Trajectory tracking of a single flexible-link robot using a modal cascaded-type control.

The control problem of a single flexible-link robot is addressed for tip position and trajectory tracking control, with no other actuators into the mechanical system than a servomotor installed at the rigid joint. A multi-modal cascaded-type model of the robot is obtained, where the angle of the rigid joint is considered as the control input for the flexible-link rather than the torque provided by the servomotor. A Sliding-Mode Control approach is used to overcome the rigid mode dynamics and ensure a precise tracking of a flexible-state dependent trajectory at the joint level. The proposed control scheme is simple, easy to implement and yet robust against parametric uncertainties. The main results show that, trajectory tracking at the tip of the flexible-link is achieved, with guaranteed closed-loop stability, since the problem is reduced to the tracking of an adequate trajectory at the joint level. The proposed results are validated with several experimental results. Finally, the control scheme is quantitatively compared with two different controllers for flexible robots.

Autor:

Gerardo Silva Navarro

https://www.sciencedirect.com/science/article/pii/S0307904X21005758