Abstract: Through the studies of the configuration bifurcation characteristics of a 6-SPS Gough-Stewart manipulator under the action of the single input parameter, and the transform characters of singular points under the disturbances of the other input parameters, a novel method for parallel manipulators to pass through singular points with a persistent configuration is presented. Taking a semi-regular hexagons Gough-Stewart manipulator as an example, the disturbance function for the manipulator to pass through the singular point with a persistent configuration is constructed. Numerical result shows that under the action of the disturbance function, the manipulator can approach the singular point with a very small error and go back with its original configuration. The method presented has solved the problem of the uncertainty of motion at the singular point. In this way, parallel manipulators can give the determinate output in the entire workspace.

Key words: Singularity-free, Disturbance function, Parallel manipulator, Turning point singularity