P. Lucibello et F. Bellezza, ADAPTIVE OUTPUT REGULATION OF A FLEXIBLE ARM, Journal of dynamic systems, measurement, and control, 118(1), 1996, pp. 167-172
A self-tuned version of a constoller for asymptotic trajectory trackin
g of the end point of a two-link flexible robot arm is presented. The
bounded solution to the inverse system, which is used in the control l
aw, is tuned by the estimates of the unknown robot parameters, generat
ed by a least square identification scheme. Boundness of the state of
the adaptive controller is achieved by a stabilizing linear feedback f
rom the output error, with fixed gains and robust with respect to vari
ations of the parameters. This guarantees the total stability of the s
ystem, which is the main ingredient used in the proof of the controlle
r properties, through a Lyapunov-like approach. The controller perform
ance is finally illustrated by numerically simulating the tracking of
an end point ramp under payload mass variations.