“…where u = [u 1 ; u 2 ; u 3 ] and J = diag{J x , J y , J z } are the control input and inertial matrix, respectively; d = [d 1 ; d 2 ; d 3 ] denotes the disturbance disturbance factor. Assumption 1 [21]: With the consideration of the structural flexibility and load changes, the inertial matrix J can be described as J = J 0 + J ∆ , where J 0 = J 0,x ; J 0,y ; J 0,z and J ∆ = J ∆,x ; J ∆,y ; J ∆,z denote the ideal part and uncertain part of J , respectively, which is reasonable to assume ∥J ∆ ∥ ≤ J with J > 0 denoting an unknown scalar.…”