In order to obtain the high-quality fast response control for helicopter/turboshaft engine with variable rotor speed, a nonlinear model predictive control (NMPC) method based on piecewise objective function is proposed. The piecewise objective function takes into account both the control index of power turbine speed and the rotor dynamics of engine output shaft, which optimizes the transient overshoot and sag of the power turbine speed caused by torques mismatch during variable rotor speed from the root. The results show that compared with conventional MPC method with single objective function only involving the control index of power turbine speed, the novel NMPC method proposed can reduce the overshoot or sag of the power turbine speed by more than 30% during variable rotor speed, which possesses superior control effect of turboshaft engine without losing real-time performance.

中文翻译：

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基于分段目标函数的变旋翼直升机/涡轴发动机非线性模型预测控制研究

为获得直升机/涡轴发动机变旋翼转速的高质量快速响应控制，提出了一种基于分段目标函数的非线性模型预测控制(NMPC)方法。分段目标函数同时考虑了动力涡轮转速控制指标和发动机输出轴转子动力学，从根本​​上优化了变转子转速时转矩失配引起的动力涡轮转速瞬态超调和下垂。结果表明，与仅涉及动力涡轮转速控制指标的单一目标函数的传统MPC方法相比，所提出的新型NMPC方法可将动力涡轮转速的超调或下垂降低30%以上。