Analysis and comparison of control strategies for normal adjustment of a robotic drilling end-effector

Abstract

Robotic drilling technology for aircraft flexible assembly has challenges and is under active investigation. In this work, a robotic drilling end-effector is designed and its normal adjustment system is dynamically modeled for comparison of advanced control strategies in terms of position tracking precision and dynamic quality. Three control algorithms with different computational complexity are proposed and compared: Based on computation torque control method first, a proportional and differential controller (PDC) and a sliding mode controller (SMC) are proposed respectively, and then is a model reference adaptive controller (MRAC). Simulation results show that the SMC has higher precision and a more excellent tracking property than the PDC of which the proportional and derivative gains have been optimally tuned using a modified Ziegler-Nichols' (Z-N) tuning methods. An experiment platform is established in MatLab xPC environment to validate the effect of the SMC and MRAC. The experiment results show that the MRAC delivers a better robust performance that allows adaptiveness to the nonlinear factors such as disturbance and parameter variations than the SMC. . His research interests include high precision machine tools, robotics, and error compensation for machine tools.

A Variable Parameter Ambient Vibration Control Method Based on Quasi-Zero Stiffness in Robotic Drilling Systems

“…Due to the large size and complex profile of the parts of aircraft to be assembled, such as the wing, fuselage, engine and so on, it is difficult for traditional multiaxis machining centers to meet the flexibility of manufacturing and assembly of such large and complex structural parts. Robotic drilling has advantages of high efficiency, spatial accessibility, stability, flexibility and a fast refactoring capability for the assembly of large parts with complex shapes [2,3].…”