This paper presents a new parallel algorithm for the operational space dynamics of unconstrained serial manipulators, which outperforms contemporary sequential and parallel algorithms in the presence of two or more processors. The method employs a hybrid divide and conquer algorithm (DCA) multibody methodology which brings together the best features of the DCA and fast sequential techniques. The method achieves a logarithmic time complexity ($O(log(n)$) in the number of degrees of freedom ($n$) for computing the operational space inertia ($Λe$) of a serial manipulator in presence of $O(n)$ processors. The paper also addresses the efficient sequential and parallel computation of the dynamically consistent generalized inverse ($J¯e$) of the task Jacobian, the associated null space projection matrix ($Ne$), and the joint actuator forces ($τnull$) which only affect the manipulator posture. The sequential algorithms for computing $J¯e$, $Ne$, and $τnull$ are of $O(n)$, $O(n2)$, and $O(n)$ computational complexity, respectively, while the corresponding parallel algorithms are of $O(log(n))$, $O(n)$, and $O(log(n))$ time complexity in the presence of $O(n)$ processors.

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