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In high-end commercial vehicles, technologies like Electronic Braking Systems (EBS) help pull away the vehicle from a standstill on steep gradients with no risk of rolling back. Tata Motors has developed an indigenous Anti-Roll Back (ARB) system that effectively minimizes this risk but without the use of EBS/HSA. The ARB delivers identical functionality to the HSA feature in the EBS but autonomously, and by purely electric means. In the proposed system, the electric traction motor develops a high positive torque when the vehicle tries to roll back upon minimal accelerator pedal press. The system is autonomous in the sense that the driver does not need to press any HSA switch on the dashboard and the system works on relatively flatter road also which otherwise is not the case with HSA as it negatively affects the operation on flatter road by locking wheels and vehicle launches with a very high torque when brakes are automatically released by EBS upon threshold torque build-up.

Sound signature design is gaining more importance within global auto manufacturers. ‘Sportiness’ is one of the important point to consider while designing a sound character of a car for passionate drivers and those who love aggressive driving. Nowadays automobile manufacturers are more focused in developing a typical sound signature for their cars as a ‘unique design strategy’ to attract a niche segment of the market and to define their brand image. Exhaust system is one of the major aggregate determining the sound character of ICE vehicles which in turn has the direct influence on the customer perception of the vehicle and the Brand image and also the human comfort both inside and outside the cabin. This research work focuses on novel approaches to identify frequency range and order content by a detailed study of subjective feelings based on psycho-acoustics. Sound samples of various benchmark sporty vehicles have been studied and analyzed based on sound quality parameters.

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.

Road infrastructure in India is being upgraded at a rapid pace. Quality of life of people has also improved significantly in the last decade. Such trends have significantly impacted design of commercial vehicles and vehicular systems in the country. This paper deals with the design and development of a modern futuristic instrument panel for trucks. Methodology to arrive at product features and solutions which retain their novelty and appeal for a longer term has also been illustrated. Regulatory scenario, modularity, HMI, Perceived Quality, Driver Comforts, evolving technologies, trends and materials are some of the considerations which have discussed in detail. International benchmarks and customer requirement have been analyzed for setting Performance targets. A digital approach for evaluating these considerations evolved during the design and development process has been elaborated in detail.

The automotive world is rapidly moving towards achieving shorter lead time using high-end technological solutions by keeping up with day-to-day advancements in virtual testing domain. With increasing fidelity requirements in test cases and shorter project lead time, the virtual testing is an inevitable solution. This paper illustrates method adopted to achieve best approximation to emulate driver behavior with 1-D (one dimensional) simulation based modeling approach. On one hand, the physical testing needs huge data collection of various parameters using sensors mounted on the vehicle. The vehicle running on road provides the real time data to derive durability test specifications. One such example includes developing duty cycle for powertrain durability testing using Road Torque Data Collection (RTDC) technique. This involves intense physical efforts, higher set-up cost, frequent iterations, vulnerability to manual errors and causing longer test lead-time.

Advent of EV powertrain has considerable effect on transmission development activities as competed to regular ICE transmission. Conventional ICE transmission and the transmission for an e-powertrain differ on fundamental level. The conventional transmission has number of gear ratios, shift mechanism which enables the transmission to deliver a smooth power output as per demand from the driver. Whereas the e-powertrain transmission is mostly a single gear ratio transmission (reducer) which primarily depends on speed and torque variation from the motor to cater the driver requirement. Hence, the operating speeds of such e-transmissions can vary from 0 to 20000 rpm in both forward and reverse directions. Such a large speed variation as compared with conventional transmission calls for special attention towards the lubrication of internal components. High speeds and lower oil viscosities tend to disrupt the oil films in between contact surfaces causing metal to metal contact.

The brake systems are given top priority by automotive OEMs in the development of medium and heavy commercial trucks and buses, which can carry increased loads. When trucks and buses are travelling at high speeds or crossing downhill, during braking operations, the friction faces (brake drum and liner) experience a significant rise in temperature due to the conversion of kinetic energy into heat energy within seconds. This lowers the friction coefficient at the interface, resulting in distortions, thermal cracks, hub grease burning, and overheating. Drum brake system designs must be improved and optimized to dissipate more heat from the brake drum assembly and prevent brake failure. Nowadays advance transient numerical simulations assist in the design, development and optimization of the brake system to visualize 3D flow physics and temperature variations throughout the brake duty cycles. In the current study, different Cases of drum brakes to improve cooling efficiency are evaluated.

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.

The basic function of steering system is to control the direction of the vehicle. The driver applies effort on the steering wheel and receives feedback through the steering system as a result of tire to road interaction. This feedback consists of a haptic (force) feedback which is directly felt by the driver and it is termed as steering feel. Precise steering feel gives better driving experience and is decisive factor for customer to buy a vehicle as well as for OEMs in building brand image. Along with steering parameters, suspension and tire parameters also has significant impact on steering feel. In past, modelling of the steering system was done at component level or with simplified vehicle system. Such approaches had not given accurate results of steering feel metric and resulted in incorrect steering design parameter selection. In order to replicate actual vehicle characteristics, complex and detailed modelling of steering, tire and suspension subsystems is necessary.

The goal of reducing fuel consumption and CO2-Emission is leading to turbo-charged combustion engines that deliver high torque at low speeds (down speeding). To meet NVH requirements damper technologies such as DMF (Dual Mass Flywheel) are established, leading to reduced space for the clutch system. Specific measures need to be considered if switching over from SMF (Single Mass Flywheel) to DMF [8]. Doing so has an impact on thermal behavior of the clutch system, for example due to reduced and different distribution of thermal masses and heat transfer to the surroundings. Taking these trends into account, clutch systems within vehicle powertrains are facing challenges to meet requirements e.g. clutch life, cost targets and space limitation. The clutch development process must also ensure delivery of a clutch system that meets requirements taking boundary conditions such as load cycles and driver behavior into account.

The traditional method of collecting the Road Torque Data of a vehicle is by instrumenting and running the vehicle on different road terrains. Every time, physical testing becomes tedious & most challenging task due to unavailability of unit under tests, kind of resource required and so on. However, in view of response to the fast emerging technology & limit less competition, it has become mandatory to develop & launch products in market within no time. In recent times, there is increased demand for physical road torque data measurements for a vehicle program based on its application and different powertrain configurations, which clearly shows that unless we front load the data to design it is practically impossible to meet the deadlines. Each of these measurements cost and consumes valuable resources of the company in collecting and analyzing the data.

Engine Stop/Start System (ESS) promises to reduce greenhouse emissions and improve fuel economy of vehicles. Previous work of the Authors was concentrated on bridging the gap of improvement in fuel economy promised by ESS under standard laboratory conditions and actual driving conditions. Findings from the practical studies lead to a conclusion that ESS is not so popular among the customers, due to the complexities of the system operation and poor integration of the system design with the driver behavior. In addition, due to various functional safety requirements, and traffic conditions, actual benefits of ESS are reduced. A modified control algorithm was proposed and proven for the local driving conditions in India. The ways in which a given driver behaves on the controls of the vehicles like Clutch and Brake Pedals, Gear Shift Lever were not uniform across the demography of study and varied significantly.

Authors were challenged with a task of developing a full vehicle simulation model, with a target to simulate the electrical system performance and perform digital tests like Battery Charge Balance, in addition to the fuel efficiency estimation. A vehicle is a complicated problem or domain to model, due to the complexities of subsystems. Even more difficult task is to have a control algorithm which controls the vehicle model with the required control signals to follow the test specification. Particularly, simulating the control of a vehicle with a manual transmission is complicated due to many associated control signals (Throttle, Brake and Clutch) and interruptions like gear changes. In this paper, the development of a full vehicle model aimed at the assessment of electrical system performance of the vehicle is discussed in brief.

The AMT (Automated Manual Transmission) has attracted increasing interest of automotive researches, because it has some advantages of both MT (Manual Transmission) and AT (Automatic Transmission), such as low cost, high efficiency, easy to use and good comfort. The hill-start assistance is an important feature of AMT. The vehicle will move backward, start with jerk, or cause engine stalling if failed on the slope road. For manual transmission, hill-start depends on the driver's skills to coordinate with the brake, clutch and throttle pedal to achieve a smooth start. However, with the AMT, clutch pedal is removed and therefore, driver can’t perceive the clutch position, making it difficult to hill-start with AMT without hill-start control strategy. This paper discussed about the hill start control strategy and its functioning.

Steering pull during high speed braking of heavy commercial vehicles possesses a potential danger to the occupants. Even with negligible wheel-to-wheel brake torque variation, steering pull during the high speed braking has been observed. If the steering pull (i.e. steering rotation) is forcibly held at zero degree during high speed braking, the phenomena called axle twist, wheel turn and shock absorber deflection arise. In this work the data have been collected on the mentioned measures with an intention to develop a mathematical model which uses real time data, coming from feedback mechanism to predict the values of the measures in coming moments in order to aid steering system to ‘auto-correct’. Driven by the intention, ‘Time Series Analysis’, a well-known statistical methodology, has been explored to see how suitable it is in building the kind of model.

Brake noise is one of the common complaints and an irritant not just for the vehicle occupants but equally for the passers-by. Brake noise is actually vibration that is occurring at a frequency that is audible to the human ear. This occurrence of brake noise like brake squeal (>1 kHz) and groan (<1 kHz) is often very intense and can lead to vehicle complaints. During a brake noise event, vehicle basic structure and suspension system components are excited due to brake system vibration and result in a resonance that is perceived in the form of a noise. Proposed work discusses an experimental study that is carried out on a vehicle for addressing concern regarding disc brake squeal and groan noise. Based on the preliminary inputs, vehicle level study was carried out in order to simulate the problem and objectively capture its severity.

Pneumatic brake system is widely used in heavy truck, medium and heavy buses for its great superiority and braking performance over other brake systems. Pneumatic brake system consists of various valves such as Dual Brake Valve (DBV), Quick release Valve (QRV), Relay Valve (RV), Brake chambers. Dynamics of each valve is playing a crucial role in overall dynamic performance of the braking system. However, it is very difficult to find the contribution of each valve and pipe diameters in overall braking performance. Hence, it is very difficult to arrive a best combination for targeted braking performance as it is not possible to evaluate all combination on the actual vehicle. Hence, it is very important to have a mathematical model to optimize and evaluate the overall braking performance in early design phase. The present study is focusing on the mathematical model of a pneumatic brake circuit.

Brake drum is an important component in automotive, which is a link between axle and wheel. It performance is of utmost importance as it is related to the safety of the car as well to the passengers. Many design parameters are taken into consideration while designing the brake drum. The sensitivity of these parameters is studied for optimum design of brake drum. The critical parameters in terms of reliability, safety & durability could be the cross section, thickness of hub, interference & surface roughness between bearing and hub, wheel loading, heat generation on drum, manufacturing and assembly process. The brake drum design is derived by considering these parameters. Hence the sensitivity of these parameters is studied both virtually & physically, in detail. The optimum value of each parameter could be chosen complying each other's values.

Better ride and comfort, enhanced safety, reliability and durability, lower running cost as well as cost of ownership continue to be challenges for automotive OEMs. Higher fuel efficiency is considered as USP not only for lower running cost but also is hygiene factor from sustainability point of view. This has necessitated the need for Augmenting Light weighting horizon in automotive OEMs. Augmenting this leads to invention of innovative materials and processes for emerging cost competitive market. This paper focuses on technology efforts towards augmenting light weighting Horizon in Automotive. Light weighting concepts being explored by OEMs with the help of automotive component manufacturers from Powertrain - Engines & Transmission, Chassis and Suspension are discussed.

New noise regulations, with reduced noise limits, have been proposed by UN-ECE. A new method which aims at representing urban driving of the vehicles more closely on roads is proposed and is considerably different from the existing one (IS 3028:1998). It is more complex; we also found that some of the low powered vehicles can not be tested as per this method. The paper proposes ways of improvement in the test method. The new noise reduction policy options will have a considerable impact on compliance of many categories of vehicles. Technological challenges, before the manufacturers, to meet all performance needs of the vehicle along with the cost of development will be critical to meet the new noise limits in the proposed time frame.