A minimal kinematic model for serial robot calibration using POE formula

• We first propose a continuous, complete, and minimal model for robot calibration.
• The model follows uniform and generic modeling rules and applies to any serial robot.
• Adjustment operations which are necessary in the traditional model are avoided.
• The model is more deeply converging, more accurate, and less time-consuming.

Traditional methods based on the product of exponentials (POE) formula are parametrically continuous and complete for the calibration of the kinematic parameters of serial robots. However, these methods are not minimal due to the constraints of joint twists. This paper puts forward a new POE-based model, whose parameters are totally independent and conform to the formula of minimality. This is the first model that simultaneously satisfies the requirements of parametric continuity, completeness, and minimality with uniform and generic modeling rules. The proposed approach avoids the operations of normalization and orthogonalization which are necessary redundancy elimination steps with the traditional model. Simulations on a SCARA robot and experiments on an ABB IRB 120 robot prove that the new model outperforms in convergence, accuracy, and efficiency.