基于特征空间变换的运载火箭Pogo模型降阶方法

针对运载火箭Pogo状态空间模型存在维数高和奇异性的问题，开展了Pogo模型的降阶方法研究。基于特征空间变换理论，导出了一般形式的Pogo状态空间模型的解耦形式。该形式与推进系统和结构系统的模态频率相对应，从而通过模态截断或保留感兴趣的模态实现有效的模型降阶。同时，还给出了降阶方法的实数运算公式。在两种不同型号推进系统的火箭Pogo问题中进行了仿真校验。结果表明所提出的降阶方法对奇异和非奇异Pogo状态空间模型都能给出正确的降阶模型，显著地提高计算效率，具有很好的通用性，为Pogo时域仿真和主动抑制提供了合适的模型。

Reduction Method of Pogo Model of Launch Vehicles Based onEigenspace Transformation

Aimed at the problem of high dimension and singularity in the Pogo state space model of large liquid launch vehicles, the reduction method of Pogo model is studied. Based on the eigenspace transformation theory, a decoupling form of the general Pogo state space model is derived, which corresponds to the modes of the propulsion system and the structural system. Therefore the model can be effectively reduced by truncating the high modes or preserving the interested modes. Furthermore, a real number operation of model reduction method is obtained. The Pogo problem of two different types of propulsion system is simulated and verified. Results demonstrate that the proposed model reduction method can give the correct reduction model for both singular and non singular Pogo state space models, significantly improving the computational efficiency. And it is of good universality so as to provides an appropriate model for time domain simulation and active suppression of Pogo problem.