汽油直接喷射(Gasoline Direct Injection,缩写为GDI)发动机的整个工况范围被分成两个区域,即低工况区域和高工况区域.在低工况区域,最重要的目标是经济性,所以低工况时控制空燃比为25至40,采用分层充量,节气门全开,扭矩调节采取定量变...汽油直接喷射(Gasoline Direct Injection,缩写为GDI)发动机的整个工况范围被分成两个区域,即低工况区域和高工况区域.在低工况区域,最重要的目标是经济性,所以低工况时控制空燃比为25至40,采用分层充量,节气门全开,扭矩调节采取定量变质方式,喷油在压缩冲程晚期,喷油压力较高,燃油雾化较好,但油束穿透不深.展开更多
Due to the coexistence and coupling of continuous variables and discrete events, the vehicle height adjustment process of electronic air suspension system can be regarded as a typical hybrid system. Therefore, the hyb...Due to the coexistence and coupling of continuous variables and discrete events, the vehicle height adjustment process of electronic air suspension system can be regarded as a typical hybrid system. Therefore, the hybrid system theory was applied to design a novel vehicle height control strategy in this paper. A nonlinear mechanism model of the vehicle height adjustment system was established based on vehicle system dynamics and thermodynamic theory for variable-mass gas charge/discharge system. In order to model both the continuous/discrete dynamics of vehicle height adjustment process and the on-off statuses switching of solenoid valves, the framework of mixed logical dynamical(MLD) modelling was used. On the basis of the vehicle height adjustment control strategy, the MLD model of the adjustment process was built by introducing auxiliary logical variables and auxiliary continuous variables. Then, the co-simulation of the nonlinear mechanism model and the MLD model was conducted based on the compiling of HYSDEL. The simulation and experimental results show that the proposed control strategy can not only adjust the vehicle height effectively, but also achieve the on-off statuses direct control of solenoid valves.展开更多
文摘汽油直接喷射(Gasoline Direct Injection,缩写为GDI)发动机的整个工况范围被分成两个区域,即低工况区域和高工况区域.在低工况区域,最重要的目标是经济性,所以低工况时控制空燃比为25至40,采用分层充量,节气门全开,扭矩调节采取定量变质方式,喷油在压缩冲程晚期,喷油压力较高,燃油雾化较好,但油束穿透不深.
基金supported by the National Natural Science Foundation of China(Grant Nos.51375212 and 51105177)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20133227130001)the China Postdoctoral Science Foundation(Grant No.2014M551518)
文摘Due to the coexistence and coupling of continuous variables and discrete events, the vehicle height adjustment process of electronic air suspension system can be regarded as a typical hybrid system. Therefore, the hybrid system theory was applied to design a novel vehicle height control strategy in this paper. A nonlinear mechanism model of the vehicle height adjustment system was established based on vehicle system dynamics and thermodynamic theory for variable-mass gas charge/discharge system. In order to model both the continuous/discrete dynamics of vehicle height adjustment process and the on-off statuses switching of solenoid valves, the framework of mixed logical dynamical(MLD) modelling was used. On the basis of the vehicle height adjustment control strategy, the MLD model of the adjustment process was built by introducing auxiliary logical variables and auxiliary continuous variables. Then, the co-simulation of the nonlinear mechanism model and the MLD model was conducted based on the compiling of HYSDEL. The simulation and experimental results show that the proposed control strategy can not only adjust the vehicle height effectively, but also achieve the on-off statuses direct control of solenoid valves.
