Abstract
It is shown that structure parameters of a flexible manipulator can be virtually adjusted via tip-displacement feedback. By rearranging the structure parameters, transient performance can be significantly enhanced with the help of a collocated PD law. A procedure is developed to transform a lumped-parameter flexible arm into a set of simple mass-spring pairs connected in parallel to the base. The effect of tip-displacement feedback on each substructure can be visualized through this serial-to-parallel transformation, and the gain margin be readily found. It is seen that proportional feedback of the tip displacement virtually scales up or down each of the lumped masses and the lumped springs. A case study is provided to illustrate the design procedure and to demonstrate the performance of the proposed scheme.
