Improvement of Force Performance in Robotic Polishing Tasks with Position Compensation

Contact force control is one of the main issues in an automated polishing system. This paper presents position compensation with force control in a robotic polishing task. The proposed method not only decrease the overshoot of the initial contact force, but also reduces the excessive position displacement and maintains the contact force stability during polishing. We validated the proposed method in the robot simulation and the wood furniture polishing task using a 6-DoF industrial robot equipped with an F/T force sensor. The experiments were conducted to compare the plain force control with the proposed position compensation. In the experiments, the proposed method reduced the overshoot of the initial contact force from 116.153 N to 38.513 N. Furthermore, the minimum contact force during the polishing was improved from -4.553N to 14.613 N to maintain a sufficient constant force for the polishing task. Finally, the standard deviation of the contact force was improved from 7.76 N to 2.529 N, showing that the proposed system is more stable than the plain force control.