Modelling and control of a two-link flexible robot manipulator

Over the last years, flexible structured manipulators have increased in popularity in aeronautical research because of their advantages compared to conventional rigid structures. Unfortunately, the flexibility of the structure has one big disadvantage; it causes undesired motions of the spacecraft. The flexibility of the structure generates structural vibrations that strongly interferes with rigid-body attitude dynamics. The dynamics of the structure increases drastically when the amount of bodies increase, and so far researchers were not capable to develop an adequately dynamical model. This study describes the derivation of a new dynamical model for a two-link flexible robot manipulator with, usually unconsidered, incorporated effects of practical parameters. Based on this theoretical framework, three different controller designs are introduced. To regulate the rigid body motions a proportional-plus-derivative (PD) control method is implemented and a notch filter is introduced to suppress the residual vibrations. The three control cases are individually designed by a combinations of these control techniques. Finally, computer simulation results are used to analyze the effects of the three different control cases.