采用双线性变换的线性离散系统模型降阶

Model Reducted-order of Linear Discrete Time Systems Based on Bilinear Transformation

针对线性定常离散系统,提出一种新的不受稳定性限制的降阶方法,即利用双线性反变换,将离散系统转化为连续系统,利用已知的连续系统的降阶方法进行降阶,之后再经双线性变换为离散系统,得到了原离散系统的降阶模型,给出并证明了误差上界。数值算例说明了此方法的有效性。

To reduce the model order of discrete time LTI system,a new method without the limitation of stability was proposed.By using bilinear trsformation between discrete time systems and continuous time systems,a continuous time model order-reducted method was extended to discrete time systems.An upper bound of the model order-reducted error was given.Finally,a numerical example show the effectiveness of this method.