Geometric Identification of Denavit-Hartenberg Parameters with Optical Measuring System

The absolute accuracy of robots plays an essential role in modern robotics applications that go beyond the typical industrial environment. This paper proposes a method to improve absolute robot accuracy by using an optical measurement system. The method is based on geometric operations used to calculate the rotation axes of each joint. Once all the rotation axes are identified, the complete kinematic model is calculated using the Denavit-Hartenberg (DH) parameters. The effectiveness of the proposed method was validated on a 7-DoF Franka Emika Panda robot. The results show a significant improvement in absolute accuracy. Thanks to the optical measurement system, the proposed method can be easily automated to improve collaborative robot accuracy, especially in applications that require high positioning accuracy.