基于模型预测控制的废气循环HCCI发动机的多变量控制

摘要

A two-input and two-output physical model for pressures and combustion phases was built to realize the coordinated control of the peak pressures and combustion phases for a homogeneous charge compression ignition (HCCI) engine. This model is based on the Shaver' residual-affected HCCI engine model with the constant wall temperature heat transfer model suitable for HCCI combustion. A cooperative control system of pressure and combustion phase was designed using the model predictive control (MPC) theory with the variable valve timing (VVT) as the control method. The coordinated simulation experiment was done by using GT-Power and Matlab/Simulink. The results show that the control model satisfies the engine control demand, realizes the collaborative control of the pressure and combustion phase with control accuracies of ±30 kPa and ±0.6° CA and the response time of 6-7 engine cycles.%为了协调控制均质压燃（HCCI）发动机的峰值压力及燃烧相位，建立了压力-燃烧相位的两输入两输出的物理模型。基于Shaver提出的废气循环HCCI发动机物理模型，该模型加入了适用于HCCI燃烧模式的定壁温传热模型。采用模型预测控制（MPC）理论，设计了压力及燃烧相位的协同控制器。以可变气门正时（VVT）为控制手段，进行了GT-Power与Matlab／Simulink联合仿真实验。结果表明：该控制模型能够满足发动机的需求，实现了压力-燃烧相位的协同控制，控制准确度分别为±30kPa和＋0.6°，响应时间约6～7个发动机循环。