Control Methodologies For High-speed Solenoid Valve Of IC Engine

This paper details with the design and research on the high-speed solenoid valve that is used inthe air-assisted direct fuel injector. At first, the mathematical model and the physical model isestablished, the precision of the two models is verified with simulation method and test means.Second, performance requirements of the high-speed solenoid valve that are used in the air-assisteddirect fuel injector is analysis, the effects of some important structural parameters on the performanceof the high-speed solenoid valve. At last, the magnitude-frequency characteristic of some statequantity transfer function is discussed. Loop control structure is designed, and this paper focus onrebound suppression strategy, solenoid valve closure start-point feedback control strategy and variableneedle lift control strategy.The mathematical modeling method and physical modeling method are combined, the modelingprocess of the high-speed solenoid valve is analysis from three aspects: electronic, magnetic andmechanical. The mathematical modeling is used for feedback analysis, feedback parameters selectionand controller structure design, the physical modeling is used for static characteristic analysis,dynamic characteristic analysis and control strategy validation. Adopting both simulation method andtest analysis manner, the thesis validates the effectiveness and precision of the models.The structure design principles of the high-speed solenoid valve are discussed, includinghigh-speed solenoid valve pull characteristics, maximum power output and structure factor. Based onthe design principles, the choice of the structure parameters is analysis. The effect of the key structureparameters on the high-speed solenoid valve is analysis, some structure parameters are optimized.Design results show that the peak electromagnetic force of the high-speed solenoid valve is improvedwith the optimized structure parameters.Based on the mathematical modeling of high-speed solenoid valve, the strengths and weaknessesof feedback parameters are analysis, including the armature displacement, the operating current andthe magnetic flux. The feedback control structure is designed, and the armature displacement andmagnetic flux are combined as the feedback parameters.In terms of the motion control strategy for high-speed solenoid valve, the solenoid valve closurestart-point electronic driver circuit is designed, and the open time and closing moment of high-speedsolenoid valve can be detected. Based on the method, the problem of uneven fuel injection from thecylinders is solved, and the control precision of fuel injection is improved. The nonlinear controller isresearched, including the open controller and close controller, so that the speed of the high-speedsolenoid valve of terminal stage is controlled. The rebound of valve needle is suppressed and the fuelinjection control precision is improved. Through the combination of the above control strategy, therebound of valve needle is suppressed, and the fatigue life of solenoid valve is improved. The controlstrategy can also solve the problem of uneven fuel injection from the cylinders, thus improving the control precision of fuel injection.