Dynamic Compensation Control of Flexible Macro–Micro Manipulator Systems

Macro-micro architecture, which consists of macro and micro manipulators, is used here to eliminate errors at the tip of a flexible manipulator. The macro uses long arms and has such advantages as larger work volume and lower energy consumption but suffers from large deformations and vibrations. The micro is a smaller rigid manipulator and is attached on the end of the macro to isolate the system endpoint from the undesirable flexibility of the macro. Using perturbation theories, a new kinematical method is introduced, first, by redefining the micro´s motion as a means of compensating for the errors at the endpoint of the macro. Then, an excellent practical control scheme is proposed to realize the endpoint control with the feedback of joint angles and vibrations. A PD controller is applied to the micro, which augmented the compensation quantities. To damp out vibrations, a nonlinear control law is proposed for the macro, taking the interacting dynamics of the micro to the macro into account. The compensation and control algorithms work very well on a macro-micro setup, and numerous experimental results prove the applicability of the proposed schemes.