A manipulator for supporting and displacing an object comprises a base. A
moving portion supports the object. Two articulated mechanisms each
having five rotational joints between links, with each articulated
mechanism being connected to the base by two of the rotational joints.
The moving portion is connected to both the articulated mechanisms by
moving-portion joints. The articulated mechanisms and moving-portion
joints are arranged with respect to each other between the base and the
moving portion so as to constrain movement of the moving portion to
displacements in two translational degrees of freedom and two rotational
degrees of freedom with respect to the base. Four actuators are each
operatively connected to a different one of the rotational joints between
the base and the articulated mechanisms so as to selectively control the
displacements of the moving portion in any one of the four degrees of
freedom of the moving portion.