基于单自由度振动模型的IIR数字滤波器设计

摘要

Infinite Impulse Response(IIR) digital filter is designed usually inS-domain firstly, then theS-domain transfer function is transferred toZ-domain. To simplify the design process, a direct design method of filter based on Single Degree of Freedom(SDOF) model is presented, including the types of LP filter, HP filter, BP filter, BS filter. Simulation results show that the design process is direct and simple, and the designed filter bears good frequency characteristics. Another advantage of the proposed method is that the filter parameters needn’t change with system sample time. Therefore, it is a new method for IIR digital filter design with good usability.%无限冲击响应(IIR)数字滤波器设计通常需要先设计S域滤波器，再变换到Z域。为简化 IIR数字滤波器的设计过程，本文提出利用单自由度系统(SDOF)模型直接设计 IIR数字滤波器的方法，包括低通、带通、高通、带阻等。仿真结果表明设计过程直接、简单，滤波器参数不需要随采样频率而变，具有良好特性，是一种设计 IIR数字滤波器的简便易用的新方法。