“…It is particularly meaningful when the control goal is to stabilize an equilibrium at, and near which, observability is lost. The study of such systems, for about three decades, has yielded an ever-growing literature-see, e.g., [1][2][3][4][5]. It is that beyond the significant mathematical difficulty imposed solely by designing observer design [6][7][8], the stabilization problem is well-motivated by concrete engineering applications, such as sensorless motor control [9], bioreactor systems [10,11], electrical systems [12], and automotive applications [13], in which stabilization covers importance beyond intellectual curiosity.…”