Optimal strain gauge placement for an instrumented disk drive suspension

Dual-stage servo systems and vibration compensation in computer hard disk drives

“…Most often, sensors are placed according to some measure derived from system observability. Hac & Liu (1993) proposed a measure based on eigenvalues of the observability Grammian, which was later applied to disk drives (Banther, Huang, & Messner, 1998;Huang et al, 1999), while (Lim, 1996) proposed to use Hankel singular values to evaluate observability. Unfortunately, open-loop observability approaches do not necessarily provide an optimal location from a controlled, closed-loop perspective.…”