Abstract: In order to adapt to the change of workpiece surface curvature, the tool orientation needs to be flexible during robot polishing. However, both the pressure and velocity distribution of abrasive particles in the tool-workpiece contact region are subject to the changes of tool orientation, which will make the accurate prediction of the material removal depth complicated. Therefore, a novel material removal modeling method for robot surface polishing combining tool orientation and material removal mechanism is proposed. Firstly, Hertz contact theory and tool orientation are used to establish the pressure distribution and abrasive particle velocity distribution in the contact area between ball-end tool and curved surface. Aiming at the difficulty of calculating the material removal depth caused by abrasive particles, the relationship between single abrasive particle pressure and indentation depth is established by combining abrasive particle properties and elastic-plastic contact theory. Subsequently, the material removal depth per unit contact length is obtained by combining both the pressure and velocity distribution, abrasive particle properties and indentation depth. Finally, the material removal model is established by integrating along the polishing tool trajectory. The simulation and experimental results demonstrate that the maximum relative error between the material removal model prediction value and the experimental value is 4.92%, and the average relative error is 2.61%, which verifies the feasibility of the modeling method. The novel model can not only lay a theoretical foundation for the precise control of the robot surface polishing, but also is of great significance to the uniformity of workpiece material removal and the improvement of polishing quality.

Key words: robot surface polishing, tool orientation, grain feature, material removal model