Mechanism-parameter-calibration method for robotic arm system

A mechanism-parametric-calibration method for a robotic arm system, the robotic arm system comprising a robotic arm, a calibration block and a measuring instrument, wherein the mechanism-parametric-calibration method comprises:

• controlling, according to nx mechanism parameter sets corresponding to nx first-direction predictive positioning-points, the robotic arm performing nx actions such that an end of the robotic arm moves toward the nx first-direction predictive positioning-points which are in front of a first precision plane of the calibration block, wherein the first precision plane is perpendicular to a first direction;
• sensing, using the measuring instrument, a first-direction measured displacement between the first precision plane and the end of the robotic arm when the robotic arm performs each of the nx actions;
• determining, according to the nx first-direction measured displacement, a first-direction measured relative-displacement moved by the end of the robotic arm when the robotic arm performs each two of the nx actions;
• determining a first-direction predictive relative-displacement equation of each two of the nx first-direction predictive positioning-points;
• deriving an optimization equation corresponding to the robotic arm from the first-direction predictive relative-displacement equations and the first-direction measured relative-displacements;
• obtaining, by the optimization equation, a set of mechanism parametric deviations of the robotic arm;
• and
• calibrating, by the set of mechanism parametric deviations, the nx mechanism parameter sets corresponding to the nx first-direction predictive positioning-points of the robotic arm.