On the Minimum Phase Property of Mass-Dashpot-Spring Sampled Systems

Abstract

In literature, it is shown by Åström et al. that a sampled system may become nonminimum phase for sufficiently fast sampling, even though the continuous-time system is minimum phase. However, it is verified in this paper that the sampled system of a modal damping mass-dashpot-spring structural dynamics with sufficient condition B=CTΓ is minimum phase independent of the sampling period. From a control point of view, this significant result is essential and beneficial to the digital controllers design for a large-scale structure. In addition, it also provides a criterion to locate the sensors and actuators of a structural system.