Optical measurement of robotic end-effector motion using digital image correlation
摘要
Accurate end-effector motion measurement is essential for robotic manipulation and automated manufacturing. However, existing systems rely heavily on internal encoders, which may be unavailable, difficult to access, or insufficient for independent verification. This study presents a non-contact optical metrology approach based on Digital Image Correlation (DIC) for external measurement of end-effector pose and estimation of joint angles. By integrating robotic kinematics with full-field optical tracking, the proposed method enables simultaneous characterization of translational and rotational motions and demonstrates the feasibility of using DIC as an external sensing approach for robotic systems. Experimental validations, including trajectory tracking and pick-and-place operations, show reasonable agreement between the DIC-based measurements and the robot’s built-in encoders. In addition, a moment-based object-recognition module is incorporated to improve grasping stability. The results indicate that DIC can function as an external, independent, and cost-effective measurement tool, providing a practical solution for robotic system monitoring and performance evaluation in advanced manufacturing environments.