文档介绍：Available online at hanism
and
Machine Theory
Mechanism and Machine Theory 43 (2008) 1349–1351
ate/mechmt
Letter to the editor
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”
Abstract
Considering the novelty of the method and creativity of the research that is detailed in the two papers [Mechanism and
Machine Theory, Vol. 33, , pp. 993–1012, 1998 and Vol. 33, , –1152, 1998], we believe that correcting the
following errors appearing in these two papers would enhance their valuable contribution to this field of research.
Ó 2008 Elsevier Ltd. All rights reserved.
Errors and the proposed corrections
Error 1:
In [1,2] the moment of each universal joint is considered to be along the direction of its corresponding leg.
For a universal joint with revolute joints in the ^k and ^y directions, as shown in Fig. 1, there is no restriction
moments in those directions; the notation ^x is used for unit vector in the x direction. Therefore the universal
joint can only impose a moment in the h^ direction, where h^ is the normal vector of the plane formed by the
vectors ^k and ^y, that is
h^ ¼ ^k  ^y ð1Þ
Thus instead of writing the moment of the universal joint Muniversal as
M universa