Valg: Vision-Based Adaptive Laser Gripper for Model-Free Pose Control of Floating Objects at Air-Liquid Interface

Abstract

Non-contact manipulation at the air-liquid interface holds significant potential for applications in microrobotics, non-invasive assembly, and biochemistry analysis. However, achieving simultaneous position and orientation (pose) control of floating objects remains a considerable challenge, particularly for adaptive control without prior modeling of the objects. Here, we introduce the Vision-based Adaptive Laser Gripper (VALG) system addressing these challenges. By leveraging the distributed thermocapillary flow induced by patterned laser scanning, a pose control strategy based on the equidistant contour scanning laser is proposed and validated. The proposed system relies solely on visual recognition to generate adaptive laser grippers, which achieve static equilibrium to simultaneously constrain the position and orientation of the floating objects. Experimental validation demonstrates the effectiveness of the VALG system in independent position and orientation control, coupled pose control, and path following. The VALG system facilitates smooth, precise, fast, and adaptive pose control of generalized floating objects, establishing it as a universal and versatile platform for non-contact manipulation at the air-liquid interface.