Five-Bar Double-Slider Two-DOF Parallel Manipulators for Singularity-Free Path Generation

Parallel manipulators are closed-loop multi-degree-of-freedom linkages, which have the merits of high stiffness, load-bearing, operation speed and precision positioning capabilities that are required in many industrial applications. The main challenges for parallel manipulators are the limited workspace and singularity-free path generation capability. This paper is focused on the singularity-free path generation of five-bar double-slider two-DOF parallel manipulators. The linkage feasibility conditions are derived based on the elimination of dead point position within the workspace. The workspace is generated using the curve-enveloping theory. The singularity characteristics and linkage configurations are presented. The singularity-free path generation capability is analyzed. The performance index contours within the workspace are produced using the condition number of the manipulator Jacobian matrix. This paper shows that five-bar double-slider two-DOF parallel manipulators can be used as effective singularity-free path generators if properly designed. The results of this paper provide a useful map for the proper design of this type of parallel manipulator.