废气再循环–可变几何截面涡轮增压柴油发动机 燃气双环系统建模及协同控制

针对废气再循环(EGR)与可变几何截面涡轮增压(VGT)的柴油发动机,作者联合考虑其燃油动力转速调节回路与气体回路,提出了内外双环稳定动态反馈的控制策略.其中,内环回路是利用Lyapunov函数设计的控制器,控制燃油质量流量来跟踪柴油发动机转速;外环回路则设计EGR–VGT控制器,跟踪气体回路的进排气歧管压力及压气机空气质量流量,并克服了柴油发动机建模中的不稳定零动态问题.同时,研究了气体流量与EGR和VGT阀门开度之间的关系,通过设计流量开度转换模块实现了两者控制的转换.最后,通过专业发动机软件AMESim与仿真软件MATLAB/Simulink的联合仿真试验,验证了该控制策略对柴油发动机燃油动力转速调节与气体回路控制的有效性.

Modeling and collaborative control for exhaust gas recirculation and variable geometry turbocharger diesel engine fuel-air dual-loop system

For diesel engine equipped with Exhaust Gas Recirculation (EGR) and Variable Geometry Turbocharger(VGT), the fuel-speed regulation path and air path are considered simultaneously in this paper, and an inner-outer dual-loop based dynamical feedback stabilization control approach is proposed. Specifically, the inner loop concerns a control strategy based on Lyapunov function which achieves the engine speed trajectory tracking by designing the fuel mass flow rate; the outer loop designs a EGR-VGT controller to obtain trajectories tracking of intake manifold pressure, exhaust manifold pressure and compressor mass flow rate in the air path, which also eliminates the unstable zero dynamics in the modeling of diesel engines. The transformation between gas flow rate through EGR/VGT and their corresponding valves positions is realized in the flow-position module. Finally, through co-simulation results from the professional engine software - AMESim and the simulation software - MATLAB/Simulink , the effectiveness of the proposed control strategy is demonstrated.