一种变旋翼转速直升机/涡轴发动机非线性模型预测控制方法研究

A Novel Nonlinear Model Predictive Control Method for Helicopter /Turboshaft Engine with Variable Rotor Speed

关键词:  直升机  涡轴发动机  变旋翼转速  快速响应控制  非线性模型预测控制

Key words:  Helicopter  Turboshaft Engine  Variable rotor speed  Fast response control  Nonlinear model predictive control

摘要:

为了实现变旋翼转速直升机/涡轴发动机快速响应控制，提出了一种基于神经网络的直升机旋翼预测模型与基于状态变量模型的涡轴发动机预测模型的新型非线性模型预测控制方法。所建目标函数除了包含转速控制指标外，还考虑了经两级变速双离合器传动机构传扭后发动机输出轴的转子动力学特性。不同飞行任务下的数值仿真结果表明：相对于PID控制器而言，非线性模型预测控制器可在满足压气机转速、发动机静强度等限制条件下使动力涡轮转速在变旋翼转速过程中的超调量减小50%，下垂量降至0.2%以内，实现了涡轴发动机的快速响应控制的同时，有利于改善发动机使用寿命。

Abstract:

In order to realize the fast response control of the integrated helicopter/turboshaft engine system with variable rotor speed, a novel nonlinear model predictive control (NMPC) method based on the prediction model of helicopter rotor obtained through neural network and the prediction model of turboshaft engine based on state variable model is proposed. In addition to the control index of power turbine speed, the objective function designed also takes into account the rotor dynamics characteristics of the engine output shaft with torque transmitted through the two-speed dual clutch transmission (DCT). The simulation results under different flight mission show that compared with the PID controller, the NMPC can reduce the overshoot of power turbine speed by 50% and decrease the droop to less than 0.2% during variable rotor speed under the premise of meeting the constraint conditions such as the compressor speed and static strength. It can not only realize the rapid response control, but also extend the service life of the turboshaft engine.