Error Constrained Hybrid Force/Position Control of a Grinding Robot

For a grinding robot, it is necessary to grind the workpiece with appropriate force while tracking the target trajectory. Considering this requirement, this paper first establishes the contact force model between the robot end-effector and the environment in the grinding process, and considers the unmodeled dynamics, so as to make the description of the contact force closer to the reality. On this basis, an error-constrained hybrid force/position control method is given. Specifically, a force controller is proposed, which can achieve accurate force tracking and ensure that the force tracking error always remains within the preset bound. Then, Lyapunov methods are utilized to prove the stability of the force control closed-loop system. At last, the effectiveness of the designed force controller is verified by numerical simulations.