基于Padé 近似法的零阶保持器幅频特性仿真

摘要

For present the Amplitude-Frequency characteristics of Zero Order Holder only gives theoretical analysis as well as general conclusions and analysis of the fuzzy,the simulation of it based on Padé Approximation was proposed in this paper.The transfer function of Zero Order Holder was improved to give the same order of the numerator and denominator of the rational transfer function by this method.Through freqs and Nyquist functions provided by MATLAB Control System Toolbox,the Amplitude-frequency characteristic curve and Nyquist plot were drawn,and its detailed analysis was also given.The simulation results of the amplitude-frequency characteristics showed that: the conclusion obtained by this method was consistent with the result the theoretical analysis,it solved the question at present that has not been able to maintain clear intuitive display zero order amplitude frequency characteristics change,and zero order holder has characteristics of low-pass filter and phase angle hysteresis.%针对目前零阶保持器幅频特性只给出理论性的分析,以及一般性的结论,分析较模糊,提出了基于Padé 近似法的零阶保持器幅频特性仿真.该方法对零阶保持器的传递函数进行了改进,得到了分子与分母同阶次的有理传递函数.通过MATLAB控制系统工具箱提供的freqs()以及nyquist()函数,绘制了幅频特性曲线以及奈奎斯特图;并对其进行了详细的分析.对零阶保持器幅频特性仿真结果表明:运用该方法得到的结果与理论性分析的结论一致,解决了目前未能清晰直观的展示零阶保持器幅频特性变化的问题,同时零阶保持器具有低通以及相角滞后的特性.