Calibration of a six-DOF parallel manipulator for chromosome dissection

This article proposes a calibration method for a six-PPPS parallel manipulator which is the macro-part of a dual-drive chromosome dissection system. The calibration model is built with respect to Denavit–Hartenberg notation. Certain adjustment matrices are utilized to provide independent error parameters. The pose of the moving platform as while as relative motion of all prismatic joints and spherical joints are measured by the latest API T3 laser tracker. Other than general methods that need reconstruction of the location and orientation of the platform with point coordinates, these data can be obtained directly within one single measurement in the proposed method. For data processing, a step-by-step calculation method has been presented to select initial error parameters. With this method, partial error parameters can be derived in advance to be substituted into the calibration model providing calculation efficiency superior to simultaneous computation. Simulation based on the geometry of this manipulator shows a decent convergence performance of the calibration model. The experimental results also validate the efficiency and the convenience of the proposed method.