Enhanced precision in robot arm positioning: A nonlinear damping approach for flexible joint manipulators

This article introduces an advanced nonlinear controller designed for optimizing the performance of a single-link robot arm featuring a flexible joint. The proposed nonlinear control strategy incorporates a Proportional-Integral (PI) controller in conjunction with a nonlinear velocity feedback component, aimed at providing effective nonlinear damping and suppressing vibrations. To validate the controller's performance, extensive simulations are conducted utilizing machine learning techniques within the Python environment. The performance of the proposed nonlinear damping controller is benchmarked against a conventional linear cascaded P-PI control structure, with both controllers fine-tuned using the Nelder-Mead algorithm. Simulation results demonstrate that the nonlinear damping controller yields substantial improvements in the dynamic behavior of the robot axis arm, showcasing superior step and sinusoidal position tracking performance, along with active vibration damping capabilities. This research contributes valuable insights into the enhanced nonlinear control strategies for flexible-joint robot arms, offering promising advancements in their overall dynamic performance.