Dynamic control of a flexible macro-micro manipulator based on rigid dynamics with flexible state sensing

A macro-micro manipulator system is formed by attaching a small (or micro) manipulator at the end of a conventional large (macro) manipulator. The sys tem can provide high-precision motion of the micro robot for local operatio n and retain the versatility, speed, and workspace of a larger robot. In th is study the macro-micro manipulator approach is intended to enhance the tr acking/positioning performance of flexible manipulators. Additional actuati on of the micro rigid manipulator is employed to compensate for the deflect ions due mainly to the link flexibility involved. The manipulator system is firstly modelled based on the rigid dynamics by taking into account the fu ll coupling between the macro and micro manipulators. For accomplishing fas t and gross motion of the macro flexible manipulator, the PD controller is employed incorporating a fuzzy adaptive tuner, A control scheme is then pro posed for the micro manipulator, where the sensed flexible states are used as feed-forward signals and added to the control command for the rigid-moti on control of the micro manipulator, for the purpose of deflection compensa tion. An integrated laser-optical system is dedicated to sense the tip defl ections of the flexible links. The control schemes proposed are verified th rough simulation experiments. (C) 1999 Elsevier Science Ltd. All rights res erved.