有限字长对数字控制系统极点的影响

The Effect of Finite-Wordlength on the Poles of Digital Control Systems

本文应用扩展状态模型研究了多输入多输出(MIMO)闭环数字控制系统因受计算机字长限制而产生的系统极点漂移问题,推导出了系数量化误差引起的系统单极点(包括共轭复极点)漂移的简单计算公式,根据此公式编制了计算机程序,并给出了对实际数字控制系统的分析结果.

In this paper,the problem of system pole drift which is due to the computer finite-wordlength in multi-input multi-output (MIMO) closed-loop digital control systems is studied.The simple formula which can be used to calculate the drifts of of single poles (including conjugate complex poles),which are caused by the coef- ficient quantization errors,is also proved.According to the formula,a computer programme is programmed.Finally,the calculating results on a actual digital con- trol system are given.