Comparison Between Adaptive Fuzzy and PID Fuzzy Automotive Engine Controllers in Idle Speed Mode


Automatic control of automotive engines provides benefits in the enginesperformance like emission reduction, fuel economy and drivability. To ensure betterachievement of these requirements the engine is equipped with an electronic controlunit (ECU) that is a microprocessor based system. This control unit continuallymonitors the engine state using several sensors and selects better control actions toachieve what is demanded from an engine under different defined operating modes.One of the most important modes in automotive engines is the idle speed mode. Dueto high dropping in the rotational speed in the presence of load torque and disturbance,which may lead to engine stalling, the ECU has to keep the engine speed at thereference idling speed.In this paper, The problem of maintaining the engine idle speed at a referencevalue with minimum overshoot, minimum undershoot, minimum settling time andminimum steady state error with the presence of load is studied. A Self Tuningadaptive Fuzzy Logic Controller (ST-FLC) is designed to solve this problem.Comparisons between fuzzy controller and adaptive fuzzy controller are made.Simulation results of this adaptive fuzzy controller show good improvement over thePID fuzzy controller in the idle speed response.All simulations are carried out using MATLAB software. Simulink is used inthe simulation, which comprises system model, controllers design andimplementation