Research on Adaptive Impedance Control and Stiffness Optimization for Mobile Manipulator Drilling Tasks

The large dimensions of thin-walled components result in relatively low work efficiency during the drilling process. Mobile manipulator (MM) systems have gained widespread application in the drilling of large-scale thin-walled components due to their workspace adaptability, multifunctional capabilities, and high efficiency. However, existing systems generally suffer from technical limitations such as insufficient stiffness of the manipulator's joints and inadequate control accuracy of the force error control for the end-effector's contact force, which directly affect the quality of drilling operations. To address these issues, this paper establishes an existing machining stiffness evaluation index system and proposes a stiffness-optimized drilling strategy based on an adaptive impedance feedback regulation mechanism. To validate the effectiveness of the proposed method, a simulation experimental platform was constructed for empirical analysis, and the experimental data fully demonstrate the significant advantages of the proposed method in improving system stability and machining quality of different materials.