Table 1 Parameters used in the analysis

\(G_r\)

Gear ratio

30

\(J_{n}\)

Nominal motor inertia

1.59 \(\times 10^{-6}\)

\(K_{tn}\)

Nominal torque constant

6.5 \(\times 10^{-2}\) Nm/A

D

Nominal viscosity

2.2 \(\times 10^{-3}\)  Nms/rad

\(K_e\)

Environmental stiffness

1.0 \(\times 10^{4}\)  Nm/rad

\(D_e\)

Environmental viscosity

0 Nms/rad

\(J_{f}\)

Virtual mass gain

1.0 \(\times 10^{-3}\)\(\hbox {kgm}^2\)

\(g^{\mathrm{dis}}\)

Bandwidth of DOB

600 rad/s

\(g^{\mathrm{ext}}\)

Bandwidth of RTOB

1200 rad/s

\(g^{\mathrm{pd}}\)

Bandwidth of pseudo-differential

1200 rad/s

\(g_I\)

Bandwidth of integration

325 rad/s