Modeling and control of a new three-degree-of-freedom flexible arm with simplified dynamics

This article describes the modeling, control scheme and experimental validation of a new three-degree-of-freedom flexible arm. This arm was built with light links, has most of its mass concentrated at the tip, and uses a special mechanical configuration to approximately decouple radial tip motion from angular tip motions. This special configuration facilitates the dynamic modeling and control of the arm. The compliance matrix can be used to model the oscillations of the structure. Due to this simple dynamics, minimum sensing effort is required (only motor and tip measurements) and the use of complex observers is avoided because the state of the system is obtained directly. A two-nested loop controls the tip position. Experimental results are presented