Accommodation Closed-loop Control of Dieseline Fueled Flexible Fuel Engine Based on In-cylinder Pressure Sensor

This paper conducts investigation on accommodation closed-loop control of dieseline fueled flexible fuel engine. In our previous work, gasoline/diesel blend ratio estimation method was proposed and acted as a feedforward controller. In this paper, power performance closed-loop control systems with or without blend ratio estimation model are simulated respectively at constant and variable load to demonstrate the necessity of feedforward controller to control system. Results show that, whether at constant or variable load, power indicators of the system with feedforward controller track the target value well. However, for system without feedforward controller, power performance deteriorates obviously, especially in variable load condition. Besides, accommodation closed-loop control system for dieseline fueled flexible fuel engine is established. The algorithm is executed by adjusting the main injection timing to seek the most economy point on the premise that the power performance of the engine can be ensured simultaneously. Compared with open-loop control algorithm, closed-loop control system is less sensitive to fuel estimation model error, which proves to be of better consistency. Moreover, the practical output torque follows the target value well and the indicated efficiency can also be optimized.