基于dSPACE的模糊PID算法在CNG发动机空燃比控制中的应用

The Research on Application of Fuzzy PID to Air-Fuel Ratio Control of CNG Engines based on dSPACE

发动机工作过程具有复杂的不确定性、时变性和非线性且空燃比的传输存在着迟延,尤其在瞬态工况下波动剧烈,为提高空燃比的控制精度以及经济性和排放性,利用MATLAB/Simulink软件建立空燃比模糊PID控制算法,算法平台为d SPACE公司的Micro Auto Box,在NQ150N天然气发动机上进行了测试试验,试验结果分析表明,与经典PID算法相比,模糊PID控制算法在稳态工况下性能良好,在过渡工况下能明显改善空燃比控制效果。

The working process of a natural gas engine has factors of complex uncertainty, time - variation and nonlinear. Also, the transmission of the air - fuel ratio is delayed, and has fluctua- tion especially under transient conditions. In order to improve the control accuracy, the efficiency and the emissions of air - fuel ratio, we use MATLAB / Simulink software to establish a fuzzy PID control algorithm of the air - fuel ratio. The platform of algorithm is the MicroAutoBox designed by the company of dSpace. The test - experiments are done on NQ150N natural gas engines. Compared with the normal PID algorithm, the results of experiments show that the fuzzy PID algorithm has a better performance in the steady - state condition, significantly improving the effects of fuel ratio control under the transition condition.