Delayed reference control for multi-degree-of-freedom elastic systems: Theory and experimentation

The objective of this paper is to provide an experimental proof of the effectiveness and ease of implementation of a non-time based control strategy for the simultaneous active vibration control and path tracking of multi-degree-of-freedom linear systems. What is peculiar in the proposed scheme, named DRC, is that it allows reducing elastic vibrations while guaranteeing coordinated motion among the system rigid-body degrees of freedom, and hence the accurate tracking of desired paths through space. The DRC is here applied to damp the oscillation of a load suspended to the moving platform of an Adept Quattro parallel robot by means of a cable.

► We propose a non-time based vibration control and path tracking strategy named DRC.
► DRC allows precise tracking of desired paths through space in mdof linear systems.
► DRC is here applied to suppress the swing of the suspended load of a four-dof crane.
► Experimental results prove the effectiveness and ease of implementation of DRC.