Idle speed control of FSAE racing engines based on Mid-ranging ADRC

Idle speed control is very important for the fast start to move and smooth gear shift of FSAE racing cars. Also low idle speed can reduce the fuel consumption, though with the cost of increased risk of missing fire or even engine stall, caused by disturbances such as intake fluctuation, combustion fluctuation or load fluctuation. In order to reject these disturbances, a novel control solution, called Mid-ranging ADRC, was proposed in this paper, based on a Nonlinear Mean Value Engine Model (NMVEM). Through the spark timing in charge of the speed directly and the idle motor for the spark timing to avoid going into saturation region, the effective coordinated control of the Double-Input-Single-Output (DISO) system was achieved. Two ADRCs were also designed for the two control loops to estimate and cancel the total disturbances in real time. The superiority of the proposed method was confirmed in simulation in terms of disturbance rejection and response speed, compared with single ADRC or PID, making it a practical solution for FSAE racing cars´ idle speed control.