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The ever-tightening regulation norms across the world emphasize the magnitude of the air pollution problem. The decision to leapfrog from BS4 to BS6 – with further reduction in emission limits -showed India’s commitment to clean up its atmosphere. The overall cycle emissions were reduced significantly to meet BS6 targets [1]. However, the introduction of RDE norms in BS6.2 [1] demanded further reduction in emissions under real time operating conditions – start-stop, hard acceleration, idling, cold start – which was possible only through strategies that demanded a cost effective yet robust solutions. The first few seconds of the engine operation after start contribute significantly to the cycle gaseous emissions. This is because the thermal inertia of the catalytic converter restricts the rate at which temperature of the catalyst increases and achieves the desired “light-off” temperature.

Adaption of EV powertrains in existing vehicle architecture has created many unique challenges in meeting performance, reliability, safety, ease of manufacturing & serviceability at optimum cost. Mounting of large size battery packs in existing vehicle architecture is one of them. Specific energy & the energy density of Lithium ion batteries are very lower compared to Diesel & Petrol, which requires high volume & weight for equivalent energy storage. For movement of many passengers and to ensure sufficient range EV buses typically needs large amount of energy and for storage of same bigger size battery packs are required. These large size batteries directly affect vehicle architecture, seating layout, ease of assembly & serviceability. Moreover the heavy mass of batteries directly influences vehicle dynamics & performance characteristics such as vehicle handling, roll & NVH. The most important consideration in design of EV vehicles in general and buses in specific is safety.

Fuel cell electric vehicles generally have two power sources – the fuel cell power system and a high voltage battery pack - to power the vehicle operations. The fuel cell power system is the main source of power for the vehicle and its operations are supported by the battery pack. The battery pack helps to tackle the dynamic power demands from the vehicle such as during acceleration, to which the response of the fuel cell might be slower. The battery is also used to recover the energy from regeneration during braking and can also be used to extend the range of the vehicle in case the storage tanks runs out of hydrogen. In order to maximize the fuel efficiency of the fuel cell power system it is critical that these two power sources are used in conjunction with each other in an optimal manner.

Fuel cell electric vehicles (FCEVs) and battery electric vehicles are being touted worldwide by the automotive industry and policy makers as the answer to decarbonizing the transportation sector. FCEVs are especially suited for commercial vehicle applications as they offer very short re-fueling times that is comparable to conventional internal combustion engine vehicles. While this is entirely possible there are host of challenges that include safety, that need to be addressed to make short refilling times possible for commercial vehicles where the hydrogen storage requirement is higher (25 kg or more). This is due to the rise in temperature of the hydrogen in the cylinder due to compression and the negative Joule-Thompson coefficient. The SAE J2601 standard limits the safe temperature limit of hydrogen gas in the cylinder to 85 °C during filling.

This paper addresses challenges in current Fuel Cell Stack Buses and presents a novel Fuel Cell Electric Vehicle Bus (FCEV-Bus) powertrain that combines fuel cells, ultra-capacitors, and batteries to enhance performance and reliability. Existing Fuel Cell Stack Buses struggle with responsiveness, power fluctuations, and cost-efficiency. The FCEV-Bus powertrain uses a Fuel Cell stack as the primary power source, ultra-capacitors for quick power response, and batteries for addressing power variations. Batteries also save costs in certain cases. This combination optimizes power management, improves system efficiency, and extends the FCEV-Bus's operational life. In conclusion, this paper offers an innovative solution to overcome traditional fuel cell system limitations, making FCEV-Buses more efficient and reliable for potential wider adoption.

Worldwide automotive sector regulatory norms have changed and become more stringent and complex to control environmental noise and air pollution. To continue this trend, the Indian Ministry of Road Transport is going to impose new vehicle exterior pass-by noise regulatory norms IS 3028:2023 (Part2) to control urban area noise pollution. This paper studies the synthesis of M1 category vehicle driving acceleration, dominant noise source, and frequency contribution in exterior PBN level. A vehicle acceleration analysis study was carried out to achieve an optimized pass by noise (PBN) level based on the vehicle’s PMR ratio, reference, and measured test acceleration data. Based on the analysis, test gear strategy was decided to achieve a lower PBN level. This strategy involved increasing the effective final drive ratio and optimizing engine calibration, resulting in improvement with acceleration in the ith gear.

NVH is of prime importance in buses as passengers prefer comfort. Traditionally vehicle NVH is analysed post completion of proto built however this leads to modifications, increases cost & development time. In modern approach physical validation is replaced by CAE. There are many sources of NVH in vehicle however this article is focused about the methodology to improve NVH performance of bus by analysing and improving the stiffness and mobility of various chassis frame attachment points on which source of vibrations are mounted or attached. In this study chassis frame attachment stiffness of Engine mounts and propeller shafts is focused.

Computed Tomography (CT) has become a potent instrument for non-invasive assessment of battery cell integrity, providing detailed insights into their internal structure. The present study explores the capabilities and advantages of employing CT for cell characterization through a systematic evaluation from various parameters. The evaluation results will be based on real-world experiments conducted on a standard battery cell, assessing the CT system’s ability to provide precise internal measurements, detect defects, and ensure the overall integrity of the cell. We outline a comprehensive framework that includes criteria such as system specifications, image quality, software capabilities, maintenance, service, and cost-effectiveness.

A bus is integral part of public transportation in both rural and urban areas. It is also used for scheduled transport, tourism, and school transport. Buses are the common mode of transport all over the world. The growth in economy, the electrification of public transport, demand in shared transport, etc., is leading to a surge in the demand for buses and accelerating the overall growth of the bus industry. With the increased number of buses, the issue of safety of passengers and the crew assumes special importance. The comfort of driver and passenger in the vehicle involves the vibration performance and therefore, the structural integrity of buses is critically important. Bus safety act depicts the safety and comfort of bus operations, management of safety risks, continuous improvement in bus safety management, public confidence in the safety of bus transport, appropriate stakeholder involvement and the existence of a safety culture among bus service providers.

This paper aims at analysing the effect of regeneration braking on the amount of energy harnessed during vehicle braking, coasting and its effect on the drive train components like gear, crown wheel pinion, spider gear & bearing etc. Regenerative braking systems (RBS) is an effective method of recovering the kinetic energy of the vehicle during braking condition and using this to recharge the batteries. In Battery Electric Vehicles (BEV), this harnessed energy is used for controlled charging of the high voltage batteries which will help in increasing the vehicle range eventually. Depending on the type of the powertrain architecture, components between motor output to the wheels will vary, i.e., in an e-axle, motor is coupled with a gear box which will be connected with differential and the wheels. Whereas in case of a central drive architecture, motor is coupled with gearbox which is connected with a propeller shaft and then the differential and to the wheels.

Since last decade automotive Industry is witnessing transition from ICE to EV due to stringent environmental laws by government bodies and technological breakthrough. EV technology is emerging day by day. Biggest challenge in front of OEM is the phase shift from ICE to EV. OEM need to decide on glide path for test rig development for this change to support ICE & EV powertrain validation to deliver reliable product to their customers. In EV development, major focus is on investment for battery development. Hence, for the Motor and Gearbox validation balanced approach is to upgrade existing ICE test bench for the EV with minimum effort and cost. This paper provides details on need and approach required to make the ICE test bench capable for EV powertrain validation. Proposed methodology helps to support both type of powertrain and have maximum utilization of the test bench.

This paper introduces a novel approach to automate PID calibration for closed-loop control systems and the creep control function in an electric vehicle. Through a comprehensive literature survey, it is found that this method is the first of its kind to be applied in the field of automated electric vehicle calibration for Creep function. The proposed approach utilizes a systematic methodology that automatically tunes the PID parameters based on predefined performance criteria, including energy consumption and jerk. To implement this methodology, the ETAS INCA FLOW software, which provides guided calibration methods for in-vehicle testing & calibration, is employed. The calibration process is performed on a real-time electric vehicle platform to validate the effectiveness of the proposed approach. The results of this study showcases the advantages of automated PID calibration for closed-loop control systems and creep control function in small commercial electric vehicle.

Global concerns over availability and environmental impact of conventional fuels in recent years have resulted in evolution of Electric Vehicles. Research and development focus has shifted towards one of its main components, Lithium-ion battery. Development of high performing, long lasting batteries within challenging timelines is the need of the industry. Lithium-ion batteries undergo “battery ageing”, limiting its energy storage and power output, affecting the EV performance, cost & life span. It is critical to be able to predict the rate of battery ageing & the impact of different environmental conditions on battery lifetime/capacity. Conventionally, extensive physical vehicle level testing is carried out on batteries to map the battery capacity in various conditions. This is a lengthy & expensive process affecting the product development cycle, paving the way for an alternative process.

Groan is a low frequency noise generated when moderate brake pressure is applied between the surfaces of the brake disc and the brake pad at a low-speed condition. Brake groan is often very intense and can cause large numbers of customer complaints. During a groan noise event, vehicle structure and suspension components are excited by the brake system and result in a violent event that can be heard and felt during brake application. The cause of noise is friction variation of stick-slip phenomenon between friction material and disc. Creep groan is the structure-borne noise that is related to dynamic characteristic of the vehicle. However, it has been mainly improved through friction material modifications in the past. In this paper, transfer path of creep groan noise was analyzed by means TPA and structural countermeasure to creep groan noise was suggested. This paper discusses the approach for prediction and mitigation of brake groan noise for passenger vehicles having disc brakes.

This paper highlights the transition of multi-axis suspension test rig from fixed reacted type to semi-inertial type and the benefits derived thereof in simulation accuracies. The critical influence of ‘Mx’ and ‘Mz’ controls on simulation accuracies has been highlighted. The vital role of ‘Mz’ control in the resonance of wheel pan along ‘Z’ axis and thereof arresting unwanted failures modes in spindle has been duly emphasized. Finally, the role of constraints and boundary conditions on simulation accuracies has been demonstrated by replacing the reaction frame with vehicle body.

Tire inflation pressure has a significant impact over vehicle driving dynamics, fuel consumption as well as tire life. Therefore, continuous monitoring of tire pressure becomes imperative for ride comfort, safety and optimum vehicle handling performance. Two types of tire pressure monitoring systems (TPMS) used by vehicles are - direct and indirect TPMS. Direct systems deploy pressure sensors at each wheel and directly send pressure value to the vehicle Controller Area Network (CAN). Indirect sensors on the other hand use the information from already existing sensors and some physics-based equations to predict the value of tire pressure. Direct TPMS tend to be more accurate but have higher cost of installation while indirect TPMS comes with a minimum cost but compromised accuracy. A digital proof-of-concept study for indirect TPMS development of a non-ESP vehicle based on machine learning (ML) technique is elaborated in this paper.

The vehicle Heating, Ventilation and Air conditioning (HVAC) system is designed to meet both the safety and thermal comfort requirements of the passengers inside the cabin. The thermal comfort requirement, however, is highly subjective and is usually met objectively by carrying out time dependent mapping of parameters like the velocity and temperature at various in-cabin locations. These target parameters are simulated for the vehicle interior for a case of hot soaking and its subsequent cool-down to test the efficacy of the AC system. Typically, AC performance is judged by air temperature at passenger locations, thermal comfort estimation along with time to reach comfortable condition for human. Simulating long transient vehicle cabin for thermal comfort evaluation is computationally expensive and involves complex cabin material modelling.

Polymer Electrolyte Membrane Fuel Cell (PEMFC) technology is considered for automotive applications due to rapid start up, energy efficiency, high power density and less maintenance. In line with National Hydrogen Energy Roadmap of Govt. of India that aims to develop and demonstrate hydrogen powered IC engine and fuel cell based vehicle. TATA Motors Ltd. has designed, developed and successfully demonstrated “Low Floor Hydrogen Fuel Cell Bus” which comprises of integrated fuel cell power system, hydrogen storage and dispensing system. The fuel cell power system, converts the stored chemical energy in the hydrogen to DC electrical energy. The power generated is regulated and used for powering the traction motor. The development of fuel cell bus consists of five stages: Powertrain sizing as per vehicle performance targets, fuel cell stack selection and balance of plant design and development, bus integration, hydrogen refueling infrastructure creation and testing of fuel cell bus.

Drive components of live axle undergoes different loading conditions during field usage depending upon terrain conditions, vehicle loading and traffic conditions etc. During vehicle running, drive components of axle experiences variable torque levels, which results in the fatigue damage of the components. Testing of these drive components of axle on test rig for endurance life is an imperative part of axle development, owing to limitations of vehicle testing because of time and cost involved. Similarly, correlating field failures with rig testing is equally critical. In such situation, if a test cycle is derived correlating the field usage, rig testing can be effectively used for accelerated life testing and reliability prediction of these components. An approach is presented in the paper wherein test cycle is derived based on the data collected on vehicle in the field under service road and loading conditions.

Gasoline engines with Multi point fuel injection (MPFI) technology are being developed with naturally aspirated and/or turbocharged engines. Wherein a MPFI and turbo charged combination engines have certain challenges during development stages. One of the important challenge is design of air intake and exhaust system. With MPFI turbocharged engine combination, the under bonnet heat management is crucial task for drivability. The heat management of air intake plays a vital role in drivability part therefore a design layout of air intake path is an important aspect. Drivability can be categorized as low end, mid-range and top end drivability. Turbocharged MPFI engines have a typical phenomenon of ‘Lag in response’ in the low-end region. This ‘Lag in response’ phenomenon at low-end drivability region can be overcome through optimization of air intake system and optimization of exhaust back pressure.