Kinematic parameters calibration of redundant planar 2-dof parallel manipulator with a new error function

In this paper, with a new proposed error function, and by eliminating the passive joint variables of the closed-loop constraint equations, the auto-calibration method and design procedure are proposed, and the superiority of the new error-function is studied. Experimental results show that, with fewer variables involved, the minimization process of the error function proposed is easier, and the precision of the calibration results can be improved. Furthermore, by decoupling the product items of the kinematic parameters of the error function into linear combinations of a group of new variables, we simplified the error function and improved the calibration precision further. In the end, new experimental results are obtained. Among the 12 kinematic parameters of the parallel manipulator, 11 kinematic parameters of the parallel manipulator can be calibrated with the proposed error function.