Driven by stringent requirements, the auto industry as a whole is bent upon revolutionising the Powertrain to deliver emission compliance with economy.
Automotive Powertrain can be defined as the value chain from the output power of the prime mover (internal combustion engine or electric motor) to the driving wheels of an automobile. Energy efficiency, emission compliance, safety, reliability and cost efficiency are the main drivers governing the revolutionary developments in the new-generation power trains.
In response to engine and transmission actuation and new technologies to reduce energy losses and recover waste energy, the complexity of Powertrain control systems has increased rapidly.
OEMs in India have started focusing on alternative fuel/Powertrain combinations to gain strategic advantage with stricter emission norms coming into place. There is a need for close partnership with component suppliers, right from the product design and development stage to bring in the requisite innovation.
Engine: Engines with port-fuel injection still feature in more than every second petrol -powered vehicle. Downsizing is becoming ever more popular, and with it the efficient and economical Bosch gasoline direct injection systems. Combining gasoline direct injection with downsizing can reduce fuel consumption by up to 15 per cent. At the same time, turbo charging helps the engine deliver more torque, especially at low engine speeds. This improves acceleration and adds to driving enjoyment.
Bosch offers a complete system that allows vehicles to run on this inexpensive fuel at all times. This is a significant advantage for drivers, since CNG is up to 50 per cent cheaper than petrol, and can reduce CO2 emissions by up to 25 per cent.
Electronically controlled load sensing, fuel injection for both gasoline and diesel fuel with electronic governing and auto mode sensing are the latest inclusion to light weighting in various components like engine block, cylinder heads, crankshaft and cam shafts.
The base engine power is augmented by using regenerative modules by addition of Motor Generation Unit (MGU) which transfers energy from brakes and hydraulics to specially developed batteries capable of quick charging and discharging capability. During deceleration, the energy is transferred to the battery while during acceleration the battery augments the engine output power. These systems are more commonly termed as hybrids.
A lot of heat energy was being wasted in the exhaust of an engine. Exhaust driven turbo charging is deployed to increase the density of intake air to an engine by routing the compressed air through an after cooler, to ensure highly improved fuel burning characteristics. Secondly, all the pollutants are also being discharged through the exhaust system. In order to control the emissions, modern automobiles are equipped with an exhaust gas heated catalytic converter which prevents discharge of harmful gases followed by a module of SCR, a means of converting nitrogen oxides, also referred to as NOx, with the aid of a catalyst into diatomic nitrogen (N2) and water (H2O), and Diesel Particulate Filters (DPFs) to prevent particulates in the exhaust of the vehicle.
Going further, intensive research is in progress for use of alternative fuels like biomass, ethanol and others along with more methods to increase thermal energy efficiency in various parts of the world.
Some other futuristic ideas under research are six-stroke cycle engine and opposed piston engines which may deliver better overall engine performance.
Power transmission: The first step in power transmission is the clutch mechanism, to engage and disengage the power unit from the rest of the vehicle during speed change or reversing. In this area, dual clutch, automatic clutch through torque convertor, auto manual and e-clutch systems are finding their way into the vehicles being manufactured in India.
The second step is forward to reverse and speed upshift and downshift operations done through a gearbox or transmission system. For ease of operation, the first to be introduced was hydraulic and electronic assisted power shift. The new upcoming systems are graduating into Continuous Variable Transmission (CVT), Auto Manual Transmission (AMT) and of course the fully automatic transmission. Each has its own advantages and disadvantages.
However, in light of the prevalent driving conditions, in most urban areas of the country requires frequent start and stop driving mode. In order to achieve better fuel economy and power on demand requirements AMT or Electronic Gear Shift (EGS) have become very popular as affordable driving comfort solutions. Led by Maruti for ALTO and later extended to other models from its stable, this method is gaining momentum with other automakers. In fact TVS in collaboration with Magneti Marelli and Bosch as standalone supplier have become the leaders in this aspect and others are following suit.
It is important to understand that clutch less transmission is almost the same as the manual transmission, but in this case, the clutch operation is automated. Like the manual transmission system, gear has to be selected by the driver only, depending on his/her selection, he/she has to change the gears, but without operating the clutch lever. In this case, an electronically controlled (microprocessor-based) system is used to identify when the driver changes the gear, an electrically operated (power operated) system depresses the clutch automatically when the gear is changed. The components of the system are almost the same as manual transmission, just than an automated clutch mechanism is added to it for the comfort of the driver. The most tiring part of a manual transmission is to operate the clutch lever; once that it eliminated, the effort is reduced to just selecting and changing gears. In a nutshell, it takes out the tiring part of the driving from the manual transmission and still leaves the choice of changing gears with the driver.
A motor vehicle’s driveline or drivetrain consists of the parts of the powertrain excluding the engine and transmission. In a wider sense, the powertrain includes all of its components used to transform stored (chemical, solar, nuclear, kinetic, potential, etc) energy into kinetic energy for propulsion purposes. This includes the utilisation of multiple power sources.
Drivelines are the connect between the transmission to the driving wheels through a differential mechanism. It is the portion of a vehicle, after the transmission that changes depending on whether a vehicle is front-wheel, rear-wheel and four-wheel drive configuration.
There are many interesting developments in this critical auto component in terms use of alternate materials like carbon fibre with high torque transmission capability and damping mechanisms ensure minimum energy loss due to vibrations.
Disc brakes and high performance carbon fibre materials for providing friction required during braking or deceleration are today a global standard for all high performance vehicles. They are now finding applications in all small segment vehicles and also two-wheelers. In fact, to comply with the regulation of ABS, this is a must.
Interestingly, the heat energy released during the braking process is being recycled to generate additional power through an MGU.
Wheels and tyres
Lightweight but very sturdy aluminum and magnesium alloy wheels have replaced the traditional steel rims. The new generation alloy wheels are fitted with numerous tyre options commensurate with driving requirements. The tyres made of innovative rubber materials and tread designs are being brought forth by all tyre majors to beat the dichotomy of tyre grip for traction being directly proportional to resistance to driving causing drag on the vehicles coupled with variable load patterns emerging out their driving requirement in terms of steering or driving or driven wheels and various climatic and underfoot conditions.
Electric vehicles an option
Electric vehicles (EVs) globally haven’t yet made commercial profits but combined with governmental incentives in polluted cities, they make for a socially beneficial proposition. Under the Faster Adoption and Manufacturing of hybrid and Electric vehicles (FAME) scheme, which is based on the National Electric Mobility Mission Plan (NEMMP) 2020, the EV industry in India is on a firmer ground than before. The 25 per cent growth in overall EV sales during the April-June 2015 quarter over the previous quarter could be seen as an indication that the industry is finally seeing some traction. -
The rising popularity of AMT is not just limited to the passenger vehicle industry and commercial vehicle manufacturers are also betting big on the technology for their products.
India’s commercial vehicle industry is witnessing a changing regulatory landscape and with emphasis on cutting fuel emissions and saving costs, manufacturers are turning towards hybrid and electric technologies to keep up.
The FAME initiative announced by the government in April this year is now showing some results as more and more manufacturers are ready with their EV portfolio to take advantage from the subsidies on offer.
Success of product development is closely linked to efficacy of local sourcing of components. As players increasingly focus on being cost competitive with better after sales service, localisation as an imperative is gaining more significance than ever. Companies need to develop a robust supplier base and collaborate closely for product design.
Product development as a capability can be a key differentiator as companies look at rolling out new models customised for India. New product development is a key driver of market and financial performance. As such, it is time Auto India Inc to bring in the required revolution to meet the challenges.