Control of a one-mode model on the minimum-time of a flexible structure

In a previous article, a set of five conditions were given to describe the switching hypersurface of the minimum-time, single-axis controller for an undamped, one-mode model of a flexible slewing structure. The purpose of this paper is to show that the five conditions have been found to be reducible to three. This oversight is amended and a new plot of the three conditions in a two-dimensional plane is isolated. This characterization of the switching structure depends only on the rigid-body states, and can be easily used in real-time.