于 峰，滕 勤，马 标  

摘要：针对柴油机废气再循环（EGR）和可变几何截面涡轮增压器（VGT）控制回路存在的强烈耦合作用，讨论了EGR-VGT的协调控制问题。根据不同控制器对排放的影响，基于平均值模型，通过对被控对象的控制特性分析，选择与排放密切相关的氧气/燃油比和EGR率作为反馈变量，建立了EGR-VGT协调控制器。在MATLAB/Simulink环境下，通过仿真验证了所建立的控制器的瞬态控制效果。结果表明，被控变量能够很好地跟踪其目标值，未出现明显的超调，稳态误差控制在5%以内，瞬态响应时间小于1s。

关键词：柴油机；废气再循环；可变几何截面涡轮增压器；协调控制

Abstract: Aimed at the strong coupling effects between the exhaust gas recirculation (EGR) control loop and the variable geometry turbocharger (VGT) control loop, the coordinated EGR-VGT control problem was discussed. According to influences of the different controllers on the engine emission, the control characteristic of the controlled plant was analyzed based on a mean value engine model. The oxygen / fuel ratio and the EGR rate closely related to the engine emission were selected as feedback variables, and an EGR-VGT coordinated controller was established. The transient control effect of the controller was verified by simulation in the environment of MATLAB/Simulink. The results show that the target values can be tracked well by the controlled variables without obvious overshoot, and steady-state error is controlled within 5%, and the transient response time is less than 1s.

Key words: Diesel Engine; Exhaust Gas Recirculation; Variable Geometry Turbocharger; Coordinated Control