利用遗传算法和LMI设计固定结构H2/H∞飞行控制律

 在设计飞翼式无人机(UAV)的横航向飞行控制系统时，为了使无人机具有较好的动态特性和阵风抑制能力，同时又便于工程实现，提出了固定结构的H₂/H_∞控制律设计方法。对于由此遇到的双线性矩阵不等式(BMI)问题，先用线性矩阵不等式(LMI)方法得到控制律参数和H₂/H_∞性能指标的映射关系，再用此映射关系作为适应度函数，用改进的遗传算法求解使H₂/H_∞性能最优的控制律参数。仿真结果表明，使用固定结构的H₂/H_∞控制方法的无人机动态响应迅速平滑，在侧风干扰下的滚转角振荡幅值仅是原经典控制方法的一半。

DesignofFixedStructureH2/H∞FlightControlLawbyGeneticAlgorithmandLMI

A lateral directional flight control system of a flying wing unmanned aerial vehicle(UAV) must enable the UAV to exhibit excellent dynamic response and be insensitive to wind turbulence. At the same time, the controller must be simple enough to be easily applied in reality.Therefore a fixed structure H₂/H_∞ control method is proposed. To deal with the bilinear matrix inequality(BMI) that arises in the proposed method, the mapping of control law parameters and H₂/H_∞ performance is derived from linear matrix inequality (LMI) first, and then by taking the mapping as a fitness function, the optimal H₂/H_∞ performance and the control law parameters can be solved with the improved genetic algorithm. Simulation results show that when the UAV is under the disturbance of a lateral wind, the dynamic responses of the UAV with the fixed H₂/H_∞ controller are smooth and rapid and the oscillation amplitude of the angle of bank is only half of what could be obtained by the original classical controller.