The discrete-time equivalent of an analogue controller by the parabolic approach

Abstract

A new discretization method is proposed to convert an analogue controller to its corresponding counterpart for the discrete-time system. This method is suitable for the natural response curve and can be more eVective for some digitally redesigned systems. From the mapping region of s domain to z domain, the paper shows that such an approach can generate a corresponding stable discrete-time controller for a stable continuous-time controller. The discrete-time controller via an approach of parabolic transformation shows a good performance for its originally continuous-time response and can tolerate a comparatively large sampling period of the discrete-time system. An illustrated example is simulated to demonstrate the eVectiveness of these results.