针对舰载机对中着舰过程中,滚转速率与侧滑角运动之间存在固有耦合的问题,特别是在低攻角的情况下,这种耦合导致滚转速率与侧滑角符号方向相反,并有较大侧滑,严重降低了飞机的飞行品质,分散了飞行员对中着舰操控过程的精力.推导出了一类具有参考模型H∞/H2 LFr(linear fractional transformation)的控制方法来解决这类耦合的侧向控制问题,H∞控制不仅可抑制噪声干扰,还可降低通道间的耦合,实现着舰过程的解耦控制,使飞机的操纵响应满足参考模型的期望飞行品质,减少飞行员的工作负荷.对于着舰过程中由攻角变化而产生模型的大范围变化情况,采用线性变参数方法可解决这类具有模型不确性的参数依赖时变系统的精确控制问题.此外文中采用多Lyapunov函数的切换控制,进一步提高了闭环系统的整体性能.
Due to an inherent coupling between roll rate and angle of sideslip during powered approach phase, the research study seeks to examine aircraft lateral mixed H∞/H2 linear parameter varying (H∞/H2 LPV) model reference control during a powered approach. The notion of sideslip with large amplitude is direct opposite to the sign of roll rate, especially in low angle of attack scenarios. This coupling will degenerate the handling quality and distract the pilot's attention from landing. Currently, there is a methodology being used to solve the lateral control problem of coupling with mixed H∞/H2 linear fractional transformation (H∞,/H2 LFT) which has reference model. The H2 model is able to restrain noise disturbance and reduce the coupling between different channels, which enables decoupling control during the landing and make the aircraft handling quality achieve the desired handling quality and at the same time reduce the workload of the pilots. A linear parameter varying (LPV) methodology, scheduled on angle of attack, was used for solving the parameter-dependent time-varying system having model uncertainty. In addition, the closed-loop system performance can further be improved, by exploiting the switching control theory of piecewise muhi-Lyapunov functions.