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Presented byVaibhav AnuseUnder able guidence of Prof. Adlinge P.SHigh tech vehicles

INDEX ABSTRACT INTRODUCTION ELECTRONIC CONTROL MODULE ELECTRONIC INJECTION SYSTEM ELECTRONIC EXHAUST SYSTEM ADVANTAGES AND LIMITATIONS CASE STUDY FUTURE PROJECTIONS CONCLUSION BIBLIOGRAPHY

ABSTRACTTo cope up the burning problem of high priced and vanishing fossil fuels; with research in renewable energies, we should think for utilization of present amount of fuels in most efficient way. This need gives rise to advancement in design, construction and control of automotive engines. This has given rise to new generation of more developed, light, fuel efficient High Tech vehicles. Recent innovations in engine design and control have been adopted very widely and rapidly. The principle of Electronic Fuel Injection System is, the different sensors like TPS, CPS senses the changes in engine assembly and send electric signal to Electronic Control Module (ECM) which continuously calculates how much fuel is to be injected to achieve stoichiometric combustion. In the Ignition System, Knock, Throttle Position Sensors feed corresponding information to computer which decides correct timing of spark.

This system of spark ignition can develop 47,000 V or more and produces longer and correct timed spark which ignites leaner air fuel ratios for better fuel economy and reduces exhaust emission. In Exhaust System, oxidizing and 3-way catalysts reduce harmful combustion products like NOx, CO from exhaust gas and protect environment from these gases by reducing them up to 90% along with reducing exhaust noise by electronic mufflers. Advantages of computer controlled engines are improvement in fuel economy, improved reliability, system failure diagnosis, warning of engine malfunctioning. Most of recent vehicles are now equipped with electronic ignition systems. A few of these include electronic engine control and management to which we are now familiar as VTi, DTSi, DICOR, AMI engines; sequential port injection, multiport fuel injection and throttle body fuel injection. Suitable combinations of advanced control systems and alternate fuels in vehicles will surely solve the most critical problem of fossil fuel up to some extent.

1) INTRODUCTIONAutomobile It can be defined as self propelled vehicle used primarily on public roads but adaptable to other surfaces.First gasoline four stroke engine was developed by Nikoluas August Otto (Germany) in year 1876. Since then, there have been continuous developments in world of automobiles. But along with better mobility and job creation, automobiles have brought noise and air pollution. At present, fossil fuels account for about 77% of the global energy consumption. It is universally known that this pattern of energy consumption is not sustainable. These needs give rise to advancement in design, construction and control of automotive engines. The automobile industries and governments in all over the world are pursuing the research and developments of advanced vehicles and fuel technologies that could minimize present energy consumptions and environmental effects of automobiles.

Need of Electronics in Automobiles: - In early days, all systems in automobiles were controlled mechanically which often are not as accurate as the emission laws require. Inaccurate fuel metering may cause excessive HC, NOx and CO in exhaust gas which is due to improportionate air-fuel mixture. It also consumes more fuel.Thus computer control is introduced in automobiles. It is incharge of monitoring engine emissions and adjusting the engine to keep emissions as low as possible. The computer receives information from different sensors. Using this information, the computer can control devices like the fuel injectors, spark plugs (ignition) and the idle speed to get the best performance possible from the engine while keeping emission low. In this paper, we are concentrating on Fuel Control Systems in automobiles as they have direct contribution in fuel economy and environmental safety. Fuel Injection, Ignition, Exhaust Systems are the main components of control system. All three systems are interrelated with each other and controlled by preplanned computer installed above the glove box within the passenger compartment called as ECM (Electronic Control Module).

2) ELECTRONIC CONTROL MODULE (ECM):- This is unit of automobile computer system which can receive signals, process them, make decisions and send commands that control other devices.

Following sensors monitor the engine, transmission, air-intake, exhaust, vehicle speed, fuel flow, and many other things that affect engine performance. The ECM uses this information to control fuel supply, the timing of fuel injections, and the mix of fuel and air in the engines combustion chambers. Modern ECMs also control the engines ignition system, which ignites fuel in the combustion chambers at precisely timed intervals to operate the engine efficiently. Such systems may be controlled by single engine computer or by separate computers.

BLOCK DIAGRAM OF ELECTRONIC CONTROL SYSTEM.

3) ELECTRONIC FUEL INJECTION SYSTEM:-In trying to keep up with emission laws and fuel efficiency, the fuel system used in modern cars has changed a lot, over the years. The fuel-injection system replaces the carburetor in most new vehicles to provide more efficient fuel delivery system. The components of an electronic fuel-injection system include injectors, a pump that delivers fuel from a storage tank to the injector, a variety of sensors throughout the vehicle and ECM.There are two types of Injection system used in SI engines are 1) Multiport Fuel Injection (MFI): It has fuel injector in each intake port. 2) Throttle Body Fuel Injection (TBI): It has one or two fuel injectors located above the throttle valve.Principle:-Electronic sensors respond to varying engine speeds and driving conditions by changing the ratio of fuel to air. The sensors send a fine mist of fuel from the fuel supply through a fuel-injection nozzle into a combustion chamber, where it is mixed with air. The mixture of fuel and air triggers ignition.

BLOCK DIAGRAM OF ELECTRONIC FUEL INJECTION SYSTEM.

Working: - ECM continuously receives information about engine speed, throttle position, intake air amount, pressure and temperature, amount of oxygen from sensors. ECM checks this data with other data stored in lookup tables in its memory. Then ECM decides when to open the fuel injectors and for how long. The length of pulse opens injection valve for the proper duration of time. In order to provide the correct amount of fuel for every operating condition, the engine control unit (ECU) has to monitor large number of input sensors. Here are some of them:- Mass Airflow Sensor It measures flow rate of air by speed density or air flow metering and provides electrical output to ECM that is proportional to flow rate of air entering the engine. Coolant Temperature Sensor It is a thermistor. It continuously reports ECM about engine coolant temperature. It allows the ECU to determine when the engine has reached its proper operating temperature.

Oxygen sensor It is installed in exhaust manifold and measures amount of oxygen in exhaust gas. It works by comparing the oxygen content of exhaust gas to that of outside air and produces small voltage varying with amount of oxygen and sends to ECM. So the ECM can determine how rich or lean the fuel mixture is and make adjustments accordingly. Throttle Position Sensor It is mounted on throttle body monitors the throttle valve position which determines how much air entering into the engine so the ECU can respond quickly to changes, increasing or decreasing the fuel rate as necessary Manifold Absolute Pressure Sensor It monitors the pressure of the air in the intake manifold. The amount of air being drawn into the engine is a good indication of how much power it is producing and the more air that goes into the engine, lower the manifold pressure, so this reading is used by ECM to gauge how much power is being produced. Engine Speed Sensor It reports about speed of crankshaft. ECM uses this data to control fuel metering, ignition spark advance and the shifting of electronic automatic transmission.

5) EXHAUST SYSTEM To solve burning problem of pollution, the governments have created clean-air laws. To keep up with these laws, automakers have made many refinements to car engines and fuel systems. In order to reduce emissions, modern car engines carefully control the amount of fuel they burn. The main emissions of a car engine are Nitrogen gas (N2), Carbon dioxide (CO2), Water vapor (H2O). These emissions are not that much harmful. But because the combustion process is never perfect; some smaller amounts of more harmful emissions are also produced in car engines which are: Carbon monoxide (CO) Hydrocarbons or Volatile Organic Compounds (HC) Nitrogen oxides (NOx) To reduce the emissions, there is a device called a catalytic converter, which treats the exhaust before it leaves the car and removes a lot of the pollution.

How Catalytic Converters Reduce Pollution?Most modern cars are equipped with three-way catalytic converters. "Three-way" refers to the three regulated emissions it helps to reduce - carbon monoxide, HCs and NOx molecules. There are two main types of structures used in catalytic converters - honeycomb and ceramic beads. Most automobiles today use a honeycomb structure. The converter uses two different stages of catalysts, a reduction catalyst and an oxidation catalyst. Both consist of a ceramic structure coated with a metal catalyst, usually platinum, rhodium and/or palladium. The Reduction Catalyst (first stage)It uses platinum and rhodium to help reduce the NOx emissions. When an NO or NO2 molecule contacts the catalyst, the catalyst separates the nitrogen and the oxygen in the form of N2 and O2. For example: 2NO => N2 + O2 or 2NO2 => N2 + 2O2The Oxidization Catalyst (second stage) Platinum and palladium catalyst oxidizes CO and hydrocarbons with the remaining oxygen in the exhaust gas. For example: 2CO + O2 => 2CO2

The Electronic Control System (Third Stage)It monitors the exhaust stream, and uses this information to control the fuel injection system. This control scheme allows the engine computer to make sure that the engine is running at close to the stoichiometric point, and also to make sure that there is enough oxygen in the exhaust to allow the oxidization catalyst to burn the unburned hydrocarbons and CO. Muffler: - An electronic muffler uses sensors to monitor the sound waves of the exhaust noise. The sound wave data are sent to a computer that controls speakers near the tailpipe. The system generates sound waves 180 degrees out of phase with the engine noise. The sound waves from the electronic muffler collide with the exhaust sound waves and they cancel each other out, leaving only low-level heat to emerge from the tailpipe.

ADVANTAGES OF COMPUTER CONTROLLED ENGINES:-1) Longer spark can ignite leaner air fuel mixture.2) The electronic ignition system is capable of over 500 sparks per seconds and permitting engine speed more than 8000 rpm. 3) The higher voltage (>47,000 V) produces a hotter spark for cleaner burning, longer plug life. 4) Increase in Fuel Economy and Environmental Safety.6) Improve reliability, System failure diagnosis, warning of engine malfunctioning. LIMITATIONS1) These systems are very expensive and delicate.2) These systems are difficult to repair. 3) Still it is difficult to lower amount of CO2 (carbon dioxide) emissions as it is a known greenhouse gas and contributing to global warming.

CASE STUDYNew DTSi engines utilize Dual Spark ignition for faster and better combustion. The DTSi engine on the Bajaj Pulsar comes with Digital CDI for optimum ignition timing and TRICS III ignition control system to further optimize performance.The DTSi (Digital Twin Spark Ignition) technology incorporates twin sparkplugs at either ends of the combustion chamber for faster and better combustion. Single sparkplug meant slower burning of the air-fuel mixture and sub-optimal combustion chamber characteristics. This is the Heart of the New Technology from Bajaj.The digital CDI (Computerized Direct Ignition) in the new Pulsar, which features an advanced eight-bit microprocessor, handles the spark delivery. The programmed chip's memory contains the optimum ignition timing for any given engine rpm. Working together with the (TRICS III) it delivers the optimum ignition timing for varying load conditions.

FUTURE PROJECTIONSThe computer control will change the field of automobile dramatically over next few years. Fuel cells, computerized spark-ignition and direct-injection engines for conventional and hybrid electric vehicles (HEVs) are promising options in coming years. DICOR, VTi engines, turbochargers are related advancements in this field. Upcoming BMW's Double-VANOS and Valvectronic technologies will allow the engine to adjust the burning hydrogen/air or gasoline/air fuel mixtures and also help prevent nitrogen oxide (NOx) emissions. The automobiles, which will come out in coming years, will be the gleaming, high-tech fruit of over 25 years of experimentation and innovation.

CONCLUSIONIn this paper, we have seen main three systems of an automobile engine which are controlled electronically. Fuel injection system controlled by ECM can supply appropriate amount of fuel each time according to the varying engine speed and conditions. Electronic Ignition system can produce longer and high voltage spark for complete combustion of fuel. Modern exhaust systems can sufficiently reduce harmful pollutants and noise by incorporating the catalytic converters and mufflers. By comparing these systems with conventional systems it is clear that electronic control systems are going to lead the automobile industry to the new generation of Fuel Efficient and High-Tech vehicles.

REFERENCES1) AUTOMOTIVE ENGINES: CROUSE & ANGLIN 2) PRINCIPLES OF ELECTRICITY & ELECTRONICS for AUTOMOBILES: NORM CHAPMAN. 3) AUTOMOTIVE MECHANICS: CROUSE & ANGLIN 4) AUTOMOTIVE DIGNOSIS & TUNE-UPS: JAMES A. JOHNSON6) http//www.sensorsweb.com7) http//www.howstuffworks.com

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