Zeros of Sampled Systems with Fractional Order Hold Implemented by Zero Order Hold

摘要

For a sampled control system, replacing zero order hold with fractional order hold has been shown to be able to improve the stability of zeros of the system. However, it is diffucult to use the fractional order hold in practice. In this study, an approximated method of using the fractional order hold is proposed. The theorem for stability of zeros of the sampled system is proved as sampling period is small. It is shown that the approximated fractional order hold has the same advantages as the accurate one. The results could be useful in the design of digital control system.