLC-Sugeno controller is optimal for the quick ending of the oscillations of vehicle body displacement. The result shows that the proposed controlling scheme can be extended and applied to more complex active damping system models.

LQR-Based Suspension for Heavy Vehicles Considering the Time-Varying Characteristics of Vehicle–Road Interaction

The rapidly increasing demand for heavy vehicles in the transportation sector has led to more severe road damage and significantly higher road maintenance costs. Investigation of active suspension system incorporating vehicle–road interaction (VRI) can provide effective means to reduce the road damage and improve the ride comfort of vehicles. In this paper, an active vehicle suspension controller based on the strongly stable and robust linear–quadratic regulator (LQR) principle is developed for the time-varying VRI system. The coupled system is modeled by a quarter-car traveling on the road modeled by an Euler–Bernoulli beam resting on a viscoelastic foundation. Two types of road irregularities, deterministic sine wave and random, are considered in the numerical studies. A time-frozen technique, by which the linear time-varying system is converted to a time sequence of time-invariant systems, is applied to solve for the coupled responses. Three variables, the dynamic tire load, vehicle body acceleration, and suspension relative displacement, are used to assess the effectiveness of the LQR-based controller in comparison to the passive suspension system. The performance of the active control is investigated for different vehicle speeds, vehicle loads, and road profiles. Numerical studies show that the controller can effectively reduce the road damage and improve the ride comfort, with a slight increase in the suspension relative displacement. This work lays a useful foundation in the problem formulation and system parameter influences for future vehicle suspension design and road damage mitigation including VRI.

Study on electromagnetic dosimetry of the power cable in electric vehicle

To calculate the induced fields in the human body of the driver in an electric vehicle, the power cables of the electric vehicle are taken as the electromagnetic exposure source. The finite elements method is used to construct the electromagnetic environment model, which consists of the vehicle body, the power cables, and the driver body. The maximal values of the magnetic flux density inside the driver’s trunk and head are 4.63 μT and 0.12 μT, respectively. The maximal induced electric field intensity values are 670 mV/m and 99.7 mV/m, respectively. All values are below the safety limits of the ICNIRP. The results show that the electromagnetic environment induced by the power cables is safe for the driver. The study could provide a reference for improving electromagnetic exposure standards for electric vehicles.

Pemanfaatan Data Transaksi Untuk Mewujudkan Kepuasan Pelanggan, Brand Awareness Dan Loyalitas Pelanggan

Business development and growth is the ultimate target of establishing a company. Apart from being sales data, transaction data can also be a company asset that can be used for operational management and marketing strategies. For operational purposes, transaction data that reflects customer capabilities and conditions can be used for inventory management purposes by predicting the need for raw materials to guarantee the availability of products or services within a certain period of time according to customer needs. Companies can also develop products according to customer needs and minimize unnecessary expenses resulting from excessive procurement of raw materials. For marketing purposes, transaction data can be a reference for determining demographic customer characteristics. Customer characteristics can be used as a tool to determine current customer segments and how to provide maximum service to customers. The overall condition of customers will be valuable information for companies in carrying out marketing strategies. This research will explain how to utilize sales transaction data during a certain period using qualitative methods to achieve customer satisfaction through good raw material inventory management and appropriate product and service development, creating brand awareness (customer awareness of the brand) through digital marketing (digital marketing) and customer loyalty through customer relationship management strategies in the Exist Autodetailing Yogyakarta vehicle body maintenance business.

PEMBUATAN BODI PROTOTYPE MOBIL HEMAT ENERGI BERBAHAN FIBERGLASS DI POLITEKNIK NEGERI JEMBER

The use of fiberglass in Indonesia is still limited for manufacturing. That only vehicle body components for mini buses and buses, there are still not many domestically assembled custom car vehicles that include their original specifications as bodies made of fiberglass. This study aims to: Determine the right type of body material to be used in Energy Saving cars” Jember State Polytechnic, Knowing the design of the KMHE Polije car body with fiberglass as the main material. This study used the Research and Development (R & D) method with the research object taken was the design of the KMHE Polije car. Data collection methods were carried out in making the body, namely the literature method, the observation method and the interview method. After determining the desired method, then the manufacture of the car body is carried out. In its manufacture, several preparations are required, namely making designs, making molds, and making bodies using fiberglass media. Making the body adjusted to the dimensions of the length. The conclusion of this research is that the body of the Energy Saving Car prototype can be attached to the frame properly after the car is used or driven and the Energy Saving Car prototype body made of fiberglass material is very appropriate because it has a light character, easy to shape. This research was conducted from the feasibility stage with design validation to making the product and testing it. Based on the validation results by design experts, an average score of 85% is obtained with the "Valid" criteria so that the product is feasible to use.

Multi-Objective Prediction of the Sound Insulation Performance of a Vehicle Body System Using Multiple Kernel Learning–Support Vector Regression

The sound insulation performance of an electric vehicle’s body system serves as a critical metric for evaluating the noise, vibration, and harshness (NVH) quality of the vehicle. The accurate and efficient prediction of sound insulation performance is foundational for undertaking noise reduction design and optimization. Current engineering practices predominantly rely on Computer-Aided Engineering (CAE) methodologies to address this challenge. However, inherent shortcomings such as low modeling efficiency and difficulty in ensuring prediction accuracy often characterize these approaches. In an effort to overcome these limitations, we propose a decomposition framework for predicting the sound insulation performance of the electric vehicle body system. This framework is established based on a comprehensive analysis of the noise transmission paths within the system. Subsequently, the support vector regression (SVR) method is introduced to construct a machine learning model specifically designed for predicting the sound insulation performance of the body system. This approach aims to mitigate the inherent weaknesses associated with the conventional CAE processes using a ‘data-driven’ paradigm. Furthermore, the Multiple Kernel Learning (MKL) method is used to enhance the processing efficacy of the SVR model. The proposed method is validated using practical application and testing on a specific electric vehicle. The results demonstrate commendable performance in terms of prediction accuracy and robustness. This research contributes to advancing the field by presenting a more effective and reliable approach to predicting the sound insulation performance of electric vehicle body systems, offering valuable insights for noise reduction strategies and optimization efforts in the automotive industry.

Obstacle Avoidance Model of Two-Wheeled Vehicles for Nonrigid Obstacles Based on Social Forces

To describe the microtrajectory change behavior of two-wheeled vehicles when encountering nonrigid obstacles, this paper proposes an obstacle avoidance model of two-wheeled vehicles for nonrigid obstacles based on the improved social force method. In the model, the obstacle avoidance characteristics of two-wheeled vehicles for nonrigid obstacles and the safety operation requirements of two-wheeled vehicles are considered. The calculation methods of the minimum boundary distance of avoidance and the boundary avoidance force range edge function are proposed based on the ultimate turning angle and boundary avoidance characteristics, respectively. The speed control and direction control behavior of the rider to the vehicle is abstracted as the form of social force, and the two-wheeled vehicle/rider individual is subjected to the avoidance force and correction force perpendicular to the direction of the longitudinal axis of the vehicle body. The centrifugal trajectory obstacle avoidance motion obeying the Newtonian mechanics is studied based on the characteristics of the vehicle body turning angle change. Different traffic environments are constructed by MATLAB software and simulated according to the model running logic, and sensitivity analysis is performed based on the actual data collected in the survey. The simulation results show that, under the same conditions, compared with μi = 50N, when μi = 200N, the X-axis displacement of the simulated vehicle in the avoidance process is shortened by 26.31%, and the body deflection angle increases by 50.75% at the end moment of the avoidance process. Compared with electric motorcycles, the displacement of the X-axis in the avoidance process of the electric bicycle is shortened by 16.92%, and the body deflection angle at the end moment of the avoidance process is increased by 13.68%. The simulation results show that the model can well describe the trajectory change behavior characteristics of two-wheeled vehicles/riders encountering nonrigid obstacles in real situations, and the obstacle avoidance model of two-wheeled vehicles proposed in this paper is considered to be traffic justified.

Material-Structure Integrated Design and Optimization of a Carbon-Fiber-Reinforced Composite Car Door

This paper develops a material-structure integrated design and optimization method based on a multiscale approach for the lightweight design of CFRP car doors. Initially, parametric modeling of RVE is implemented, and their elastic performance parameters are predicted using the homogenization theory based on thermal stress, exploring the impact of RVE parameters on composite material performance. Subsequently, a finite element model of the CFRP car door is constructed based on the principle of equal stiffness, and a parameter transfer across microscale, mesoscale, and macroscale levels is achieved through Python programming. Finally, the particle generation and updating strategies in the Multi-Objective Particle Swarm Optimization (MOPSO) algorithm are improved, enabling the algorithm to directly solve multi-constraint and multi-objective optimization problems that include various composite material layup process constraints. Case study results demonstrate that under layup process constraints and car door stiffness requirements, plain weave, twill weave, and satin weave composite car doors achieve weight reductions of 15.85%, 14.54%, and 15.35%, respectively, compared to traditional metal doors, fulfilling the requirements for a lightweight design. This also provides guidance for the lightweight design of other vehicle body components.

Information Extraction and Three-Dimensional Contour Reconstruction of Vehicle Target Based on Multiple Different Pitch-Angle Observation Circular Synthetic Aperture Radar Data

The circular synthetic aperture radar (CSAR) has the ability of all-round continuous observation and high-resolution imaging detection, and can obtain all-round scattering information and higher-resolution images of the observation scene, so as to realize the target information extraction and three-dimensional (3D) contour reconstruction of the observation targets. However, the existing methods are not accurate enough to extract the information of vehicle targets. Through the analysis of the vehicle target scattering model and CSAR image characteristics, this paper proposes a vehicle target information extraction and 3D contour reconstruction method based on multiple different pitch-angle observation CSAR data. The proposed method creatively utilizes the projection relationship of the vehicle in 2D CSAR imaging to reconstruct the 3D contour of the vehicle, without prior information. Firstly, the CSAR data obtained from multiple different pitch-angle observations are fully utilized, and the scattering points of odd-bounce reflection and even-bounce reflection echoes are extracted from the two-dimensional (2D) coherent CSAR images of the vehicle target. Secondly, the basic contour of the vehicle body is extracted from the scattering points of the even-bounce reflected echoes. Then, the geometric projection relationship of the “top–bottom shifting” effect of odd-bounce reflection is used to calculate the height and position information of the scattering points of odd-bounce reflection, so as to extract the multi-layer 3D contour of the vehicle target. Finally, the basic contour and the multi-layer 3D contour of the vehicle are fused to realize high-precision 3D contour reconstruction of the vehicle target. The correctness and effectiveness of the proposed method are verified by using the CVDomes simulation dataset of the American Air Force Research Laboratory (AFRL), and the experimental results show that the proposed method can achieve high-precision information extraction and realize distinct 3D contour reconstruction of the vehicle target.

Using STAR-CCM+ Software in Aerodynamic Performance of Bogies under Crosswind Conditions

INTRODUCTION: STAR-CCM+ is a CFD software that uses continuum mechanics numerical techniques and is a tool for thermodynamic and fluid dynamics analysis. STAR-CCM+has expanded the functions of surface treatment, such as surface wrapper, surface remesh, and volume mesh generation.With the increase of train speed, the aerodynamic phenomena become more prominent, and the aerodynamic phenomena of high-speed trains in crosswind environment become more complicated. OBJECTIVES: Bogie is an important part of high-speed train. It is of great significance to study the aerodynamic performance Three groups of trains operating in a strong wind environment are modeled, and the surface pressure distribution characteristics of the car body and bogie, as well as the aerodynamic and aerodynamic torque distribution characteristics of each car and bogie, are analyzed when the train operates at 350km/h under a Class 12 crosswind condition. RESULTS: The results of the study show the variation rules of surface pressure, aerodynamic force and aerodynamic moment of the car body and bogie with wind speed. CONCLUSION: The windward surface pressure of the vehicle body increases linearly with the increase of wind speed, and the surface pressure of the roof and leeward side decreases linearly with the increase of wind speed.

Analysis of procedures for assessing the technical condition of passenger car bodies after post-accident repairs

The rapid development of the automotive industry is associated with a large number of motor vehicles on public roads. As the number of active road users increases, the probability of a road accident increases. As a result of a collision, cars have minor or major damage, often related to damage to the vehicle's body structure. The paper discusses issues related to the assessment of the quality of post-accident repairs and their impact on the technical condition of the post-accident vehicle in further operation.

Fatigue strength of adhesively bonded deep drawn sheet specimens under multiaxial loading with variable amplitudes

Adhesive bonding is a frequently used joining technology in the manufacturing of vehicle bodies. In comparison to conventional spot-welded designs, adhesive bonding provides a higher stiffness due to a planar load transfer. Furthermore, there are advantages in damping behavior and chemical separation in multi-material designs.Up to now, there exists still quite some uncertainty in the fatigue assessment of adhesively bonded joints due to a lack of reliable assessment approaches. This is especially true for the case of more complex in-service loading conditions as variable amplitude loading, due to the sparse database of experimental fatigue results, which are needed for the development of new methods. For this reason, the results of such tests are presented in this paper on component-like specimens, so called bowl specimens, where even uniaxial loading results in multiaxial stress state due to the complexity of the geometry. These specimens consist of a deep drawn sheet that is bonded with a thermosetting structural adhesive to a planar sheet and are subjected under cyclic loading. They were loaded uniaxially and multiaxially, with (φ = 90°) and without phase shift (φ = 0°).As a complex shaped and stressed sheet metal specimen, the bowl specimen closely resembles components of e.g. vehicle bodies, which is why the conducted tests are presented for a better understanding of such vehicle structures. It is shown that a phase shift leads to an increase of the fatigue life. Furthermore, the cyclic stiffness degradation is discussed, which often serves as a failure relevant parameter in real structures.

Combining Optimal Controller and Luenberger Observer for an Active Roll Control System on Trucks to Avoid Rollover Phenomenon at High Speeds

The propensity for roll instability in automobiles, particularly trucks, often arises during high‐speed maneuvers and emergency scenarios. The active roll control (ARC) system presents a promising solution for enhancing truck roll stability. This study delves into designing a controller for the ARC system adapted to high‐speed truck operations. It entails formulating a cost function for the linear quadratic regulator (LQR) optimal controller, incorporating variables directly pertinent to truck roll stability: vehicle body’s roll angle, unsprung masses’ roll angle, and normalized load transfer at the two axles. To streamline sensor usage and prioritize cost‐effectiveness, the Luenberger observer is integrated with the full‐state feedback LQR controller. The investigation involves executing double lane change maneuvers, simulating overtaking and obstacle avoidance, at speeds of 70, 100, 130, and 160 km/h. The maximum absolute value of the normalized load transfer coefficient at the axles is assessed up to speeds of 200 km/h. Research findings underscore the efficacy of the ARC system in enhancing truck safety by reducing the normalized load transfer of all axles over 30% compared to the passive system, particularly during high‐speed operations.

Methodology for qualifying the use of green steel in body components: A contribution to the life cycle engineering of steel

The use of materials with low environmental footprint will become more important for global car manufacturers in the future to comply the requirements and achieve the sustainability targets. The vehicle body of an electric vehicle is largely made of different steel grades and its production has a major impact on greenhouse gas emissions within the production stage. Future steel production will include a scrap-based electric arc furnace route. This route produces CO2-reduced steel products. However, these products are dependent on the scrap quality. Due to the high scrap content, impurities or tramp elements can be in the molten steel, reducing the steel end-quality or the properties of the final material and limiting reuse of the steel scrap. Therefore, a methodology is developed to perform an experimental analysis for data collection. Through this methodology, a recovery-process-structure-property correlation can be established and thus the influence of manufacturing-related impurities on the mechanical properties can be investigated. A case study shows initial research results using exemplary steel grades. The concept can examine the possibility of using steel with low carbon footprint to advance the life cycle engineering (LCE) idea in terms of recycling steel scrap and to reduce the environmental impact of body components by using CO2-reduced steel.

Numerical investigation of the natural transition in boundary layers on underwater axisymmetric bodies with superhydrophobic surfaces

The natural transition in boundary layers on axisymmetric bodies with superhydrophobic surfaces is studied using numerical methods. By boundary layer, we mean the boundary layer around the forebody and around the parallel body of an underwater vehicle. A method of calculating basic laminar flows on axisymmetric bodies with superhydrophobic curved surfaces is proposed, and a method of linear stability analysis for the boundary layers that considers the slip-velocity boundary condition for small disturbances is established. The eN method is used to predict the transition locations of the boundary layers. On a superhydrophobic surface, the slip velocity on the wall increases and then decreases along the streamwise direction, resulting in a maximum value at the forebody. The boundary layer thickness on a superhydrophobic surface becomes smaller than that on an ordinary surface. The superhydrophobic surface stabilizes the boundary layer and thus delays the natural transition. As the slip length on the superhydrophobic surface increases, the unstable zone shrinks, and the transition location moves further downstream, indicating that the delay effect of the superhydrophobic surfaces becomes stronger. As the oncoming flow velocity increases, the transition location on the superhydrophobic surface moves upstream and then downstream, leading to a “dangerous” velocity, at which the transition location is closest to the leading edge. The underlying mechanism of the dangerous velocity phenomenon is discussed: An increasing velocity has both stabilizing effect and destabilizing effect on the boundary layer.