H_∞控制理论在飞行力学中的应用

APPLICATION OF H_∞ CONTROL THEORY TO FLIGHT DYNAMICS PROBLEMS

对 H∞ 控制理论在飞行力学中的应用进行了研究。以典型战斗机的横航向飞行机动为例 ,介绍了将飞行控制系统设计问题转化为标准的 H∞ 控制问题 ,继而进行 H∞ 控制器设计 ,以提高其机动特性的鲁棒性。采用显模型跟踪技术 ,飞行品质的要求包含在反映状态变量侧滑角、稳定轴角速率对指令输入响应的理想模型中 ,通过使理想模型输出和实际对象输出之间的加权误差最小 ,同时保证控制面不饱和来达到控制的目的。计算结果表明 ,在飞机模型气动参数存在不确定性的情况下 ,增广系统达到了期望的性能指标 ,显示出良好的鲁棒性。

The application of H ∞ control theory to flight dynamics problems is studied. The lateral directional maneuver of a representative aircraft is used as an example. The flight control system design problem is formulated as the standard H ∞ control problem. The H ∞ controller is designed for the generalized plant in order to improve the robustness. The explicit model following technology is used in which the desired flying qualities are embedded in ideal models of the sideslip angle and stability axis roll rate responses to commanded inputs. The control objective is met by minimizing the weighed error between the ideal model outputs and the actual plant outputs; at the same time, all the control surfaces are not saturated. Numerical computations indicate that the generalized plant can attain desired performance and robustness despite uncertainties in the aircraft's aerodynamic coefficients.