Error modelling and experimental validation for a planar 3-PPR parallel manipulator

In this paper, the positioning error of a 3-PPR planar parallel manipulator is studied with an error model and experimental validation. First, the displacement and workspace are analyzed. An error model considering both configuration errors and joint clearance errors is established. Using this model, the maximum positioning error was estimated for a U-shape PPR planar manipulator, the results being compared with the experimental measurements. It is found that the error distributions from the simulation is approximate to that of the measurements.