Research on Robotic Polishing Process of Marble with Complex Curved Surface Based on Sol–Gel Flexible Tools

Newly developed Sol–gel (SG) flexible tools are used to polish complex marble surfaces with a robot to achieve a high-gloss, low-roughness, and scratch-free surface. The SG tool is composed of semi-solid abrasive and flexible fiber pads, which can realize a dual yielding effect at both the micro and macro levels so that the SG flexible tool can better fit the complex curved surface. Through the simulation analysis of the contact of SG flexible tools, the relationship between different curvature surfaces and polishing forces was obtained. Based on the Preston material removal theory, constant-pressure polishing of surfaces of different curvatures was achieved by simulating the contact force distribution between the SG flexible tool and the marble surface, as well as the constant-pressure material removal profile. By optimizing the space of the polishing trajectory, the uniformity of the material removal depth was improved, and the consistency of surface quality after polishing was enhanced. By establishing a model that correlates the optimum polishing trajectory space with curvature for surfaces of different curvatures, the effective prediction of material removal profiles for robotic polishing of surfaces of different curvatures was achieved. These strategies aim to ensure surface consistency after polishing complex curved surfaces under different conditions, thereby increasing the product’s added value. This research provides initial theoretical guidance for the application of SG flexible tools in the robotic polishing of marble with complex curved surfaces.