Hybrid interactive learning control scheme with acceleration feedback of flexible manipulator

Abstract

This chapter proposes the development of a hybrid iterative learning control scheme with acceleration feedback. The learning schemes considered are the PD-type, PI-type and PID-type. The experimental flexible manipulator rig is used to demonstrate the effectives of the proposed control strategy. A collocated PD controller utilizing hub-angle and hub-velocity feedback is developed for control of rigid-body motion of the system. This is then extended to incorporate non-collocated and iterative learning control with acceleration feedback using a heuristic approach to optimise the learning parameters for control of vibration (flexible motion) of the system. The hybrid collocated and non-collocated control scheme has previously been proposed for control of the flexible manipulator (Tokhi and Azad, 1996). The controller design utilised end-point deflection feedback through a PID control scheme and a PD configuration for control of the rigid body motion of the flexible manipulator. This control scheme is thus tested and investigated within the new hybrid learning control schemes. The system performance with the controllers is presented and analysed in the time and frequency domains. The performance of the learning algorithms and hybrid learning control scheme without and with acceleration feedback is assessed in terms of level of vibration reduction at resonance modes, robustness and input tracking. The effectiveness of the control schemes in handling various payloads is also studied.