Search Results

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.

As technology gets upgraded every day, automotive manufacturers are paying more attention towards delivering a highly reliable product which performs its intended function throughout its useful life (without any failure). To develop a reliable product, accelerated combined stress testing should be conducted in addition to the conventional design validation protocol for the product. It brings out most of the potential failure modes of the product, so that necessary actions can be taken for the reliability improvement. This paper discusses about the field failure simulation and reliability estimation of automotive headlamp relays using accelerated combined stress testing. To analyze various field failure modes, performance and tear down analysis were carried out on the field failure samples. Field data (i.e. electrical, thermal and vibration signals) were acquired to evaluate normal use conditions.

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.

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.

Every class of commercial vehicle has an entirely different usage pattern based on customer application and needs. To perform accurate durability testing, these prototypes should run on real customer usage locations and loading conditions for the target life. However, this is time consuming and not practical, hence resulting in Proving Ground (PG) testing. It is also known that a standard PG durability cycle cannot be valid for every class of vehicle and every application. So a statistical approach was followed to develop an accelerated durability test cycle based on in-house PG test surfaces in order to match the real customer usage to the durability target life. This paper summarizes the methodology to develop Durability Validation test cycles for commercial vehicle based on the work carried out on a heavy duty tipper and an intermediate commercial vehicle.

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.

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.

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.

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.

As part of transformation from BS4 to BS6 automobile emission standard in India, engine manufactures are focusing on continuous development of emission control technologies and suitable strategies. Exhaust tail pipe emission and Crankcase emission are added together to meet the regulation acceptable limit. The crankcase emissions contribute substantially to the total Particulate Matter (PM) emitted from an engine. Hence there is a need of design and development of suitable Crankcase ventilation system. This paper presents investigation of high PM contributed from Open Crankcase ventilation (OCV) system in Diesel engine and experiment based solutions.

In an era of global manufacturing and reduced costs, it is imperative that the manufacturing floor is visible to top management in a boardroom to enable them to make key decisions. Manufacturing Execution System (MES) is a method of connecting the shop floor to the top floor covering the complete gamut of activities from production sequence to finished goods. It aims to reduce the delay in transmitting production related data by linking the Production environment, Quality management, IT systems and Delivery. At Ashok Leyland’s Commercial Vehicle manufacturing facility in Ennore, India, an engine and axle components machine shop have been networked and data pertaining to production of Cylinder Block, Cylinder Head, Camshaft, Crankshaft, Axle Arm and Axle Beam components are accessible from anywhere in the company irrespective of location.

In the present scenario, delivering right product at the right time is very crucial in automotive sector. Today, most of the OEMs have started to produce FBS (Fully Build Solution) such as oil tankers, mining tippers and two-wheeler carriers based on the market requirements. During product development phase, all automotive components undergo stringent validation protocol either in on-road or laboratory which consumes most of the product development time. This project is focused on developing validation methodology for two-wheeler carrier structure (deck) of a commercial vehicle. For this, road load data were acquired in the typical routes of customers at different loading conditions. Roads were classified as either good or bad based on the axle acceleration. To shorten the test duration, actual road load data was compressed using strain based damage editing techniques. The spectrum and transmissibility of acceleration signals at the decks were analyzed to select a deck for validation.

The gearbox is a crucial aggregate in a diesel truck. Gearboxes must work efficiently to get the job done properly and lubrication is vital to this efficiency. Lubricating oil is like the circulation system of a gearbox. If the oil levels fall too low, the gearbox will likely fail. Gearbox failure can lead to expensive repairs that could be prevented. Besides added costs due to replacement or repair, costs associated with a loss of production could be significant. These issues are why; it is important to understand the consequences of having low lubricant levels. Similarly, higher oil level creates higher churning losses, heating of the Gear oil and oxidation, reduction in efficiency and increased oil leaks. Understanding the functions of gearbox lubricating oil can help you choose the right quantity of prevent gearbox failures.

In competitive vehicle market, the product must be designed and validated in shorter time span without compromising the quality. The durability of the vehicle is tested either by on road trials undertaken at the actual customer supplication sites for large time period or in the accelerated rough surfaces called “Proving ground” to validate in shorter time span. Accelerated proving ground durability testing plays a vital role in enabling shorter product development cycles by simulating the road load influences alone from the actual field conditions. It is imperative to simulate the test vehicle at proving ground (PG) testing such that it replicates the same damage that occurs in the field due to road loads. PG validation requires a specific durability test sequence for every segment of commercial vehicles due to different customer usage applications and terrain conditions. This diversity in applications and terrains induce structural damage at different range of frequencies.

In the commercial vehicle business, vehicle availability is a pivotal factor for the profitability of the customer. Nonetheless, the intricate nature of the technologies embedded in modern day engines and exhaust after-treatment systems coupled with the variability of the duty cycles of end applications of the vehicles imposes added challenges on the vehicle's sustained performance and reliability. In this context, the ability to predict potential failures through tools like telematics and real-time data analytics presents a significant opportunity for original equipment manufacturers (OEMs) to deliver distinctive value to their customers.