Adaptive Force Control for Robotic Grinding of Complex Blades

Abstract

Abstract Aiming at solving the robotic grinding problem of aircraft engine blades with complex surface, this paper proposed an adaptive force control method using fuzzy PID algorithm, which can ensure that blade surface is completely polished to eliminate residual texture and harmful stress concentration. First, an intelligent digital compliant grinder with active and passive compliance was developed. Second, a fuzzy PID adaptive algorithm was proposed, which can stabilize the contact force between the grinder and the blade. Third, a protection scheme was proposed to prevent excessive grinding. In the polishing process, the robot arm was fitted with the blade. According to the surface profile of the blade, the robot arm moved in a specific trajectory, keeping the blade in contact with the grinder. During grinding, some parameters, such as the abrasive belt velocity, the abrasive belt type and contact force, could affect the quality of the grinding process. Therefore, appropriate parameters were selected. The experimental results showed that the actual force fluctuates within 0.5N. In addition, the original surface roughness was 1.672um, which was reduced to 0.054um by adaptive force control method, comparing to 0.589 urn with the non-force control. Not only is the contact force more precisely controlled, but the grinding accuracy is greatly improved.