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Road accidents are a major concern worldwide and vulnerable road users make up more than half of the victims of road accident deaths. In order to combat this issue, several countries worldwide have mandated pedestrian safety test regulations viz., AIS100 & UN-R127. One of the requirements of the regulations is when Flexible Pedestrian Legform Impactor (Flex-PLI) is impacted onto the frontal structure of the vehicle at a speed of 40kmph, the Bending moment (BM) of tibia bone of Flex-PLI shall not exceed the regulatory limit of 340Nm. In this paper, we have built a statistical model for predicting the BM of tibia in Flex-PLI using regression analysis. 13 vehicles have been selected from all applicable vehicle categories viz., Sedan, hatchback, Coupe & SUV/MUV for this undertaking. An exhaustive analysis of the vehicle frontal structures and Flex-PLI test videos have been done to identify & measure the design parameters to be used as predictor variables.

MSIL (Maruti Suzuki India Limited), India’s leading carmaker, has various SUVs (Sports Utility Vehicle) in its model lineup. Traditionally, SUVs are considered to have a bold on-road presence and this bold design language often deteriorates aerodynamic drag performance. Over the years, the demand for this segment has significantly grown, whereas the CAFE (Corporate Average Fuel Economy) norms have become more stringent. To cater this growing market demand, MSIL planned for two new SUVs: (1) New BREZZA - A bolder design with similar targeted aerodynamic performance compared to its predecessor (BREZZA-2016) and (2) FRONX - A new cross-over SUV vehicle targeted best-in-class aerodynamic performance in this category at MSIL. This paper illustrates the aerodynamic development process for these two SUVs using CFD (Computational Fluid Dynamics) and full scale WTT (Wind Tunnel Test).

With the advancement of regulatory norms in automobile industry, there is a challenge to meet performance efficiency targets, especially with a lightweight platform, while providing superior driving experience to customers. The shift towards weight optimization, makes the vehicle structure more susceptible to transfer a diverse range of noise and vibrations through body. Although most undesirable noises perceived inside the cabin can be reduced by superior technology engine mounts and NVH packaging, all such solutions lead to cost addition. Intelligent considerations in part design can be used to supplement predictable transfer paths to quell the unwanted vibrations. One such case is of the gear whine noise in certain rpm bands caused by inherent gear meshing frequency coinciding with natural frequency of an engine mounting bracket.

The Indian passenger vehicle market has grown by more than 40% by volume in the last decade and has reached a record high in FY23. This has created a more diverse and demanding customer base that values interior design and quality. The modern customer expects a high level of aesthetics and sophistication in their vehicle interiors - including in the luggage area. The Luggage Cover (Parcel Tray) is a component in the luggage area of a passenger vehicle that is used to conceal the luggage & improve its aesthetics. The cover is generally made of thermoplastic material with rotating hinges and is held in its place by the compression from the back door, which is frequently opened and closed. The parts that connect the cover to the door (usually an elastomer interface on the thermoplastic tray) tend to change over a period due to climatic conditions and leads to rattling concerns over a period.

With the advent of upcoming stringent automobile emission norms globally, it is inevitable for original equipment manufacturers (OEMs) to shift towards greener alternatives. Use of compressed natural gas (CNG) is a preferred solution as it is a relatively clean burning fuel and it doesn’t have significant loss in vehicle efficiency and performance. Modern day customers are more aware and sensitive towards vehicle noise, vibration and harshness (NVH). Hence, OEMs must cater to this demand through optimized design and layout. In a passenger vehicle, CNG is stored at high pressure and delivered to injectors after pressure reduction at a regulator. During engine idling, the opening and closing motion of the CNG injector generates back pulsation and these pulsations cause vibrations which may propagate through other components in the delivery path and perceived as noise inside vehicle cabin.

The advent of BS6 coupled with RDE emission norms has increased the development efforts and costs due to the shear amount of testing and validation on real engines and vehicles which are necessitated by these stringent norms. Front-loading of tasks by moving actual vehicle and engine tasks on to virtual setup, will reduce the development efforts and costs significantly. This front-loading of tasks on to a LABCAR would need real time and highly accurate plant models, tools to parameterize these plant models and accurate data driven models to predict dynamic parameters like emissions. In this collaborative work between Maruti Suzuki India Ltd and ETAS India, ETAS VVTB and ICE plant models were parameterized with the data generated on engine test with ASCMO Global DoE test plan by using ASCMO MOCA. The ASCMO Global test plan also ensures the coverage of data points across the entire engine operating space. These plants models were optimized to an accuracy level of more than 95%.

The outside visibility through the windshield and ORVM visibility through the side glasses are critical for safe driving. The frost deposition on the Windshield and side glasses in the cold climatic condition impairs the outside and ORVM visibility during driving and hence leads to an unsafe driving condition. In India, the regulation AIS-084 governs the defrosting standard. The defrosting performance evaluation by testing cannot be performed at concept stage when the vehicle prototype is not available. It also increases the cost of vehicle development due to increase in the number of prototype used for testing. This paper explains about the in-house developed CFD methodology to evaluate the windshield defrosting performance of the vehicle in the concept stage when no vehicle proto is available and cost of countermeasure for defrosting performance improvent is very less. This methodology is implemented for some of the existing models.

In manual transmission vehicles, Clutch has direct interaction with the driver and plays a significant role in defining the drivability and NVH of a vehicle. These key performance factors depend on the interaction of diaphragm and cushion springs of a clutch. For an automobile manufacturer, it’s essential to optimize the characteristics of these springs based vehicle performance requirements. A state of the art analytical model has been developed by modeling the diaphragm and cushion spring with exponential equations. Based on these models, response functions for release load, torque build-up, and pressure plate lift have been derived. Results achieved from these response functions are correlated with test data. Key contributing factors for peak clutch pedal load, vehicle launch acceleration, and disengagement point have been identified by sensitivity analysis. Multi-objective optimization is performed to select optimized parameters for vehicle performance improvement

Today automotive sector has become very dynamic. There is renewed emphasis on safety through adoption of new regulations, electric vehicles are on the verge of replacing ever evolving engine technology, emission norms are getting stringent year by year & several companies are trying to make vehicles more efficient by adoption of new light weight or high strength materials and altering manufacturing methods. In one of the new vehicle programs, there was focus on vehicle styling. In order to improve the styling, back door spoiler was to be considered from design stage itself. Back door spoiler is added in high speed vehicles for creating a downward force to improve the vehicle hold on road. However, nowadays in passenger vehicles that purpose has been subsided and spoiler is given in automotive vehicles for aesthetics or giving vehicle a sporty appearance. For instance in our case it was given to augment aesthetics. This would have resulted in additional cost and weight.

In this study, an alternate way of development and implementation of control strategy for torque split of a Hybrid Electric Vehicle (HEV) is proposed. The control strategy evaluates each and every operating point for Internal Combustion Engine (ICE) and electric motor-generator (E-machine) corresponding to all possible torque split combinations at present time instant and finally chooses one combination with the least cost function, which is estimated by converting electrical energy into equivalent fuel consumption[2]. Henceforth, the control strategy is able to perform real time iterations to choose the E-machine and ICE torque combinations with least effective fuel consumption also referred herein to as the optimal operating points. As a result, by running the vehicle at optimal operating points, overall fuel consumption over the complete drive cycle is reduced.

Clutch actuation system in manual transmission is one of the key systems of power-train with which driver interacts frequently. Therefore its load and travel feeling are important to customer. Clutch actuation system consists of clutch pedal assembly, flexible cable mounted on body panel, and clutch release arm/ shaft assembly inside transmission unit assembly. Clutch pedal load, travel and engagement point are important parameters to specify the actuation feeling while designing the clutch actuation system. Validation of actual values is being done at proto vehicle testing stage, as final output calculation may not be accurate due to dependency on variables difficult to estimate. To overcome these difficulties a virtual dynamic model of the entire clutch actuation mechanism has been created in MBD software. Model input factors are based on actual testing results to improve the accuracy. The model predicts the clutch pedal load and travel values for a given set of vehicle inputs.

During the conceptualization of vehicle, it is big challenge for automotive manufacturer to design a vehicle which has an excellent aesthetic looks as well as meet the stringent vehicle regulations. In the vehicle styling, bumper plays an important role in deciding of the contemporary looks of the vehicle. To improve customer satisfaction, it is important to design a bumper which provides feeling and sense of durability. In addition, bumper should sustain low-speed impact and protects the peripheral components such as parking lights, headlamps, hood, back door and safety related installed equipments like Rear parking camera, parking sensors, etc. Bumper should be dent resistant and be able to regain its original shape on removal of the applied load. An elegant design of bumper should be light weight with high strength. This paper explains about a new CAE methodology developed to simulate the real life loading condition of bumper and to calculate the deformation in the bumper.

The automobile market is witnessing a different trend altogether - the trend of shifting preference from powerful to fuel efficient machines. Certain factors like growing prices of fuel, struggling global economy, environmental sensitiveness and affordability have pushed the focus on smaller, efficient and cleaner automobiles. To meet such requirements, the automobile manufacturers, are going stringent on vehicle weights. Using electric and hybrid power-plants are other options to meet higher fuel efficiency and emission requirements but significant cost of these technologies have kept their growth restricted to only few makers and to only few regions of the globe. Optimizing the vehicle weight is a more attractive option for makers as it promises lesser time to market, is low on investment and allows use of existing platforms.

Offset crash compliance of a compact car is severe due to the compact layout and stringent fuel economy, weight and cost targets. Scope of the current work is to improve the structural crash performance of a compact car through CAE, in order to meet the offset frontal crash requirements as per ECE R94 Regulation. The project has been classified in three main phases. First phase includes the evaluation of baseline vehicle in CAE. In order to ensure the accuracy of CAE prediction, a methodology for predicting Spotweld rupture was implemented. Using this methodology, it is possible to find out the location and time of spotweld rupture as well as propagation of spotweld rupture in CAE. CAE results of spotweld rupture prediction showed good agreement with the physical test. In second phase, design iterations were carried out in order to meet the performance targets of structural deformation.

The side impact accident is one of the very severe crash modes for the struck side occupants. According to NHTSA fatality reports, side impact accounts for over 25% of the fatalities in the US. Similar fatality estimates have been reported in the EU region. Side crash compliance of a compact car is more severe because of the less space available between the occupant and the vehicle structure, stringent fuel economy, weight and cost targets. The current work focuses on the development of Side body structure of a compact car through Computer Aided Tools (CAE), for meeting the Side crash requirements as per ECE R95 Regulation. A modified design philosophy has been adopted for controlling the intrusion of upper and lower portion of B-pillar in order to mitigate the injury to Euro SIDII dummy. At first, initial CAE evaluation of baseline vehicle was conducted.

The durability evaluation of overhanging components of a vehicle (Ex: horn, radiator) is a challenge to durability engineers as resonance plays an important role in determining their fatigue life. As resonance cannot be avoided always, it is desirable to develop methods to evaluate life of the component in the presence of resonance. Though the existing vibration test standards suggest test profiles to evaluate resonance failures, there are cases in which, these methods do not yield the proving ground results. This may lead to unnecessary overdesign or unrealistic failures. In such cases it is suggested to generate a sweep endurance test procedure customized to the proving ground or actual roads. This paper studies a methodology for generating a sweep endurance test procedure for evaluation of resonating components. Responses like stress and accelerations were measured in test components in proving ground. Contribution of each frequency band towards overall damage is determined.

Recent advancement in numerical solutions and advanced computational power has given a new dimension to the design and development of new products. The current paper focuses on the details of work done in order to improve the vehicle performance in Offset deformable Barrier (ODB) crash as per ECER-94. A Hybrid approach involving the Structural Crash CAE as well as Multi-body Simulation in MADYMO has been adopted. In first phase of the development, CAE results of Structural deformation as well as Occupant injury of the baseline model were correlated with physical test data. The second phase includes the improvement in intrusion and crash energy absorption by structural countermeasures in the vehicle body. In third phase parametric study has been carried out via Madymo simulation in order to decide on the factors which can be controlled in order to mitigate the Occupant injury. Recommendations of Madymo simulation have been confirmed by conducting Physical sled tests.

Manual transmission is one of the key system of power-train to which driver directly interacts, so its shift feeling is important for the merchantability. The importance of the gear shift quality of manual transmissions has increased significantly over the past few years as the refinement of other vehicle systems has increased and also due to rise in customer expectations. Shift Tower is a system to assist the driver during selecting and shifting of Gears. The dynamic interaction of shift Tower at a component level is difficult to interpret by traditional test methods and virtually impossible at concept stage. To overcome these difficulties a dynamic model of the entire Shift Tower mechanism i.e. Shift select lever, 3D Ramp, Detent Pin, Spring, Interlock mechanism has been created. The model predicts the gearshift quality i.e. Shift and Select force values for a given set of input parameters, which can be correlated against test data.

In this paper, a mild hybrid system is studied for Indian drive conditions. The study is focused to first come up with detailed component sizing through simulation. Different features of mild hybrid system are studied for their individual and cumulative contribution in the fuel economy improvement over the base non-hybrid vehicle. Model based development approach has been employed to develop a supervisory control strategy for such a system. Model based design saves time and cost as it gives flexibility to the control engineer to validate the control design at an early stage of development. The supervisory control strategy is first tested in a simulated environment and then, on a vehicle. To prove the system function, a full hybrid vehicle is experimented as a mild hybrid configuration. Experiments are conducted on the test vehicle over MIDC (certification cycle) to understand the impact of mild hybridization on fuel economy and tail pipe emissions

Single body architecture designed for various global markets and subjected to varied load cases is a challenge for Body in White (BIW) engineers. Optimization of structural design to meet regulatory, insurance and assessment requirements is an iterative and time consuming task. With focus on reduction of vehicle's damageability and ease of repairability Original Equipment Manufactures (OEM), insurance companies and Research Council for Automobile Repairs (RCAR) [1] are striving for better designs. A space constraint crash box structure installed behind the bumper plays a significant role in absorption of energy, before transmitting to longitudinal rails. In this study, crashworthiness of a multipurpose crash box for a hatch segment vehicle is presented with the various design of experiments conducted with a focus on light weighting, cost and ease of manufacturing.