A fundamental limitation on the control of end-point force in a very flexible single-link arm

Abstract

In this paper, a phenomenon is presented that severely restricts control of end-point force via actuation at the other end in a constrained very flexible single-link arm. This limitation is different from and can be more severe than its known non-minimum-phase characteristic. The link flexibility, contact compliance, and stick–slip friction forces at the hub and end-point areas are incorporated into a unique dynamic model and individual effects of friction forces at the hub and the tip on the control performance are investigated. Experimental results are presented to verify the phenomenon and evaluate the validity of the proposed model.