Model-Free Pose Control of Floating Objects via Vision-Based Adaptive Laser Gripper

Micromanipulation of floating objects at the air–liquid interface holds significant potential applications in biochemistry analysis, microassembly, micromanufacturing, and microrobotics. However, achieving simultaneous position and orientation (pose) control of floating objects remains a considerable challenge. Here, we present the vision-based adaptive laser gripper (VALG) system to address these challenges. A model-free pose control strategy based on equidistant contour scanning lasers (laser grippers) that leverage distributed thermocapillary flow induced by patterned laser scanning is proposed. The adaptive laser gripper can be generated within seconds and relies solely on visual recognition, making it applicable to a wide range of floating objects without the need for prior modeling or additional information. The effectiveness and control precision of the VALG system are experimentally validated through discrete pose verification and continuous pose control tests. The maximum pose errors are 0.05 mm and 2.6$^\circ$for discrete pose verification, and 0.37 mm and 14.5$^\circ$for continuous pose control, respectively. The VALG system enables smooth, precise, fast, and adaptive pose control of floating objects, establishing it as a universal and versatile platform for noncontact manipulation at the air–liquid interface.