论文部分内容阅读
基于弹性飞机的降阶模型设计控制器时需要考虑模型降阶带来的降阶误差,这就需要设计的控制器具有较强的鲁棒性。为此,以某弹性飞机12阶模型为例,研究了基于弹性飞机降阶模型的混合H2/H∞最优PID控制器的参数优化。首先基于平衡截断法得到了6阶降阶模型。然后,根据全阶模型和降阶模型的频域降阶误差选取了合适的鲁棒加权函数。之后,给出了闭环系统跟踪误差H2范数的一种简化计算方法用于H2/H∞优化指标的计算。最后基于差分进化算法进行了混合H2/H∞最优PID控制器的参数寻优。仿真结果表明,与H∞混合灵敏度控制器相比,优化得到的混合H2/H∞最优PID控制器具有更强的鲁棒性,能同时镇定参数和非参数两种不确定性。对弹性形变模态也有较好的抑制作用,刚性模态也取得了很好的响应效果。
When designing a controller based on the reduced-order model of a flexible aircraft, the step-down error caused by the model reduction needs to be considered, which requires that the designed controller has strong robustness. Therefore, taking the 12th order model of a flexible aircraft as an example, the parameter optimization of the hybrid H2 / H∞ optimal PID controller based on the elastic aircraft reduced order model is studied. First, based on the balanced truncation method, a 6-order reduced order model is obtained. Then, the robust robust weighting function is selected according to the frequency-domain reduction error of the full-order model and the reduced-order model. Then, a simplified calculation method of the H2 norm of tracking error of closed-loop system is given for the calculation of H2 / H∞ optimization index. Finally, the parameters optimization of hybrid H2 / H∞ optimal PID controller based on differential evolution algorithm is carried out. The simulation results show that the hybrid H2 / H∞ optimal PID controller is more robust than the H∞ hybrid sensitivity controller, and can stabilize both the non-parametric and non-parametric uncertainties. It also has a good inhibition effect on the elastic deformation mode, and the rigid mode has also achieved a good response effect.