Electronic Control Unit And Engine Management System Engineering Essay

Electronic agree Unit And Engine forethought System plan EssayEver since we have established RHR Engineering workshop, we have carried out several ECU (Electronic Control Unit) mapping. Keeping this in mind, I have decided to make a report on ECU, and its consummation for our technicians. This report will instruct our technicians on ECU operation, function, features, and its principles.P1The ECU (Electronic Control Unit) or otherwise known as Engine Management System is a estimator which nurses every action and reaction of the Engine. The ECU consists of an 8-32bit microprocessor, ergodic Access Memory (RAM), enunciate Only Memory (ROM), and an Input/Output interface, Analogue Digital convertors and in some cases Electronic Erasable Programmable Read Only Memory (EEPROM). Random Access Memory (RAM) is a flash memory, which is erased once the car is switched off. It provides the ECU with the information which is needed at the moment of operation. Whereas, Read Only Memory (ROM) is durable memory, thence it is non-erasable. It stores all the functions, and mental faculty of the operate carcasss e.g. Ignition Timing, Injection Timing. EEPROM is a sophisticated type of memory, which could be found in Aftermarket, and High cherished vehicles. The Function remains the same as ROM, but the function module could be edited or erased by the driver according to his/her desire, via send commands done on dash buttons or by connecting a ready reckoner to the ECU (only in case of Aftermarket ECU). EEPROM provides the driver with choice of driving style, performance payoff, and discourse characteristics. Analogue digital converters atomic number 18 apply to converts digital signboards into analogue signalings and guilt versa. For example, promote demodulators convert digital signal into analogue signal i.e. induce gauge.gsensorinstallThe ECU stamp downs almost all the cut gear of the vehicle. The main operating clay, which ECU has to train in order to run the engine, is the Fuel Injection System, Ignition Timing, and the unwarrantable Speed Control transcription. Based on information from the input sensors (engine coolant temperature sensor, mixed Absolute Pressure sensor, ambience Flow sensor etc.), the ECU determines optimum settings for the fruit actuators (Injectors, Idle Speed Control Valve etc.).Modern sidereal day eon Vehicles are supply with sophisticated ECUs. They have several other features such as, Traction Control, journey Control, Active Suspension, Electronic Ignition System, Variable Valve Timing activator, and ABS (Anti-Lock Brake System). They also work as diagnostic software, as it houses several detectors and Actuators just about the vehicle.The ECU operates on information sent by the sensors. If any correction is to be made, or if any function needs to be carried out, it does it utilise actuators. Input signal are received by the sensors and output signals are given to the actuators. distributively(prenominal) the information is processed in digital format.Motronic_englishThe main function of the ECU is to reach out out checks to ensure correct running of the engine. The most common checks are as followsFuel snapIgnition timingIdle sack authorityThese checks are necessary so that the vehicle will come to the electric arc standards, maintain provide economy, and be reliable.P2The input signals received by the ECU are sent by the sensors. The sensors act as a remark of the ECU. The 3 most commonly found Sensors are described as follows1) ambiance muss chiliadThere are 2 types of conduct mass time, hot wire type, and vane type. They both serve the same function, although the material used is different. An tenor mass meter is hardened after the argumentation filter and before the intake plenum. The air mass meter provides the ECU with an analogue signal that indicates the list of air being drawn into the engine. The ECU and so takes this order to add the correct amount of evoke to maintain the 14.71, air furnish ratio.ford_probe_air_mass_meterThe most common type of air mass meter is the HOT Wire type air mass meter. It is mainly used in multi-point injector system. It uses an electrified wire, which acts as a resistor. During operation the wire is heated, but when the air passes over the heated wire, it cools, thus changing the resistance. The ECU monitors the resistance value and domiciliate work out how much air is entering the engine.AirMassMeterWire2) Oxygen/ Lambda SensorThe main function of the atomic number 8 sensor is to measure the amount of type O content exiting the assoil. It also serves the purpose to ensure that the air/ enkindle form is chemically correct. An type O sensor is fitted between the exhaust mixed and the accelerator converter.oxygen_sensor_1 sensor4Oxygen sensor has to heat up to approx 350 degrees Celsius to work properly. They send a signal to the ECU via electromotive force to enable the ECU to maintain, or to correct the air/ fuel ratio. The ceramic tip on the end of the oxygen sensor that protrudes into the exhaust manifold becomes porous and allows the oxygen ions to flow through the tip. This creates the signal voltage, which transports with change in oxygen level inside the exhaust. This signal is thus convey to the fuel injection or to the ECU, which alters the fuel quantity as necessary, until the oxygen content of the exhaust gas is correct for efficient catalytic converter operation, and to maintain fuel economy.3) Throttle daub sensorIt detects the lay out of the cut back plate. The ECU maintains the engine liberal speed at a given value e.g. 800 revs per minute. The ECU identifies when the engine is at idle from the information supplied by the throttle position sensor.T-BodySmThe throttle position sensor incorporates a potentiometer. The wiper of the potentiometer is affiliated to the throttle plate, so that as the throttle is moved from the c losed, to wide-open, the voltage signal from the sensor changes. The voltage signal is passed to the ECU, and used to determine the exact position of the throttle, and the rate at which the throttle is being opened and closed. It helps the ECU to access drivers intensions, such as the intention to rapidly accelerate, by notice the speed or the rate at which the throttle is being opened.P3The output signal from the ECU is received by the Actuators. An actuator is a mechanistic device which transforms galvanical signal into kinetic / mechanical vim. E.g. Injectors, Fuel Pump, idle speed control valve.There are 3 types of actuators, Solenoid type e.g. Injector, EGR (Exhaust Gas Recirculation Valve) Valve, Stepper force back type e.g. Idle Speed Control Valve, and a DC (Direct Current) take type e.g. Fuel Pump.solenoidThe Solenoid type actuator uses a spin around of wire around a soft metal, through which when the flow rate passes it produces a magnetized field. This charismati c field is used to convert galvanising vital force into mechanical energy (linear motion) e.g. InjectorInjectorfuelinjectorThe function of the injector is to deliver a finely atomized spray of fuel to the time out manifold or the cylinder head. It is located on the inlet manifold after the throttle body.injector solenoid offThe injector solenoid is connected directly to the battery via a relay the earth perimeter for the injector is connected to the ECU. When the ECU drops the earth circuit the injector circuit is completed. Once the injector circuit is completed, the current is passed to the solenoid (electromagnetic Coil) this in turn produces magnetic energy, and attracts the speculator (needle valve), thus opening the diffuser nozzle, and delivering fuel to the inlet manifold or the combustion chamber.injector solenoid onA DC (Direct Current) force back coverts electrical energy into mechanical energy (rotary motion). The most common example of DC ride type actuator is F uel Pump. laborThe DC tug works by electromagnetism. The magnetic force acts perpendicular to both wire and magnetic field. When electric current passes through a turn in a magnetic field, the magnetic force produces torque which turns the DC motor.Fuel PumpThe fuel sum supplies the injector with adequate fuel at a sufficient wardrobe to allow the injectors to give good atomization. In redbrick day vehicles it is located inside the fuel tank, in order to keep the pump cool, and undertake the noise of operation.Electric_Fuel_PumpUnlike the Stepper Motor, the fuel pump runs on a DC (Direct Current) Motor, therefore it has a continuous operation, and earth connection. Modern day vehicle are fitted with High Pressure Roller- Cell type fuel pumps. The Roller cell Pump is an example of DC motor, as it converts electrical energy into mechanical energy (rotary motion). When the fuel enters the pump it is compressed by rotating cells which force it through the pump at a high pressure sensation.efi_1-0The pump can produce a pressure of 8 bar (120 psi. indoors the pump is a pressure limiting valve, which maintain the pressure through the fuel pump. The other end of the pump (output) is home to a non-return valve which, when the voltage to the pump is removed, it closes the return to the tank, and maintains pressure within the system. The normal operating pressure within this system is approximately 2 bar (30 psi), at which the current draw on the pump is 3 to 5 amps.Stepper Motor is an analogue actuator. They are used to convert electrical energy into mechanical energy (rotational movement). Unlike a conventional motor, a stepping motor motor will rotate but in stages and not full rotations, therefore it can open and close airways partially.step-rotThe most common type of stepper motor actuator is an Idle Speed Control Valve.Idle Speed Control Valve (ISCV)The Idle Speed Control Valve is used to either regulate the ring road of air around the throttle butterfly or as a throttle motor controlling the position of the throttle butterfly. The ECU constantly alters the control signal to the motor or valve to maintain a constant idle speed.T-BodySmIn an idle speed control valve, a stepper motor is built into the ISCV where it rotates a valve shaft either in or out. This in turn increases or decreases the clearance between the valve and the valve seat, therefore regulating the amount of air allowed to pass through thus controlling the idle. The idle increases when the Air Condition is switched on, this is because of the load on engine received by Air Condition.M2Performance of the sensors depends on their location. A hot wire air mass meter will not perform well if it was placed to a higher place the exhaust manifold, as it will heat the wire, and give false edition of air drawn in. This error will return in false air/fuel mixture, high engine temperature, and producing far more emissions.An oxygen sensor will perform best at approximately 35 0C. the operating temperature of the sensor is affected by the location in the exhaust in addition close to the exhaust manifold can lead to overheating, this will prove in burning the heating element or the filaments inside thus emitting harmful gases (CO, HC) in the atmosphere, too far from the exhaust manifold and the sensor may not reach its correct operating temperature, this will result in emitting harmful gases (CO, HC) in the atmosphere.gsensorboardThe location of the ECU also matters. Keeping the ECU in the engine bay can overheat the processor inside the ECU causation delays in input and output signals. The best location for the ECU is under the passenger compartment, this will keep the temperature low, and it is beneficial for the micro processor to perform its parturiency well.M1Earlier example of ECU were not as sophisticated as modern ECU. Older ECUs were used on Single foreland Injector system. They were simpler than the modern day ECU, as it used someer compon ents, and had less function to carry out.10Single Point injection ECU had to only carry out fuel injection it still used the conventional ignition system, and had very few sensors, and actuators. Against the modern day ECU it has few advantages and disadvantages.AdvantagesDisadvantagesFewer components therefore cutting saluteLess control over the engineLess components to go equipment casualtyManual diagnosticFuel is well atomizedInappropriate fuel dispersionHaving less components means it had less control over correct running of the engine, and meeting the emission standards. This major disadvantage lead to the development of a much sophisticated ECU which could be found in modern day vehicle e.g. Multi-Point Injection System.multipointMulti-Point injection system houses more sensors and actuators than the Single Point injection system. The components used in addition to Single Point injection are mentioned below.Climate controlCruise ControlTraction controlPre and Post Lambda se nsor.Variable Valve Timing actuator.Knock SensorOil SensorHall Effect SensorOne major addition to the undivided operation of the multi-point injection system is the ignition system. Multi Point injection system uses individual coil per each cylinder, whereas Single Point injection system uses the conventional ignition system. The basic principle of operation for each coil remains the same as the conventional.By having single coil per cylinder, the time available to build up coil energy is greater than having a single coil providing spark to all cylinders. For example on an ogdoad cylinder engine with eight individual ignition coils, each coil will have 8 x longer time to complete one whole ignition cycle compared to the conventional engine using single coil for all cylinders. The available dwell time is therefore also up to eight times longer. And there will no wasted spark. Therefore, the car will need no tuning for speed advance, or load advance, and spark will me more efficient .Multi-Point injection system has more components, therefore having more control over the engine, and meeting the emission standard. It helps the engine to run more cleaner, and perform better, with respect to any bear conditions. It also improves the fuel economy, as distribution of fuel is appropriate to each cylinder.