This paper presents an experimental validation of a state observer for flexible-link manipulators (FLM). The design of this observer is based on an accurate dynamic model of the mechanisms, able to take into account the coupled rigid-flexible dynamics of the system. Experimental results on a single-link manipulator affected by gravity force show that the proposed observer achieves a good estimation of the plant dynamics even if the displacement signal is not measured. The evaluation of the performance is done experimentally by comparing the estimated elastic displacement with the measures obtained on the field
