In the design of pose and position fine adjustment instrument about secondary mirror in optical telescope

aiming at drawing a comparison between different designs of the Gough-Stewart platform

a new concept Universal Workspace is proposed

its analytic method is also discussed in detail. Universal Workspace is the intersection of movement ranges in 36 special directions with the strut-length qualification. The merits of Universal Workspace are as follows

Firstly

the Universal Workspace can be described in Image directly without any additional changes such as reduce dimension from 6 to 3. Secondly

figure of the Universal Workspace is simple and regular revolving solid. Thirdly

analytic solution is the boundary of Universal Workspace

and the solution is exclusive. Compared a performance index between several designs

the results indicate that

despite of the distinct differences of mechanism parameters between different designs

the Universal Workspaces have the universal characteristic

that is Universal Workspaces are all similar simple and regular revolving solids which makes the same performance index comparable within the scope of Universal Workspace

and the results of comparison lays a foundation for further optimal design.