Abstract: In order to keep the control accuracy of robotic grinding and improve quality of grinding workpiece, a robotic grinding system based on the floating platform is developed and a constant force grinding strategy of linear active disturbance rejection control (LADRC) is proposed.The robotic floating grinding system mainly includes robots, force feedback sensors, grinding system and floating platform mechanism.Taking the robotic grinding system as the research object, grinding contacting force model between the workpiece at the end of the robot and the grinding disc is established.According to the nonlinear robot grinding model, the extended state observer is designed. The closed-loop stability of LADRC is analyzed, and the corresponding grinding experiments are designed to verify the feasibility of LADRC algorithm. Finally experiments and analyses show that LADRC can realize an effective robotic constant force control for disk grinding.Comparing with proportion integration differentiation (PID) control, LADRC can significantly reduce the force fluctuation during the grinding process and greatly decrease the surface roughness of abrasive workpiece.

Key words: robot; grinding; force control; active disturbance rejection control