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Diesel Exhaust Fluid (DEF) concentration monitoring is done to detect the concentration at which the emission thresholds are exceeded in BSVI engines [1]. This paper introduces a novel method to model the fault monitoring system with enable conditions designed to detect deterioration in DEF concentration, while reducing misdetection. This eliminates the need for dedicated sensor, reduces complexity, cost, and potential sensor-related failure modes. Traditionally, Diesel Exhaust Fluid quality sensors have been employed to measure the absolute concentration of Diesel Exhaust Fluid in the aqueous solution of urea [2]. This information is used to detect usage of poor quality DEF which results in increase in NOx emission beyond legal limits.

Multi Body Dynamics (MBD) simulation software is used in product development cycle to reduce the lead time to market. These software have standard parametric templates for modeling metallic suspension systems, which can be quickly modified and used in full vehicle models for ride, handling analysis and the durability load predictions. Generally every Original Equipment Manufacturer (OEM) has unique air suspension arrangement and hence standard template is not available for air suspension modeling in commercial MBD software. Air suspension with self-leveling control mechanism is preferred over metallic suspension in the commercial passenger vehicle like bus for smooth ride comfort. Hence custom made templates for these systems need to be developed for use with MBD software. In this paper, a simplified model of air suspension is presented.

In the modern automotive sector, durability and reliability are the most common terms. Customers are expecting a highly reliable product but at low cost. Any product that fails within its useful life leads to customer dissatisfaction and affects the reputation of the OEM. To eradicate this, all automotive components undergo stringent validation protocol, either in proving ground or in lab. This paper details on developing an accelerated lab test methodology for steering gearbox bracket using fatigue damage and reliability correlation by simulating field failure. Initially, potential failure causes for steering gearbox bracket were analyzed. Road load data was then acquired at proving ground and customer site to evaluate the cumulative fatigue damage on the steering gearbox bracket. To simulate the field failure, lab test facility was developed, reproducing similar boundary conditions as in vehicle.

Commercial vehicle NVH attributes primarily focus on interior noise for driver's comfort and exterior noise for environmental legislation. Major sources for both the interior and exterior noise are power train unit, exhaust and air intake system. This paper focuses on development of Air Intake System (AIS) for better interior and exterior NVH performance for medium and heavy commercial vehicles. For air intake system, structural radiations from its panels and nozzle noise are significant contributors on overall vehicle NVH. Noise generation mechanism in air intake system occurs due to opening and closing of the valves and inlet air column oscillation by sharp pressure pulse from cylinder. Based on benchmarking, vehicle level targets have been arrived, and then cascaded to system and sub-system level targets. For air intake system, targets for nozzle noise at wide open throttle condition have been set for exterior NVH performance.

In the present scenario, delivering the right product at the right time is very crucial in automotive sector to grab the competitive advantage. In the development stage, validation process devours most of the product development time. This paper focuses on reducing the validation time for damper (shock absorber) variants which is a vital component in commercial vehicle suspension system. New test facility is designed for both performance test and endurance testing of six samples simultaneously. In addition, it provides force trend monitoring during the validation which increases the efficiency of test with an enhanced control system. This new facility is also designed to provide side loading capability for individual dampers in addition to the conventional axial loading. The key parameter during validation is control of damper seal temperature within the range of 70-90°C. A cooling circuit is designed to provide an efficient temperature control by re-circulating cold water.

Demand for a refined Heavy Commercial Vehicle (HCV) is increasing due to rapid Indian economic growth, while the operating conditions and road infrastructures are still in a transition state of development. The same vehicle model will be operated in a range of operating road conditions like mining sites, construction sites, and highways with varying payloads and speeds by customers that are spread across the country. This variety of road inputs, payloads and speeds has made ride tuning as one of the major challenging process in the development process. This paper describes the attempt to assess ride comfort of HCV with fully suspended cab using numerical based simulation tools and its correlation with physical test results. The best suspension combination was finalized based on vertical and pitch acceleration at Center of Gravity (CG) of the cab. The trend of vertical acceleration obtained from the virtual model was correlated with the same obtained from physical test.

The automotive industry is constantly looking for new alternate material and cost is one of the major driving factors for selecting the right material. ABT is a safety critical part and care has to be taken while selecting the appropriate material. Polyamide (PA12) [1] is the commonly available material which is currently used for ABT applications. Availability and material cost is always a major concern for commercial vehicle industries. This paper presents the development of ABT with an alternative material which has superior heat resistance. Thermoplastic Elastomer Ether Ester Block Copolymer (TEEE) [3] materials were tried in place Polyamide 12 for many good reasons. The newly employed material has better elastic memory and improved resistance to battery acid, paints and solvents. It doesn't require plasticizer for extrusion process because of which it has got excellent long term flexibility and superior kink resistance over a period of time.

Lifting axles are auxiliary axles that provide increased load carrying capacity in heavy commercial vehicles. Lift axle gives better fuel efficiency as well as it reduces the operational costs by means of increasing the loading carrying capacity. These axles are raised when the vehicle is in unloaded condition, thus increasing the traction on remaining wheels and reducing the tire wear which in turn lower down the maintenance cost of the vehicle. Lifting height and force requires to lift the whole mechanism and are two main considerable factors to design the lifting axle mechanism. Although in India currently, the use of lift mechanism of single tire with continuous axle is more common. But in the case of pusher axle, continuous axle is unable to lift more after certain height because of the draft angle of the propeller shaft, and single tire axle which has less load carrying capacity up to 6T (Tons).

Automotive component light weighing is one of the major goals for original equipment manufacturers (OEM's) globally. Significant advances are being made in developing light-weight high performance components. In order to achieve weight savings in vehicles, the OEM's and component suppliers are increasingly using ultra-high-strength steel, aluminum, magnesium, plastics and composites. One way is to develop a light weight high performance component through multi material concept. In this present study, a bimetal brake drum of inner ring cast iron and outer shell of aluminum has been made in two different design configurations. In two different designs, 40 and 26% weight saving has been achieved as compared to conventional gray cast iron brake drum. The component level performance has been evaluated by dynamometer test. The heat dissipation and wear behavior has been analyzed. In both designs, the wear performance of the bimetal brake drum was similar to the gray cast iron material.

A case study was conducted on the design, optimization and material replacement for an automobile suspension link. The link is part of a four bar mechanism. The mechanism was developed in Adams/Car® and multibody simulation was carried out on it. The joint forces arrived from the simulation were exported for finite element analysis of the components in OptiStruct®. Finally, topology and shape optimization was conducted to reduce the weight of the original component. A feasibility study was also carried out to replace the fabricated steel link with a heat treated cast iron link. Heat treated cast iron being lighter than steel, ensures reduction in weight without compromising on strength. The experiment resulted in a feasible optimized shape which was 32% lighter than the current shape of the link being used in the vehicle, while keeping the stresses and displacements within limits.

Vehicular Emission testing is gaining importance over the past years in the wake of requirements for real driving emissions with implementation of RDE packages across Europe / USA and various developing countries. Extending the same concept for other countries poses slight challenges in terms of geographical and climatic conditions prevailing in the country, where the climatic conditions are differing from Europe / USA. It is a challenge to accept the same boundary conditions as in Europe, at the same time the challenge is to find a threshold number in a more scientific manner. This study concentrates on determination and recommendation of thresholds for ambient temperature and altitude. The basis for temperature threshold would be to determine the percentage of time the temperature exceeded beyond the threshold over year in the country. The basis for Altitude is considered based on the percentage of total length of roads beyond the threshold altitude limit.

One of the important factors strongly required by customers nowadays is lower noise and vibration in vehicle. In this paper the prime focus is made on the study of effect of driveline angles on the noise and vibration behavior in a 4X4 configuration commercial vehicle. The impact of propeller shaft angles in the transfer of driveline excitations to the transmission and the resulting noise and vibration is studied. An abnormal noise was perceived from transmission and the root cause was investigated for the same. These excitations were high due to the higher driveline angles as this was design requirement to maintain higher ground clearance. A two-stage approach was adopted to modify the effect (transmission) and cause (propeller shaft angle) there by reducing the abnormal noise and vibration perceived in the vehicle.

In this work, durability of the bus structure is evaluated with a Virtual Test Model (VTM).Full vehicle Multi Body Dynamics (MBD) model of the bus is built, with inclusion of flexibility of the bus structure to capture structural modes. Component mode synthesis method is used for creation of flexible model for use in MBD. Load extraction is done by performing MBD analysis with measured wheel inputs. Modal Superposition Method (MSM) is employed in FE along with these extracted loads for calculation of modal transient dynamic stress response of the structure. e-N based fatigue life is estimated. The estimated fatigue life from the modal superposition method show good correlation with the physical test results done in 6-poster test rig.

Spring seat plays major role in bogie suspension; which is guiding and controlling the leaf spring for better suspension and also to withstand the compressive load from leafs. Currently used spring seats are failing frequently in medium and heavy duty vehicles, which lead to customer concerns by higher idle time and part replacement cost. Thickness of the spring seat can't be increased by large extent due to packaging constraints in the vehicle. Stress levels identified by FEA method are found higher than the current material capacity. With these constraints, the spring seat has been re-designed with improved strength and ductility of material by modern technology - Austempered Ductile Iron (ADI). The parts have been developed and assembled in various tipper applications and performance was studied. The developed spring seat shows five times superior durability compare to existing design.

The primary factors influencing vehicle's dynamic behavior are the vehicle hard point definition, driver behavior and road inputs. The more the latter two are random and incorrigible in nature, the former one is quantifiable and can be controlled from designer's standpoint. In this paper, we have made an attempt to set targets to the vehicle hard point definition and thereby to optimize the vehicle for better ride behavior. This approach hence helped to converge to vehicle specifications set fundamentally designed to respond to random operating conditions and driving behavior intelligently. The work also involves study of various methodologies to predict roll, pitch, bounce and dive behaviors on a typical commercial passenger vehicle and is concluded by a sensitivity analysis to understand significance of these hard points on vehicle's real time behavior.

Non air-conditioned buses constitute a major portion of public transportation facilities in many countries across the world. Inadequate cabin air circulation is a major cause of passenger discomfort in these buses. The aim of this study is to model the air flow pattern inside the passenger compartment of a bus and to establish the effect of solutions such as roof vents in improving the air circulation. RANS based CFD simulations with Shear Stress Transport (SST) turbulence model have been carried out using a commercial CFD solver. The CFD methodology has been verified by comparing results with experimentally validated LES simulation results available in literature. The vehicle model used in this study was the shell structure of a bus with an overall length of 7 m and a wheel base of 3.9 m. Simulations were carried out for a four vent configuration which showed an increase of 131% in the average in-cabin air velocity over the baseline model without any roof-vents.

Driver safety is one of the key considerations in truck design and development. Virtual simulation offers opportunities to reduce development time and the number of physical prototypes consumed for design verification and validation for safety parameters. Thus, the application of virtual simulations of crash has become an integral part of the vehicle development process. The continuously emerging scenarios involving challenging test requirements can only be tested by means of virtual simulation techniques. This paper presents simulations that are performed to verify various safety aspects to ensure crashworthiness of the truck cabin. The cabin structure was evaluated for various national/international safety regulations. The FE model and simulation methodology was validated through physical testing and correlated for frontal impact test and roof strength test as per AIS 029/ECE R29. Analysis performed to ensure compliance to upcoming regulation ECE R29 Revision 03 is also discussed.

Automotive business is more focused towards delivering a highly durable and reliable product at an optimum cost. Anything falls short of customer expectation will ruin the manufacturer’s reputation. To exterminate this, all automotive components shall undergo stringent testing protocol during the design validation process. Nevertheless, there are certain factors in the field which cannot be captured during design validation. This paper aims at developing a validation methodology for engine oil sump by simulating field failure. In few of our vehicles, field failure was observed in engine oil sump near the drain plug location. Preliminary analysis was carried out to find the potential causes for failure. Based on the engine test bed results, multi frequency swept sine testing was carried out in laboratory. Field failure was simulated in the lab test and the root causes for failure were found out.

In automobiles, front axle assembly is a main load bearing member and houses steering linkages. Front axle assembly has two main parts namely axle beam and axle arm, interconnected by a kingpin. This kingpin allows the rotation of axle arm during steering events. To avoid metal to metal contact between axle arm and kingpin, bushes are housed on the top and bottom half of the axle arm & in axle beam. Due to radial load and steering rotation, as a weak member, bushes will wear out faster. This affects the proper functioning of steering mechanism. Hence, the bushes need to be evaluated prior to its implementation in vehicle. In general, bushes are evaluated using Pin-On-Disc test as a comparative study, but it does not simulate exact boundary conditions as in vehicle. Next option is vehicle level validation but leads to more testing time and cost. Hence, as an optimized solution, the same vehicle operating conditions can be replicated in component level testing.

Sustainable development is the ultimate focus for all the upcoming inventions and innovations in the modern world. Automotive manufacturers contribute their research in terms of producing eco-friendly vehicles since it is proven that internal combustion engine–powered vehicles directly affect the air quality with their polluting exhaust gas. The rapid emergence of zero tailpipe emission vehicles such as electric and fuel cell electric vehicles (FCEVs) obtained the attention of major automotive giants worldwide. owing to their green mobility, battery-operated electric vehicles have already hit the road despite the challenges of recharging time, availability of recharging stations, range-to-weight ratio, and battery life and its recycling process. Drastic upscaling research and development of hydrogen FCEVs paves the way to reach the goal of sustainable transportation with its air cleaning effect, long range, zero tailpipe emission, and quick refueling time.