Browse Topic: Frames

Items (1,449)
The weave mode of a motorcycle is known to be affected by the flexibility of the vehicle frame. The weave mode has been shown to be more unstable in the 10-DOF model than in the 4-DOF model. However, it is not clear why the weave mode would be unstable, given the six different frame flexibilities. In this study, the authors analyzed the stability of the weave mode in a 4-DOF model when the same was integrated with two types of frame flexibilities. In the vehicle specifications used in the analysis, the combination of the bending flexibility of the front forks and the torsional flexibility of the main frame destabilizes the weave mode. The analysis results show that the phase delay of the front tire lateral force is caused by the phase delay of the steering angle. The combined bending flexibility of the front forks and the torsional flexibility of the main frame results in a large phase lag in the steering angle.
Haraoka, ReiyaKatayama, TsuyoshiYoshino, Takahiko
The rear swing arm, a crucial motorcycle component, connects the frame and wheel, absorbing the vehicle’s load and various road impacts. Over time, these forces can damage the swing arm, highlighting the need for robust design to ensure safety. Identifying potential vulnerabilities through simulation reduces the risk of failure during the design phase. This study performs a detailed fatigue analysis of the swing arm across different road conditions. Data for this research were collected from real-vehicle experiments and simulation analyses, ensuring accuracy by comparing against actual performance. Following CNS 15819-5 standards, road surfaces such as poorly maintained, bumpy, and uneven roads were tested. Using Motion View, a comprehensive multi-body dynamic model was created for thorough fatigue analysis. The results identified the most stress-prone areas on the swing arm, with maximum stress recorded at 109.6N on poorly maintained roads, 218.3N on bumpy surfaces, and 104.8N on
Chiou, Yi-HauHwang, Hsiu-YingHuang, Liang-Yu
The arc welding process is essential for motorcycle frames, which are difficult to form in one piece because of their complex shapes, because a single frame has dozens of joints. Many of the damaged parts of the frames under development are from welds. Predicting the strength of welds with high reliability is important to ensure that development proceeds without any rework. In developing frames, CAE is utilized to build up strength before prototyping. Detailed weld shapes are not applicable to FE models of frames because weld shapes vary widely depending on welding conditions. Even if CAE is performed on such an FE model and the evaluation criteria are satisfied, the model may fail in the actual vehicle, possibly due to the difference between CAE and actual weld bead geometry. Therefore, we decided to study the extent to which the stresses in the joint vary with the variation of the weld bead geometry. Morphing, a FE modeling method and design of experiment method, was utilized to
Hada, YusukeSugita, Hisayuki
This article analyses the fundamental curving mechanics in the context of conditions of perfect steering off-flanging and on-flanging. Then conventional, radial, and asymmetric suspension bogie frame models are presented, and expressions of overall bending stiffness kb and overall shear stiffness ks of each model are derived to formulate the uniform equations of motion on a tangent and circular track. A 4 degree of freedom steady-state curving model is formulated, and performance indices such as stability, curving, and several parameters including angle of attack, tread wear index, and off-flanging performance are investigated for different bogie frame configurations. The compatibility between stability and curving is analyzed concerning those configurations and compared. The critical parameters influencing hunting stability and curving ability are evaluated, and a trade-off between them is analyzed. For the verification, the damped natural frequencies and mean square acceleration
Sharma, Rakesh ChandmalSharma, Sunil KumarPalli, SrihariRallabandi, Sivasankara RajuSharma, Neeraj
Accurate reconstruction of vehicle collisions is essential for understanding incident dynamics and informing safety improvements. Traditionally, vehicle speed from dashcam footage has been approximated by estimating the time duration and distance traveled as the vehicle passes between reference objects. This method limits the resolution of the speed profile to an average speed over given intervals and reduces the ability to determine moments of acceleration or deceleration. A more detailed speed profile can be calculated by solving for the vehicle’s position in each video frame; however, this method is time-consuming and can introduce spatial and temporal error and is often constrained by the availability of external trackable features in the surrounding environment. Motion tracking software, widely used in the visual effects industry to track camera positions, has been adopted by some collision reconstructionists for determining vehicle speed from video. This study examines the
Perera, NishanGriffiths, HarrisonPrentice, Greg
While numerous advancements have been made in autonomous navigation for structured indoor and outdoor environments, these solutions often do not generalize well to off-road settings. There are unique challenges in such settings such as unreliable GPS, limited computational and memory resources, and sparse environmental features, making navigation particularly difficult. In our work, we propose a novel data structure called Hierarchical Dynamic Scene Graphs (HDSG) to address these challenges. HDSG captures environmental information at different resolutions, integrating both geometric and semantic features. It enables various navigation tasks such as localization, loop closure, and human interaction through the visualization of environmental features for remote operators. We evaluated the performance of localizing a robot’s position within the world frame by comparing compact spatial descriptors extracted from semi-consecutive scene graphs, derived from 3D LiDAR point clouds. Compared to
Alam, Fardifa FathmiulLuricich, FedericoLi, NianyiJia, YunyiLi, Bing
The trends of intelligence and connectivity are continuously driving innovation in automotive technology. With the deployment of more safety-critical applications, the demand for communication reliability in in-vehicle networks (IVNs) has increased significantly. As a result, Time-Sensitive Networking (TSN) standards have been adopted in the automotive domain to ensure highly reliable and real-time data transmission. IEEE 802.1CB is one of the TSN standards that proposes a Frame Replication and Elimination for Reliability (FRER) mechanism. With FRER, streams requiring reliable transmission are duplicated and sent over disjoint paths in the network. FRER enhances reliability without sacrificing real-time data transmission through redundancy in both temporal and spatial dimensions, in contrast to the acknowledgment and retransmission mechanisms used in traditional Ethernet. However, previous studies have demonstrated that, under specific conditions, FRER can lead to traffic bursts and
Luo, FengRen, YiZhu, YianWang, ZitongGuo, YiYang, Zhenyu
This paper summarizes work on the application of a new and fully parallelized native GPU-based finite-volume solver on the DrivAER Notchback configuration using a wall-function LES approach. A series of meshes generated using a Rapid-Octree strategy have been investigated, and results for drag, surface pressure coefficient and velocity profile are compared with available experimental data.
Menter, FlorianDalvi, AshwiniFlad, DavidSharkey, Patrick
In automotive engineering, seam welds are frequently used to join or connect various parts of structures, frames, cradles, chassis, suspension components, and body. These welds usually form the weaker material link for durability and impact loads, which are measured by lab-controlled durability and crash tests, as well as real-world vehicle longevity. Consequently, designing robust welded components while optimizing for material performance is often prioritized as engineering challenge. The position, dimensions, material, manufacturing variation, and defects all affect the weld quality, stiffness, durability, impact, and crash performance. In this paper, the authors present best practices based on studies over many years, a rapid approach for optimizing welds, especially seam welds, by adopting Design For Six Sigma (DFSS) IDDOV (Identify, Define, Develop, Optimization, and Verification) discrete optimization approach. We will present the case testimony to show the approach throughout
Qin, Wenxin (Daniel)Li, FanPohl, Kevin J.
Two wheelers motorcycles are used for many purposes e.g. commuting from one place to another, long highway rides, racing and off-roading. Motorcycles which are used in off-road conditions require higher suspension strokes to absorb large oscillations due to terrain conditions. These motorcycles undergo jumps of varying heights and different vehicle orientations. In some of the dynamic situations front wheel may land on the ground before the rear and in other cases it may be vice versa. To make sure that the vehicle is durable enough to withstand loads in such operating conditions, vehicle drop test was developed in test lab where vehicle is dropped from predefined heights in both front & rear wheel landing conditions. Same test case is simulated in multibody dynamics to capture loads at important connections of the frame. This paper presents the correlation exercise carried out to validate MBD model and simulation process with test data captured during lab test. Accelerations at
Jain, Arvind KumarNirala, Deepak
Taking a commercial vehicle cab suspension system as the research focus, a rigid-flexible coupled dynamics model was established based on the nonlinear characteristics of the integrated damper air spring and bushings. Time-domain vibration acceleration signals were acquired at the connection points between the frame, cab, and suspension. The vibration signals at the frame and suspension connection points were input into the simulation model, where the vibration responses at the cab and suspension connection points were calculated and analyzed using the established cab suspension system model. The accuracy of the model was verified by comparing the simulation results with experimental data. The established cab suspension system model was further used to evaluate human vibration comfort within the cab, following national standards for subjective human perception. A piecewise polynomial function was employed to fit the stiffness-damping characteristics of the integrated damper air spring
Hao, QiZhu, YuntaoSun, WenSun, KaiSun, ZhiyongHuang, YuZhen, RanShangguan, Wen-Bin
In recent years, the issue of highway maintenance has become increasingly prominent. How to precisely detect and classify fine cracks and various types of pavement defects on highways through technical means is an essential foundation for achieving intelligent road maintenance. This paper first constructs the DenseNet201-PDC and MobileNetV2-PDC sub-classification networks that incorporate the three-channel attention judgment mechanism MCA. Secondly, based on the principle of parallel connection, a brand-new dual-branch fusion convolutional neural network DBF-PDC capable of classifying pavement defects in highway scenarios is proposed. Finally, this paper builds the Pavement Distress Datasets of Southeast University and conducts relevant ablation experiments. The experimental results demonstrate that both the attention mechanism module and the feature fusion strategy can significantly enhance the network's ability to classify pavement defects in highway scenarios. The average
Zhang, ZiyiZhao, ChihangShao, YongjunWang, Junjun
This paper presents a complete approach to the optimized design and analysis of a trach-focused quad bike suitable for the Indian market. The process of design integrates several analytical factors, including driver ergonomics, aesthetics, and strategic component placement, to establish optimum vehicle dimensions. The primary objective is to address the unique demands of the Indian terrain and user preferences through ensure comfort, functionality, and visual appeal. The selection process for tires and suspension geometry is precisely conducted with the advanced OptimumKinematics software. This optimization provides greater performance and stability that the vehicle can accurately manage a variety of road conditions. The space frame chassis of a vehicle’s core structure features, engineered to minimalize tubing and facilitate ease of fabrication, contributing to both structural integrity and weight reduction. A robust 600cc four-cylinder engine is selected that emphasizing an optimal
Thanikonda, Praveen KumarShaik, AmjadTappa, RajuRatlavath, RamuNavar, AdarshChalla, Ajith Kumar
The present aim of the investigation is to prepare and evaluate the excellence of boron nitride (BN) and silicon carbide nanoparticles on characteristics of magnesium alloy (AZ91D) hybrid nanocomposite. This constitution of AZ91D alloy hybrid nanocomposite is made through the liquid state processing route, which helps to improve the spread of particles in the AZ91D matrix. The impact of BN and SiC on microstructural and mechanical properties like tensile strength, hardness, and impact strength of AZ91D alloy composites are studied, and its investigational results are compared. Besides, microstructural studies have revealed that the structure of composite is found to have better BN and SiC particle dispersion and uniformity. The 5 percentage in weight (wt%) of BN and 5 wt% of SiC facilitated better tensile strength (183 MPa), hardness (85HV), and impact strength (21.4J/mm2) behaviour, which are 26, 30, and 35% better than the monolithic AZ91D alloy. This AZ91D/5wt% BN and 5wt% SiC
Venkatesh, R.Kaliyaperumal, GopalManivannan, S.Karthikeyan, S.Mohanavel, VinayagamSoudagar, Manzoore Elahi MohammadKarthikeyan, N.
The grain refinement of aluminium alloy has the potential for various engineering utilization like automotive, marine, and aviation. Besides, the choice of grain refinement influences better performance and compatibility action. Aluminium alloy processed with zirconium grain refinement, high cost and risk of grain coarsening reasons, this research focused on Ti-C grain refinement with sodium modifier for T6 processing by aluminium alloy (AA6013) made by stir cast route. Impacts of Ti-C grain refinement with sodium modifier T6 processing on microstructural behaviour, hardness, and tensile performance are investigated, and the hardness and tensile are followed by ASTM E384 and ASTM E8 standards. The AA6013-T6 (1:1 Ti/C) with 0.15Na is found to have better grain refinement and found the TiC particle during the casting process, which leads to better enhancement of overall mechanical behaviour. The hardness, ultimate tensile, elongation percentage, and Young's modulus of AA6013-T6 (1:1 Ti/C
Venkatesh, R.Manivannan, S.Daniel Das, A.Mohanavel, VinayagamSoudagar, Manzoore Elahi Mohammad
Magnesium is the lightest material than aluminium and has a better specific strength, which is utilized for weight management applications. This research developed the magnesium (Mg) matrix with 0.1, 0.2, 0.3, and 0.5 percentages in weight (wt%) of zirconium (Zr) particles (grain refinement agent) via the squeeze cast technique. The argon inert gas is limit oxidation during the melting of Mg. The influence of Zr on the functional properties of Mg is studied and related to monolithic Mg without the Zr phase. The microstructural analysis provides the Zr particles are dispersed uniformly in the Mg matrix and exposed to superior mechanical properties. The Mg processed with 0.5 wt% of Zr offered maximum hardness, ultimate tensile strength, and elongation percentage, which are 53, 48.8, and 43.5 % better than the values of monolithic Mg. Besides, the optimum Mg refining with 0.5 wt% Zr microstructure is detailed with EDS and conforms to the contribution of Zr. This is used for automotive
Venkatesh, R.Manivannan, S.Das, A. DanielMohanavel, VinayagamSoudagar, Manzoore Elahi Mohammad
The undercarriage is a critical component in machines such as crawlers, excavators, and compact track loaders. It includes vital elements such as the track frame, chain guides, rollers, track chains, idlers, carrier rollers, final drive, and sprockets. Among all these machines, crawler dozers encounter harsh environments with various ground conditions. During operations, the chains are subjected to traverse and side loads, which cause the chains to tend to slip out of the bottom rollers. The chain guide plays a crucial role in assisting and maintaining the chain in the correct position. The forces acting on chain guides are influenced by factors such as track chain tension, roller wear, chain link wear, and counter-rotation (where one track moves forward while the other moves in reverse). Among all the load cases, there are two critical load cases which are vital to be studied in order to determine the required number of chain guides along with other attributes like profile or section
Masane, NishantBhosale, DhanajiSarma, Neelam K
The stiffness and positioning of engine mounts are crucial in determining the powertrain rigid body modes and kinetic energy distribution. Therefore, optimizing these mounts is essential in the automotive industry to separate the torque roll axis (TRA) and minimize vibration. This study aims to enhance mount locations by isolating the engine rigid body modes and predicting the inter-component force (ICF) and transfer function of the vehicle. The individual ICFs for engine mountings are calculated by applying a unit force at the bearing location. Critical frequencies are identified where the amplification exceeds the unit force at the mounting interface between the engine and the frame. The transfer function approach is utilized to assess the vibration at the handlebar. Both ICF and transfer functions analyze the source and path characteristics linked to critical response frequencies. This understanding aids in enhancing mounting positions to minimize vibration levels, thereby enhancing
Jha, Niraj KumarYeezaku, Antony NeominVictor, Priyanka EstherKrishnamurthy, Govindasamy
In recent years, autonomous vehicles (AVs) have been receiving increasing attention from investors, automakers, and academia due to the envisioned potentials of AVs in enhancing safety, reducing emissions, and improving comfort. The crucial task in AV development boils down to perception and navigation. The research is underway, in both academia and industry, to improve AV’s perception and navigation and reduce the underlying computation and costs. This article proposes a model predictive control (MPC)-based local path-planning method in the Cartesian framework to overcome the long computation time and lack of smoothness of the Frenet method. A new equation is proposed in the MPC cost function to improve the safety in path planning. In this regard, an AV is built based on a 2015 Nissan Leaf S by modifying the drive-by-wire function and installing environment perception sensors and computation units. The custom-made AV then collected data in Norman, Oklahoma, and assisted in the
Arjmandzadeh, ZibaAbbasi, Mohammad HosseinWang, HanchenZhang, JiangfengXu , Bin
Squeak and rattle (SAR) noise audible inside a passenger car causes the product quality perceived by the customer to deteriorate. The consequences are high warranty costs and a loss in brand reputation for the vehicle manufacturer in the long run. Therefore, SAR noise must be prevented. This research shows the application and experimental validation of a novel method to predict SAR noise on an actual vehicle interior component. The method is based on non-linear theories in the frequency domain. It uses the Harmonic Balance Method (HBM) in combination with the Alternating Frequency/Time Domain Method (AFT) to solve the governing dynamic equations. The simulation approach is part of a process for SAR noise prediction in vehicle interior development presented herein. In the first step, a state-of-the-art linear frequency-domain simulation estimates an empirical risk index for SAR noise emission. Critical spots prone to SAR noise generation are located and ranked. In the second step, the
Rauter, AndreasUtzig, LukasWeisheit, KonradMarburg, Steffen
Design verification and quality control of automotive components require the analysis of the source location of ultra-short sound events, for instance the engaging event of an electromechanical clutch or the clicking noise of the aluminium frame of a passenger car seat under vibration. State-of-the-art acoustic cameras allow for a frame rate of about 100 acoustic images per second. Considering that most of the sound events introduced above can be far less than 10ms, an acoustic image generated at this rate resembles an hard-to-interpret overlay of multiple sources on the structure under test along with reflections from the surrounding test environment. This contribution introduces a novel method for visualizing impulse-like sound emissions from automotive components at 10x the frame rate of traditional acoustic cameras. A time resolution of less than 1ms eventually allows for the true localization of the initial and subsequent sound events as well as a clear separation of direct from
Rittenschober, ThomasKarrer, Rafael
REE Automotive is aiming to be a major disruptor in the medium-duty truck space with the rollout of its P7 EV chassis. The P7 frame is built around its “REEcorners” suspension, which are modular suspension units featuring REE's x-by-wire design. By packaging components into the area between the chassis and the wheel, REE claims that it was able to design the P7 with a completely flat chassis with up to 35% more interior volume for passengers, cargo and batteries. “The REEcorners suspension system is the core of the technology that we built this truck around,” Peter Dow, VP of engineering for REE Automotive, said during an interview with Truck & Off-Highway Engineering. “It also allows us to achieve the level of vehicle dynamics we were looking for. We were trying to make a truck that was very exciting and easy to drive.”
Wolfe, Matt
Catalytic converters have been considered as an integral part of the vehicle powertrain for over a decade now, their application along with the engines increased significantly with the constant evolution of emission standards. Recent regulations keep a strict control on the major four pollutants of engine exhaust gas, i.e., Carbon Monoxide (CO), Nitrogen Oxides (NOx), Hydrocarbons (HC) & Particulate Matter (PM), which demands a highly efficient aftertreatment system. Efforts are continuously being made to downsize the engine for better fuel economy and low emissions, this puts additional requirement of designing a compact aftertreatment system equipped with Diesel Oxidation Catalyst (DOC), Diesel Particulate Filter (DPF) and Selective Catalytic Reduction (SCR). Compact catalytic converters experience larger vibration force transferred from the vehicle and hence the durability of the product is significantly impacted. Vibration sources are a) Engine, b) Road Load, using a long flex pipe
Gupta, BipinLi, JiangongSingaravel, Vinothkumar
This paper analyzes the mechanism of vibrational energy propagation and panel vibration generation at the point joints between frame and panel which can be applied to reduce the vehicle interior noise. In this study, we focused on the traveling wave in the early stage of propagation before the mode is formed and investigated the mechanism of panel vibration generation due to wave energy propagation and its reduction method. First, we show theoretically that the out-of-plane component of the transmitted power at the point joint between frame and panel that contributes to panel vibration is associated with frame deformation. Then, we show through numerical verification that panel vibration can be reduced by reducing the transmitted power of the out-of-plane component and explain the effectiveness of the frame-to-panel joint design guidelines based on energy propagation analysis. Next, this analysis method was applied to the vehicle body FEM model. Assuming road noise, an energy
Abe, KeisukeTanaka, YunosukeYamazaki, Toru
A road test on semi-trailers is carried out, and accelerations of some characteristic points on the braking system,axles,and truck body is measured,also brake pressure and noise around the support frame is acquired.The measured data was analyzed to determine the causes of the brake noise, and the mechanism of the noise of the drum brake of semi-trailers during low-speed braking was investigated. The following conclusions are obtained: (1) Brake noise of the drum brake of the semi-trailer at low-frequency is generated from vibrations of the brake shoes, axle, and body, and the vibration frequency is close to 2nd natural frequency of the axle. (2) Brake noise is generated from stick-slip motion between the brake shoes and the brake drum, where the relative motion between the brake drum and the brake shoes is changed alternately with sliding and sticking, resulting in sudden changes in acceleration and shock vibration. A multi-body dynamic model of the semi-trailer is established for
Tang, HaoShangguan, Wen-BinKang, YingziZheng, Jing-YuanLan, Wen-Biao
SLAM (Simultaneous Localization and Mapping) plays a key role in autonomous driving. Recently, 4D Radar has attracted widespread attention because it breaks through the limitations of 3D millimeter wave radar and can simultaneously detect the distance, velocity, horizontal azimuth and elevation azimuth of the target with high resolution. However, there are few studies on 4D Radar in SLAM. In this paper, RI-FGO, a 4D Radar-Inertial SLAM method based on Factor Graph Optimization, is proposed. The RANSAC (Random Sample Consensus) method is used to eliminate the dynamic obstacle points from a single scan, and the ego-motion velocity is estimated from the static point cloud. A 4D Radar velocity factor is constructed in GTSAM to receive the estimated velocity in a single scan as a measurement and directly integrated into the factor graph. The 4D Radar point clouds of consecutive frames are matched as the odometry factor. A modified scan context method, which is more suitable for 4D Radar’s
Zihang, HeXiong, LuZhuo, GuirongGAO, LetianLu, ShouyiZhu, JiaqiLeng, Bo
The current automotive industry has a growing demand for real-time transmission to support reliable communication and for key technologies. The Time-Sensitive Networking (TSN) working group introduced standards for reliable communication in time-critical systems, including shaping mechanisms for bounded transmission latency. Among these shaping mechanisms, Cyclic Queuing and Forwarding (CQF) and frame preemption provide deterministic guarantees for frame transmission. However, despite some current studies on the performance analysis of CQF and frame preemption, they also need to consider the potential effects of their combined usage on frame transmission. Furthermore, there is a need for more research that addresses the impact of parameter configuration on frame transmission under different situations and shaping mechanisms, especially in the case of mechanism combination. Firstly, this paper comprehensively reviews the schedulability analysis of the combined usage of CQF and frame
Luo, FengWang, ZitongRen, YiWu, MingzhiZhang, Xiaoxian
In the early stages of vehicle development, it is critical to establish performance goals for the major systems. The fundamental modes of body and chassis frames are typically assessed using FE models that are discretized using shell elements. However, the use of the shell-based FE method is problematic in terms of fast analysis and quick decision-making, especially during the concept phase of a vehicle design because it takes much time and effort for detailed modeling. To overcome this weakness, a one-dimensional (1D) method based on beam elements has been extensively studied over several decades, but it was not successful because of low accuracy for thin-walled beam structures. This investigation proposes a 1D method based on thin-walled beam theory with comparable accuracy to shell models. Most body pillars and chassis frame members are composed of thin-walled beam structures because of the high stiffness-to-mass ratio of thin-walled cross sections. However, thin-walled cross
Kim, Jin HongLee, Dong KiKim, Gyu SikJang, Gang-WonKim, Han Kil
This paper addresses the issues of long-term signal loss in localization and cumulative drift in SLAM-based online mapping and localization in autonomous valet parking scenarios. A GPS, INS, and SLAM fusion localization framework is proposed, enabling centimeter-level localization with wide scene adaptability at multiple scales. The framework leverages the coupling of LiDAR and Inertial Measurement Unit (IMU) to create a point cloud map within the parking environment. The IMU pre-integration information is used to provide rough pose estimation for point cloud frames, and distortion correction, line and plane feature extraction are performed for pose estimation. The map is optimized and aligned with a global coordinate system during the mapping process, while a visual Bag-of-Words model is built to remove dynamic features. The fusion of prior map knowledge and various sensors is employed for in-scene localization, where a GPS-fusion Bag-of-Words model is used for vehicle pose
Chen, GuoyingWang, ZiangGao, ZhengYao, JunWang, Xinyu
The new idea discussed in this paper pertains to the carrier mechanism for spare wheels in heavy commercial vehicles. Typically, these vehicles are equipped with a spare wheel carrier featuring a rope mechanism for loading and unloading the spare wheel. The conventional placement of this system is on the side of the frame/chassis or within the limits of the side member. However, the tire-changing process in this system is often arduous, time-consuming, and requires significant effort. The proposed invention addresses these challenges by repositioning the spare wheel to a vertical orientation, facilitating easier access to its bolts and simplifying the removal process from the mountings. Furthermore, the innovation incorporates a three-way actuation system (Air Actuated, Electric motor-driven, or Hydraulic cylinder actuated mechanisms), thereby reducing the need for manual effort and enhancing driver comfort. The advantages of this invention over traditional carrier mechanisms include
Bonde, DevendraUpkare, Piyush PradipVerma, Rubal
For the design optimization of the electric bus body frame orienting frontal crash, considering the uncertainties that may affect the crashworthiness performance, a robust optimization scheme considering tolerance design is proposed, which maps the acceptable variations in objectives and feasibility into the parameter space, allowing for the analysis of robustness. Two contribution analysis methods, namely the entropy weight and TOPSIS method, along with the grey correlation calculations method, are adopted to screen all the design variables. Fifteen shape design variables with a relatively high impact are chosen for design optimization. A symmetric tolerance and interval model is used to depict the uncertainty associated with the 15 shape design variables of key components in the bus body frame to form an uncertainty optimization problem in the form of an interval, and a triple-objective robust optimization model is developed to optimize the shape design variables and tolerances
Yang, XiujianLiu, Beizhen
An experiment is carried out to measure creep groan of a drum brake located in a trailer axle of a truck. The noise nearby the drum brake and accelerations on brake shoes, axle and trailer frame are collected to analyze the occurring conditions and characteristics of the creep groan. A multi-body dynamics model with 1/4 trailer chassis structures is established for analyzing brake component vibrations that generates the creep groan. In the model, the contact force between brake cam and brake shoes, the contact friction characteristics between brake linings and inner circular surface of brake drum, and the properties of chassis structure are included. Dynamic responses of brake shoes, axle and trailer frame during the braking process are estimated using the established model and the responses are compared with the measured results, which validate the model. Three conclusions of measurement and calculation are obtained. (1) The creep groan is usually generated when braking speed is lower
Zheng, Jing-YuanShangguan, Wen-BinTang, HaoLan, Wen-biao
The present study introduces a novel approach for achieving path tracking of an unmanned bicycle in its local body-fixed coordinate frame. A bicycle is generally recognized as a multibody system consisting of four distinct rigid bodies, namely the front wheel, the front fork, the body frame, and the rear wheel. In contrast to most previous studies, the relationship between a tire and the road is now considered in terms of tire forces rather than nonholonomic constraints. The body frame has six degrees of freedom, while the rear wheel and front fork each have one degree of freedom relative to the body frame. The front wheel exhibits a single degree of freedom relative to the front fork. A bicycle has a total of nine degrees of freedom. The expression of the kinetic energy of a bike is formulated using quasi-coordinates in the local body-fixed coordinate frame, which provides a more simplified representation compared to the utilization of absolute coordinates in the global coordinate
Cheng, KaizhuoDuan, YupengWu, JinglaiZhang, Yunqing
Mechanical drawing plays an important role in managing, designing and implementing engineering projects, especially in the field of the automotive industry. The need for accuracy in element design and manufacturing is greater now than ever before in engineering industries. In order to increase accuracy, the part design and function must be clearly communicated between the design engineer and the manufacturing technicians, especially in automotive industry and feeder industries projects. Geometric Dimensions and Tolerances (GD&T) system of elements determines the quality, importance and price of the designed product. The standard used in the United States to define GD&T methodology is ASME Y14.5-2009 while the standard used in Europe is ISO 1101-2017. This article discussed the importance of using GD&T system including the types of geometrical features, limitations and accuracy, datum references frame and feature control frame to handle these symbols seamlessly. Moreover, the paper
Ali, Amr S.H.R.Ali, Akram M. S.Amin, Youssef W.R.Ali, Salah H. R.
During mining material hauling, the chassis frame structure of rear dump trucks is subjected to fatigue loading due to uneven road conditions. This loading often leads to crack propagation in the frame rails, necessitating the determination of stresses in the critical zone during the design stage to ensure structural integrity. In this study, a computer-aided engineering (CAE) methodology is employed to size and select the rectangular profile cross section of the chassis frame rail. A detailed design investigation of the chassis frame is conducted to assess its load resistance, structural flexibility, and weld joint fatigue life under critical stresses arising from combined bending and torsion loads. The optimization process aims to determine the optimal rail size and material thickness, striking a balance between minimizing mass and maximizing structural reliability. By achieving this, the risk of major structural failures during the transportation of large payloads can be
J, Avinash
Electric vehicles (EV) are much quieter than IC engine powered vehicles due to less mechanical components and absence of combustion. The lower cabin noise in electric vehicles make customers sensitive to even small noise disturbances in vehicle. Road boom noise is one of such major concerns to which the customers are sensitive in electric vehicles. The test vehicle is a front wheel driven compact SUV powered by electric motor. On normal plain road, noise levels are acceptable but when the vehicle has been driven on coarse road, the boom noise is perceived, and the levels are objectionable. Multi reference Transfer Path Analysis (MTPA) is conducted to identify the path through which maximum forces are entering the body. Based on MTPA, modifications are proposed on the suspension bushes and the noise levels were assessed. Operational Deflection Shape (ODS) analysis is conducted on entire vehicle components like suspension links, sub frame, floor, roof, and doors to identify the
S, Nataraja MoorthyRao, ManchiRaghavendran, PrasathSelvam, Ebinezer
NVH is of prime importance in buses as passengers prefer comfort. Traditionally vehicle NVH is analysed post completion of proto built however this leads to modifications, increases cost & development time. In modern approach physical validation is replaced by CAE. There are many sources of NVH in vehicle however this article is focused about the methodology to improve NVH performance of bus by analysing and improving the stiffness and mobility of various chassis frame attachment points on which source of vibrations are mounted or attached. In this study chassis frame attachment stiffness of Engine mounts and propeller shafts is focused.
Dhadiwal, Nishant SurendraPathak, RahulBijwe, VilasGore, Pandurang
For any two wheeler vehicle development, rider and pillion comfort while driving the vehicles over different kinds of road perturbations holds high importance. Designing a vehicle for comfort starts at the very beginning of its layout definition through vehicle geometric parameters, key hardpoints, mass-inertia distribution of subsystems and suspension characteristics. There is a need for highly reliable simulation models for comfort predictions as any change in layout during subsequent design stages is a very costly affair. Accurately predicting comfort using a full vehicle model is a challenging task though as it depends on how realistic the Simulation Model is to that of actual vehicle. While suspension stiffness and damping characteristics remain critical parameters for the comfort, selection of tyres are known to hold equal importance in vehicle comfort. The details to which the tyres are captured in the simulation model and the formulation of tyre interaction with roads in a
Govindula, SrikanthPandey, PradyumnSaraswat, UditMishra, Ashish
Machine learning exerts a significant influence on the autonomous driving industry, enabling the development of self-driving vehicles. However, the performance of these models heavily relies on the quality and diversity of the training data. In situations where valid data is scarce, models struggle to make informed decisions. To address this obstacle, active learning methodologies are utilized for the purpose of choosing the most informative data frames from an extensive reservoir of unlabeled data. Uncertainty scores are calculated using methods like Least Confident and Entropy-based sampling, and frames with high uncertainty scores are manually annotated and added to the training dataset. This iterative process improves the model’s performance over time. This research study centers on assessing the application of active learning in diminishing the manual labor needed for data labeling through the selection of frames containing valuable information. A pre-trained YOLOv3 model is
Katariya, RashmiKumari, Anita
As the world rapidly moves from IC engine powered vehicles to the ‘more sustainable’ electrified vehicles, the Powertrain Mounting System needs to be re-engineered to meet refinement requirements of customer. Electric vehicles are quieter but due to lack of the “masking effect”, are sensitive to minor disturbances that are perceived to be objectionable by passengers. Also, E-powertrains are lighter, produce higher torque at low rpms & operate at higher rpms which calls for different countermeasures for mounting systems compared to conventional single isolation 3-point mounting system as used in IC engines. Double isolation mounting system, where powertrain is connected to an auxiliary mass (sub frame/cradle) via mounts, which is suspended to the vehicle body via subframe bushes results in 12 rigid body modes, 6 for each mass, is highly effective in lowering the transmission of vibration at high frequencies. This paper discusses 12 DOF analytical tool developed to rapidly analyze the
Verma, ShemonJayachandran, Suresh KumarMane, YogirajPaua, KetanVellandi, Vikraman
The current approach of hybrid RLDA is typically incapable of providing accurate dynamic loads coming on cab at chassis-to-cab load transfer locations, primarily due to the following two reasons. Firstly, all of the model parameters of the vehicle, which is put on the 4-post, are not known. Secondly, MBS (Multi-body System) Cab model is multi degree of freedom with rigid bodies, flex bodies, contacts and non-linear force elements. Therefore, if the system identification is to be performed manually it becomes an arduous and humanly impossible task. Towards generating accurate dynamic loads on cab, an approach using FEMFAT LAB - VI & MI has been developed which involves a two-step process: a) Generating MBS excitation by back calculating from measured frame response – VI (Virtual iterations). b) Fine tuning modelling parameters to match measured cab response – MI (Model Improvement). To execute the VI & MI approach for calculating dynamic loads on cab through 4-poster & 7-poster
Singh, PrempalPrasad, Tej
Light weighting in the automotive industry without the use of finite element methodologies is now inconceivable. With the development and enhancement of various CAE tools available, CAE-driven optimization has become part of the product development cycle. Using a variety of CAE techniques in a lightweight optimization process can significantly reduce product development lead time with good results. Traditional light weighting can be done through different iterative approaches with different manual inputs from cross-domain teams, which is usually time consuming and leads to repeated analysis. This method describes the case of a multi-domain optimization approach with the reduction of the frame weight of an e-scooter while considering important cross-domain load cases using CAE. For frame optimization, the important load cases such as Durability/Strength (Normal and Abusive), and NVH (Stiffness, Modes and Vibration) - were taken into account. This Multi Domain/Disciplinary Optimization
S, VishnuKakanur, AshokU PE, ManjunathaBhat, SachinPoojary, KiranV N, Kishor
A research team has developed a robotic system that can be unobtrusively built into the frame of a standard honeybee hive. Composed of an array of thermal sensors and actuators, the system measures and modulates honeybee behavior through localized temperature variations.
For intelligent vehicles, a fast and accurate estimation of road slope is of great significance for many aspects, including the steering comfort, fuel economy, vehicle stability control, driving decision-making, etc. But the commonly used estimation methods nowadays usually demand additional sensors or complex dynamic models, causing increase in system complexity as well as decrease in accuracy. To solve these problems, this paper puts forward a real-time road slope estimation algorithm leveraging the relationship between pitch angle and road slope, which only requires low sensors cost and computational complexity. Firstly, a GNSS/INS fusion system is established to obtain the pitch angle with respect to the navigation frame, which couples the vehicle’s pitch angle in vehicle frame and road slope angle. Then, based on the different characteristics in frequency domain of the two components, frequency domain analysis is conducted and low-pass filter is used to separate out road slope
Chen, MengyuanXiong, LuGao, Letian
All two-wheeler industries validate their product’s fatigue life on proving track before heading for mass production. Proving test tracks are made to simulate the end-user environment in order to find out the possible fatigue failures during each development stage of vehicle design, which in turn helps the CAE analysts to verify the design before it goes to the end-user hands. In this article we present the design and failure analysis of sub-frame assembly of motorbike observed during the accelerated fatigue test on proving track. Sub-frame main rod was found broken exactly between two weld endings during fatigue test before reaching 6% of the target fatigue life. Possible causes of sub-frame failures have been identified/analyzed in detail using fish bone diagram. A finite element analysis (FEA) model of sub-frame assembly was developed and a random response analysis was carried out on initial design. Acceleration input loads measured from test track have been given at the sub-frame
Sharma, AshishKhare, Saharash
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