A system of n rigid bodies with m generalized coordinates has the kinetic energy T = ∑ ∑ i = 1 n ( 1 2 M V i ⋅ ⋅ V i + 1 2 ω ω i ⋅ ⋅ [ I R ] ω ω i ) , which can be used to calculate the m generalized inertia forces Q j ∗ ∗ = − − ( d d t ∂ ∂ T ∂ ∂ q ˙ ˙ j − − ∂ ∂ T ∂ ∂ q j ) , j = 1 , … … , m .