Simulation of flexible-link manipulators: basis functions andnonlinear terms in the motion equations

摘要

Two important issues relevant to modeling of flexible-link roboticmanipulators are addressed. The authors examine the question of whichterms should be included in the equations of motion for purposes ofsimulation. A complete model incorporating all nonlinearities thatcouple rigid-body and elastic motions is presented, along with arational scheme for classifying their inclusion. The issue of basisfunction selection for spatial discretization of the elasticdisplacements is discussed. The finite element method and aneigenfunction expansion techniques are presented and compared. Bothissues are examined numerically in the context of the Space Shuttleremote manipulator system. It is shown that certain key nonlinearelastic terms are required if numerical instability of the simulation isto be averted. Simulation results for two discretization schemes areincluded