DESIGNANDCONSTRUCTIONOFELECTRONICENGINECONTROL UNIT(GASOLINE)

ABSTRACT This project presents the Design and Construction of an Electronic Engine Control Unit (ECU) specifically for gasoline internal combustion engines. As automotive technology advances, traditional mechanical controls for air-fuel mixtures and ignition timing have been replaced by electronic solutions to solve functional limitations and reduce engine failures. The primary goal of this device is to function as the engine's "brain" by generating sparks at the appropriate time, metering fuel accurately, and estimating the amount of air entering the engine while monitoring engine speed. To achieve this, the system utilizes a high-performance ATMEGA 2560 microcontroller based on the Speeduino open-source platform. The ECU interfaces with a comprehensive array of sensors, including Manifold Absolute Pressure (MAP) for air flow, Intake Air Temperature (IAT), Coolant Temperature, Crankshaft, Camshaft (TDC), and Oxygen (O_2) sensors. These inputs allow the processor to interpret real-time data and adjust actuators such as the Ignition Coil and Injector Nozzles to maintain optimal performance. The system utilizes the Speed Density algorithm, grounded in the Ideal Gas Law (n = PV / RT), to determine the precise quantity of fuel required for combustion. Furthermore, the unit features a USB port for interfacing with computers to facilitate real-time tuning, monitoring, and software updates. Comprehensive testing conducted on a Honda D15 engine platform demonstrated that the ECU effectively manages engine operations, ensuring efficient performance, reduced fuel consumption, and compliance with modern emission standards.