Comments to the: “Closed-form dynamic equations of the general Stewart platform through the Newton-Euler approach” and “ A Newton-Euler formulation for the inverse dynamics of the Stewart platform manipulator”

The inverse dynamics of the general configured Stewart platform manipulator, with the frictional forces and leg inertia, was derived through the Newton-Euler approach in the two papers [Mechanism and Machine Theory, Vol. 33, No.7, pp. 993–1012, 1998 and Vol. 33, No.8, pp.1135–1152, 1998]. The work has made a significant contribution to this research field. After that, Fu and Yao [3] [Mechanism and Machine Theory, Vol.42, No.12, pp.1668–1671, 2007], Vakil et al. [Mechanism and Machine Theory, Vol.43, No.10, pp.1349–1351, 2008] proposed some corrections in details as comments on these researches. We believe that there still exist following problems in these original papers.