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In the recent years steering feel characteristics have emerged as one of the important brand image attributes of automotive OEMs. Since past few decades, the hydraulic assisted steering system (HPAS) on which lot of research was done to tune the steering feel has been taken over by electric power assisted steering (EPAS) system. The EPAS primarily uses an electric motor controlled by an electronic control unit to assist the driver in maneuvering the vehicle. The next big leap in the steering system advancement is steer-by-wire (SbW) technology where the mechanical linkage between the steering wheel and the road wheels is eliminated. The advantages of this system are ease to use, elimination of noise-vibration-harshness of steering system caused by road forces, modularly of steering system for packaging, improved visibility to front-end displays and road ahead and a fun to drive concept.

The fuel economy of heavy commercial vehicles can be significantly improved by reducing the rolling resistance of tires. To reduce the rolling resistance of 6×4 tractor, the super single tires instead of rear dual wheel tires are tried. Though the field trials showed a significant increase in fuel economy by using super single tires, it posed a concern of road safety when these tires blowout during operation. Physical testing of tire blowout on vehicle is very unsafe, time consuming and expensive. Hence, a full vehicle simulation of super single tire blowout is carried out. The mechanical properties of tires such as cornering stiffness, radial stiffness and rolling resistance changes during the tire blowout; this change is incorporated in simulation using series of events that apply different gains to these mechanical properties.

In today's scenario, most of the OEMs use manual transmissions with synchronizer gear shifting system for ease of gear shifting. It gives very high fuel efficiency. Gear shifting is a customer touch point, hence it is very important to select adequate synchronizer capacity so that it will perform in better and last longer. To test the synchronizers, there are many test methods which give the idea about life of synchronizer and its performance, in different conditions. Regular synchronizer rig tests consume lot of time in deriving the results. So it is very important to find out a way which will give same results within short time period. To carry out the short time test or accelerated test, we need to understand the effect of various factors like reflected inertia, drag torque, differential speed, synchronizing time, and gear shifting force on synchronizer capacity.

Nowadays, a higher amount of time is being spent inside the vehicles on account of varied reasons like traffic, longer distances being travelled and leisure rides. As a result, better comfort and convenience features are added to make the driver and passenger feel at ease. Thermal comfort and acoustic isolation are the primary parameters looked at by both the customers and the original equipment manufacturers. Seats are one of the primary touch points inside the vehicle. Perspiration caused at the contact patch areas between the seats and passengers leads to high thermal discomfort. A ventilated seat, with or without an air-conditioning system, is one such attribute offered to improve passenger thermal comfort. Ventilation becomes even more essential for front-row seats, as these are more likely to be exposed to external solar loading through the front windshield.

Vehicle floor vibration is the resultant of different road inputs damped through various transfer paths. Seat comfort, which depends on these floor vibrations, can be evaluated with a single input signal “Pink noise”; which constitutes various road inputs. Transmissibility of seat structure on a vibration shaker with pink noise input includes all possible responses of road inputs. Still, transmissibility profile at vehicle end and component level varies. This is due to the utilization of “dummy” on component level testing on vibration shaker, which acts as a dead weight with dissimilar damping characteristics of human. A transmissibility correlation between human and dummy is attained by replacing the dummy in place of human and actuating it to find the difference in contribution between them for different class of vehicles. This contribution extrapolation from the damping effects of human and dummy is applied on dummy transmissibility.

Traditionally, vehicle ride and comfort is evaluated, subjectively as well as objectively. Based on the outcome of subjective and objective tests, it is refined by optimizing primary suspension system, secondary suspension system, seating system, rubber bushings, frame and BIW for mass, stiffness, damping, geometry etc. Many a time subjective assessment results stands in contradiction to the objective assessment results; emphasizing need for having good correlation between subjective and objective test results. In such cases, it is ambiguous to decide suitable design refinement action and can lead to no improvement situation. Hence, it is essential to have concurring test procedures for subjective and objective ride evaluation. This paper describes a novel methodology to address the above said challenge. There are defined set of test events and measurement data points to be used in subjective and objective testing.

Passenger utility vehicles like car, SUVs, MPVs are used in wide application all over the world. Luxuries are becoming essential features of product mix along with comfort and ergonomics. Customer desires best shift quality with emerging technologies like AT, DCT, CVT, etc. and every OEM is working hard to achieve it. It is very difficult to satisfy the customer desire because of diversities in demographics and geographic. Gear shift quality (GSQ) is very crucial touch point in overall drive feel of vehicle. It consist of various parameters like mode selection feel, precision, comfort, select Noise, etc. It demands tradeoff practices among various parameters as stated. In this paper, external mode selection system of automatic transmission is explained. Various contributing parameters are explained with practical design approach for detent profile, mode selection mechanism, cable & dampers, etc.

The Indian automotive industry is going through a rapid transformation phase. Regulatory emission norms such as, migration from BSIV to BSVI engine, increased adoption of μ-hybrid, full electric and autonomous cars are examples of such rapid transformation. The upgradation of internal combustion engines for compliance with new regulatory norms (e.g., from BSIV to BSVI) has caused a significant change in the automotive acoustic performance. As the powertrain system are being upgraded and getting quieter, the on-board Heating, Ventilation and Air-Conditioning system (HVAC) system emerges as one of the prominent noise sources which strongly influences overall refinement levels inside the cabin. This in turns is affecting overall feeling of passenger’s comfort. The HVAC system of an automobile is a compact and yet a complex system designed to provide thermal comfort inside the car cabin.

Twist beam is a semi-independent suspension having two trailing arms attached to the chassis via rubber bushes. Closed profile ‘V’ shaped cross beam interconnects left and right side arms. It provides roll stiffness of the suspension, by twisting as the two wheels moves relative to each other. Due to driving and road conditions twist beam structures are subjected to cyclic twist loads resulting into roll fatigue failure mode [1]. To design twist beam for mass, package and performance it is required to find realistic cross articulations based on vehicle application, usage pattern and protect twist beam from roll fatigue failure mode. The objective of this paper is to develop a virtual method using ‘ADAMS ®’ multibody dynamics software for maximum relative wheel center displacements during realistic hilly areas conditions. This paper describes half and full vehicle based virtual approach for twist beam cross articulations in hilly area conditions.

Apart from being an active safety system the brake system represents an important aspect of the vehicle dynamics. The vehicle retardation and stopping distance completely depend upon the performance of brake system and the functionality of all components. However, the performance prediction of the entire system is a challenging task especially for a complex configuration such as multi-axial vehicle applications. Furthermore, due to its complexity most often the performance prediction by some methods is limited to static condition. Hence, it is very important to have equivalent mathematical models to predict all performance parameters for a given configuration in all different conditions This paper presents the adopted system modelling approach to model all the elements of the pneumatic brake system such as dual brake valve, relay valve, quick release valve, front and rear brake actuators, foundation brake etc.

Twist-beam suspensions are an example of design solution presenting acceptable performance when applied to passenger cars & light vehicles and it can provide an optimal between cost & performance in the automotive market. For these reasons, twist beam is quite popular in use in rear suspension of light vehicles. In contrary to other types of suspension, the twist-beam has a flexible torsion beam connecting the swing arms. The study of the deformation of this flexible element becomes important to understand its performance and durability behavior. As the name signifies, twist beam major performance attribute is control of twist or opposite wheel travel arising from vehicle roll or road input. Current approach for the study this deformation is through FEA & Multi-body dynamics software tools.

With increased awareness about environmental issues, the trend of automobile industry is to use ‘Recycled’ or ‘Biodegradable’ or ‘Energy Recoverable’ material. As a part of this programme, to make the vehicle ‘Green’ in nature, many automobile OEMs have taken the initiative to make use of natural fibre composite in their vehicles. Natural fibre based composite has been successfully proven for less critical as well as for semi-structural applications in an automobile. These typical applications are insulations, headlining, carpets, door pad etc. There is a demanding task for automotive OEMs to meet 85% Recyclability and 95% Recoverability targets by year 2015. To meet the RRR (Reuse, Recycle & Recover) and the ELV (End of Life) regulatory requirements, increased use of natural fibre based composite/ biopolymers is unavoidable. Natural fibre can offer potential advantages such as weight saving and improve overall green rating of the vehicle.

Cabin noise is a significant product quality criteria which enables the customers for product differentiation. There are various sources of cabin noise such as wind, structures(panels), engine, suspension, tire and roads. During product development phase, extensive tests has been conducted to improve vehicle dynamics behavior on various climatic conditions. One such test is accelerating vehicle on low mu or icy surface. While performing acceleration manoeuvre (tractions) on a low mu tracks, Cabin noise with source identified from front underbody & low tractive torque build up is reported. This undesirable behavior may occur due to following reason (1) Excitation of coupled modes between suspension and powertrain which induces torque fluctuation. (2) Transmissibility of various subsystem can be the reason for above problem statement. (3) Poorly chosen tire compounds and design leads to fluctuation in torque.

For a modified electric vehicle on the same internal combustion engine (ICE) platform, the primary consideration is to have no change in long member and pendulum type conventional engine mounting system to save development cost and timeline. Electric vehicle (EV) powertrain is comparatively lighter w.r.t the ICE. As a result, the engine mount’s static preload setting point or powertrain centre of gravity under static powertrain load gets changed resulting in a change in stiffness for the same engine mount. As the static stiffness changes, the dynamic stiffness and modal frequency also change. The 6 degrees of freedom (DOF) modal frequency has almost no impact on powertrain modes as EV powertrain modes, mainly, the motor frequency, is much higher than engine mount Eigen modes. In this scenario, the gap management gets disturbed due to less static preload, and non-linearity gets affected.

Commercial electric vehicle air conditioning system keeps occupants comfortable, but at the expense of the energy used from the battery of vehicle. Passengers around the world are increasingly requesting buses with HVAC/AC capabilities. There is a need to optimise current air conditioning systems taking into account packaging, cost, and performance limits due to the rising demand for cooling and heating globally. Major elements contributing to heat ingress are traction motor, front firewall, windshield & side glasses and bus body parts. These elements contribute to the bus’s poor cooling and lack of passenger comfort. This topic refers to the reduction of the heat ingress through usage of different glass technology like IR Cut & solar green glass with different types of coating.

Aerodynamics performance evaluation of passenger cars is important during early vehicle development phase as it influences fuel economy, vehicle stability and drivability. Usually during initial styling phase, scale model is prepared and tested in wind tunnel to check aerodynamic performance like drag coefficient and these are used to predict aerodynamic performance of full scale model as testing on full scale model is costly and time consuming. To ensure its correctness, it is important to understand difference in physics from scale model to full scale model. In predicting full vehicle aerodynamics performance from scale model assessment; importance of Reynolds number, effect of geometric scaling on flow i.e. flow separation and wake zone change needs to be understood and addressed. This paper discusses about effect of scaling on aerodynamic flow behavior and drag.

Interdependency of automotive transmission aggregates on electrical/ electronics systems is increasing day by day, offering more comfort and features. For a system integrator, it becomes very much important while selecting/designing any such component to take into consideration the relationship between such interdependent components from performance as well as endurance point of view. DMF failures due to inadequate starting system, is a major stumbling block in development of DMF for a particular vehicle application. The interface of DMF and starting system of a vehicle makes it essential to consider the effect of one on another. The study shows that the majority of DMF failures happen because of resonance phenomenon in the DMF during engine starting. The improper selection of starter motor makes the DMF more vulnerable for such failures.

Automotive Industry is constantly upgrading the value offered on their products at optimized cost. Scratch and mar resistance of interiors and exterior parts, is an important attribute which is linked to perceived quality and value offered to customers. Polypropylene material is optimum material of choice for these parts due to its unique advantages. However, filled polypropylene material has poor scratch and mar resistance. Many techniques for scratch resistance improvement are available such as additions of slip agents, co additives, special fillers, siloxanes, etc. However, some of them may offer some disadvantages like stickiness or tackiness on the surfaces. The choice depends on its effectiveness & cost. This paper deals with design of experiments to evaluate effectiveness of 4 types of additives and their optimum % to give scratch resistance improvement without having detrimental impact on other critical properties.

The primary function of an engine mounting bracket is to support the powertrain system in all road conditions without any failure. The mount has to withstand different road conditions and driving maneuvers which exert loads on it. Also, it is challenging to change the mounting locations and types after the engine is built; hence it is paramount to verify the mounting brackets against all abuse loads in the design stage. The Car manufacturers ensure engine mount bracket design meets CAE's (Computer-aided engineering) static and fatigue load cases. The CAE is performed using digital RLD (Road load data) loads. The design checks cumulative strain or stress against specified service life requirements during break and fatigue FOS (Factor of safety) calculations. However, it is difficult to simulate the material's fracture toughness to estimate the effect of the impact load on the mounting bracket.

Transportation has significant and long-lasting economic, social and environmental impacts which makes it an important dimension of urban sustainability. The World is witnessing rapid changes in modern traveling behavior, and efforts are continuously being made to stimulate sustainable mobility solutions with smart policies, new business models, and advanced technologies (connected cars, sensors, electrification). However, the shift is gradual in India when compared to developed countries due to unique barriers to emerging green mobility solutions. This paper empirically investigates public travel satisfaction and the primary factors for the selection of modes for different types of commutes. Quantitative data were collected including socio-demographic, travel mode choices, and preferred future mobility solutions from the western states of India.