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Viewing 1 to 30 of 7467
2015-03-30
Technical Paper
2015-01-0080
Pornporm Boonporm, Supakit Retired Chaiyo
Handling behavior of FSAE during cornering is proposed by means of analytical and experimental for assisting our suspension geometry design. Roll rate, yaw rate and weight transfer were investigated based on vehicle’s geometry and parameters and calculated by varying camber angle, longitudinal velocity and radius of curvature. The example case with radius 7.63 meter and 1.65g lateral acceleration, there was 2.82% weight transfer difference and it assumed oversteer. The experiment was set up to prove our method concerning inertial measurement unit. These results were compared in various cases and it has shown the correlation between each other
2015-03-30
Technical Paper
2015-01-0081
Chunguang Duan, Hsin guan
With the development of computer and vehicle research to high frequency, the driving simulator plays an important role on vehicle research and pre-development. The driving simulator have already used for research about human factor, advanced active system (ABS, ESP et al), the vehicle engineering, intelligent transportation system (ITS) et al. The requirements for a driving simulator are that it should have realistic behavior. One aspect of the realistic behavior is that the driving simulator needs to be able to stop and to start again. The realistic behavior base on high-fidelity dynamic models especially tire model. “Tire/road” model is of special importance model for its influence on vehicle simulation results. The forces for accelerating, braking and steering are all come from tire road contact. The simulator simulation faces all possible driving situations as driving the real vehicle, like parking on the hill, stop and start again, sharp steering, sharp braking et al.
2015-01-14
Technical Paper
2015-26-0167
Thomas Lich, Girikumar Kumaresh, Joerg Moennich
Around one in four deaths that occurs on the road in India involves a motorcyclist, according to Ministry of road transport and highways, Government of India 2012. Nearly 26 % of the fatalities (~ 33 873 people) are from powered two wheelers which constitute the highest contributor for fatal accidents in India. European Transport Safety Council (ETSC) analysis shows the risk of a motorcyclist having a fatal accident is 20 times greater than for a car driver traveling the same route. An investigation conducted by Bosch based on the RASSI accident database (Road Accident Sampling System for India), revels interesting facts of Indian powered two wheeler (PTW) riders behaviour and their braking patterns during the precrash phase of the accident. This research is undertaken to evaluate the benefit of modern vehicle safety systems like a PTW Antilock-Braking System (ABS) which are essential to avoid accidents.
2015-01-14
Technical Paper
2015-26-0078
Parth Lunia, Mrigendra Prajapati, V Jayashankar, Varun Parakh, Samir Rawte
A parking brake or hand brake is the mechanical hand or foot operated secondary braking system that prevents the vehicle from rolling or slipping when parked on the gradient or leveled surface and provides assistance to stop/slowdown the vehicle in case of service brake failure. This paper is an attempt to compile a systematic approach which can be easily incorporated in a product development system to design and develop parking brake system for passenger cars having rear drum brakes which in turn can effectively reduce the lead time and give a better performance. Vehicle GVW, percentage gradient and maximum effort limits (As per IS 11852-Part 3), Tire and drum brake specifications were taken as front loading. This data is further used for target setting of functional and engineering parameters, such as Lever Pull Effort, Lever Ratio and angular travel of lever. Design calculations were performed to obtain theoretical value of critical parameters like lever effort and travel.
2015-01-14
Technical Paper
2015-26-0079
Ram Ranjan Sahu, Jayant Sinha
Brake drum is an important component in automotive, which is a link between axle and wheel. It performance is of utmost importance as it is related to the safety of the car as well to the passengers. Many design parameters are taken into consideration while designing the brake drum. The sensitivity of these parameters is studied for optimum design of brake drum. The critical parameters in terms of reliability, safety & durability could be the cross section, thickness of hub, interference & surface roughness between bearing and hub, wheel loading, heat generation on drum, manufacturing and assembly process. The brake drum design is derived by considering these parameters. Hence the sensitivity of these parameters is studied both virtually & physically, in detail. The optimum value of each parameter could be chosen complying each other's values.
2015-01-14
Technical Paper
2015-26-0186
Mohitkumar R. Chauhan, Girish Kotwal, Abhijeet Majge
Numerical Simulation of Tire and Wheel Assembly Impact Test using Finite Element Method M R Chauhan1 Prof. G N Kotwal2 A S Majage3 1,2Department of Mechanical Engineering, VIT, Pune, India 3Finite Four Technologies, Pune, India Abstract: The major concern in design of wheel is their potentiality to bear impact loads. Therefore, wheel impact test is required to fulfill the safety requirement. In this study, there are two objectives; first, the simulation of impact test for wheel is developed according to SAE wheel impact test. Often when vehicle interacts with guardrails, bridge rails and curbs the interaction between roadside hardware and wheel causes wheel damage. The test setup consists of vertically acting striker of mass 480 kg and having prescribed velocity. Energy based approach and total plastic work concept of ductile fracture mechanics is used to predict wheel impact failure.
2015-01-14
Technical Paper
2015-26-0181
Mukund Trikande, Sujithkumar Muralidharan, Vinit Jagirdar
Road disturbances introduce a combination of vertical and angular motions of pitch and roll that affect the stability and ride comfort of a military vehicle. This study focuses on the enhancement of stability and ride comfort. A half car model with 4 Degree of freedom (DOF), whose vehicle chassis can pitch and bounce, is modeled in Simulink with the objective of attitude control using Stability Augmentation System (SAS). Control is implemented at two levels, one at the suspension level which is an open loop control for improving the ride and the other is closed loop for controlling the body motion by sensing pitch and bounce displacement. The inner loop is utilised to reject the effect of road disturbances and outer loop is to stabilize heave and pitch response. In other words, inner loop provides ride control and the outer loop provides the attitude control. The control force is obtained by using an active damper.
2015-01-14
Technical Paper
2015-26-0170
Chaitanya Pendurthi, Sourabh Tiwari, Sujit Chalipat, Ganesh Bhagwant Gadekar
Tyre plays a pivotal role in frontal impact, as it acts as a load path to transfer loads from barrier to side sill or rocker panels. Conventionally, tyres are represented with less modelling detail which can potentially effect CAE prediction. Aim of this study is to improve CAE prediction through more realistic way of representing tyre for crash event. This involves detailed study ranging from coupon level tests to full tyre model. Different tyre components like steel-belts, body plies, steel-beads, tread and sidewall, which influence tyre characterization have been considered for this study. This paper explains in detail about various experimental test and their CAE predictions to arrive at acceptable level of performance. The approach in this study is to have systematic process of rubber tyre characterization which includes quasi-static tensile coupon tests, static compression test on tyre assembly and dynamic impact test with moving trolley.
2015-01-14
Technical Paper
2015-26-0059
Rahul R Kartha, Mohammad Jamadar, Kishor Kumar Kavathekar, S D Rairikar, S. S Ramdasi, S.S Thipse, N. V Marathe
The paper deals with the simulation of a Light Commercial Vehicle (LCV) using vehicle performance algorithms. This method speeds up the product development process. Also by using these kind of methodology in vehicle simulation there is much noticeable reduction in cost of testing. The simulation model is used for parametric studies of the vehicle and also to attain objectives such as to optimize transmission ratio, full load acceleration, maximum tractive force, gradient performance, fuel consumption and the exhaust emission . In this case study, simulation model of a CNG LCV is used to analyse the performances similar to that done in a chassis dynamometer. The simulation leads to the prediction and evaluation of various parameters such as fuel consumption, exhaust emissions, full load acceleration, gradient performance & maximum tractive effort for Indian Driving Cycle.
2015-01-14
Technical Paper
2015-26-0062
Pankaj Kumar Verma, Shashi Bhushan Singh, Kalyan Vedula
The Armoured fighting vehicle designers are continuously fighting for ways to reduce vehicle weight, increase fuel efficiency, improve reliability, and reduce cost. Customized engineering design, and materials are becoming more widespread on all fronts. Also, vehicle emission norms are getting stringent day by day and there is increasing pressure to reduce fuel consumption. One important method of achieving the fuel economy and improve vehicle performance is to reduce vehicle weight. In view of the above advanced materials like Carbon Fiber Reinforced Polymer (CFRP) composites are promising to be the material to look for when it comes to reduce weight of structural elements due to its high strength to weight and high stiffness to weight ratios and hence was used for the development of Bogie Wheel of a light tracked vehicle. This paper illustrates the developmental methodology of Carbon Fiber Reinforced Polymer (CFRP) Road wheel for 20 ton class of tracked vehicle.
2015-01-14
Technical Paper
2015-26-0084
Ishwar Patil, Kiran P Wani
With the increasing competition in automotive sector, the customer is available with more options when it comes to buying a vehicle. So it has become necessary to improve the vehicle’s characteristics which affect its impression on the customer. Handling and ride comfort are very important characteristics that influence the quality of the vehicle. These characteristics depend on the suspension system of the vehicle. The three main objectives that a suspension system of an automobile must satisfy are ride comfort, vehicle handling and suspension working space. Ride comfort is directly related to the vehicle acceleration experienced by the driver and the passengers. Higher vertical acceleration, lesser is the level of comfort. The aim of this paper is to design and analyze the semi active suspension system models using skyhook, ground hook and hybrid control method.
2015-01-14
Technical Paper
2015-26-0221
Jitesh Agrawal
In commercial Vehicles, the purpose of suspension is not only passenger's ride comfort and load carrying, but also accompanying vehicle's handling. Road profile, vehicle design and driver input contribute a lot to the vehicle behavior specially when vehicle is turning, braking and bouncing. One of the vehicle behaviors is brake steering where vehicle itself steers on braking and can be a major cause for life threatening accidents on highways and express ways. In this paper, leaf spring wind-up and vehicle behavior on braking is studied analytically, observed experimentally and characteristics were analyzed. Also, the effect of the same on design parameters is studied and thereby recommendation is derived. In analytical part of paper, various spring's wind off parameters such as Dynamic load on spring, perpendicular distance of projected twisted surface, Angle of spring wind-up, and Induced stress during braking are calculated.
2015-01-14
Technical Paper
2015-26-0004
Jitendra Shah
A first step towards autonomous rear-end collision avoidance is to start providing natural support to driver in avoiding collision by steering and braking intervention. The proposed system detects slower-moving and stationary vehicles ahead and classifies the risk of having a rear-end-collision. If the risk is high and there is insufficient space to avoid a collision by braking only, the system helps the driver to steer around the obstacle by steering rear toe angle of the wheels individually. A lot of research already exist in the rear wheel steering but the role of rear wheel steering in collision avoidance is not researched yet in great details. Rear wheel steering is used to increase agility and maneuverability of vehicle at lower vehicle speed and stability of vehicle at higher vehicle speed. In the situation of the high speed rear end collision where steering is more effective than braking the strategy of control design of rear wheel steering needs to be dynamically updated.
2015-01-14
Technical Paper
2015-26-0225
Prashant R Pawar
The tire is generally characterized on the basis of forces and moments being generated at the contact patch, which generally describes the friction potential of the tire in both longitudinal and lateral directions at different load conditions. The field conditions under which the tires perform is diverse which results in varied performance for the same product. To understand this there is a need to understand range of friction values the tire undergoes in different conditions which cannot be replicated in indoor test-rigs. The longitudinal potential of tire is the important factor in determining the acceleration and braking behaviour, so braking test was performed to measure the longitudinal slip and forces. A joint project has been undertaken between Apollo Tyres and ARAI, where both have used their technical expertise to work on tire characterization out of road test.
2015-01-14
Technical Paper
2015-26-0080
Wen Zhang, Bo Yang
Abstract Commercial vehicle plays an important role during transportation process under the demand of high speed, convenience and efficiency. So improving active safety of commercial vehicle has become a research topic. Due to the fact that braking characteristic is the basic and most closely related to safe driving of vehicle's performances, this paper aims to improve the braking performance by researching into an integrated control method based on the mature ABS products. Firstly, a strategy which gives priority to ABS and differential yaw moment control, complementary with the hydraulic active suspension control is proposed. In comparison with ABS, the combined control of brake system and suspension system is designed not only for preventing wheels lock. But the directional control to avoid roll or spin is more focused on. Then in order to run the novel method correctly, the controlled variables and evaluation criteria are illustrated briefly.
2015-01-14
Technical Paper
2015-26-0077
Deepak Sharma, Abhishek Atal, Abhay Shah
Abstract In this paper, design methodology of antiroll bar bush is discussed. Typical antiroll bar bushes have slide or slip mechanism, to facilitate the relative motion between ARB and bush. Inherently, this relative motion causes wear and noise of bush. To eliminate stated failure modes, the next generation bushes have been developed, which are using torsion properties instead of slip function. These bushes are already being used in various vehicles. This paper focuses on developing the simple mathematical model, design approach and optimization of ARB bushes. Also, comparison study is presented exploring, the differences and design criteria's between conventional and new generation anti-roll bar bushes.
2015-01-14
Technical Paper
2015-26-0085
Boris Belousov, Tatiana I. Ksenevich, Sergei Naumov
Abstract The modular designing principle is generally recognized in the automotive industry. However, the issue of building a wheel open-link locomotion module (OLLM) as a combination of steering (wheel turning), springing, traction drive and braking systems is not properly developed yet. An automated control system (ACS) is needed to able to unite and coordinate all the vehicle systems intended to manage the wheel. The automated control system intended to manage the steering and wheel springing parameters is a combination of an information and power channels, through which the wheel is electro-hydraulically driven, and the steering, springing and braking systems are controlled. The number of such channels in a wheeled mover of the vehicle or mobile robot is defined by the wheel type (driving, driven, steered or non-steered wheel). The plurality of such channels forms a complex of automated control systems of the wheeled mover.
2015-01-14
Technical Paper
2015-26-0082
Jeevan N. Patil, Sivakumar Palanivelu, Vaibhav Aswar, Vipin Sharma
Air brake system is widely used in heavy truck and intercity buses for its great superiority and braking performance over other brake systems. Pneumatic brake system consists of various valves such as Dual Brake Valve (DBV), Quick release Valve (QRV), Relay Valve, Brake chambers. Dynamics of each valve is playing crucial role in overall dynamic performance of braking system. Also, it is very difficult to find the contribution of each valve in overall braking performance. In addition to this, there are various pipe diameters, which can be used between various valves. Hence, it is very difficult to find the best possible pipe diameter combination between various valves as well as contribution of each valve in overall performance through experiment as we cannot try all possible combinations on the actual vehicle.
2015-01-14
Technical Paper
2015-26-0150
Sanjay Chaudhuri, Vikram Saini
Special purpose, high payload carrying capacity, live gooseneck, multi axles, hydraulic suspension semi trailer is ab-initio designed for transportation and tilting of heavy cargo from horizontal to vertical by hydraulically actuated mechanism integrated on the trailer. The chassis is levelled on hydraulic jacks followed by tilting of cargo. Hence the chassis experiences variable forces during tilting and estimated from kinematic model of tilting mechanism. These forces are input for finite element based structural design of chassis. Structural deflection of a step is made as initial condition for certain load cases of the analysis. Live gooseneck of this semi-trailer consists of hydraulically actuated mechanism, interconnected with multiple hydraulic suspensions in appropriate ratios. Estimation of Axles and fifth wheel force distributions of such trailer is complex. Mathematical modelling made to estimate these forces and applied as inputs for finite element analysis.
2015-01-14
Technical Paper
2015-26-0143
Navneet Chaudhari, K.V.V. Rao Srinivasa, Phillips Cecil
Abstract The purpose of a differential is to allow the wheels of an automobile to turn at different speeds so that it does not skid during turning. However when a vehicle runs on a slick or muddy surface (especially in Agricultural and constructional Field applications) that same feature causes the wheel with less traction to spin freely as this unit transmits power to the tire with least amount of traction. The function of a difflock is to lock the differential gears, by locking the differential, both the axles receive equal power and hence equal traction is available at both the tires. This Paper describes the positive locking of a differential by stopper, and also in detail the problems associated with its engagement and disengagement in tractors and construction equipment's. Additionally a concept for a difflock stopper which has been experimentally proven for tractors and construction equipment's is also discussed.
2015-01-14
Technical Paper
2015-26-0172
Girikumar Kumaresh, Thomas Lich, Moennich Joerg
Abstract In the year of 2012 in India the total number of accidents with injuries is registered by Ministry of Road Transport and Highway with 490,383 out of which injured people are 509,667 and fatalities are 138,258 [1]. Nearly 17% of the fatalities are occupants of passenger cars which constitute the second highest contributor for fatal accidents in India [1]. In order to understand the root causes for car accidents in India, Bosch accident research carried out a study based on in-depth accidents collected in India. Apart from other accident contributing factors e.g. infrastructure the driver behaviour and his actions few milliseconds just prior to the crash is an extremely important and a key valuable data for the understanding of accident causation. Further on it supports also the development of modern automotive safety functions. Hence this research was undertaken to evaluate the benefit of the state-of-the art vehicle safety systems known as Antilock Braking System (ABS).
2015-01-14
Technical Paper
2015-26-0068
Muthuraj Ramasamy, Vignesh E, Sundararajan Thiyagarajan
Speaking of industrial design in automotive engineering, safety, aesthetics (user driven aspects), ergonomics (technology driven aspects) and product economics play a key role in the success and sustenance of any auto component or product in service. One such auto component in a vehicle which necessitates equal attention from all the above said aspects is a “WHEEL”. A conventional tube type wheel for commercial vehicles is made of steel with steel side rings (multi-piece construction). In course as headway in wheel design the single piece wheels were developed which used the tubeless tires. These wheels were made available in both steel and aluminium versions. Wherein the aluminium wheels were lighter in weight than steel, aesthetically more appealing and had other significant advantages. Despite the advantages of these tubeless tire wheels, the end user had to invest for both wheels and tubeless tires to replace conventional tube type steel wheels.
2015-01-14
Technical Paper
2015-26-0086
Prakhar Srivastava, Manish Laxman Karle, Ujjwala Shailesh Karle, Anand A Deshpande
Abstract Electric Power Assist Steering (EPAS) is a safety critical system because it affects vehicle stability and dynamics. In EPAS, electric motor takes the power from the battery and delivers this power to rack and pinion only on demand. Since EPAS contains electrical component such as Motor and electronic component such as Electronic Control Unit (ECU), reliability of these components is very important. To ensure safety and reliability, ISO 26262 standards are adapted which are derived from IEC 61508. This standard regulates the product development on system, hardware and software level and manages functional safety for electrical and electronic components. This paper discusses the applicability of the ISO 26262 standard to the development of EPAS ECU with respect to its hardware and software design. Hazard analysis and risk assessment of the basic EPAS architecture is performed and architecture is improved to achieve safety goal as per the standard.
2014-11-11
Technical Paper
2014-32-0088
Claudio Annicchiarico, Renzo Capitani
Abstract In a Formula SAE car, as for almost all racecars, suppressing or limiting the action of the differential mechanism is the technique mostly adopted to improve the traction exiting the high lateral acceleration corners. The common Limited Slip Differentials (LSDs) unbalance the traction torque distribution, generating as a secondary effect a yaw torque on the vehicle. If this feature is electronically controlled, these devices can be used to manage the attitude of the car. The yaw torque introduced by an electronically controlled LSD (which can also be called SAD, “Semi-Active Differential”) could suddenly change from oversteering (i.e. pro-yaw) to understeering (i.e. anti-yaw), depending on the driving conditions. Therefore, controlling the vehicle attitude with a SAD could be challenging, and its effectiveness could be low if compared with the common torque vectoring systems, which act on the brake system of the car.
2014-11-11
Journal Article
2014-32-0053
Yoshihiro Nakagawa, Shinya Takahashi, Mikihito Masaki, Ranju Imao
Abstract In brake squeal analyses using FE models, minimizing the discrepancies in vibration characteristics between the measurement and the simulation is a key issue for improving its reproducibility. The discrepancies are generally adjusted by the shape parameters and/or material properties applied to the model. However, the discrepancy cannot be easily adjusted, especially, for the vibration characteristic of the disc model of a motorcycle. One of the factors that give a large impact on this discrepancy is a thermal history of the disc. That thermal history includes the one experienced in manufacturing process. In this paper, we examine the effects of residual stress on the natural frequency of motorcycle discs. The residual stress on the disc surface was measured by X-ray stress measurement method. It was followed by an eigenvalue analysis. In this analysis, we developed a unique method in which the residual stress was substituted by thermal stress.
2014-11-11
Technical Paper
2014-32-0017
R Varunprabhu, Himadri Bushan Das, S Jabez Dhinagar
Abstract The steering system of a 3-wheeler vehicle comprises a single column steering tube. The steering inclination at handle bar end is converted to wheel slip or inclination by the steering column. A compromise in either ride or handling is considered in the functional requirement of the 3-wheeler vehicle. The 3- wheeler vehicle under study is designed for ride comfort and the handling levels are compromised. Variants of the vehicle under study are meant for public passenger transport requirements. Drivers' ride comfort is considered as the primary functional requirement during design and driver's steering fatigue is not given importance. For the comfort of driver, steering effort has to be less without compromise in handling characteristics. The driver of this type of vehicle drives the vehicle for 15-18 hours a day. Driver's feedback suggests high steering effort as a human fatigue failure mode and also a cause of shoulder pain.
2014-11-01
Journal Article
2014-01-0085.01
Andrew Pennycott, Leonardo De Novellis, Aldo Sorniotti, Patrick Gruber
The previously published equation found on page 492 contains an error which is corrected in the erratum.
2014-10-01
Journal Article
2014-01-9026
Christopher Gill, Christopher Knight, Scott McGarry
Vehicle shock absorbers are designed to dissipate kinetic energy through frictional viscous forces. In some circumstances, this can be in the order of kilowatts of instantaneous power dissipation. This study quantitatively assesses the vehicle damper system energy dissipation of a low-mass utility vehicle and a high-mass hauling vehicle, using empirically derived regression models of the working dampers and custom data logging equipment. The damper force and power is derived from post-processing of the measurement of critical damper metrics, including linear velocity and temperature. Under typical operating conditions, the low-mass utility vehicle showed an average power dissipation of 39 W for a single shock absorber, and approximately 150 W for a complete vehicle-damper model. The high-mass hauling vehicle demonstrated an average power dissipation of 102 W for a single shock absorber, and approximately 600 W for a complete vehicle-damper model under laden operating conditions.
2014-10-01
Journal Article
2014-01-9028
Theodoros Kosmanis, Georgios Koretsis, Athanasios Manolas
Abstract The implementation of an electronic differential system in a delta-type, electrically assisted, three wheel Human Powered Vehicle is the subject of this paper. The electronic differential algorithm is based on the turning angle of the vehicle and its geometrical characteristics. The theoretical analysis is applied in a realistic human powered tricycle constructed in the premises of the Alexander Technological Educational Institute of Thessaloniki. The system's efficiency is validated through test measurements performed on the rear wheels during vehicle's operation in appropriately selected routes. The measurements are performed for both typical cornering and oversteering.
2014-09-30
Journal Article
2014-01-2408
Mehdi Ahmadian
The 2014 SAE Buckendale Lecture will address the past developments and challenges of electromechanical “smart” systems for improving commercial vehicles' functionality. Electromechanical systems combine traditional mechanical devices with electrical components to provide far higher degree of functionality and adaptability for improved vehicle performance. The significant advances in microprocessors and their widespread use in consumer products have promoted their implementation in various classes of vehicles, resulting in “smart” devices that can sense their operating environment and command an appropriate action for improved handling, stability, and comfort. The chassis and suspension application of electromechanical devices mostly relate to controllable suspensions and vehicle dynamic management systems, such as Electronic Stability Control.
Viewing 1 to 30 of 7467