Control of flexible link manipulators using nonlinear feedback

Abstract

Flexible-link manipulators enable lightweight and energy-efficient robotic systems, but their inherent vibrations pose significant challenges in attaining precise trajectory tracking. This study tackles the challenge of achieving precise trajectory tracking in these robotic manipulators by designing nonlinear control laws grounded in system inversion. The results shows stable closed-loop performance with accurate tracking of smooth joint trajectories. The research also demonstrates that the proposed method provides minimal end-effector errors and oscillations during trajectory tracking. The approach uses the connections between the inversion control laws and the assumed modes framework, demonstrating that clamped boundary conditions at the actuators simplify the control process. The resulting control strategy integrates nonlinear state feedback with a linear feedback stabilization component. Simulation results, applied to a planar two-link flexible manipulator, illustrate the effectiveness of the proposed control approach in joint tracking and end-effector performance. • Rayleigh beam theory to model structural flexibility in the links. • Joint trajectory tracking of flexible link manipulators using inversion-based control. • Validation of the proposed method using numerical study. • Reduced Joint tracking errors by a factor of 3. • Able to increase the controller gains without compromising input torques. • Maximum end effector error reduced by a factor of 6.