2015 Volume 28 Issue 10 Pages 419-425
A SPAN filter is a nonlinear filter that can modulate the gain and phase of input signals independently, and it is expected that the feedback system that contains the SPAN filter can show better control performance than linear systems. However, it is very difficult to design it so that the design specifications such as overshoot and settling time are satisfied simultaneously. Since the SPAN filter contains three design parameters, drawing the permissible sets of the parameters is suitable for the understanding of the solution set. In this paper, a parameter space design method by volume rendering is proposed, where volume data is obtained by calculating the performance indexes for grid points in the parameter space. This method is applied to SPAN filter design, and its usefulness is shown numerically.