Modeling and Engine Speed Control of LPG Injection System

The purpose of this paper is to show precise and robust control of an automotive LPG engine speed, including a modeling method of an automotive engine system and a model base control technique. The modeling is performed for an electronic throttle servo system, an air intake system and an engine drive system. Since the system is highly nonlinear, the sliding mode controller design method with the VSS (Variable Structure System) observer is applied for the throttle control system where the design parameters are optimized by GA (Genetic Algorithm). In order to verify the effectiveness of the proposed modeling method and controller design, the simulation and experiments are performed. The results show the precise control of engine speed. The simulation results show good agreement with experimental results. Also, the robustness of the controller is confirmed by the precise speed control ability under sudden change of the load of the engine.