Output predictive adaptive control of a single-link flexible arm

Abstract

A non-dimensionalized model is developed for studying the dynamic behaviour of a single-link flexible robot. Its zero-order equivalence in the discrete-time domain is represented in an autoregressive and moving average form. This non-dimensionalized model has the advantage that the results obtained in this way can be applied to a large class of systems of different dimensions. A lattice filter is utilized for the real-time parameter estimation of an ARM A model. A predictive adaptive output feedback controller has been developed and, together with the lattice filter, it forms a special self-tuning regulator. A stability criterion for this control algorithm is also presented. This control algorithm provides an optimal control in the sense that a quadratic cost function is minimized in the control design. To help find proper weighting parameters for this function, a convenient strategy is suggested with the help of a discrete-time root locus. The noise rejection capability of the control algorithm is also investigated. Encouraging simulation results are obtained in the precision, high-bandwidth, tip position control of a flexible one-arm robot.