State observers of linear control systems with nonlinear outputs. - Torvald Ersson; Xiaoming Hu 001 (CDC, 2001)

Implicit observers and active perception. - Torvald Ersson; Xiaoming Hu 001 (IROS, 2001)

Path planning and navigation of mobile robots in unknown environments. - Torvald Ersson; Xiaoming Hu 001 (IROS, 2001)

Active state estimation of nonlinear systems. - Xiaoming Hu 001; Torvald Ersson (Autom., 2004)