Kinematic Calibration for a Large Hybrid Spraying Robot Considering Gravity Deformation

For large robot, gravity deformation has an impact on the calibration of kinematic parameters. This paper proposes a kinematic parameter calibration method considering gravity deformation for a large hybrid spraying robot. Firstly, the kinematic error model of the hybrid robot is formulated by combining the error models of the main serial chain and the parallelogram mechanism through passive joint angle. Then the stiffness model of the hybrid robot is established by combining finite element method and matrix structural analysis. Finally, a kinematic parameter calibration method considering gravity deformation is proposed. The effectiveness of the accuracy compensation strategy proposed is verified through experiments.