Car Front Research Articles

Improving the load distribution in the automobile front collision zone by adding 'S' shaped curved collision rail

Improving the load distribution in the automobile front collision zone by adding 'S' shaped curved collision rail

Modeling & Simulation as Industry 4.0 enabling technology to support manufacturing process design: a real industrial application

This research work, first, briefly describes the educational offer of University of Calabria (UNICAL) related to Modeling & Simulation (M&S) and, secondly, presents a case study, developed by UNICAL students, as attempt to transfer the theoretical knowledge on M&S, gained over the university studies, into a real industrial application. As case study, the development of a new racing car front wing, from the mechanical design to the manufacturing process design and optimization, is presented. The manufacturing process design and optimization has been achieved by proposing an approach based on the combination of M&S tools, multiple design parameters and multiple performance measures. In particular, a simulation model has been used to assess the effect of different design parameters on several performance measure. The quantitative evaluation of the effects of the multiple design parameters on the multiple performance measures is achieved by using the Design of Experiments (DOE) being validated by means of the analysis of variance (ANOVA).

카메라-IMU 센서 융합 기반 자세 추정을 통한 전방 객체 거리 정밀 보정

This paper presents a novel method to correct with only the camera and IMU sensors an estimated distance error due to a rapid change in a vehicle’s posture while driving, as it is very important to estimate the distance of a front car in autonomous driving. To estimate the change in vehicle’s posture, the proposed method adopts a visual odometry method using the optical flow and the camera-IMU fusion. The error in the estimated distance caused by an instantaneous change in the vehicle

Design of Multi-Station Progressive Die for Mounting Bracket of Automobile Front Bumper Spotlight

The mounting bracket of the front bumper spotlight of the automobile is mainly produced by the method of wire cutting and processing. This method is difficult to achieve mass production and the performance becomes poor after processing. In order to improve this phenomenon, this paper adopts the method of sheet metal stamping to form it. The main tasks include the determination of the process plan, the simulation of Dynaform 5.9, the design of the layout, the calculation of the punching force, the bending force and the design of a set of 7-station progressive die. This design has certain practical guiding significance for the processing of the same type of products.

Materials selection of 3D printed polyamide-based composites at different strain rates: A case study of automobile front bumpers

The selection of 3D printed composite materials considering multiple criteria has become a challenging issue for designers/engineers and can be regarded as a typical decision-making problem. Especially for diverse engineering applications, the different strain rates encountered need to be addressed in the decision-making process. In this study, a systematic hierarchical evaluation model of 3D printed polyamide-based composites with 27 indicators is established considering economic, environmental, social and mechanical aspects. The mechanical responses at four strain rates (8 × 10−4 s−1, 8 × 10−3 s−1, 1700 s−1 and 3510 s−1) are incorporated into the model. A hybrid decision-making approach combining the fuzzy DEMATEL (Decision Making Trial and Evaluation Laboratory)-Entropy and fuzzy TODIM (Tomada de Decisão Interativa Multicritério)-VIKOR (VlseKriterijumska Optimizacija I Kompromisno Resenje) methods is proposed to solve the composite material selection problem. An automobile front bumper, as an empirical application, is investigated to demonstrate the proposed model and decision-making approach. The results show that PACF-C, that is the short carbon fibre reinforced polyamide printed with a concentric strategy, is the optimal alternative. This study provides an effective approach for solving the material selection problem of 3D printed composites.

Collision avoidance helping system for drivers


 
 
 This paper is used to enhance the driver assistance system for collision avoidance. The advanced driver assistance system (ADAS) is the most innovative technology in the auto mobile industry. Our paper focuses on the problem of road mishaps. Most road accidents occur due to driver negligence. The main purpose of our paper is to propose a method to avoid such accidents using advanced technology at a low cost. We focus on the functions of collision avoidance and liquor detection to give a suitable result for all the problems. We implemented this method using the Arduino UNO, along with the required sensors. The collision avoidance can be reduced by using a cruise control system using an ultrasonic sensor. The system alerts the driver when the oncoming cars are getting too close to the front cars. Using an alcoholic sensor, we can detect the liquor detection of the driver, respectively. With all these functionalities, there is a possibility to avoid accidents. There is future scope for our method by including additional features to reduce accidents.
 
 

Characteristics of human movement and injury in a side collision between the front of a small car and a bicycle

ObjectiveOur research groups have studied the movement and injury characteristics of the human body in a side collision between the front of a small car and a pedestrian. This study discusses the movement and injury characteristics of the human body in a side collision between the front of a small car and bicycle. MethodsA total of 31 cases of traffic accidents caused by small car collisions when riding a bicycle across a road were collected. Through on-site inspection and trace inspection of the accident vehicles and bicycles, the speed of the car during the collision was calculated, the collision relationship between the small car and bicycle was determined, and the injury site and degree were determined through autopsy. The car speed was divided into two groups: <60 km/h and >60 km/h. Injuries of the skull, cervical spine, ribs, pelvis, femur and tibiofibular were analysed, and the correlations with the height of the bicycle controller, the height of the bicycle seat, the height of the car hood and the length of hood were discussed. PC-Crash was used for simulation analysis to further clarify the injury process. ResultsThe ratio of the height of the bicycle seat to the height of the hood plus the length of the hood in the windshield-damaged group was larger than that in the undamaged windshield group (P < 0.05). No cervical fracture was found when V < 60 km/h, and 52.94% of cases had cervical fracture when V > 60 km/h. The ratio of the height of the bicycle seat to the height of the hood in the pelvic fracture group was smaller than that in the nonpelvic fracture group (P < 0.05). The incidence of tibiofibular fracture was less than 65%. ConclusionsWhen a side impact between a car front and a bicycle occurs, the resulting human injury is related not only to the speed but also to the height of the bicycle seat and the height and length of the hood of the car. The incidence of tibiofibular fractures was significantly lower than that of small car front-pedestrian side impacts.

Application of modelling and simulation to evaluate the theta method used in diagnostics of automotive shock absorbers

The dynamic properties of the car's suspension largely depend on the damping that results from the state of the shock absorbers. Their technical condition is essential for vehicle occupants’ comfort and traffic safety. It changes with the time and intensity of use of the vehicle. Therefore, adequate methods of non-destructive (diagnostic) testing of suspension damping have been sought for many years. The on-vehicle tests are particularly useful thanks to their low cost and short test duration time. The newest method is the ‘theta’ method which is the subject of the presented article. Notation ‘theta’ usually means relative damping (damping ratio) in the vibrating system. The paper asses four variants of the method. Two versions come from modal analysis and are also known as the ‘peak-picking method’ or ‘half-power method’. Two other versions are described in cited patent documentations. Three linear ‘quarter car' models with their description in the frequency domain were used to assess mentioned variants of the ‘theta’ method. Calculations were made for two typical datasets corresponding to the front and rear suspension system of a medium-class motor car. This provided grounds for general qualitative and (within a limited scope) quantitative assessment of the usefulness of individual variants of the method under analysis and for comparisons between them. The paper is to help in choosing the variant of the ‘theta’ method that would most likely find the application and that might be recommended to manufacturers and would-be purchasers of diagnostic suspension testers. The author has also highlighted the importance of possible further research.

Рекомендації щодо виготовлення пристроїв пасивного захисту головного вагона з різних матеріалів

High-speed multiple-unit trains in Ukraine must be developed according to the Ukrainian Standards DSTU EN 12663 and DSTU EN 15227, which specify the car crashworthiness and active and passive safety. This paper addresses issues involving the development of recommendations on the passive safety of a multiple-unit head car in emergency collisions with obstacles, the determination of the parameters of the energy-absorbing devices (EADs) that are a part of the passive safety system (PSS) of the head car, and the possibility of using aluminum alloys in the EAD manufacturing. Researchers of the Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine developed a passive protection concept for home high-speed passenger trains in emergency collisions according to the DSTU EN 15227 requirements and methods and finite-element models for the study of the impact plastic deformation of the EAD honeycomb structures. It was proposed that lower- and upper-level energy-absorbing devices EAD 1 and UL EAD, respectively, be used at head car front end and low-level energy-absorbing devices be used at the head car rear end in place of buffers (EAD 2 or EAD 3 if the intermediate cars have a mass of 50 t or 64 t, respectively). EAD 1 includes two tandem elements. Element 1 is a box with a single-layer pack of hexagonal honeycombs inside. Element 2 is a truncated pyramid made up of honeycombs with triangular cells. The UL EAD has three stages in the form of Element 2. EAD 2 and EAD 3 were designed based on Element 1. The parameters of EAD 1, EAD 2, and EAD 3 of energy capacity 0.95 MJ, 0.25 MJ, and 0.3 MJ, respectively, made of type 08Yu steel were determined. A 3D geometrical model of the home head car front end was developed, and an EAD placement scheme was proposed. It was recommended to install two EAD 1 devices at the head car front end and two UL EAD and two EAD 2 or two EAD 3 devices at the head car rear end and at the ends of the intermediate cars. The aim of this paper is to develop recommendations on manufacturing head car passive protection devices with the use of different materials. A comprehensive study was conducted to choose advisable parameters of a UL EAD made of 08Yu steel and to analyze the possibility of replacing 08Yu steel in the EAD 1, EAD 2 (EAD 3), and UL EAD manufacture with AMr2 and AMr6 aluminum alloys, which have high plastic properties, a low density, and a high resistance to an aggressive environment. As a result, it was shown that 08Yu steel can be replaced with AMr6 aluminum alloy in the EAD 1 and EAD 3 manufacture and with AMr6 or AMr2 aluminum alloys in the UL EAD manufacture. The parameters of the above-mentioned EADs made of the aluminum allows were determined. Recommendations on head car passive protection according to the DSTU EN 15227 were developed. The methods, mathematical models, and recommendations developed may be used in the design of a new-generation head car according to the DSTU EN 15227 requirements.

Analysis of the Effects and Causes of Driver Horn Use on the Acoustic Environment at Urban Intersections in Taiwan

Car horns were originally installed in vehicles for safety. However, many urban areas in several countries face noise problems related to the use of car and motorbike horns. To propose measures to suppress the use of horns, relationships between horn use and factors including driver awareness and behavior, traffic environment, and the transportation system should be investigated. The present study therefore conducted surveys to grasp the current circumstances of horn use and traffic at urban intersections in Taiwan. The relationship between horn use and the traffic volume of standard-sized vehicles was found. According to an analysis of horn use during traffic signal cycles, in many cases, horns were honked after entering intersections to turn left. In particular, horns were honked when the driver waited more than 4 s for the car in front to start moving after the green light allowing left turns was turned on. An analysis of noise levels at intersections showed that the maximum noise level value (LAmax) could be reduced if vehicle horns were not used. Multiple regression analysis also indicated that LAmax values increased with the frequency of horn use. The equivalent continuous A-weighted sound pressure level (LAeq,10min) did not change with driver horn use, and increased with the traffic volume of motorcycles.

Recognition of Car Front Facing Style for Machine-Learning Data Annotation: A Quantitative Approach

Car front facing style (CFFS) recognition is crucial to enhancing a company’s market competitiveness and brand image. However, there is a problem impeding its development: with the sudden increase in style design information, the traditional methods, based on feature calculation, are insufficient to quickly handle style analysis with a large volume of data. Therefore, we introduced a deep feature-based machine learning approach to solve the problem. Datasets are the basis of machine learning, but there is a lack of references for car style data annotations, which can lead to unreliable style data annotation. Therefore, a CFFS recognition method was proposed for machine-learning data annotation. Specifically, this study proposes a hierarchical model for analyzing CFFS style from the morphological perspective of layout, surface, graphics, and line. Based on the quantitative percentage of the three elements of style, this paper categorizes the CFFS into eight basic types of style and distinguishes the styles by expert analysis to summarize the characteristics of each layout, shape surface, and graphics. We use imagery diagrams and typical CFFS examples and characteristic laws of each style as annotation references to guide manual annotation data. This investigation established a CFFS dataset with eight types of style. The method was evaluated from a design perspective; we found that the accuracy obtained when using this method for CFFS data annotation exceeded that obtained when not using this method by 32.03%. Meanwhile, we used Vgg19, ResNet, ViT, MAE, and MLP-Mixer, five classic classifiers, to classify the dataset; the average accuracy rates were 76.75%, 78.47%, 78.07%, 75.80%, and 81.06%. This method effectively transforms human design knowledge into machine-understandable structured knowledge. There is a symmetric transformation of knowledge in the computer-aided design process, providing a reference for machine learning to deal with abstract style problems.

Fine-grained classification of automobile front face modeling based on Gestalt psychology*

Fine-grained classification of automobile front face modeling based on Gestalt psychology*

Effects of asna fibre reinforced with epoxy resin with and without steel wire mesh and simulation of car bumper

The utilization of natural fiber composites has been increased in replacing various parts in the automobile sector made up of synthetic fiber due to its degradability nature and environment friendliness. In this work, the naturally available Asna fiber was processed and the composites were prepared without and with steel wire mesh in various volume fractions (vf) of the fiber. In the present experimental investigation, the influence of different composite on the thermal, mechanical, and water absorption characteristics. Various properties such as tensile, flexural and impact strength were tested for the multiple composites. Subsequently, a simulation model of a car front bumper was prepared using ANSYS to test it while defining the determined properties of the composites. The test results showed that when vf was increased from 0.4 to 0.5%, the tensile and flexural were decreased by 0.72% and 59%, respectively, whereas impact strength was increased by 5.9% for the composite without wire mesh. The tensile and flexural strengths were decreased by 18.2%, whereas impact strength was increased by 1.6% for 0.5 vf of the composite when steel wire mesh was added to the composite. The investigation of composite’s thermal behavior showed that when the temperature range comes within 330 °C–370 °C, the composites started decomposing. Various images were captured using Scanning Electron Microscope to investigate the fibers’ dispersion in epoxy polymers and its interfacial bonding. The simulation results showed that the bumper made up of the composite with wire mesh provides a better impact strength as compared to other composites and steel.

Purity Effect of High-Strength Steel on Failure Behavior of Automobile Front Axle

As unpredictable fracture of the front axle will lead to serious safety accidents, its failure behavior study is essential. This paper analyzes typical cracks on I-shaped and leaf springs of the front axle made by Steel A and Steel B. Steel B has a lower content of S, N, Cu, and Sn than Steel A. In order to identify the failure mechanism difference, the low magnification etch test, and metallographic and scanning electron microscope analyses were conducted. The results show that the microstructures are tempered sorbite, and the cracks are with intergranular fracture characteristics. The aggregated distribution of sulfide inclusions in the matrix of Steel A is higher than that of Steel B. Copper-rich particles are detected in the cracks of Steel A. The result indicates that the purity distinction of raw steel can have a big difference on the cracking rate of the front axle even under the same manufacturing process. Relevant suggestions to reduce the cracking are put forward from the aspects of raw materials and process conditions.

Оцінка динамічної навантаженості екіпажів моторвагонного поїзда з сис-темою пасивної безпеки при його зіткненні з великим транспортним засо-бом

A topical problem of the home railway transport is motor-car train renewval, speed increase, and safety improvement in accordance with the Ukrainian State Standards DSTU EN 12633 and DSTU EN 15227, which specify the passenger car crashworthiness and passive safety, respectively, in emergency collisions with various obstacles. Relying on the world experience, researchers of the institute of Technical Methanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine developed a passive protection concept for home high-speed passenger trains in emergency collisions according to the DSTU EN 15227 requirements, proposals on the passive propection of a home motor-car train head car, lower- and upper-level honeycomb energy-absorbing devoces (EAD 1 and UL EAD, respectively) for the head car front part, and EAD 2 and EAD 3 low-level devices to be installed in intercar connecteions. The upper- and lower-level protective devices for home motor-car trains were developed based on finite-element simulation results using previous experience in the development of a passive protection device for a high-speed passenger locomotive and the results of a successful crash test of its proptotype. For Scenario 3, which chraracterizes a collision of a reference motor-car train at 110 km/h with a 15 t large road vehicle at a railway crossing, a model of a large deformable obstacle (LDO) was developed in compliance with the DSTU EN 15227 requirements. Finite-element models were developed to determine the force characteristics of interaction between the proposed head car passive protection devices and an LDO. The aim of this paper is to determine dynamic loads on a motor-car train equipped with passive protection devices in its collision with a large road vehicle. Based on a mathematical collision model for identical motor-car trains, a mathematical model was developed for a collision of a reference train with a large road vehicle at a railway crossing (Scenario 3) with account for the determined force characteristics of obstacle ? two EAD 1 low-level devices and obstacle ? two UL EAD upper-level devices interaction and the in-collision work of the head car structure. Dynamic loads on the cars of a reference train with a passive safety system (a head car mass of 80 t and intermediate car masses of 50 t or 64 t) were analyzed for its collision by Scenario 3. Two EAD layouts in the head car front part were studied. It was found that the proposed passive protection of the reference train cars meets the DSTU EN 15227 criteria for Scenario 3 for both EAD layouts and the determined variants of lower- and upper-level EAD use according to the intermediate car masses. The proposed mathematical model of dynamic loads on a passenger train with a passive safety system in its collision with a large road vehicle and the results obtained may be used in designing an up-to-date high-speed motor-car train to the DSTU EN 15227 requirements.

DDPG-based controller of enhanced adaptive cruise control with lane-change assistance for an articulated vehicle

Traditional adaptive cruise control (ACC) would choose to follow when encountering low-speed cars in front, but this may lead to low driving efficiency. This paper proposes a controller of enhanced adaptive cruise control with lane-change assistance (LCACC) for an articulated vehicle. A two-layer hierarchical control structure is adopted in this study. The upper determines high-level commands, while the bottom consisting of two modified deep deterministic policy gradient (DDPG) networks, controls the steering wheel and throttle/brake, respectively, according to the commands made by the upper layer. The vehicle’s lateral and longitudinal control are decoupled and controlled by two modified DDPG networks. Through proper design of the state and reward function, the actions of the articulated vehicle such as steering and acceleration/braking are closer to those of humans, thus ensuring ride comfort. Compared with traditional ACC, the LCACC proposed in this study increases the driving efficiency of the articulated vehicle by an average of 16% when there is a low-speed lead car.

Safe speeds: fatality and injury risks of pedestrians, cyclists, motorcyclists, and car drivers impacting the front of another passenger car as a function of closing speed and age

As crash speed increases, so does the probability of injury. The vulnerability of different road users varies greatly, in part due to differences in their protective equipment. Therefore, for the same speed, their injury probabilities are different. The objective of this study is to define injury risk curves, mathematical relations between closing speed (the relative speed between two crash partners) and injury outcome, for different road users. These risk curves can be used to rank road user vulnerability and define safe speeds, i.e. speeds not exceeding tolerable injury probabilities. Crashes involving pedestrians, cyclists, motorcyclists, and car drivers impacting the front of another passenger car (i.e. frontal impacts from the other car’s perspective) were extracted from the German in-depth accident study (GIDAS). The injuries were modelled as a function of closing speed and road user age using a weighted binary logistic regression. In accordance with the Abbreviated Injury Scale 2015 revision, three injury severities were modelled: at-least-moderate injury severities, at-least-serious injury severities, and fatal injuries. The constructed risk curves predicted injury outcomes with an average Area under the Curve ranging from 0.66 to 0.94 in cross-validation. A 10% risk of sustaining at-least-serious injuries corresponds to a closing speed of 29 km/h for pedestrians, 44 km/h for cyclists, 48 km/h for motorcyclists, and 112 km/h for car drivers. If a 10% risk of serious injury is acceptable, the closing speeds can be translated into safe speed limits of 25 km/h for cars with pedestrian encounters; 20 to 25 km/h for cyclists, motorcyclists, and cars when they encounter each other; and 55 km/h for cars in head-on impacts. These safe speeds align with current speed limits of 20 to 30 km/h in urban centers but bring into question the current practices of much higher speed limits on rural roads shared by bicycles, motorcycles, and cars. However, safe speed limits could be increased (maintaining a 10% serious injury risk) if road users have more protective equipment and Automated Emergency Braking reliably reduces impact speeds in all crash types.

Influence of Graded Surface Decarburization of Automobile Forging Front Axle on the Bending Behavior Based on a Third-Order Shear Deformation Beam Theory

During the forging process of automobile front axle, the steel near the surface is often decarburized for a certain depth. The mechanical properties at the decarburization layer are graded and different from the inner area, influencing the bending behavior of axles under heavy loads. In this paper, the decarburized forging of front axle is regarded as a rectangular thick sandwich beam, composed of a homogeneous core and the functionally graded layer coated on both bottom and top surface. A Third-order Shear Deformation Theory (TSDT) is employed to investigate the static bending behaviors under two point−loads. The properties of sandwich FG material are represented with a piecewise power−law function, and the displacement field governing equations are derived through the virtual work principle. The Navier analytical method and numerical DQM procedures are employed to obtain the bending responses under simply supported boundary conditions, and the results are validated through the comparison with an example in the literature. Then, the transverse deflection, rotation, axial stress, and shear stress are studied in terms of different power−law exponents, decarburization depth, unsymmetrical decarburization depth, unbalance loading, and beam sectional dimension. The study reveals the influence of surface decarburization on the bending behavior of forged automobile front axles, and contributes to the optimization of structure design.

Separation Control by Streamwise Vortices in Flow around Automobile Front Bumper

Separation control by plasma actuator is performed in flow around car front bumper to improve electric economy by reducing drag. The evaluation of flow separation control was performed using numerical simulation by OpenFOAM. A front bumper corner model was made in order to reproduce the actual model used in the wind tunnel experiments. Plasma actuator was installed in two different ways, common flow up type (CFU) and common flow down type (CFD) on the surface of front bumper corner model. The effect of separation control in PA both installations was analyzed in the distributions of streamwise velocity u in the various X-Y planes. The vorticity distribution in Y-Z plane showed the same tendency as the experimental results that the streamwise vortices created by the induced flow setting decreased as the flow downstream. From the results of Q-criterion, CFD case archived the development of streamwise vortices for the downstream direction, more than the case of in CFU. It provides insight into the understanding of the phenomenon of the separation control effect. In the evaluation using momentum thickness, CFD had the greatest separation control effect in the central area.

Experimental Investigation on the Effect of the Crash on Automobile Front Bumper

Experimental Investigation on the Effect of the Crash on Automobile Front Bumper