Car Model Research Articles

Numerical Simulation of Aerodynamic Characteristics of Electric Vehicles with Battery Packs Mounted on Chassis

Aerodynamic characteristics are of great significance to the fuel economy and handling the stability of electric vehicles. The battery pack of electric vehicles has a huge structure and is usually arranged in the chassis area of the vehicle, which inevitably occupies the space at the bottom of the vehicle and affects the aerodynamic characteristics of the vehicle. To study the effect of the power battery pack installed in the chassis on the aerodynamics characteristics of the electric vehicle, the Computational Fluid Dynamics (CFD) method is used to study the flow and pressure fields of the SAE (Society of Automotive Engineers) hierarchical car model with battery packs mounted on chassis. The influence of the structure parameters of the battery pack on the automobile’s aerodynamics are also analyzed in detail. Based on the simulation results, it can be seen that the battery pack installed on the chassis has a great impact on the flow and pressure field at the bottom and tail of the vehicle, causing the drag coefficient and lift coefficient to increase. The structural parameters of the battery pack have contradictory effects on the drag and lift coefficients. As the length of the battery pack increases, the drag coefficient decreases, and the lift coefficient increases. As the battery pack width and height increase, the drag coefficient increases, and the lift coefficient decreases. The research results provide a reference for the optimization of the aerodynamic characteristics of electric vehicles with battery packs mounted on chassis.

AUTOMATION OF CALCULATING THE POSITION OF THE BOUNDARY COLUMN BETWEEN ADJACENT TRACKS OF DIFFERENT DESIGNS

The purpose of the study is to develop appropriate algorithms and procedures used in simulating the movement of a model car along adjacent tracks. These algorithms will automate the process of calculating the position of the boundary column between adjacent tracks of different designs with a given accuracy and compliance with traffic safety requirements. Scientific methods. In the course of the study, simulation methods were used to model the movement of the design car along the adjacent tracks. Analytical geometry methods were used to determine the main geometric characteristics of the car in terms of its relative position relative to the track axis. Results. The following conclusions were obtained as a result of the research. The multivariability of the design of adjacent tracks in the plan does not make it possible to create a universal analytical expression for determining the position of the boundary column. Existing methods for calculating the position of the boundary post provide for the maximum spread of the dimension in curved sections, which results in an excessive distance between the boundary post and the switch and inefficient use of the useful track length. The developed algorithms and procedures for determining the position of the boundary column are universal and allow automating the process of calculating the position of the boundary column between adjacent tracks of different designs in the plan, even when technical standards or parameters of the design cars change. In this case, only the initial data for the calculation need to be changed. Scientific novelty. The scientific novelty lies in the development of algorithms and procedures for formalizing the design of adjacent tracks and simulating the movement of design rolling stock on them. Practical significance. The developed algorithms and procedures can be implemented in the form of a software package for automated calculation of the position of the boundary column with high accuracy. Also, the obtained results of calculations can be used in the analysis and creation of an analytical description of the position of the boundary column for complex structures of adjacent tracks.

Study on the Influence of Synthesized Nano Ferrite Powder and Micron Ferrite Powder on Damping of a Single Degree of Freedom System

Magneto Rheological Fluid (MRF) damper has been opted as a promising semi active element of advanced suspension system. This work focuses on the damping nature of magnetorheological fluid under the influence of a magnetic field strength, size and shape of the of the iron oxide particles. A reduced scale single degree of freedom quarter car model with two stage magnetorheological damper, viscosity measurement setup, synthesized and commercially available Fe2O3 powders are used for the experimental study. An air cooled electro-dynamic shaker, Data acquisition system, accelerometers and the Lab view software acquires and analyzes the response of the quarter car model. X-ray Diffraction and Scanning electron microscopy characterize the morphology of iron oxide particles. The vertical acceleration, the displacement, the transmissibility ratio and the damping characteristics are analyzed based on the response of the top plate at different frequencies of base excitation. The results show that the magnetorheological fluid made with nano iron oxide powder has better damping characteristics than that of micron sized iron oxide powder

Vehicle’s Turning Time Span Estimation Based on Linear and Non-linear Computational Turning Model

The time span of a vehicle making turns, which is from the time a turn starts to the time the turn ends, are the basis of determination of essential data of vehicle motion like slip angles, forces on tires, except the vehicle is in an ideal one-dimensional motion. When the road condition is sensed by sensors on vehicle’s driver assistance systems, how to take a turn is the next step that should be calculated. After the turn starts, the end time of the turn should be adjusted in real time to remedy the imperfection digital simulation of the road sensed by the sensors. This paper compares two turning models and proposes an algorithm to adjust the end time of the turning time span during the turning motion of the vehicle. Subsequently, the algorithm is applied to two classic models of car, BMW M3 and Chevrolet Cavalier in four common motions: U-turn, lane change, sharp U-turn and sharp lane change. The algorithm proposed can be applied to every scenario that should take use of the turning time length, including the mathematical model of crossings, traffic flow of rush hours, or simply estimate the time span in unmanned vehicle control systems.

РАСЧЕТНО-ЭКСПЕРИМЕНТАЛЬНАЯ ОЦЕНКА ПРОЧНОСТИ ПАССАЖИРСКОГО ЭКСКУРСИОННОГО ОБЗОРНОГО ВАГОНА МОДЕЛИ 61-941

Experiment-calculated evaluation of the strength of the load-bearing body metal structure of a passenger observation car model 61-941 is done. The car is designed for tourist and sightseeing passenger trips. The project is created on the basis of a serial passenger car model 61-4179 as part of the capital repairs by Tambov Railway Car Repair Plant VRM. In accordance with the design andengineering specification, the body of the base car was significantly modernized, new planning solutions were applied for the internal equipment of the car, the frame of the car body was strengthened. Some theoretical studies using the finite element method were carried out to assess the compliance of the observation car model 61-941 with regulatory requirements. The strength and stability of the body metal structure is evaluated. At the second stage, full-scale tests of the car were carried out in static and dynamic conditions with longitudinal collisions. Additional attention is paid to the attachment points of passenger seats to the elements of the car body. The analysis of the results of theoretical and experimental studies shows their satisfactory compliance with the requirements of regulatory documents required for passenger car bodies.

ОБОСНОВАНИЕ РАЦИОНАЛЬНОЙ КОНСТРУКЦИИ СКОЛЬЗУНОВ ТЕЛЕЖКИ ПАССАЖИРСКОГО ВАГОНА

At the first stage, a detailed dynamic solid-state model of a passenger car is developed which has a bolsterless truck. The dynamic model is a system of absolutely rigid bodies interconnected by elastically dissipative linear and nonlinear force elements, hinges and contact forces. The adequacy of the car dynamic model and the reliability of the results obtained are evaluated the results of running tests. Based on the developed solid-state dynamic model, a comprehensive study of the effect of the friction factor on the guide block support surfaces on the safety and dynamic performance of a passenger car under various modes of movement along the track, taking into account irregularities is carried out. As a result of modeling, a range of rational values of friction moments on the support guide blocks is obtained. The composition of the composite material for the support surfaces of the truck guide blocks is selected using neurocomputer modeling methods, the manufacture of the proposed composite material is tested, experimental studies of the characteristics of composite elements confirming their properties and safety were carried out.

Semi-active Suspension Control with PSO Tuned LQR Controller Based on MR Damper

As the Linear Quadratic Regulator (LQR) approach is applied extensively in the system control of automobile suspension, the accuracy improvement of the weighting Q and R matrices is getting concern. The Particle Swarm Optimization (PSO) algorithm is being introduced to identify parameters and optimize matrix Q and R in order to fix the insufficiency of these experienced values because of the fast convergence and a more accurate solution. In this article, a quarter car model and a Bouc-Wen-based magnetorheological (MR) damper model are developed to combine the control of PSO identification and PSO-LQR controller in the semi-active suspension system. The MR damper was performed with an experimental test for running identification using experimental data as input into the Bouc-Wen model to obtain six unknown parameters, where the parameters were estimated with the PSO algorithm. Since the numerical model has been done with all parameters clear, the need for damping force from suspension is obtained by means of running the model using an input current. In the employment of PSO for damper model and vehicle control, the dual applications succeeded in verifying the feasibility of parameter identification in the MR damper and successfully tuned the LQR controller in the semi-active suspension, which decreases the vehicle body acceleration and displacement so that the improvement of ride comfort and drive stability achieved.

Laboratory-Scale Low-Speed Water Tunnel: Comparison of Experimental Flow Visualization and Computer-Aided Simulation

This study aimed at developing the laboratory-scale low-speed water tunnel design by first evaluating the effect of varying the number of wide-angle diffuser vanes and then confirming flow visualization against object geometries tested by experiments and computer-aided simulation. The low-speed water tunnel design in this study consists of a wide-angle diffuser, a honeycomb, a convergent section, and a working section. To ascertain the laminar flow of water would act in the experiment, a prior simulation using 3, 6, and 12 vanes and without a vane was conducted. Some geometries, including tube, triangle, aerofoil, and car models have been tested and then compared to the experimental results. The results indicate that the twelve vanes diffuser is more effective in minimizing turbulent flow and producing a streamlined pattern in the water tunnel. Laminar flow with a Reynolds number of 2238 and flow velocity of 0.008 m/s was obtained in the working section. The flow visualization by experiment and computational fluid dynamics simulation was almost similar.

PASCAR: a multiscale framework to explore the design space of constitutive and inducible CAR T cells.

CAR T cells are engineered to bind and destroy tumor cells by targeting overexpressed surface antigens. However, healthy cells expressing lower abundances of these antigens can also be lysed by CAR T cells. Various CAR T cell designs increase tumor cell elimination, whereas reducing damage to healthy cells. However, these efforts are costly and labor-intensive, constraining systematic exploration of potential hypotheses. We develop a protein abundance structured population dynamic model for CAR T cells (PASCAR), a framework that combines multiscale population dynamic models and multi-objective optimization approaches with data from cytometry and cytotoxicity assays to systematically explore the design space of constitutive and tunable CAR T cells. PASCAR can quantitatively describe in vitro and in vivo results for constitutive and inducible CAR T cells and can successfully predict experiments outside the training data. Our exploration of the CAR design space reveals that optimal CAR affinities in the intermediate range of dissociation constants effectively reduce healthy cell lysis, whereas maintaining high tumor cell-killing rates. Furthermore, our modeling offers guidance for optimizing CAR expressions in synthetic notch CAR T cells. PASCAR can be extended to other CAR immune cells.

Intelligent Handling Robot Based on Mecanum Wheel

This paper proposes an intelligent handling robot based on Mecanum wheel, which can be set to recognize and handle the goods in the inherently known site, and can be adapted to the logistics sorting and other scenarios. The robot to NXP's RT1064 microcontroller as the main control, the use of RT-Thread embedded system development, the Mecanum wheel as a framework, the independent construction of the car model structure, equipped with a Raspberry Pi and robotic arm structure, as well as the MT9V032 total drilling wind camera to build the hardware circuit. The robot can recognize the position of the handling object through the off-site camera, then the upper computer for path planning, through the PID parameter adjustment and vehicle attitude solving to control the movement of the handling robot, to reach the handling location and then by the total drilling wind camera for detailed position adjustment. The robot equipped with Openart mini can recognize the type of objects to be handled, pick them up and place them on the pallet through robotic arm attitude solving, and correct the deviation through remote manual control, and finally realize fast omni-directional handling through Mecanum wheels to deliver the objects to the end point.

Computer modeling and software research of car and engine parts

Problem. The development of automotive technology for various purposes and the improvement of existing car models, requires a fast and flexible design process. Spatial models of details and nodes are the starting points for design, and the necessary design documentation is performed on their basis. When manufacturing parts on CNC machines, it is necessary to quickly obtain a control program that will increase the accuracy of the product by ensuring the optimal trajectory of the mutual movement of the part and the tool. Therefore, the creation of a comprehensive methodology for the design of car parts, their basic inspection and obtaining design documentation is an important technical task. Goal. The main goal of the work is to determine the rational sequence and basic principles of computer-aided design, research and manufacturing of car and engine parts, and the development of mathematical spatial models of surfaces in order to optimize control programs for CNC machines. Methodology. The approaches adopted in the work for solving the set goal are based on general design principles. The methods of conducting static and dynamic calculations, as well as spatial mathematical modeling of the processes of manufacturing parts were also used. Results. A comprehensive methodology for designing parts of engines and cars has been developed. The main principles of creating spatial models have been determined in order to achieve their flexibility and simple editing. Methods of automating the development of drawings and design documentation are described. The software options for the primary verification of static strength and frequency analysis are considered. A calculation program has been developed for constructing transient and amplitude-phase-frequency characteristics. The mathematical spatial modeling of typical surfaces of the camshaft is provided with the aim of further research and optimization of the development of a control program for processing on a CNC machine tool. Originality. The defined basic principles of designing parts of engines and cars provide an opportunity to create a flexible spatial model and more fully automate the process of drawing up technical documentation. The developed mathematical spatial models of the supporting and working surfaces of the camshaft make it possible to write a control program with the determination of the optimal trajectory of the mutual movement of the part and the tool. Practical value. The obtained results can be recommended when designing car parts and assemblies.

Bifurcation analysis of a rear axle tramp car model

Axle tramp is a self-sustaining vibration in the driven axle of a vehicle with a beam axle layout, known to occur under heavy braking or acceleration. A 6DOF mathematical model of this phenomenon is used to identify how the key parameters of driveline stiffness, axle mass and fore/aft stiffness change the system’s dynamics. A bifurcation analysis is performed to study this nonlinear system’s dynamics. Four Hopf bifurcations in the underlying equilibria, along with a fold bifurcation in the outermost limit cycle branch, are shown to bound the parameter space where tramp occurs. The severity of tramp was found to be minimised by increasing drivetrain stiffness, reducing axle mass or increasing fore/aft stiffness: the trade-off for minimising tramp severity is that it may be easier to excite tramp when the drivetrain stiffness is increased, and the speed range over which tramp can occur is increased as fore/aft stiffness is increased. A key outcome from this work is that future electrified powertrains may experience more tramp, albeit at a reduced magnitude, than their combustion-powered counterparts.

Ride comfort and segmental vibration transmissibility analysis of an automobile passenger model under whole body vibration

The examination of seated occupants’ ride comfort under whole-body vibration is a complex topic that involves multiple factors. Whole-body vibration refers to the mechanical vibration that is transmitted to the entire body through a supporting surface, such as a vehicle seat, when traveling on rough or uneven surfaces. There are several methods to assess ride comfort under whole-body vibration, such as subjective assessments, objective measurements, and mathematical models. Subjective assessments involve asking participants to rate their perceived level of discomfort or satisfaction during the vibration exposure, typically using a numerical scale or questionnaire. Objective measurements include accelerometers or vibration meters that record the actual physical vibrations transmitted to the body during the exposure. Mathematical models use various physiological and biomechanical parameters to predict the level of discomfort based on the vibration data. The examination of seated occupants ride comfort under whole-body vibration has been of great interest for many years. In this paper, a multi-body biomechanical model of a seated occupant with a backrest is proposed to perform ride comfort analysis. The novelty of the present model is that it represents complete passenger by including thighs, legs, and foot which were neglected in the past research. A multi-objective firefly algorithm is developed to evaluate the biomechanical parameters (mass, stiffness and damping) of the proposed model. Based on the optimized parameters, segmental transmissibilities are calculated and compared with experimental readings. The proposed model is then combined with a 7-dofs commercial car model to perform a ride comfort study. The ISO 2631-1:1997 ride comfort standards are used to compare the simulated segmental accelerations. Additionally, the influence of biomechanical parameters on most critical organs is analyzed to improve ride comfort. The outcomes of the analysis reveal that seated occupants perceive maximum vibration in the 3–6 Hz frequency range. To improve seated occupants' ride comfort, automotive designers must concentrate on the pelvis region. The adopted methodology and outcomes are helpful to evaluate protective measures in automobile industries. Furthermore, these procedures may be used to reduce the musculoskeletal disorders in seated occupants.

USING OBD-2 TECHNOLOGY FOR VEHICLE DIAGNOSTIC AND USING IT IN THE INFORMATION SYSTEM

This article considers the research of OBD-2 technology for interaction with on-board vehicle systems, the creation of a unified system that can work with different makes and models of cars. The history of OBD-2 technology, its development, existing standards and their implementation in modern cars is described. Basic diagnostic functions are described, with which you can get information about the car, as well as perform its settings and send various commands to it. In addition, the hardware part of the scanner, its technical features, nuances of interaction with it and the purpose of each of its pins are considered. Also reviewed couple models of scanners that can be used to develop this system. Conclusions are drawn on the practicability of their use, taking into account their capabilities. Existing software analogues, their main functions, advantages and disadvantages are considered. The general concept of interaction with the car via OBD-2, the interaction algorithm and step-by-step analysis of the interaction between the scanner and the car are also considered. The software part of the interaction between the car and the scanner, special codes used to send requests and responses, their further analysis and interpretation in a human-friendly form are considered. The possibilities for the unification of these codes for different car manufacturers and the common code base to create a universal system that will be suitable for different cars from different car manufacturers are highlighted. A model of the software system is proposed, which can embody a large set of useful functions for any motorist and will be compatible with a large number of modern cars equipped with universal diagnostic tools, while using an affordable scanner model without the use of expensive professional equipment.

Car Price Quotes Driven by Data-Comprehensive Predictions Grounded in Deep Learning Techniques

The used car market has a high global economic importance, with more than 35 million cars sold yearly. Accurately predicting prices is a crucial task for both buyers and sellers to facilitate informed decisions in terms of opportunities or potential problems. Although various machine learning techniques have been applied to create robust prediction models, a comprehensive approach has yet to be studied. This research introduced two datasets from different markets, one with over 300,000 entries from Germany to serve as a training basis for deep prediction models and a second dataset from Romania containing more than 15,000 car quotes used mainly to observe local traits. As such, we included extensive cross-market analyses by comparing the emerging Romanian market versus one of the world’s largest and most developed car markets, Germany. Our study used several neural network architectures that captured complex relationships between car model features, individual add-ons, and visual features to predict used car prices accurately. Our models achieved a high R2 score exceeding 0.95 on both datasets, indicating their effectiveness in estimating used car prices. Moreover, we experimented with advanced convolutional architectures to predict car prices based solely on visual features extracted from car images. This approach exhibited transfer-learning capabilities, leading to improved prediction accuracy, especially since the Romanian training dataset was limited. Our experiments highlighted the most important factors influencing the price, while our findings have practical implications for buyers and sellers in assessing the value of vehicles. At the same time, the insights gained from this study enable informed decision making and provide valuable guidance in the used car market.

Hybrid Particle Swarm Optimization Genetic LQR Controller for Active Suspension

In this paper, a hybrid particle swarm optimization genetic algorithm LQR controller is used on a quarter car model with an active suspension system. The proposed control algorithm is utilized to overcome the shortcoming that the weight matrix Q and matrix R determined by experience in the traditional LQR control method. The proposed hybrid control method makes it possible to achieve the optimal control effect. A full-order state observer is proposed to observe the state of active suspension. A quarter car active suspension model and road input model are presented at first, and the LQR controller based on the hybrid particle swarm optimization genetic algorithm is utilized in the active suspension system control. Sprung mass acceleration, suspension deflection, and tire dynamic load are selected as the control effect evaluation index. Next, simulation results are presented. According to the results, compared with the passive suspension and active suspension with a traditional LQR control, there is an obvious reduction in the sprung mass acceleration, deflection, and tire dynamic load with an optimized controller under case 1 and case 2. Simultaneously, the system state fed back by the full-order state observer can effectively reflect the true state of the active suspension system.

Modeling and Simulation of Pure Electric Passenger Vehicle Based on MATLAB and AVL CRUISE

In this paper, the vehicle control strategy of pure electric passenger vehicle is designed in MATLAB/simulink, and the driving control strategy and the braking recovery mode control strategy modeling and Simulation are analyzed in detail. The model of the pure electric passenger car is built in AVL CRUISE software, and the parameters of the pure electric passenger car, driving motor, power battery, car tire and other modules are set, and then the established modules are connected. The results show that the drive control strategy of pure electric passenger vehicle does have its unique practicability and superiority.

Experimental Study on Magnetorheological Damper Prototype and Obtaining Its Equivalent Damping Coefficients

In this work, a magnetorheological (MR) damper prototype that provides controllable damping force was designed, manufactured and tested. The design and dimensions of the MR damper piston were determined according to the static magnetic analysis results made in ANSYS/Emag (Electromagnetics) software. The MR damper’s damping performance was tested in laboratory by utilizing a damper testing device. The tests were carried out under different currents applied to coil of the MR damper. According to the test results, the equivalent damping coefficients of the MR damper were calculated for different currents. The test results show that the highest damping force is 169.4 N with frequency of 3.18 Hz and applied current of 2 A. In this case, the equivalent damping coefficient is 302 Ns/m. The equivalent damping coefficient is 181 Ns/m when no current is supplied to the coil. The area of the dynamic force range also becomes larger with increasing the applied current. In addition, according to the quarter car model based simulation results in MATLAB/Simulink, it was seen that the semi-active suspension system using MR damper was more effective and successful in vibration mitigation.

Optimal Control of an Active Suspension System Applying Distributed Parameter Simulation Test

Automotive is one of the most important industries in the world, which lead to a need for continuous improvement of vehicles and their internal systems. Suspension systems have been improved for better vehicle performance and passenger comfort, keeping the tire in contact with the road surface. Active suspensions require optimal control to modulate the flow of energy and generate the control force by implementing active actuators able to provide negative damping and a wider range of forces and velocities. This article aims the design of an active suspension system based on LQG and LQR controller evaluating its performance in a distributed parameters simulation using COMSOL Multiphysics® and MATLAB®. The quarter car model is proposed and is linearized to design the optimal control (LQG and LQR) respectively. An early mathematical simulation is developed in MATLAB (R) software to verify and compare the open and closed loop results. Finally, the full system model is implemented in COMSOL Multiphysics (R) software considering rigid materials and the controller to analyze the distributed parameters simulation results.

Optimization and experimental analysis of a cost-effective magneto-rheological (MR) fluid for application in semiactive suspension of a passenger van

The study presented in this article attempts to determine the optimal composition of iron particles in the MR fluid for vehicular application based on the size of the particles, the simulation response of a test vehicle model, and the cost of the fluid. The MRF samples with two different-sized particles in varying compositions are prepared and characterized on a rheometer. The performance of each MRF sample in the semiactive suspension of a test vehicle is determined by simulating its full car model on a random road. The response of the vehicle model during simulation, the size of the particles, the volume fraction of the particles in the carrier fluid, and the fluid’s calculated cost are input for the Response surface optimization technique. The optimization results revealed that the MR fluid with large-sized particles in a 25% volume fraction would be suitable for the said application. Moreover, it was found that the rheological performance of the optimized MR fluid was better than the commercial MR fluid. The performance of the optimized fluid in a MR damper was experimentally evaluated against the stock passive damper of the test vehicle. The results of the experiment on the test vehicle showed that the MR damper improved the test vehicle’s ride comfort by 36.58% over a speed bump and 11.3% on an off-road test track. The road handling was also improved by 45% over a speed bump and 46% over the test track.