基于非定常气动力低阶模型的气动弹性主动控制律设计

传统的气动伺服弹性系统设计主要采用基于频域的非定常气动力有理函数拟合方法。该方法用于非线性非定常气动力情况，比如跨音速飞行时往往失效。针对该问题，在发展了非线性非定常气动力建模方法的基础上，提出了将非定常气动力低阶模型用于气动弹性系统主动控制设计的一般方法。该方法将气动伺服弹性系统分解为气动、结构和控制3个子系统，分别建立各子系统状态空间模型，然后组装成完整的气动伺服弹性模型。非线性非定常气动力状态空间模型采用基于Volterra级数的非定常气动力低阶模型方法。根据研究对象的具体情况，分别建立了气动伺服弹性系统的全耦合模型和部分解耦模型。最后以一个二自由度气动弹性系统的主动控制律设计为例，详细说明了该方法建模、分析和设计的全过程。算例表明该方法能够用于非线性情况，适用性强，可扩展性好，具有良好的集成性，能方便地应用于气动伺服弹性多学科优化设计。

Design Method of Active Control Law Based on Reduced Order Model of Unsteady Aerodynamics for Aeroelasticity

The conventional design method of aeroservoelastic system was in frequency domain with RFA (rational function approximation) method of unsteady dynamics,which always lost its way in nonlinear unsteady dynamics such as transonic fly condition. Based on the ROM (reduced order model) of unsteady aerodynamics, a general method of active control design for aeroservoelastic system was developed. The aeroservoelastic system was divided into three subsystems: aerodynamics, structure, and control subsystems whose state space models were constructed separately and then were integrated. The ROM was used to build the state space model of linear and nonlinear unsteady aerodynamics. According to the characteristics of the different objects, completely-coupled model and partially-decoupled model of aeroservoelastic system were built. Then the method was applied to designing an active control law for a two-DOF(degree-of-freedom) aeroelastic system in order to illustrate the procedures of model construction, system analysis and design of the method. The example demonstrates the wide applicability, good expansibility and excellent computational efficiency of the method. In addition, such a method can be applied to nonlinear circumstance and is well fit for multidisciplinary design optimization of aeroservoelasticity.