PID-LIKE FLC FOR FOUR CYLINDERS MEAN VALUE GASOLINE ENGINE MODEL IN IDLE MODE

Abstract

Automatic control of automotive engines provides benefits in the engines performance like emission reduction and fuel economy. Due to high dropping in the rotational speed in the presence of load torque and disturbance, which may lead to engine stalling, an electronic control unit (ECU) has to keep the engine speed at the reference idling speed. In this paper, the four strokes, four cylinders, gasoline, port fuel injection engine is studied and a Mean Value Engine Model (MVEM) is used to simulate the nonlinear model of the engine. The problem of preserving the engine speed with minimum settling time, minimum undershoot and minimum overshoot in the presence of load torque or disturbance at idle speed mode is studied. PID-like Fuzzy Logic Control (PID-FLC) with minimum structure is designed to solve this problem. Comparisons among conventional PID controller and fuzzy controller is made. Simulation results of this PID fuzzy controller show good improvement over the conventional PID controller the idle speed response. The simulation results with PIDFC show that the dropping in the engine speed is reduced around (33%) compared with PID controller. The peak overshoot is reduced around (19%) compared with PID controller for the same value of the load torque. The settling time is reduced by (50 %) compared with the PID controller.