This paper presents an analytical-numerical method for linearizing the
equations of motion of mechanical systems with dosed chains. The algo
rithm developed here linearizes basic recursive kinematic relationship
s and then applies the chain rule to the derivation of the equations o
f motion under the framework of recursive formulation. This method can
be incorporated into the formulation of recursive equations of motion
for general multibody dynamic systems to handle large-scale systems.
The method is directly applicable to system Jacobian matrix computatio
n. Since the proposed algorithm uses no numerical differentiation, its
accuracy is comparable to a symbolic, closed-form linearization. More
over, without needing repetition computation in search of proper pertu
rbation quantity, this method is computationally more efficient than t
he finite difference method.