Modeling and Control of Turbocharged Gasoline Engine Intake System
|Course||Control Theory and Control Engineering|
|Keywords||Turbocharge Air Path control Gasoline engine Mechanism/map modeling Torque-based Neural Network|
The rapid development of automotive industry brought great convenience to peo-ple’s lives, but also caused energy shortage and environmental pollution problems as agreat challenge, which people must face up to. In order to reduce energy consumptionand emission for engine, automotive engineers and scholars have proposed a lot of newtechnologies to improve the performance of vehicle engine. Gasoline engine turbochargerenables the engine with a certain displacement to generate higher power and consume lessfuel. For the above reason, exhaust turbo charging technique has been widely used in au-tomotive products. In this paper, a air-path control system based on torque requirementis proposed for the control problem of four-cylinder turbocharged gasoline engine.Combined the mean value modeling mechanism with the maps commonly used inengineering, a hybrid mechanism/map model consisting of the air-path model and tur-bocharger system model is developed. Primarily, according to the structure characteristicsand action mechanism, the turbocharger system model is established. Analyzed the im-pact of turbocharger system on traditional gasoline engine air path, the model parameters(such as volumetric efciency map) are reconsidered and the air path model of the tur-bocharged engine is obtained. Secondly, to ensure the accuracy of the model, the air pathmodel of the turbocharged engine established in MATLAB/Simulink is verified by use ofthe commercial software tool enDYNA for the real-time simulation of engine dynamics.Based on the turbocharged engine air-path model mentioned above, a tracking controlsystem composed of air-path planning controller and optimal intake manifold pressuretracking controller is designed. At the start of the work, the desired throttle opening angleis reversed by the torque reference through the inverse dynamics theory. Then, aimingat the pressure limiting demand, the optimal reference of the intake manifold pressure isdefined by a pressure limiting map. finally, a neural net algorithm based PID controllerfor turbo wastegate is proposed to satisfy the requirement. Thus the coordinated controlof the throttle valve and turbo wastegate meets the engine torque demand as well assatisfies the pressure limiting requirement of intake manifold.In the last place, a simulation experiment with turbocharged engine air path model in MATLAB/Simulink environment and a co-simulation of MATLAB/Simulink and en-DYNA are respectively conducted to evaluate the efectiveness of designed turbochargedair path control system. The of-line experiments results show that the air path controlsystem designed in this article can meet the control requirements of turbocharged gasolineengine gas path.