Control of a rigid-flexible two-link robot using Passivity-based and Strain-feedback approaches

In the present work, the modeling of a rigid-flexible two link robot via the Euler-Lagrange formalism, is outlined. The flexible-link is considered to be an Euler-Bernoulli beam with a mass attached at its free end simulating a payload. Two control schemes which are known to yield acceptable results for single flexible-link robots are extended and applied to achieve regulation for the joints of the system and for the tip of the flexible-link. These control schemes are the so-called Passivity-based velocity feedback and Strain-feedback schemes. Finally, some simulation results are presented for both control schemes in which it can be seen that the system has a better performance when the Strain-feedback control scheme is used.